LENNOX EL297DFV Elite Series High Efficiency Two Stage Variable Speed Gas Furnace Instruction Manual

June 15, 2024
Lennox

LENNOX EL297DFV Elite Series High Efficiency Two Stage Variable Speed Gas

Furnace

Product Information

The EL297DFV gas furnace is a Category IV gas furnace designed for installation in the downflow position. It is equipped for natural gas applications and can be converted for use in propane/LP gas applications with a separate conversion kit. The furnace can be installed as a Direct Vent or Non-Direct Vent gas central furnace.

Unit Dimensions

  • A: 17-1/2 inches (446 mm)
  • B: 16-3/8 inches (416 mm)
  • C: 16 inches (406 mm)

Installation Instructions

CAUTION: Handle the equipment carefully to avoid contact with sharp sheet metal edges.

WARNING: Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Installation and service must be performed by a licensed professional HVAC installer (or equivalent), service agency, or the gas supplier.

NOTICE: The Flue Condensate Trap Assembly is furnished for external field installation on either side of the unit. Refer to the installation instructions for additional information.

Direct Vent Installation

In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged outdoors.

Non-Direct Vent Installation
In Non-Direct Vent installations, combustion air is taken from indoors or ventilated attic or crawlspace, and flue gases are discharged outdoors.

Shipping and Packing List

Package 1 of 1 contains:

  • 1 – Assembled EL297DFV unit
  • 1 – Bag assembly containing the following:
    • 1 – Snap bushing
    • 1 – Snap plug
    • 1 – Wire tie
    • 1 – Condensate trap
    • 1 – Condensate trap cap
    • 1 – Condensate trap clamp
    • 1 – 2 diameter Air intake screen
    • 1 – 3/4 Threaded street elbow
    • 2 – 2 Street elbows
    • 2 – Side vent sealing plates
    • 2 – Side vent sealing gaskets
    • 6 – Sheet metal screws

© 2023 Lennox Industries Inc. Dallas, Texas USA

INSTALLATION INSTRUCTIONS EL297DFV
ELITE® SERIES GAS FURNACE DOWNFLOW AIR DISCHARGE
508410-01 09/2023

THIS MANUAL MUST BE LEFT WITH THE HOMEOWNER FOR FUTURE REFERENCE

CAUTION
As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.

This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to the potential for personal injury or death.

WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional HVAC installer (or equivalent), service agency or the gas supplier.

NOTICE
A thermostat is not included and must be ordered separately. · A communicating thermostat must be used in
communicating applications. ·In non-communicating applications, the Lennox ComfortSense® 7500 thermostat may be used, as well as other non-communicating thermostats. In all cases, setup is critical to ensure proper system operation. Field wiring for both communicating and noncommunicating applications is illustrated in diagrams, which begin on Page 39.

Page 1

Unit Dimensions – inches (mm)
Flue Condensate Trap Assembly Furnished for external field installation on either side of unit. (See installation instructions for additional information.)
A B
AIR FLOW

3/4 (19)

Supply C Air

FRONT VIEW

7 (178)

COMBUSTION AIR INTAKE
EXHAUST AIR OUTLET

9/16 (14)

B

RETURN AIR OPENING

2-1/16 (52)

5 (127)

2-1/4

9/16

(57)

(14)

TOP VIEW

1-1/2 (38) Front Panel

9/16 (14)

4-1/2

1 (25)

(114)

1-7/8 (48)

33 (838)

15 (381)

5-3/16 (132)
2-1/16 (52)

2 (51) Either Side
GAS PIPING INLET (Either Side)

9-1/8 (232) Right 6-9/16 (167) Left

27-3/4 (705)

6-1/4 (157)

19-7/16 (494)

OPTIONAL LEFT SIDE VENT LOCATION (Kit Required)
ELECTRICAL INLET (Either Side)
ALTERNATE RIGHT SIDE VENT LOCATION (Parts Furnished)
ELECTRICAL INLET (Either Side)
CONDENSATE TRAP CONNECTION
(Either Side)

6-7/16 (163) Either Side

9 (229) Either Side

3/4 (19)

19-1/4 Supply (489) Air

SIDE VIEW

9/16 (14)
3/4 (19)

Model No.
EL297DFXV045P36B EL297DFXV070P48B EL297DFXV090P60C EL297DFXV110P60C

A in. (mm) 17-1/2 (446)
21 (533)

B in. (mm) 16-3/8 (416)
19-7/8 (505)

C in. (mm) 16 (406)
19-1/2 (495)

Page 2

EL297DFV Gas Furnace
The EL297DFV Category IV gas furnace is shipped ready for installation in the downflow position. The furnace is equipped for installation in natural gas applications. A conversion kit (ordered separately) is required for use in propane/LP gas applications.
The EL297DFV can be installed as a Direct Vent or Non- Direct Vent gas central furnace.
NOTE – In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged outdoors. In Non-Direct Vent installations, combustion air is taken from indoors or ventilated attic or crawlspace and flue gases are discharged outdoors. See FIGURE 1 and FIGURE 2 for applications involving roof termination.

DIRECT VENT INSTALLATION
EXHAUST OUTLET COMBUSTION
AIR INTAKE OUTSIDE OF HOUSE

NON-DIRECT VENT INSTALLATION
EXHAUST OUTLET

COMBUSTION AIR INTAKE INSIDE OF HOUSE

FIGURE 1

NON-DIRECT VENT INSTALLATION
EXHAUST OUTLET

NON-DIRECT VENT INSTALLATION
EXHAUST OUTLET

COMBUSTION AIR INTAKE INSIDE
VENTILATED ATTIC SPACE

COMBUSTION AIR INTAKE INSIDE
VENTILATED CRAWL SPACE

FIGURE 2

Shipping and Packing List Package 1 of 1 contains
1 – Assembled EL297DFV unit 1 – Bag assembly containing the following:
1 – Snap bushing 1 – Snap plug 1 – Wire tie 1 – Condensate trap 1 – Condensate trap cap 1 – Condensate trap clamp 1 – 2″ diameter Air intake screen 1 – 3/4″ Threaded street elbow 2 – 2″ Street elbows 2 – Side vent sealing plates 2 – Side vent sealing gaskets 6 – Sheet metal screws
DANGER
Danger of explosion. There are circumstances in which odorant used with LP/ propane gas can lose its scent. In case of a leak, LP/ propane gas will settle close to the floor and may be difficult to smell. An LP/propane leak detector should be installed in all LP applications.
Check equipment for shipping damage. If you find any damage, immediately contact the last carrier. The following items may also be ordered separately: 1 – Thermostat 1 – LP/Propane changeover kit 1 – High altitude pressure switch
Safety
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a licensed professional installer (or equivalent), service agency or the gas supplier.
CAUTION
As with any mechanical equipment, personal injury can result from contact with sharp sheet metal edges. Be careful when you handle this equipment.
Use only the type of gas approved for use with this furnace. Refer to unit nameplate. EL297DFV units are CSA International certified to ANSI Z21.47 and CSA 2.3 standards.

Page 3

Building Codes

In the USA, installation of gas furnaces must conform with local building codes. In the absence of local codes, units must be installed according to the current National Fuel Gas Code (ANSI-Z223.1/NFPA 54). The National Fuel Gas Code is available from the following address:
American National Standards Institute, Inc.
11 West 42nd Street
New York, NY 10036
In Canada, installation must conform with current National Standard of Canada CSA-B149 Natural Gas and Propane Installation Codes, local plumbing or waste water codes and other applicable local codes.
In order to ensure proper unit operation in non-direct vent applications, combustion and ventilation air supply must be provided according to the current National Fuel Gas Code or CSA-B149 standard.
Locations and Clearances
This furnace is CSA International certified for installation clearances to combustible material as listed on the unit nameplate and in the table in FIGURE 13. Accessibility and service clearances must take precedence over fire protection clearances.
For installation in a residential garage, the furnace must be installed so that the burner(s) and the ignition source are located no less than 18 inches (457 mm) above the floor. The furnace must be located or protected to avoid physical damage by vehicles. When a furnace is installed in a public garage, hangar, or other building that has a hazardous atmosphere, the furnace must be installed according to recommended good practice requirements and current National Fuel Gas Code or CSA B149 standards. NOTE – Furnace must be adjusted to obtain a temperature rise within the range specified on the unit nameplate. Failure to do so may cause erratic limit operation and premature heat exchanger failure.
This EL297DFV furnace must be installed so that its electrical components are protected from water.
Installation in Combination with a Cooling Coil
When this furnace is used with cooling units (FIGURE 3), it shall be installed in parallel with, or on the upstream side of, cooling units to avoid condensation in the heating compartment. With a parallel flow arrangement, a damper (or other means to control the flow of air) must adequately prevent chilled air from entering the furnace. If the damper is manually operated, it must be equipped to prevent operation of either the heating or the cooling unit, unless it is in the full HEAT or COOL setting.
When installed, this furnace must be electrically grounded according to local codes. In addition, in the United States, installation must conform with the current National Electric Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/NFPA No. 70) is available from the following address:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269

In Canada, all electrical wiring and grounding for the unit must be installed according to the current regulations of the Canadian Electrical Code Part I (CSA Standard C22.1)
and/or local codes.

GAS UNIT
Dampers (open during heating
operation only)

AIR HANDLER
Dampers (open during cooling
operation only)

FIGURE 3 NOTE – This furnace is designed for a minimum continuous return air temperature of 60°F (16°C) or an intermittent operation down to 55°F (13°C) dry bulb for cases where a night setback thermostat is used. Return air temperature must not exceed 85°F (29°C) dry bulb. The EL297DFV furnace may be installed in alcoves, closets, attics, basements, garages, utility rooms and crawl spaces. This furnace design has not been CSA certified for installation in mobile homes, recreational vehicles, or outdoors. Never use an open flame to test for gas leaks. Check all connections using a commercially available soap solution made specifically for leak detection.
Use of Furnace as Construction Heater
Units may be used for heating of buildings or structures under construction, if the following conditions are met to ensure proper operation:
DO NOT USE THE UNIT FOR CONSTRUCTION HEAT UNLESS ALL OF THE FOLLOWING CRITERIA ARE MET:
· Furnace must be in its final location. The vent system must be permanently installed per these installation instructions.
· Furnace must be installed as a two pipe system and one hundred percent (100%) outdoor air must be provided for combustion air requirements during construction.
· A room thermostat must control the furnace. The use of fixed jumpers that will provide continuous heating is prohibited.
· The input rate and temperature rise must be set per the furnace rating plate.
· Supply and Return air ducts must be provided and sealed to the furnace. Return air must be terminated outside of the space where furnace is installed.

Page 4

· Return air temperature range between 60°F (16°C) and 80°F (27°C) must be maintained.
· MERV 11 or greater air filters must be installed in the system and must be regularly inspected and maintained (e.g., regular static checks and replaced at end of life) during construction.
· Blower and vestibule access panels must be in place on the furnace at all times.
· The furnace heat exchanger, components, duct system, and evaporator coils must be thoroughly cleaned following final construction clean-up.
· Air filters must be replaced upon construction completion.
· All furnace operating conditions (including ignition, input rate, temperature rise and venting) must be verified in accordance with these installation instructions.
EQUIPMENT MAY EXPERIENCE PREMATURE COMPONENT FAILURE AS A RESULT OF FAILURE TO FOLLOW THE ABOVE INSTALLATION INSTRUCTIONS. FAILURE TO FOLLOW THE ABOVE INSTALLATION INSTRUCTIONS VOIDS THE MANUFACTURER’S EQUIPMENT LIMITED WARRANTY. LENNOX DISCLAIMS ALL LIABILITY IN CONNECTION WITH INSTALLER’S FAILURE TO FOLLOW THE ABOVE INSTALLATION INSTRUCTIONS.
NOTWITHSTANDING THE FOREGOING, INSTALLER IS RESPONSIBLE FOR CONFIRMING THAT THE USE OF CONSTRUCTION HEAT IS CONSISTENT WITH THE POLICIES AND CODES OF ALL REGULATING ENTITIES. ALL SUCH POLICIES AND CODES MUST BE ADHERED TO.

General

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities having jurisdiction before installation.
In addition to the requirements outlined previously, the following general recommendations must be considered when installing a EL297DFV furnace:
· Place the furnace as close to the center of the air distribution system as possible. The furnace should also be located close to the chimney or vent termination point.
· When the furnace is installed in non-direct vent applications, do not install the furnace where drafts might blow directly into it. This could cause improper combustion and unsafe operation.
· When the furnace is installed in non-direct vent applications, do not block the furnace combustion air opening with clothing, boxes, doors, etc. Air is needed for proper combustion and safe unit operation.
· When the furnace is installed in an attic or other insulated space, keep insulation away from the furnace.
· When the furnace is installed in an unconditioned space, consider provisions required to prevent freezing of condensate drain system.

Combustion, Dilution & Ventilation Air
If the EL297DFV is installed as a Non-Direct Vent Furnace, follow the guidelines in this section.
NOTE – In Non-Direct Vent installations, combustion air is taken from indoors or ventilated attic or crawlspace and flue gases are discharged out-doors .
WARNING
Insufficient combustion air can cause headaches, nausea, dizziness or asphyxiation. It will also cause excess water in the heat exchanger resulting in rusting and premature heat exchanger failure. Excessive exposure to contaminated combustion air will result in safety and performance related problems. Avoid exposure to the following substances in the combustion air supply:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
In the past, there was no problem in bringing in sufficient outdoor air for combustion. Infiltration provided all the air that was needed. In today’s homes, tight construction practices make it necessary to bring in air from outside for combustion. Take into account that exhaust fans, appliance vents, chimneys, and fireplaces force additional air that could be used for combustion out of the house.
Unless outside air is brought into the house for combustion, negative pressure (outside pressure is greater than inside pressure) will build to the point that a downdraft can occur in the furnace vent pipe or chimney. As a result, combustion gases enter the living space creating a potentially dangerous situation.
In the absence of local codes concerning air for combustion and ventilation, use the guidelines and procedures in this section to install EL297DFV furnaces to ensure efficient and safe operation.

Page 5

You must consider combustion air needs and requirements for exhaust vents and gas pip-ing. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSI Z223.1/NFPA 54). This reprinted material is not the complete and official position of the ANSI on the referenced subject, which is represented only by the standard in its entirety.
In Canada, refer to the CSA B149 installation codes.
CAUTION
EL297DFV unit should not be installed in areas normally subject to freezing temperatures.
All gas-fired appliances require air for the combustion process. If sufficient combustion air is not available, the furnace or other appliance will operate inefficiently and unsafely. Enough air must be provided to meet the needs of all fuel-burning appliances and appliances such as exhaust fans which force air out of the house. When fireplaces, exhaust fans, or clothes dryers are used at the same time as the furnace, much more air is required to ensure proper combustion and to prevent a downdraft. Insufficient air causes incomplete combustion which can result in carbon monoxide
In addition to providing combustion air, fresh outdoor air dilutes contaminants in the indoor air. These contaminants may include bleaches, adhesives, detergents, solvents and other contaminants which can corrode furnace components.
The requirements for providing air for combustion and ventilation depend largely on whether the furnace is installed in an unconfined or a confined space.
Unconfined Space
An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not separated by a door. Though an area may appear to be unconfined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors, follow the procedures in the air from outside section.

Confined Space
A confined space is an area with a volume less than 50 cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms. When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside.

Air from Inside
If the confined space that houses the furnace adjoins a space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of total input rating of all gas- fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm2). One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. See FIGURE 4.
EQUIPMENT IN CONFINED SPACE – ALL AIR FROM INSIDE
ROOF TERMINATED EXHAUST PIPE

SIDE WALL TERMINATED EXHAUST PIPE (ALTERNATE LOCATION)

OPENINGS (To Adjacent Unconfined
Space)

NOTE – Each opening shall have a free area of at least one square inch per 1,000 Btu (645mm2 per .29kW) per hour of the total input rating of all equipment in the enclosure, but not less than 100 square inches (64516mm.2).
FIGURE 4

Page 6

Air from Outside
If air from outside is brought in for combustion and ventilation, the confined space shall be provided with two permanent openings. One opening shall be within 12″ (305mm) of the top of the enclosure and one within 12″ (305mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of total input rating of all equipment in the enclosure. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch per 2,000 Btu (645mm2 per .59kW) per total input rating of all equipment in the enclosure (See FIGURE 5). It is also permissible to bring in air for combustion from a ventilated attic (FIGURE 6) or ventilated crawl space (FIGURE 7).
EQUIPMENT IN CONFINED SPACE – ALL AIR FROM OUTSIDE (Inlet Air from Crawl Space and Outlet Air to Outside)

ROOF TERMINATED EXHAUST PIPE

VENTILATION LOUVERS (Each end of attic)

SIDE WALL TERMINATED EXHAUST PIPE (ALTERNATE LOCATION)

OUTLET AIR
FURNACE
INLET AIR

VENTILATION LOUVERS
(For unheated crawl space)

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.
FIGURE 5

EQUIPMENT IN CONFINED SPACE (Inlet Air from Ventilated Attic and Outlet Air to Outside)

Roof Terminated Exhaust Pipe

Ventilation Louvers
Inlet Air (Minimum 12 in.(305mm) Above attic floor)

*Intake Debris Screen
(Provided)
Furnace

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.
FIGURE 6

EQUIPMENT IN CONFINED SPACE (Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)
Roof Terminated Exhaust Pipe

Ventilation Louvers

Furnace

(Crawl space)

Inlet Air (Minimum 12 in.(305mm) Above crawl space floor)

Coupling or 3 in. to 2 in. Transition (Field Provided)

*Intake Debris Screen Provided)

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.
FIGURE 7
If air from outside is brought in for combustion and ventilation, the confined space must have two permanent openings. One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. These openings must communicate directly or by ducts with the outdoors or spaces (crawl or attic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm2) per 4,000 Btu (1.17 kW) per hour of total input rating of all equipment in the enclosure. See FIGURE 5 and FIGURE 8. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm2) per 2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 9.
When ducts are used, they shall be of the same cross-sectional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3 inches (75 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective covering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 percent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

Page 7

EQUIPMENT IN CONFINED SPACE – ALL AIR FROM OUTSIDE (All Air Through Ventilated Attic)

ROOF TERMINATED EXHAUST PIPE

OUTLET AIR

VENTILATION LOUVERS (Each end of attic)

UNITS WITH 1/2 HP BLOWER MOTOR
RIGID LEG remove shipping bolt and washer

SIDE WALL TERMINATED EXHAUST PIPE (ALTERNATE LOCATION)

FURNACE

INLET AIR (Ends 12″ above
bottom)

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.

FIGURE 8
EQUIPMENT IN CONFINED SPACE ALL AIR FROM OUTSIDE
ROOF TERMINATED EXHAUST PIPE

OUTLET AIR

SIDE WALL TERMINATED EXHAUST PIPE (ALTERNATE LOCATION)

FURNACE

INLET AIR

NOTE-Each air duct opening shall have a free area of at least one square inch per 2,000 Btu (645mm2 per .59kW) per hour of the total input rating of all equipment in the enclosure. If the equipment room
cate directly with the outdoors, each opening shall have a free area of at least 1 square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all other equipment in the enclosure.
FIGURE 9
Shipping Bolt Removal
Units with 1/2 hp blower motor are equipped with three flexible legs and one rigid leg. The rigid leg is equipped with a shipping bolt and a flat white plastic washer (rather than the rubber mounting grommet used with a flexible mounting leg). See FIGURE 10. The bolt and washer must be removed before the furnace is placed into operation. After the bolt and washer have been removed, the rigid leg will not touch the blower housing.

FIGURE 10
Installation – Setting Equipment
WARNING
Do not install the furnace on its front, back or in the horizontal position. See FIGURE 12. Do not connect the return air ducts to the back of the furnace. Doing so will adversely affect the operation of the safety control devices, which could result in personal injury or death.
Select a location that allows for the required clearances that are listed on the unit nameplate. Also consider gas supply connections, electrical supply, vent connection, condensate trap and drain connections, and installation and service clearances [24 inches (610 mm) at unit front]. The unit must be level from side to side. Unit may be positioned from level to 1/2″ toward the front to aid in draining. See FIGURE 11. Allow for clearances to combustible materials as indicated on the unit nameplate. Minimum clearances for closet or alcove installations are shown in FIGURE 13.
WARNING
Blower access panel must be securely in place when blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal injury or death.
SETTING EQUIPMENT

AIR FLOW

AIR FLOW

AIR FLOW

1/2″ max.

FRONT VIEW

SIDE VIEW

SIDE VIEW

Unit must be level side-to-side. Unit may be positioned

from level to 1/2″ toward the front to aid in draining.

FIGURE 11

Page 8

Back

Front

Horizontal

NOTE – Do not install the furnace on its front, back or in the horizontal position

FIGURE 12
WARNING
Improper installation of the furnace can result in personal injury or death. Combustion and flue products must never be allowed to enter the return air system or air in the living space. Use sheet metal screws and joint tape to seal return air system to furnace. In platform installations with furnace return, the furnace should be sealed airtight to the return air plenum. A door must never be used as a portion of the return air duct system. The base must provide a stable support and an airtight seal to the furnace. Allow absolutely no sagging, cracks, gaps, etc. For no reason should return and supply air duct systems ever be connected to or from other heating devices such as a fireplace or stove, etc. Fire, explosion, carbon monoxide poisoning, personal injury and/or property damage could result.

Page 9

The unit may be installed three ways in downflow applications: on non- combustible flooring, on combustible flooring using an additive base, or on a reverse-flow cooling coil cabinet. Do not drag the unit across the floor in the downflow position. Floor and furnace flange damage will result. Refer to FIGURE 13 for clearances in downflow applications.
Downflow Application Installation Clearances
Top

3 – Set the unit over the plenum and seal the plenum to the unit.
4 – Ensure that the seal is adequate.

TABLE 1

NON-COMBUSTIBLE FLOOR OPENING SIZE

Cabinet Width

Front to Rear

in.

mm

Side to Side

in

mm

B (17.5″) 19-3/4 502 16-5/8 422

C (21″)

19-3 4 502 20-1/8 511

NOTE – Floor opening dimensions listed are 1/4 inch (6 mm) larger than the unit opening. See dimension drawing on page 2.

Left Side

Right Side

FURNACE

Bottom

Top

0

*Front

0

Back

0

Sides

0

Vent

0

Floor

NC

*Front clearance in alcove installation must be 24 in. (610 mm). Maintain a minimum of 24 in. (610 mm) for front service access. Allow proper clearances to accommodate condensate trap and vent pipe installation. tional base is installed between the furnace and the combustible floor.

FIGURE 13
Installation on Non-Combustible Flooring FIGURE 14
1 – Cut floor opening keeping in mind clearances listed on unit rating plate. Also keep in mind gas supply connections, electrical supply, flue and air intake connections and sufficient installation and servicing clearances. See TABLE 1 for correct floor opening size.
2 – Flange warm air plenum and lower the plenum into the opening.

PROPERLY SIZED FLOOR
OPENING

SUPPLY AIR PLENUM

FIGURE 14
Installation on Combustible Flooring FIGURE 15
1 – When unit is installed on a combustible floor, a downflow combustible flooring base must be installed between the furnace and the floor. The base must be ordered separately. See TABLE 2 for opening size to cut in floor.
CAUTION
The furnace and combustible flooring base shall not be installed directly on carpeting, tile, or other combustible material other than wood flooring.

Page 10

TABLE 2

COMBUSTIBLE FLOORING BASE OPENING SIZE

Cabinet Catalog Width Number

Front to Rear in mm

Side to Side

in

mm

B (17.5″) 11M60 22 559

18-3/4 476

C (21″) 11M61 22 559

22-3/4 578

FURNACE
PROPERLY SIZED FLOOR
OPENING

SUPPLY AIR PLENUM
COMBUSTIBLE FLOORING BASE

FIGURE 15
2 – After opening is cut, set the combustible flooring base into opening.
3 – Check fiberglass strips on the combustible flooring base to make sure they are properly glued and positioned.
4 – Lower supply air plenum into the combustible flooring base until plenum flanges seal against fiberglass strips. NOTE – Be careful not to damage fiberglass strips. Check for a tight seal.
5 – Set the furnace over the plenum.
6 – Ensure that the seal between the furnace and plenumis adequate.
Installation on Cooling Coil Cabinet FIGURE 16 NOTE – Downflow combustible flooring kit is not used.
1 – Refer to reverse-flow coil installation instructions for correctly sized opening in floor and installation of cabinet.
2 – When cooling cabinet is in place, set and secure the furnace according to the instructions that are provided with the cooling coil. Secure the furnace to the cabinet.
3 – Seal the cabinet and check for air leaks.

PROPERLY SIZED FLOOR
OPENING

FURNACE
COOLING COIL PLENUM

FIGURE 16
Return Air Opening — Downflow Units
Return air may be brought in only through the top opening of a furnace installed in the downflow position. The following steps should be taken when installing plenum:
1 – Bottom edge of plenum should be flanged with a hemmed edge (See FIGURE 17 or FIGURE 18).
2 – Sealing strips should be used to ensure an airtight seal between the cabinet and the plenum.
3 – In all cases, plenum should be secured to top of furnace using sheet metal screws.
4 – Make certain that an adequate seal is made.

PLENUM (Field Provided)

SECURE FROM OUTSIDE CABINET

SEALING STRIP (Field Provided)

Side View

FIGURE 17

PLENUM (Field Provided)

SECURE FROM INSIDE CABINET

Side View FIGURE 18

CABINET SIDE PANEL
SEALING STRIP (Field Provided)
CABINET SIDE PANEL

Page 11

Filters
This unit is not equipped with a filter or rack. A field-provided filter is required for the unit to operate properly. TABLE 3 lists recommended minimum filter size.
A filter must be in place whenever the unit is operating.
IMPORTANT
If a highefficiency filter is being installed as part of this system to ensure better indoor air quality, the filter must be properly sized. Highefficiency filters have a higher static pressure drop than standardefficiency glass/foam filters. If the pressure drop is too great, system capacity and performance may be reduced. The pressure drop may also cause the limit to trip more frequently during the winter and the indoor coil to freeze in the summer, resulting in an increase in the number of service calls.
Before using any filter with this system, check the specifications provided by the filter manufacturer against the data given in the appropriate Lennox Product Specifications bulletin. Additional information is provided in Service and Application Note ACC002
(August 2000).

TABLE 3

Furnace Cabinet Width

Minimum Filter Size

17-1/2″ 21″

16 x 25 x 1 (1)

Duct System
Use industry-approved standards to size and install the supply and return air duct system. Refer to ACCA Manual D. This will result in a quiet and low- static system that has uniform air distribution. See figure below for proper duct installation. NOTE – This furnace is not certified for operation in heating mode (indoor blower operating at selected heating speed) with an external static pressure which exceeds 0.8 inches w.c. Operation at these conditions may result in improper limit operation.

Duct Installation Down-Flow Unit

Supply Air Plenum
If the furnace is installed without a cooling coil, a removable access panel should be installed in the supply air duct. The access panel should be large enough to permit inspection of the heat exchanger. The furnace access panel must always be in place when the furnace is operating and it must not allow leaks into the supply air duct system.
Return Air Plenum
NOTE – Return air must not be drawn from a room where this furnace, or any other gas-fueled appliance (i.e., water heater), or carbon monoxide-producing device (i.e., wood fireplace) is installed.
When return air is drawn from a room, a negative pressure is created in the room. If a gas appliance is operating in a room with negative pressure, the flue products can be pulled back down the vent pipe and into the room. This reverse flow of the flue gas may result in incomplete combustion and the formation of carbon monoxide gas. This raw gas or toxic fumes might then be distributed throughout the house by the furnace duct system.
Use fiberglass sealing strips, caulking, or equivalent sealing method between the plenum and the furnace cabinet to ensure a tight seal. If a filter is installed, size the return air duct to fit the filter frame.
Pipe & Fittings Specifications
All pipe, fittings, primer and solvent cement must conform with American National Standard Institute and the American Society for Testing and Materials (ANSI/ASTM) standards. The solvent shall be free flowing and contain no lumps, undissolved particles or any foreign matter that adversely affects the joint strength or chemical resistance of the cement. The cement shall show no gelation, stratification, or separation that cannot be removed by stirring. Refer to the table 4 below for approved piping and fitting materials
.
CAUTION
Solvent cements for plastic pipe are flammable liquids and should be kept away from all sources of ignition. Do not use excessive amounts of solvent cement when making joints. Good ventilation should be maintained to reduce fire hazard and to minimize breathing of solvent vapors. Avoid contact of cement with skin and eyes.

SUPPLY AIR

Page 12

TABLE 4

PIPING AND FITTINGS SPECIFICATIONS

Schedule 40 PVC (Pipe)

D1785

Schedule 40 PVC (Fittings)

D2466

Schedule 40 CPVC (Pipe)

F441

Schedule 40 CPVC (Fittings)

F438

SDR-21 PVC or SDR-26 PVC (Pipe)

D2241

SDR-21 CPVC or SDR-26 CPVC (Pipe)

F442

Schedule 40 ABS (Pipe)

D1527

Schedule 40 ABS (Fittings)

D2468

ABS-DWV (Drain Waste & Vent) (Pipe & Fittings)

D2661

PVC-DWV (Drain Waste & Vent) Pipe & Fittings)

D2665

PRIMER & SOLVENT CEMENT

ASTM SPECIFICATION

PVC & CPVC Primer

F656

PVC Solvent Cement

D2564

CPVC Solvent Cement

F493

ABS Solvent Cement

D2235

PVC/CPVC/ABS All Purpose Cement For Fittings & Pipe of the same material

D2564, D2235, F493

ABS to PVC or CPVC Transition Solvent Cement

D3188

CANADA PIPE & FITTING & SOLVENT CEMENT

MARKING

PVC & CPVC Pipe and Fittings

PVC & CPVC Solvent Cement

ABS to PVC or CPVC Transition Cement
POLYPROPYLENE VENTING SYSTEM

ULCS636

PolyPro® by Duravent

InnoFlue® by Centrotherm

UL 1738 CERTIFIED GAS VENTING SYSTEM

IPEX System1738 Schedule 40 PVC Pipes and Fittings
IPEX System1738 PVC FGV Cement & Primer

UL1738

IMPORTANT
EL297DFV exhaust and intake connections are made of PVC. Use PVC primer and solvent cement when using PVC vent pipe. When using ABS vent pipe, use transitional solvent cement to make connections to the PVC fittings in the unit.

Use PVC primer and solvent cement or ABS solvent cement meeting ASTM specifications, refer to TABLE 4. As an alternate, use all purpose cement, to bond ABS, PVC, or CPVC pipe when using fittings and pipe made of the same materials. Use transition solvent cement when bonding ABS to either PVC or CPVC.Low temperature solvent cement is recommended during cooler weather. Metal or plastic strapping may be used for vent pipe hangers. Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket. Canadian Applications Only – Pipe, fittings, primer and solvent cement used to vent (exhaust) this appliance must be certified to ULC S636 and supplied by a single manufacturer as part of an approved vent (exhaust) system. In addition, the first three feet of vent pipe from the furnace flue collar must be accessible for inspection.
Venting Options
The EL297DFV is shipped with vent exhaust / air intake connection at the top cap. See FIGURE 19. Using parts provided, the furnace may be field modified to have these connections on the right side of the furnace cabinet. See FIGURE 22 and follow the steps below. For left side venting order kit 87W73.
1 – Remove inner blower door.
2 – Loosen hose clamps which attach rubber fittings to the white PVC pipes inside the vestibule area. See FIGURE 19.
3 – Loosen the clamp which secures the pipes at the blower deck. See FIGURE 19.
4 – Remove white PVC pipes, slide up and out thru the top cap.
5 – Remove the black plastic fitting in top cap which previously aligned the PVC pipes.
6 – Remove the remaining parts of the pipe clamp at the blower deck.
7 – Remove the sheet metal patch plate on the side of the cabinet which covers the openings for side venting option. Save screws for reuse.
8 – Re-use the patch plate to cover the hole in the top cap. See FIGURE 20. Remove the 2 screws which secure the top cap to the furnace on the right side and re-install securing the right edge of the patch plate and the right side of the top cap to the furnace. Use 2 self-drilling sheet metal screws (provided) to finish securing the left edge of the patch plate on the left side.
9 – Use a utility knife to cut out the cabinet insulation for the right side vent / air intake.
10 -Install the two 90° street elbows (provided) through the side of the cabinet. The male side of each elbow should extend down through the blower deck and connect to the rubber fittings below. Once the elbows are properly positioned, tighten each clamp.
11 -Peel protective backing from side vent sealing gaskets (2) and apply to side vent sealing plates (2) as shown in FIGURE 22.

Page 13

12 -Install the side vent sealing plates and gaskets on the exterior of the cabinet as shown in FIGURE 22. Secure with six mounting screws (four reused and two provided from bag assembly). Holes are pre-punched in the parts and cabinet, no drilling is required.
13 -Install sheet metal screws (provided) to seal extra two holes in cabinet not used with side vent clamps.
IMPORTANT
Side vent sealing plates and side vent sealing gaskets must be used when converting to right side venting. Failure to use gaskets and plates may lead to improper operation of unit.
Top Vent Configuration
Exhaust/Air Intake Connections

Patch Plate Top Cap
Sheet Metal Patch Plate

Pipe Clamp

FIGURE 20 Crawl Space and Extended Horizontal Venting
Lennox provides kit 51W18 (USA) and kit 15Z70 (Canada) to install 2″ or 3″ PVC exhaust piping through the floor joists and into the the crawl space. See FIGURE 21. This kit can also be used as a supplemental drain for installations with condensate run back in the vent pipe (ie. long horizontal runs, unconditioned spaces, etc.).
Venting In A Crawl Space

Hose Clamp

FIGURE 19

Basement Floor
KIT 51W18 (USA) KIT 15Z70 (CANADA)
FIGURE 21

Page 14

Right Side Vent Configuration
Side Vent Sealing Plate Side Vent Sealing Gaskets
Exhaust Intake
Street Elbows (2)

FIGURE 22

TABLE 5

OUTDOOR TERMINATION USAGE*

STANDARD

CONCENTRIC

Input Size

Vent Pipe Dia. in.

Flush Mount Kit
51W11 (US) 51W12 (CA)

Wall Kit

2 inch 22G44 (US) 430G28 (CA)

3 inch 44J40 (US) 481J20 (CA)

Field Fabricated

1-1/2 inch

2 inch

3 inch

71M80 (US) 69M29 (US) 60L46 (US) 444W92 (CA) 444W92 (CA) 444W93 (CA)

61-1/2

3YES

YES

1YES

5 YES

2 YES

2

3YES

YES

1YES

5 YES

2 YES

045

2-1/2

3YES

YES

1YES

5 YES

2 YES

3

3YES

YES

1YES

5 YES

2 YES

61-1/2

3YES

YES

1YES

5 YES

2 YES

N/A

N/A

2

3YES

YES

1YES

5 YES

2 YES

070

2-1/2

3YES

YES

1YES

5 YES

2 YES

3

3YES

YES

1YES

5 YES

2 YES

2

3YES

YES

5 YES

YES

YES

090

2-1/2

3YES

YES

5 YES

YES

YES

3

3YES

YES

5 YES

YES

YES

N/A

N/A

2

YES

YES

5 YES

YES

YES

110

2-1/2

YES

YES

5 YES

YES

YES

3

YES

YES

5 YES

YES

YES

NOTE – Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must be included in total vent length calculations. See vent length tables.

  • Kits must be properly installed according to kit instructions.

1Requires field-provided outdoor 1-1/2″ exhaust accelerator.
2Concentric kits 71M80 and 44W92 include 1-1/2″ outdoor accelerator, when used with 045 and 070 input models. 1-1/2 in pipe must transition to 2 in pipe when used with a concentric kit.

3 Flush mount kits 51W11 and 51W12 includes 1-1/2 in. outdoor exhaust accelerator, required when used with 045, 070 and 090 input models. 1-1/2 in pipe must transition to 2 in pipe when used with the flushmount kit. 4 Termination kits 30G28, 44W92, 4493 and 81J20 are certified to ULC S636 for use in Canada only.
5 See table 10 for vent accelerator requirements.

6 2 in to 1-1/2 in reducer required must be field provided.

Page 15

Joint Cementing Procedure
All cementing of joints should be done according to the specifications outlined in ASTM D 2855. NOTE – A sheet metal screw may be used to secure the intake pipe to the connector, if desired. Use a drill or self tapping screw to make a pilot hole.
DANGER

DANGER OF EXPLOSION!
Fumes from PVC glue may ignite during system check. Allow fumes to dissipate for at least 5 minutes before placing unit into operation.
1 – Measure and cut vent pipe to desired length.
2 – Debur and chamfer end of pipe, removing any ridges or rough edges. If end is not chamfered, edge of pipe may remove cement from fitting socket and result in a leaking joint. NOTE – Check the inside of vent pipe thoroughly for any obstruction that may alter furnace operation.
3 – Clean and dry surfaces to be joined.
4 – Test fit joint and mark depth of fitting on outside of pipe. 5 – Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket.
6 – Promptly apply solvent cement to end of pipe and inside socket surface of fitting. Cement should be applied lightly but uniformly to inside of socket. Take care to keep excess cement out of socket. Apply second coat to end of pipe. NOTE – Time is critical at this stage. Do not allow primer to dry before applying cement.
7 – Immediately after applying last coat of cement to pipe, and while both inside socket surface and end of pipe are wet with cement, forcefully insert end of pipe into socket until it bottoms out. Turn PVC pipe 1/4 turn during assembly (but not after pipe is fully inserted) to distribute cement evenly. DO NOT turn ABS or cellular core pipe. NOTE – Assembly should be completed within 20 seconds after last application of cement. Hammer blows should not be used when inserting pipe.
8 – After assembly, wipe excess cement from pipe at end of fitting socket. A properly made joint will show a bead around its entire perimeter. Any gaps may indicate an improper assembly due to insufficient solvent.
9 – Handle joints carefully until completely set.

Venting Practices
Piping Suspension Guidelines
SCHEDULE 40 PVC – 5′
all other pipe* – 3′

  • See Piping and Fittings Specifications table
    NOTE – Isolate piping at the point where it exits the outside wall or roof in order to prevent transmission of vibration to the structure.

Wall Thickness Guidelines
24″ maximum 3/4″ minimum

inside

Wall outside

FIGURE 23
REPLACING FURNACE THAT WAS PART OF A COMMON VENT SYSTEM
CHIMNEY OR GAS
VENT (Check sizing
for water heater only)

FURNACE (Replaced)

WATER HEATER
OPENINGS (To Adjacent
Room)

If replacing a furnace which was commonly vented with another gas appliance, the size of the existing vent pipe for that gas appliance must be checked. Without the heat of the original furnace flue products, the existing vent pipe is probably oversized for the single water heater or other appliance. The vent should be checked for proper draw with the remaining appliance.
FIGURE 24

Page 16

1 – In areas where piping penetrates joists or interior walls, hole must be large enough to allow clearance on all sides of pipe through center of hole using a hanger.
2 – When furnace is installed in a residence where unit is shut down for an extended period of time, such as a vacation home, make provisions for draining condensate collection trap and lines.
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a venting system commonly run with separate gas appliances, the venting system is likely to be too large to properly vent the remaining attached appliances. Conduct the following test while each appliance is operating and the other appliances (which are not operating) remain connected to the common venting system. If the venting system has been installed improperly, you must correct the system as indicated in the general venting requirements section.
.
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance connected to the venting system being placed into operation, while all other appliances connected to the venting system are not in operation:
1 – Seal any unused openings in the common venting system.
2 – Inspect the venting system for proper size and horizontal pitch. Determine that there is no blockage, restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
3 – Close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building. Turn on clothes dryers and any appliances not connected to the common venting system. Turn on any exhaust fans, such as range hoods and bathroom exhausts, so they will operate at maximum speed. Do not operate a summer exhaust fan. Close fireplace dampers.

4 – Follow the lighting instructions. Turn on the appliance that is being inspected. Adjust the thermostat so that the appliance operates continuously.
5 – After the main burner has operated for 5 minutes, test for leaks of flue gases at the draft hood relief opening. Use the flame of a match or candle.
6 – After determining that each appliance connected to the common venting system is venting properly, (step 3) return all doors, widows, exhaust fans, fireplace dampers, and any other gas-burning appliances to their previous mode of operation.
7 – If a venting problem is found during any of the preceding tests, the common venting system must be modified to correct the problem. Resize the common venting system to the minimum vent pipe size determined by using the appropriate tables in Appendix G. (These are in the current standards of the National Fuel Gas Code ANSI Z223.1.
Exhaust Piping (FIGURE 26 and FIGURE 27)
Route piping to outside of structure. Continue with installation following instructions given in piping termination section.
WARNING
Carbon Monoxide Poisoning Hazard
Cutting or altering exhaust or air intake pipes, which are located in the blower compartment, could result in Carbon Monoxide Poisoning or Death.
CAUTION
Do not discharge exhaust into an existing stack or stack that also serves another gas appliance. If vertical discharge through an existing unused stack is required, insert PVC pipe inside the stack until the end is even with the top or outlet end of the metal stack.
CAUTION
The exhaust vent pipe operates under positive pressure and must be completely sealed to prevent leakage of combustion products into the living space.

Page 17

Vent Piping Guidelines NOTE – Lennox has approved the use of DuraVent® and Centrotherm manufactured vent pipe and terminations as an option to PVC. When using the PolyPro® by DuraVent or InnoFlue® by Centrotherm venting system the vent pipe requirements stated in the unit installation instruction ­ minimum & maximum vent lengths, termination clearances, etc. ­ apply and must be followed. Follow the instructions provided with PoyPro by DuraVent and InnoFlue by Centrotherm venting system for assembly or if requirements are more restrictive. The PolyPro by Duravent and InnoFlue by Centrotherm venting system must also follow the uninsulated and unconditioned space criteria listed in table 8.
The EL297DFV can be installed as either a Non-Direct Vent or a Direct Vent gas central furnace.

NOTE – In Non-Direct Vent installations, combustion air is
taken from indoors or ventilated attic or crawlspace and flue gases are discharged outdoors. In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged outdoors. Intake and exhaust pipe sizing — Size pipe according to TABLE 6 (minimum pipe lengths) and TABLE 7 (maxim-
mum pipe lengths). Count all elbows inside and outside
the home.

TABLE 6

MINIMUM VENT PIPE LENGTHS

EL297DFV MODEL

MIN. VENT LENGTH*

045, 070, 090, 110

15 ft or 5ft plus 2 elbows or 10 ft plus 1 elbow

*Any approved termination may be added to the minimum length listed. Two 45 degree elbows are the equivalent to one 90 degree elbow.

Regardless of the diameter of pipe used, the standard roof and wall terminations described in section Exhaust Piping Terminations should be used. Exhaust vent termination pipe is sized to optimize the velocity of the exhaust gas as it exits the termination. Refer to TABLE 10.

In some applications which permit the use of several different sizes of vent pipe, a combination vent pipe may be used. Contact Lennox’ Application Department for assistance in sizing vent pipe in these applications.

IMPORTANT
Do not use screens or perforated metal in exhaust or intake terminations. Doing so will cause freeze-ups and may block the terminations.

NOTE – It is acceptable to use any pipe size which fits within the guidelines allowed in TABLE 7. NOTE – All horizontal runs of exhaust pipe must slope backtoward unit. A minimum of 1/4″ (6mm) drop for each 12″ (305mm) of horizontal run is mandatory for drainage. NOTE – Lennox offers a glueless vent adapter kit 17H92 as an option for exhaust exiting at the furnace top cap coupling.

NOTE – Exhaust pipe MUST be glued to furnace exhaust fittings. NOTE – Exhaust piping should be checked carefully to make sure there are no sags or low spots. NOTE – If right side venting option is used, you must include the elbow at the furnace in the elbow count. If transitioning to 3″ dia pipe, this elbow equates to 20′ of equivalent vent length for all models. Use the following steps to correctly size vent pipe diameter.
Piping Size Process

What is the 1 furnace capacity?

Which style termination

2

being used?

Standard or concentric?

.

Which needs

3

most elbows? Intake or

exhaust?

How many elbows? 4 Count all elbows inside
and outside house.

5 Desired pipe size?

What is the altitude of 6 the furnace installation?
See max and min length 7 tables. Include all vent pipe
and elbows inside and outside the hpouse

FIGURE 25

Page 18

TABLE 7
Maximum Allowable Intake or Exhaust Vent Length
Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Intake and Exhaust must be same size. NOTE – Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.

Standard Termination at Elevation 0 – 4500 ft

Number

1-1/2″ Pipe

2″ Pipe

2-1/2″ Pipe

3″ Pipe

Of 90° Elbows

Model

Model

Model

Model

Used 045 070 090 110 045 070 090 110 045 070 090 110 045 070 090 110

1

20 15

71 56 34 14 105 105 83 48 128 127 108 108

2

15 10

66 51 29 9 100 100 78 43 123 122 103 103

3

10

61 46 24 4 95 95 73 38 118 117 98 98

4

56 41 19

90 90 68 33 113 112 93 93

5

51 36 14

85 85 63 28 108 107 88 88

n/a n/a

6

46 31

9

80 80 58 23 101 102 83 83

n/a

7

n/a

41 26

4 n/a 75 75 53 18 98 97 78 78

8

36 21

70 70 48 13 93 92 73 73

9

31 16 n/a

65 65 43 8 88 87 68 68

10

26 11

60 60 38 3 83 82 63 63

Standard Termination Elevation 4501 – 10,000 ft

Number

1-1/2″ Pipe

2″ Pipe

2-1/2″ Pipe

3″ Pipe

Of 90° Elbows

Model

Model

Model

Model

Used 045 070 090 110 045 070 090 110 045 070 090 110 045 070 090 110

1

20 15

71 56 34

105 105 83 48 128 127 108 108

2

15 10

66 51 29

100 100 78 43 123 122 103 103

3

10

61 46 24

95 95 73 38 118 117 98 98

4

56 41 19

90 90 68 33 113 112 93 93

5

51 36 14

85 85 63 28 108 107 88 88

n/a n/a

n/a

6

46 31

9

80 80 58 23 103 102 83 83

n/a

7

n/a

41 26

4

75 75 53 18 98 97 78 78

8

36 21

70 70 48 13 93 92 73 73

9

31 16 n/a

65 65 43 8 87 87 68 68

10

26 11

60 60 38 5 83 82 63 63

Page 19

TABLE 7 CONT.

Maximum Allowable Intake or Exhaust Vent Length

Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Intake and Exhaust must be same size. NOTE – Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.

Concentric Termination at Elevation 0 – 4500 ft

Number

1-1/2″ Pipe

2″ Pipe

2-1/2″ Pipe

3″ Pipe

Of 90° Elbows

Model

Model

Model

Model

Used 045 070 090 110 045 070 090 110 045 070 090 110 045 070 090 110

1

15 10

63

48

32

12

95

95

79

44 111 111 104 104

2

10

58

43

27

7

90

90

74

39 106 106 99

99

3

53

38

22

2

85

85

69

34 101 101 94

94

4

48

33

17

80

80

64

29

96

96

89

89

5

43

28

12

75

75

59

24

91

91

84

84

n/a n/a

6

n/a

38

23

7

70

70

54

19

86

86

79

79

n/a

7

33

18

2

n/a

65

65

49

14

81

81

74

74

8

28

13

60

60

44

9

76

76

69

69

9

23

8

n/a

55

55

39

4

71

71

64

64

10

18

3

50

50

34 n/a 66

66

59

59

Concentric Termination Elevation 4501 – 10,000 ft

Number

1-1/2″ Pipe

2″ Pipe

2-1/2″ Pipe

3″ Pipe

Of 90° Elbows

Model

Model

Model

Model

Used 045 070 090 110 045 070 090 110 045 070 090 110 045 070 090 110

1

15 10

63

48

32

95

95

79

44 111 111 104 94

2

10

58

43

27

90

90

74

39 106 106 99

99

3

53

38

22

85

85

69

34 101 101 94

94

4

48

33

17

80

80

64

29

96

96

89

89

5

43

28

12

75

75

59

24

91

91

84

84

n/a n/a

n/a

6

n/a

38

23

7

70

70

54

19

86

86

79

79

n/a

7

33

18

2

65

65

49

14

81

81

74

74

8

28

13

60

60

44

9

76

76

69

69

9

23

8

n/a

55

55

39

4

71

71

64

64

10

18

3

50

50

34 n/a 66

66

59

59

TABLE 8

Maximum Allowable Exhaust Vent Length Using Ventilated Attic or Crawl Space For Intake Air in Feet
NOTE – Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length calculation.

Standard Termination at Elevation 0 – 10,000 ft

Number

1-1/2

2″ Pipe

2-1/2″ Pipe

3″ Pipe

Of 90° Elbows

Model

Model

Model

Model

Used 045 070 090 110 045 070

090

110 045 070 090 110 045 070 090 110

1

15 10

61

46

24

90

90

68

33 108 107 88

88

2

10

56

41

19

85

85

63

28 103 102 83

83

3

51

36

14

80

80

58

23

98

97

78

78

4

46

31

9

75

75

53

18

93

92

73

73

5

41

26

4

70

70

48

13

88

87

68

68

n/a n/a

n/a

6

n/a

36

21

65

65

43

8

81

82

63

63

n/a

7

31

16

60

60

38

3

78

77

58

58

8

26

11

n/a

55

55

33

73

72

53

53

9

21

6

50

50

28

n/a

68

67

48

48

10

16

1

45

45

23

63

62

43

43

Page 20

TYPICAL EXHAUST PIPE CONNECTIONS

045/070 Only

1-1/2″

TRANSITION

2″

2″

2″

2″

2″

2″

or

Exhaust
DO NOT transition from larger to smaller pipe in horizontal runs
of exhaust pipe.

3″ TRANSITION
*2″

Exhaust
DO NOT transition from smaller to larger pipe size in horizontal
runs of exhaust pipe.

INTAKE EXHAUST
TOP VIEW

045/070 Only
1-1/2″ TRANSITION
2″

  • When transitioning up in pipe size, use the shortest length of 2″ PVC pipe possible. NOTE – Exhaust pipe and intake pipe must be the same diameter.
    FIGURE 26
    TYPICAL INTAKE PIPE CONNECTIONS

2″

2″ 2″

2″

2″

or

TRANSITION

3″
TRANSITION
*2″

*2″

3″

*2″

INTAKE EXHAUST
TOP VIEW

  • When transitioning up in pipe size, use the shortest length of 2″ PVC pipe possible. NOTE – Intake pipe and exhaust pipe must be the same diameter.

FIGURE 27

Page 21

TYPICAL EXHAUST CONNECTIONS WITH RIGHT SIDE VENT OPTION

Pipe Length

4″ Maximum

2″

(Not Furnished)

2″
Street Ell (Not Furnished)

2″

3″

TRANSITION *2″

Plate (Furnished)
TOP VIEW

  • When transitioning up in pipe size, use the shortest length of 2″ PVC pipe possible. NOTE Intake pipe and exhaust pipe must be the same diameter.

FIGURE 28

TYPICAL AIR INTAKE PIPE CONNECTIONS WITH RIGHT SIDE VENT OPTION

2″
*2″ Street Ell (Not Furnished)

2″

3″

TRANSITION *2″

Plate (Furnished)
TOP VIEW

  • When transitioning up in pipe size, use the shortest length of 2″ PVC pipe possible. NOTE Intake pipe and exhaust pipe must be the same diameter.

FIGURE 29

Page 22

Intake Piping
The EL297DFV furnace may be installed in either direct vent or non-direct vent applications. In non-direct vent applications, when intake air will be drawn into the furnace from the surrounding space, the indoor air quality must be considered. Guidelines listed in Combustion, Dilution and Ventilation Air section must be followed.
Follow the next two steps when installing the unit in Direct Vent applications, where combustion air is taken from outdoors and flue gases are discharged outdoors. The provided air intake screen must not be used in direct vent applications (outdoors).
1 – Use cement or a sheet metal screw to secure the intake pipe to the inlet air connector.
2 – If intake air is drawn from a ventilated crawlspace (FIGURE 30) or ventilated attic (FIGURE 31) the exhaust vent length must not exceed those listed in table 9. If 3″ diameter pipe is used, reduce to 2″ diameter pipe to accommodate the debris screen.
3 – Route piping to outside of structure. Continue with installation following instructions given in general guide lines for piping terminations and intake and exhaust piping terminations for direct vent sections. Refer to TABLE 7 for pipe sizes.
CAUTION
If this unit is being installed in an application with combustion air coming in from a space serviced by an exhaust fan, power exhaust fan, or other device which may create a negative pressure in the space, take care when sizing the inlet air opening. The inlet air opening must be sized to accommodate the maximum volume of exhausted air as well as the maximum volume of combustion air required for all gas appliances serviced by this space.

EQUIPMENT IN CONFINED SPACE (Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)
Roof Terminated Exhaust Pipe

Ventilation

Louvers

Furnace

(Crawl space)

Inlet Air (Minimum 12 in.(305mm) Above crawl space floor)

Coupling or 3 in. to 2 in. Transition (Field Provided)

*Intake Debris Screen Provided)

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.
See table 8 for maximum vent lenghts FIGURE 30

EQUIPMENT IN CONFINED SPACE (Inlet Air from Ventilated Attic and Outlet Air to Outside)

Roof Terminated Exhaust Pipe

Ventilation Louvers
Inlet Air (Minimum 12 in.(305mm) Above attic floor)

*Intake Debris Screen
(Provided)
Furnace

NOTE-The inlet and outlet air openings shall each have a free area of at least one square inch per 4,000 Btu (645mm2 per 1.17kW) per hour of the total input rating of all equipment in the enclosure.
See TABLE 8 for maximum vent lenghts FIGURE 31

Page 23

TYPICAL AIR INTAKE PIPE CONNECTIONS NON-DIRECT VENT APPLICATIONS
AIR INTAKE SCREEN (Provided)
NOTE – Air intake screen and elbow may be rotated, so that screen may be positioned to face forward or to either side.
FIGURE 32 Follow the next two steps when installing the unit in Non-Direct Vent applications where combustion air is taken from indoors and flue gases are discharged outdoors.
1 – Use field-provided materials and the factory-provided air intake screen to route the intake piping as shown in FIGURE 32. Maintain a minimum clearance of 3″ (76mm) around the air intake opening. The air intake opening (with the protective screen) should always be directed forward, or sideways.
2 – Use cement to secure the intake pipe to the connector, if desired.
General Guidelines for Vent Terminations In Non-Direct Vent applications, combustion air is taken from indoors and the flue gases are discharged to the outdoors. The EL297DFV is then classified as a non-direct vent, Category IV gas furnace. In Direct Vent applications, combustion air is taken from outdoors and the flue gases are discharged to the outdoors. The EL297DFV is then classified as a direct vent, Category IV gas furnace.

In both Non-Direct Vent and Direct Vent applications, the vent termination is limited by local building codes. In the absence of local codes, refer to the current National Fuel Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current CSA-B149 Natural Gas and Propane Installation Codes in Canada for details.
Position termination according to location given in FIGURE 34 or FIGURE 35. In addition, position termination so it is free from any obstructions and 12″ above the average snow accumulation.
At vent termination, care must be taken to maintain protective coatings over building materials (prolonged exposure to exhaust condensate can destroy protective coatings). It is recommended that the exhaust outlet not be located within 6 feet (1.8m) of an outdoor AC unit because the condensate can damage the painted coating. NOTE – See TABLE 8 for maximum allowed exhaust pipe length without insulation in unconditioned space during winter design temperatures below 32°F (0°C). If required exhaust pipe should be insulated with 1/2″ (13mm) Armaflex or equivalent. In extreme cold climate areas, 3/4″ (19mm) Armaflex or equivalent may be necessary. Insulation must be protected from deterioration. Armaflex with UV protection is permissable. Basements or other enclosed areas that are not exposed to the outdoor ambient temperature and are above 32 degrees F (0°C) are to be considered conditioned spaces.
IMPORTANT
Do not use screens or perforated metal in exhaust terminations. Doing so will cause freeze-ups and may block the terminations.
IMPORTANT
For Canadian Installations Only: In accordance to CSA International B149 installation codes, the minimum allowed distance between the combustion air intake inlet and the exhaust outlet of other appliances shall not be less than 12 inches (305mm).

Page 24

TABLE 9

Maximum Allowable Exhaust Vent Pipe Length (in ft.3) Without Insulation In Unconditioned Space For Winter Design Temperatures Two – Stage High Efficiency Furnace

Winter Design

Vent Pipe

Unit Input Size

Temperatures1 °F (°C) Diameter

045

070

090

110

PVC

2PP

PVC

2PP

PVC

2PP

PVC

2PP

32 to 21 (0 to -6)

1-1/2 in 2 in
2-1/2 in

22

n/a

20

n/a

n/a

n/a

n/a

n/a

21

18

33

30

46

42

30

30

16

n/a

26

n/a

37

n/a

36

n/a

3 in

12

12

21

21

30

30

29

29

1-1/2 in

12

n/a

20

n/a

n/a

n/a

n/a

n/a

20 to 1 (-7 to -17)

2 in 2-1/2 in

11

9

19

17

28

25

27

24

7

n/a

14

n/a

21

n/a

20

n/a

3 in

2

2

9

9

16

16

14

14

1-1/2 in

8

n/a

13

n/a

n/a

n/a

n/a

n/a

0 to -20 (-18 to -29)

2 in 2-1/2 in

6

4

12

10

19

16

18

15

1

n/a

7

n/a

13

n/a

12

n/a

3 in

1

1

2

2

8

8

7

7

1Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.

2 Poly-Propylene vent pipe (PP) by Duravent and Centrotherm.

3 Vent length in table is equivalent length. Consider each elbow as 5ft. of linear length.

NOTE – Concentric terminations are the equivalent of 5′ and should be considered when measuring pipe length.

NOTE – Maximum uninsulated vent lengths listed may include the termination(vent pipe exterior to the structure) and cannot exceed 5 linear feet or the maximum allowable intake or exhaust vent length listed in TABLE 7 or TABLE 8 which ever is less.

NOTE – If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace. See FIGURE 33.

Conditioned Space

Conditioned Space

Pipe Insulation
Unconditioned Space

Exhaust Pipe
Intake Pipe

FIGURE 33

Page 25

VENT TERMINATION CLEARANCES FOR NON-DIRECT VENT INSTALLATIONS IN THE USA AND CANADA
INSIDE CORNER DETAIL
G

D E B

H A

L

C

B

B

I

Fixed

Fixed

Operable

Closed

M

Closed

F

Operable

B

K

A

J

B

VENT TERMINAL

AIR SUPPLY INLET

AREA WHERE TERMINAL IS NOT PERMITTED

US Installations1

Canadian Installations2

A =

Clearance above grade, veranda,

porch, deck or balcony

12 inches (305mm) or 12 in. (305mm) above average snow accumulation.

12 inches (305mm) or 12 in. (305mm) above average snow accumulation.

B =

Clearance to window or

door that may be opened

C =

Clearance to permanently

closed window

4 feet (1.2 m) below or to side of opening; 1 foot (30cm) above opening

  • 12″

6 inches (152mm) for appliances <10,000 Btuh (3kw), 12 inches (305mm) for appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m) for appliances > 100,000 Btuh (30kw)

  • 12″

D = Vertical clearance to ventilated soffit located above the terminal within a
horizontal distance of 2 feet (610 mm) from the center line of the terminal

E =

Clearance to unventilated soffit

  • Equal to or greater than soffit depth.

  • Equal to or greater than soffit depth.

  • Equal to or greater than soffit depth.

  • Equal to or greater than soffit depth.

F =

Clearance to outside corner

  • No minimum to outside corner

  • No minimum to outside corner

G = Clearance to inside corner

H =

  • 3 feet (.9m) within a height 15 feet (4.5m) 3 feet (.9m) within a height 15 feet (4.5m)

tended above meter / regulator assembly

above the meter / regulator assembly

above the meter / regulator assembly

I =

Clearance to service regulator

vent outlet

  • 3 feet (.9m)

3 feet (.9m)

J =

Clearance to non-mechanical air

pliance

4 feet (1.2 m) below or to side of opening; 1 foot (30 cm) above opening

6 inches (152mm) for appliances <10,000 Btuh (3kw), 12 inches (305mm) for appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m) for appliances > 100,000 Btuh (30kw)

K = ply inlet

3 feet (.9m) above if within 10 feet (3m) horizontally

6 feet (1.8m)

L = Clearance above paved sidewalk or paved driveway located on public property

7 feet (2.1m)

7 feet (2.1m)

M = Clearance under veranda, porch, deck or balcony

*12 inches (305mm)

12 inches (305mm)

1 In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code 2 In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
Permitted only if veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor. Lennox recommends avoiding this location if possible.

*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1, clearance will be in accordance with local installation codes and the requirements of the lation instructions.” NOTE – This figure is intended to illustrate clearance requirement and does not serve as a substitute for locally adopted installation codes.

FIGURE 34

Page 26

D E B

VENT TERMINATION CLEARANCES FOR DIRECT VENT INSTALLATIONS IN THE US AND CANADA
INSIDE CORNER DETAIL
G

A

H

L

C

B

B

I

Fixed

Fixed

Operable

Closed

M

Closed

F

Operable

B

K

A

J

B

VENT TERMINAL

AIR SUPPLY INLET

AREA WHERE TERMINAL IS NOT PERMITTED

US Installations1

Canadian Installations2

A =

Clearance above grade, veranda,

porch, deck or balcony

12 inches (305mm) or 12 in. (305mm) above average snow accumulation.

12 inches (305mm) or 12 in. (305mm) above average snow accumulation.

B =

Clearance to window or

door that may be opened

C =

Clearance to permanently

closed window

6 inches (152mm) for appliances <10,000 6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

pliances > 10,000 Btuh (3kw) and <50,000 appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

pliances > 50,000 Btuh (15kw)

for appliances > 100,000 Btuh (30kw)

  • 12″

  • 12″

D = Vertical clearance to ventilated soffit located above the terminal within a
horizontal distance of 2 feet (610mm) from the center line of the terminal

E =

Clearance to unventilated soffit

F =

Clearance to outside corner

G =

Clearance to inside corner

  • Equal to or greater than soffit depth * Equal to or greater than soffit depth

  • Equal to or greater than soffit depth No minimum to outside corner

  • Equal to or greater than soffit depth No minimum to outside corner

H = tended above meter / regulator assembly

3 feet (.9m) within a height 15 feet (4.5m) 3 feet (.9m) within a height 15 feet (4.5m)

above the meter / regulator assembly

above the meter / regulator assembly

I =

Clearance to service regulator

vent outlet

  • 3 feet (.9m)

3 feet (.9m)

J =

Clearance to non-mechanical air

pliance

6 inches (152mm) for appliances <10,000 6 inches (152mm) for appliances <10,000

Btuh (3kw), 12 inches (305mm) for

pliances > 10,000 Btuh (3kw) and <50,000 appliances > 10,000 Btuh (3kw) and

<100,000 Btuh (30kw), 36 inches (.9m)

pliances > 50,000 Btuh (15kw)

for appliances > 100,000 Btuh (30kw)

K = ply inlet

3 feet (.9m) above if within 10 feet (3m) horizontally

6 feet (1.8m)

L = Clearance above paved sidewalk or paved driveway located on public property

  • 7 feet (2.1m)

7 feet (2.1m)

M = Clearance under veranda, porch, deck or balcony

*12 inches (305mm)

12 inches (305mm)

1 In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code 2 In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings. Permitted only if veranda, porch, deck or balcony is fully open on a minimum of two sides beneath the floor. Lennox recommends avoiding this location if possible.

*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1, clearance will be in accordance with local installation codes and the requirements of the gas supplier and these installation instructions.”
NOTE – This figure is intended to illustrate clearance requirements and does not serve as a substitute for locally adopted installation codes.

FIGURE 35

Page 27

Details of Intake and Exhaust Piping Terminations for Direct Vent Installations

NOTE – In Direct Vent installations, combustion air is taken from outdoors and flue gases are discharged to outdoors. NOTE – Flue gas may be slightly acidic and may adversely affect some building materials. If any vent termination is used and the flue gasses may impinge on the building material, a corrosion- resistant shield (minimum 24 inches square) should be used to protect the wall surface. If the optional tee is used, the protective shield is recommended. The shield should be constructed using wood, plastic, sheet metal or other suitable material. All seams, joints, cracks, etc. in the affected area should be sealed using an appropriate sealant. See FIGURE 44.
Intake and exhaust pipes may be routed either horizontallythrough an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred. FIGURE 36 through FIGURE 43 shows typical terminations.
1 – Vent terminations are not required to be in the same pressure zone. You may exit the intake on one side of the structure and the exhaust on another side (FIGURE 37). You may exit the exhaust out the roof and the intake out the side of the structure (FIGURE 38).
2 – Intake and exhaust pipes should be placed as close together as possible at termination end (refer to illustrations). Maximum separation is 3″ (76mm) on roof terminations and 6″ (152mm) on side wall terminations.
NOTE – When venting in different pressure zones, the maximum separation requirement of intake and exhaust pipe DOES NOT apply.
3 – On roof terminations, the intake piping should terminate straight down using two 90° elbows (See FIGURE 36).
4 – Exhaust piping must terminate straight out or up as shown. A reducer may be required on the exhaust piping at the point where it exits the structure to improve the velocity of exhaust away from the intake piping. See TABLE 10.

TABLE 10

EXHAUST PIPE TERMINATION SIZE REDUCTION

EL297DFV

Termination

MODEL

Pipe Size

*045 and 070

1-1/2″ (38MM)

*090

2″ (51MM)

110

2″ (51MM)

*-045, -070 and -090 units with the flush mount termination must use the 1-1/2″accelerator supplied with the kit.
5 – On field-supplied terminations for side wall exit, exhaust piping may extend a maximum of 12 inches (305mm) for 2″ PVC and 20 inches (508mm) for 3″ (76mm) PVC beyond the outside wall. Intake piping should be as short as possible. See FIGURE 44. NOTE – Care must be taken to avoid recirculation of exhaust back into intake pipe.

6 – On field supplied terminations, a minimum distance between the end of the exhaust pipe and the end of the intake pipe without a termination elbow is 8″ and a minimum distance of 6″ with a termination elbow. See FIGURE 44.

Inches(mm)

3″(76mm) MAX.

8″ (203mm) MIN
12″ (305mm) ABOVE AVERAGE SNOW ACCUMULATION

UNCONDITIONED ATTIC SPACE

3″ (76mm) OR 2″ (51mm) PVC
PROVIDE SUPPORT FOR INTAKE AND EXHAUST LINES DIRECT VENT ROOF TERMINATION KIT (15F75 or 44J41)
FIGURE 36
Exiting Exhaust and Intake Vent (different pressure zone)

Exhaust Pipe

Furnace
FIGURE 37

Inlet Air (Minimum 12 in. 305 MM) above grade or snow
accumulation

Exiting Exhaust and Intake Vent (different pressure zone)

Roof Terminated Exhaust Pipe

Furnace
FIGURE 38

Inlet Air (Minimum 12 in. 305 MM) above grade or snow
accumulation

Page 28

7 – If intake and exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, piping must be supported. At least one bracket must be used within 6″ from the top of the elbow and then every 24″ (610mm) as shown in FIGURE 44, to prevent any movement in any direction. When exhaust and intake piping must be run up an outside wall, the exhaust piping must be terminated with pipe sized per table 10.The intake piping may be equipped with a 90° elbow turndown. Using turndown will add 5 feet (1.5m) to the equivalent length of the pipe.
8 – A multiple furnace installation may use a group of up to four terminations assembled together horizontally, as shown in FIGURE 41.

Accelerator not required for 3″ concentric

12″ (305mm)
Minimum Above Average
Snow Accumulation

INTAKE

FLASHING (Not Furnished)

CLAMP

SHEET METAL STRAP (Clamp and sheet metal strap must be field installed to support the weight of the termination kit.)
FIELD-PROVIDED REDUCER MAY BE REQUIRED
TO ADAPT DIFFERENT VENT PIPE SIZE TO TERMINATION

DIRECT VENT CONCENTRIC ROOFTOP TERMINATION 71M80, 69M29 or 60L46 (US) 44W92 or 44W93 (Canada)

FIGURE 39

FIELD-PROVIDED REDUCER MAY BE REQUIRED TO ADAPT DIFFERENT VENT PIPE SIZE TO TERMINATION OUTSIDE
WALL
EXHAUST AIR

Accelerator not required for 3″ concentric
INTAKE AIR EXHAUST AIR

INTAKE AIR

CLAMP (Not Furnished)

INTAKE 12″ (305mm) Min. AIR above grade or average snow ac cumulation. GRADE

DIRECT VENT CONCENTRIC WALL TERMINATION 71M80, 69M29 or 60L46 (US) 44W92 or 44W93 (Canada)

EXHAUST VENT
INTAKE AIR
Inches (mm)

5″ (127mm)

12″ (305mm) 5-1/2″ (140mm)

18″ MAX. (457mm)

Front View

EXHAUST VENT 12″ (305mm) Min. above grade or

INTAKE cumulation. AIR

optional intake elbow

Side View

OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT INSTALLATION OF DIRECT VENT WALL TERMINATION KIT
(30G28 or 81J20)

FIGURE 41

2″ EXTENSION FOR 2″ PVC PIPE1″ EXTENSION FOR 3″ PVC PIPE
4”
FURNACE INTAKE PIPE
FLAT SIDE

FURNACE EXHAUST
PIPE
GLUE EXHAUST END FLUSH INTO
TERMINATION
1-1/2″ ACCELERATOR

FLUSH-MOUNT SIDE WALL TERMINATION KIT 51W11 (US) or 51W12 (Canada)
FIGURE 42

DIRECT VENT APPLICATION USING EXISTING CHIMNEY

STRAIGHT-CUT OR ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *

8″ – 12″ (203mm – 305mm)

3″ – 8″ (76mm203mm)

Minimum 12″ (305MM) above chimney top
plate or average snow accumulation

INTAKE PIPE INSULATION (optional)
SHEET METAL TOP
PLATE

INSULATE TO FORM
SEAL

SHOULDER OF FITTINGS PROVIDE SUPPORT
OF PIPE ON TOP PLATE
ALTERNATE INTAKE PIPE

3″ – 8″ (76mm203mm)

EXTERIOR PORTION OF
CHIMNEY

FIGURE 40

NOTE – Do tical discharge through an existing unused chimney or stack is required, insert piping inside trated. In any exterior portion of chimney, the exhaust vent must be insulated.
FIGURE 43
Page 29

NOTE – FIELD-PROVIDED REDUCER MAY BE
REQUIRED TO ADAPT LARGER VENT PIPE SIZE
TO TERMINATION
D

FIELD FABRICATED WALL TERMINATION

A- Minimum clearance

above grade or average

snow accumulation

D

B- Maximum horizontal

separation between

intake and exhaust

2″ (51mm) Vent Pipe
12″ (305 mm)
6″ (152 mm)

3″ (76mm) Vent Pipe
12″ (305 mm)
6″ (152 mm)

B

B

C1

Intake Elbow C2

C1 -Minimum from end of exhaust to inlet of intake 8″ (203 mm) 8″ (203 mm)

A

STRAIGHT

A

APPPLICATION

C2 -Minimum from end of exhaust to inlet of intake 6″ (152 mm) 6″ (152 mm)

  • WALL SUPPORT

D- Maximum exhaust pipe length

12″ (305 mm) 20″ (508 mm)

D E

E

D

E- Maximum wall support distance from top of each 6″ (152 mm) 6″ (152 mm)

pipe (intake/exhaust)

See maximum allowable venting tables for venting

B

B

lengths with this arrangement.

  • Use wall support every 24″ (610 mm). Use two

C1

A

wall supports if extension is greater than

C2

A

24″ (610 mm) but less than 48″ (1219 mm).

EXTENDED APPLICATION

NOTE – One wall support must be within 6″ (152 mm) from top of each pipe (intake and exhaust) to prevent movement in any direction.

ALTERNATE TERMINATIONS (TEE & FORTY-FIVE DEGREE ELBOWS ONLY)

B

D

C 2
A

2″ (51mm)

3″ (76mm)

Vent Pipe

Vent Pipe

B

Exhaust

A – Clearance above Grade or average snow

12″ (305 mm) Min 12″ (305 mm) Min

D

accumulation

1

B – Horizontal separation

6″ (152mm)min 6″ (152mm)min

between intake and exhaust 24″ (610mm )Max 24″ (610mm )Max

Intake Elbow

C A

3

C – Minimum from end of

9″ (227mm)

9″ (227mm)

exhaust to inlet of intake

D – Exhaust pipe length

12″ (305mm)min 12″ (305mm)min 16″ (405mm )Max 16″ (405mm )Max

D 1
E B

D 1
E B
12″ C

E – Wall support distance from 6″ (152mm) Max top of each pipe (intake/exhaust)

6″ (152mm) Max

E

D

B

Front View of Intake and Exhaust

12″ C

2 A

C

Intake

Exhaust

A

2

A

1The exhaust termination tee should be connected to the 2″ or 3″ PVC flue pipe as shown in the illustration. In

horizontal tee applications there must be be a minimum of 3 ft away from covered patios or any living ares and

cannot be within 3 ft of a window. Do not use an accelerator in applications that include an exhaust termination

tee. The accelerator is not required.

2 As required. Flue gas may be acidic and may adversely affect some building materials. If a side wall vent

termination is used and flue gases will impinge on the building materials, a corrosion-resistant shield

(24 inches square) should be used to protect the wall surface. If optional tee is used, the protective shield

is recommended. The shield should be constructed using wood, sheet metal or other suitable material.

All seams, joints, cracks, etc. in affected area, should be sealed using an appropriate sealant. 3 Exhaust pipe 45° elbow can be rotated to the side away from the combustion air inlet to direct exhaust

away from adjacent property. The exhaust must never be directed toward the combustion air inlet.

FIGURE 44

Page 30

Details of Exhaust Piping Terminations for Non-Direct Vent Applications
Exhaust pipes may be routed either horizontally through an outside wall or vertically through the roof. In attic or closet installations, vertical termination through the roof is preferred. See FIGURE 45 and FIGURE 46 for typical terminations.
1 – Exhaust piping must terminate straight out or up as shown. The termination pipe must be sized as listed in TABLE 10.The specified pipe size ensures proper velocity required to move the exhaust gases away from the building.
2 -On field supplied terminations for side wall exit, exhaus t piping may extend a maximum of 12 inches (305mm) for 2″ PVC and 20 inches (508mm) for 3″ (76mm) PVC beyond the outside wall.
3 -If exhaust piping must be run up a side wall to position above snow accumulation or other obstructions, piping must be supported every 24 inches (610mm). When exhaust piping must be run up an outside wall, any reduction in exhaust pipe size must be done after the final elbow.
4 – Distance between exhaust pipe terminations on multiple furnaces must meet local codes.
NON-DIRECT VENT APPLICATION USING EXISTING CHIMNEY
STRAIGHT-CUT OR ANGLE-CUT IN DIRECTION
OF ROOF SLOPE

12″ (305mm) ABOVE AVE.
SNOW ACCUMULATION

3″ (76mm) OR 2″ (51mm) PVC
PROVIDE SUPPORT FOR EXHAUST LINES

UNCONDITIONED ATTIC SPACE

NON-DIRECT VENT ROOF TERMINATION KIT (15F75 or 44J41)
FIGURE 46 Condensate Piping This unit is designed for either right- or left- side exit of condensate piping. Refer to FIGURE 47 and FIGURE 48 condensate trap locations. NOTE – If necessary the condensate trap may be installed up to 5′ away from the furnace. Use PVC pipe to connect trap to furnace condensate outlet. Piping from furnace must slope down a minimum of 1/4″ per ft. toward trap.
CONDENSATE TRAP AND PLUG LOCATIONS

Minimum 12″ (305MM) above chimney top
plate or average snow accumulation
SHEET METAL TOP
PLATE
INSULATE TO FORM
SEAL

SHOULDER OF FITTINGS PROVIDE SUPPORT
OF PIPE ON TOP PLATE
EXTERIOR PORTION OF
CHIMNEY

NOTE – Do tical discharge through an existing unused chimney or stack is required, insert piping inside trated. In any exterior portion of chimney, the exhaust vent must be insulated.
FIGURE 45

Trap (same on right side)
1-1/2 in.

Plug (same on left side)

FIGURE 47

Page 31

CONDENSATE TRAP LOCATION (shown with right side exit of condensation)
Trap can be installed a maximum of 5ft. from furnace (PVC only)
Field Provided Vent 1″ min. 2″ max. above
condensate drain. 1″ min. 2″ max.
5′ max.
to drain
Piping from furnace must slope down a minimum 1/4″ per ft. toward trap
FIGURE 48 1 – Determine which side condensate piping will exit
the unit, location of trap, field-provided fittings and length of PVC pipe required to reach available drain. 2 – Use a large flat head screw driver or a 1/2″ drive socket extension and remove plug (figure 47) from the cold end header box at the appropriate location on the side of the unit. Install provided 3/4 NPT street elbow fitting into cold end header box. Use Teflon tape or appropriate pipe dope. NOTE – Cold end header box drain plugs are factory installed. Check the unused plug for tightness to prevent leakage. 3 – Install the cap over the clean out opening at the base of the trap. Secure with clamp. See FIGURE 53. 4 – Install drain trap using appropriate PVC fittings, glue all joints. Glue the provided drain trap as shown in FIGURE 53. Route the condensate line to an open drain.

5 – FIGURE 50 shows the furnace and evaporator coil using a separate drain. If necessary, the condensate line from the furnace and evaporator coil can drain together. See FIGURE 51 and FIGURE 52. The field provided vent must be a minimum 1″ to a maximum 2″ length above the condensate drain outlet connection. NOTE – If necessary the condensate trap may be installed up to 5 feet away from the furnace. Piping from furnace must slope down a minimum of 1/4″ per ft. toward trap. NOTE – Appropriately sized tubing and barbed fitting may be used for condensate drain. Attach to the drain on the trap using a hose clamp. See FIGURE 49.
Field Provided Drain Components

Elbow Tubing

Barbed Fitting Hose Clamp
FIGURE 49

Page 32

6 – If unit will be started immediately upon completion of installation, prime trap per procedure outlined in Unit Start-Up section.
Condensate line must slope downward away from the trap to drain. If drain level is above condensate trap, condensate pump must be used. Condensate drain line should be routed within the conditioned space to avoid freezing of condensate and blockage of drain line. If this is not possible, a heat cable kit may be used on the condensate trap and line. Heat cable kit is available from Lennox in various lengths; 6 ft. (1.8m) – kit no. 26K68; 24 ft. (7.3m) – kit no. 26K69; and 50 ft. (15.2m) – kit no. 26K70.
Furnace with Evaporator Coil Using a Separate Drain
Field Provided Vent 1″ min. 2″ max. above
condensate drain.
Condensate Drain Connection

Evaporator Drain Line (vent required)

Drain

FIGURE 50
IMPORTANT
When combining the furnace and evaporator coil drains together, the A/C condensate drain outlet must be vented to relieve pressure in order for the furnace pressure switch to operate properly.

Furnace with Evaporator Coil Using a Common Drain
Field Provided Vent 1″ min. 2″ max. above
condensate drain.
Condensate Drain Connection

Evaporator Drain Line (vent required)

FIGURE 51

Condensate Trap With Optional Overflow Switch

From Evaporator Coil

HorizontalFurnace4″ Min. to 5″ Max.above condensatedrain connection)

Optional

FurnaceCondensate Drain Connection

FIGURE 52
CAUTION
Do not use copper tubing or existing copper condensate lines for drain line.

Page 33

TRAP / DRAIN ASSEMBLY USING 1/2″ PVC OR 3/4″ PVC Optional Condensate Drain Connection

Adapter 3/4 inch slip X 3/4 inch mpt (not furnished)

90° Street Elbow 3/4 inch PVC (not furnished)

90° Street Elbow 3/4 inch PVC ( furnished)

Condensate Drain Connection In Unit

To Trap

Optional DrainPiping FromTrap

Adapter 3/4 inch slip X 3/4 inch mpt (not furnished)

1 (25 mm) Min. 2 (50 mm) Max. Above Top Of Condensate Drain Connection In Unit

Vent

5 Feet Maximum

Condensate Drain Connection In Unit

90° Elbow 3/4 inch PVC (Not Furnished)
1/2 inch PVC Pipe (Not Furnished)

3/4 inch PVC Pipe (Not Furnished)

Drain Assembly for 1/2 inch Drain Pipe

Coupling 3/4 inch slip X slip (Not Furnished)

1/2 inch PVC Pipe (Not Furnished)

To Drain

90° Elbow 1/2 inch PVC (Not Furnished)

Drain Assembly for 3/4 inch Drain Pipe

Drain Trap Assembly (Furnished)

90° Elbow 3/4 inch PVC (Not Furnished)

90° Elbow
3/4 inch PVC (Not Furnished)

Drain Trap Clean Out

To Drain
DrainTrap Assembly (Furnished)

To Coupling 3/4 inch slip X slip

Drain

(Not Furnished)

DrainTrap Assembly with 1/2 inch Piping
1 (25 mm) Min. 2 (50 mm) Max. Above Top Of Condensate Drain Connection In Unit
Vent

DrainTrap Assembly with 3/4 inch Piping
1 (25 mm) Min. 2 (50 mm) Max. Above Top Of Condensate Drain Connection In Unit
Vent

7 (178)

1/2 inch

Condensate Drain Connection In Unit

3/4 inch

Condensate Drain Connection In Unit

To Drain

FIGURE 53

To Drain

Page 34

Gas Piping
CAUTION
If a flexible gas connector is required or allowed by the authority that has jurisdiction, black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet. The flexible connector can then be added between the black iron pipe and the gas supply line.
WARNING
Do not over torque (800 in-lbs) or under torque (350 inlbs) when attaching the gas piping to the gas valve.
1 – Gas piping may be routed into the unit through either the left- or right- hand side. Supply piping enters into the gas valve from the side of the valve as shown in FIGURE 55. The maximum torque is 800 in lbs and minimum torque is 350 in lbs when when attaching the gas piping to the gas valve.
2 – When connecting gas supply, factors such as length of run, number of fittings and furnace rating must be considered to avoid excessive pressure drop. TABLE 11 lists recommended pipe sizes for typical applications. NOTE – Use two wrenches when connecting gas piping to avoid transferring torque to the manifold.
3 – Gas piping must not run in or through air ducts, clothes chutes, chimneys or gas vents, dumb waiters or elevator shafts. Center gas line through piping hole. Gas line should not touch side of unit. See FIGURE 55.
4 – Piping should be sloped 1/4 inch per 15 feet (6mm per 5.6m) upward toward the gas meter from the furnace. The piping must be supported at proper intervals, every 8 to 10 feet (2.44 to 3.05m), using suitable hangers or straps. Install a drip leg in vertical pipe runs to serve as a trap for sediment or condensate.
5 – A 1/8″ N.P.T. plugged tap or pressure post is located on the gas valve to facilitate test gauge connection. See FIGURE 62.
6 – In some localities, codes may require installation of a manual main shut- off valve and union (furnished by installer) external to the unit. Union must be of the ground joint type.

IMPORTANT
Compounds used on threaded joints of gas piping must be resistant to the actions of liquified petroleum gases.
Leak Check
After gas piping is completed, carefully check all field-installed piping connections for gas leaks. Use a commercially available leak detecting solution specifically manufactured for leak detection. Never use an open flame to test for gas leaks. The furnace must be isolated from the gas supply system by closing the individual manual shut-off valve during any gas supply system at pressures greater than or equal to ½ psig. (3.48 kPa, 14 inches w.c.). This furnace and its components are designed, manufactured and independently certified to comply with all applicable ANSI/CSA standards. A leak check of the furnace and its components is not required.

MANUAL MAIN SHUT-OFF VALVE WILL NOT HOLD
NORMAL TEST PRESSURE
1/8″ N.P.T. PLUGGED TAP

CAP FURNACE ISOLATE
GAS VALVE

FIGURE 54
IMPORTANT
When testing pressure of gas lines, gas valve must be disconnected and isolated. See FIGURE 54. Gas valves can be damaged if subjected to pressures greater than 1/2 psig (3.48 kPa).
WARNING
FIRE OR EXPLOSION HAZARD Failure to follow the safety warnings exactly could result in serious injury, death, or property damage. Never use an open flame to test for gas leaks. Check all connections using a commercially available soap solution made specifically for leak detection. Some soaps used for leak detection are corrosive to certain metals. Carefully rinse piping thoroughly after leak test has been completed.

Page 35

MANUAL MAIN SHUT-OFF
VALVE (1/8 in. NPT plugged tap shown)

Left Side Piping (Standard)
AUTOMATIC GAS VALVE (with manual shut-off valve)

GROUND JOINT UNION

AUTOMATIC GAS VALVE (with manual shut-off valve)

MANUAL MAIN SHUT-OFF
VALVE (1/8 in. NPT plugged tap
shown) GROUND
JOINT UNION
DRIP LEG

DRIP LEG

FIELD PROVIDED AND INSTALLED
NOTE – BLACK IRON PIPE ONLY TO BE ROUTED INSIDE OF CABINET

Right Side Piping (Alternate)

FIGURE 55

TABLE 11

Gas Pipe Capacity – ft3/hr (m3/hr)

Nominal Iron Pipe Size Inches
(mm)

Internal Diameter
inches (mm)

10 (3.048)

20 (6.096)

Length of Pipe – feet (m)

30

40

50

60

70

80

90

100

(9,144) (12,192) (15.240) (18.288) (21.336) (24.384) (27.432) (30,480)

1/2 (12.7)

.622

172

(17.799) (4.87)

118 (3.34)

95 (2.69)

81 (2.29)

72 (2.03)

65 (1.84)

60 (1.69)

56 (1.58)

52 (1.47)

50 (1.42)

3/4 (19.05)

.824

360

247

199

(20.930) (10.19) (7.000) (5.63)

170 (4.81)

151 (4.23)

137 (3.87)

126 (3.56)

117 (3.31)

110 (3.11)

104 (2.94)

1 (25.4)

1.049

678

466

374

320

(26.645) (19.19) (13.19) (10.59) (9.06)

284 (8.04)

257 (7.27)

237 (6.71)

220 (6.23)

207 (5.86)

195 (5.52)

1-1/4 (31.75)

1.380

1350

957

768

657

583

528

486

452

424

400

(35.052) (38.22) (27.09) (22.25) (18.60) (16.50) (14.95) (13.76) (12.79) (12.00) (11.33)

1-1/2 (38.1)

1.610

2090 1430 1150

985

873

791

728

677

635

600

(40.894) (59.18) (40.49) (32.56) (27.89) (24.72) (22.39) (20.61) (19.17) (17.98) (17.00)

2 (50.8)

2.067

4020

2760

2220

1900

1680

1520

1400

1300

1220

1160

(52.502) (113.83) (78.15) (62.86) (53.80) (47.57) (43.04) (39.64) (36.81) (34.55) (32.844)

2-1/2 (63.5)

2.469

6400

4400

3530

3020

2680

2480

2230

2080

1950

1840

(67.713) (181.22) (124.59) (99.95) (85.51) (75.88) (70.22) (63.14) (58.89) (55.22) (52.10)

3

3.068 11300 7780 6250 5350 4740 4290 3950 3670

(76.2)

(77.927) (319.98) (220.30) (176.98) (151.49) (134.22) (121.47) (111.85) (103.92)

NOTE – Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specific gravity gas.

3450 (97.69)

3260 (92.31)

Page 36

Electrical
ELECTROSTATIC DISCHARGE (ESD) Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic components. Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control.
WARNING
Electric Shock Hazard. Can cause injury or death. Unit must be properly grounded in accordance with national and local codes.
WARNING
Fire Hazard. Use of aluminum wire with this product may result in a fire, causing property damage, severe injury or death. Use copper wire only with this product.
The unit is equipped with a field make-up box on the left hand side of the cabinet. The make-up box may be moved to the right side of the furnace to facilitate installation. If the make-up box is moved to the right side, clip the wire ties that bundle the wires together. The excess wire must be pulled into the blower compartment. Secure the excess wire to the existing harness to protect it from damage.
EXTERIOR MAKE-UP BOX
(FIELD PROVIDED RIGHT SIDE)
MAKE-UP BOX
OUTSIDE CABINET
Right Side
FIGURE 56 Refer to FIGURE 60 for unit schematic and field wiring. See FIGURE 57 and FIGURE 58 for thermostat wiring in communicating applications. DIP Switch Settings and Field Wiring Ignition Control 103130-XX shows DIP switch and on-board link settings for non-communicating thermostat applications. Typical wiring schematic is shown in FIGURE 60.

CAUTION
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit breaker(s) per Product Specifications bulletin (EHB) and unit rating plate.

The power supply wiring must meet Class I restrictions. Protected by either a fuse or circuit breaker, select circuit protection and wire size according to unit nameplate. NOTE – Unit nameplate states maximum current draw. Maximum over-current protection allowed is shown in TABLE 12.

TABLE 12

EL297DFV Model

Maximum Over-Current Protection (Amps)

045V36B, 070V48B

15

090V60C, 110V60C

20

Holes are on both sides of the furnace cabinet to facilitate wiring.

Install a separate (properly sized) disconnect switch near the furnace so that power can be turned off for servicing.
Before connecting the thermostat or the power wiring, check to make sure the wires will be long enough for servicing at a later date. Remove the blower access panel to check the length of the wire.

Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wiring diagrams shown in DIP Switch Settings and Field Wiring Ignition Control 103130-XX and FIGURE 60. Use 18-gauge wire or larger that is suitable for Class II rating for thermostat connections.

Electrically ground the unit according to local codes or, in the absence of local codes, according to the current National Electric Code (ANSI/NFPA No. 70). A green ground wire is provided in the field make-up box. NOTE – The EL297DFV furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

One line voltage “ACC” 1/4″ spade terminal is provided on the furnace integrated control. Any electronic air cleaner or other accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to the one of the provided neutral terminals. See FIGURE 61 for control configuration. This terminal is energized when the indoor blower is operating.

Page 37

An unpowered, normally open (dry) set of contacts with a 1/4″ spade terminal “HUM” are provided for humidifier connections and may be connected to 24V or 120V. Any humidifier rated up to one amp can be con nected to these terminals. In 120V humidifier applications the neutral leg of the circuit can be connected to one of the provided neutral terminals. This terminal is energized in the heating mode.
Install the room thermostat according to the instructions provided with the thermostat. See DIP Switch Settings and Field Wiring Ignition Control 103130-XX for field wiring connections in varying applications. If the furnace is being matched with a heat pump, refer to the instruction packaged with the dual fuel thermostat.
Thermostat Selection
CAUTION
Field wiring for both communicating and noncommunicating applications is illustrated in diagrams, which begin on Page 39.
Non-Communicating
In non-communicating applications the EL297DFV is designed to operate in a SINGLE-STAGE mode or TWOSTAGE mode using a conventional thermostat.
For optimal performance in non-communicating applications, Lennox recommends use of a ComfortSense® 7000 high quality electronic digital thermostat or any other with adjustable settings for 1st stage / 2nd stage on / off differentials and adjustable stage timers.
Communicating
In communicating applications a communicating thermostat must be used. Refer to the instructions provided with the thermostat for installation, set-up and operation. In communicating system all unused thermostat wire in the wire bundle needs to be terminated inside and out. The extra wires can terminate on the `C” terminal strip. (RSBus). Using an additional wire come off “C” terminal and wire nut all the extra wires together. Termination on the outdoor control must match the indoor control.

Indoor Blower Speeds
Non-Communicating
When the thermostat is set to “FAN ON,” the indoor blower will run continuously at a field selectable percentage of the second-stage cooling speed when there is no cooling or heating demand. The factory default setting is 38% of cool speed. When the EL297DFV is running in the heating mode, the indoor blower will run on the heating speed designated by the positions of DIP switches 11, 12 and 13. When there is a cooling demand, the indoor blower will run on the cooling speed designated by the positions of DIP switches 5 and 6. First stage cooling will run at 70% cool speed.
Communicating
NOTE – When the EL297DFV is used with a communicating thermostat, proper indoor blower speed selections are made by the communicating thermostat. When the thermostat is set to “FAN ON,” the indoor blower will run at setting determined during system configuration. See TABLE 22 on page 55 for allowable circulatuion speeds.
When there is a heating demand the fan will run on heating speeds for firing rate. See TABLE 21 on page 55 for allowable heating speeds. When there is a cooling demand, the fan will run on the first stage and second stage cooling speed set using thermostat in the installer setup mode. The factory default is based upon 400 CFM a ton.
Generator Use – Voltage Requirements
The following requirements must be kept in mind when specifying a generator for use with this equipment:
· The furnace requires 120 volts (Range: 102 volts to 132 volts)
· The furnace operates at 60 Hz + 5% (Range: 57 Hz to 63 Hz)
· The furnace integrated control requires both correct polarity and proper ground. Both polarity and proper grounding should be checked before attempting to operate the furnace on either permanent or temporary power
· Generator should have a wave form distortion of less than 5% THD (total harmonic distortion)

Page 38

Communicating and Non Communicating Wiring – Ignition Control 103130-XX

Communicating Enabled Furnace with a Non-Communicating Outdoor Unit

Communicating Enabled Furnace with a Communicating Enabled Outdoor Unit

COMMUNICATING FURNACE
OPTIONAL DISCHARGE AIR SENSOR
COMMUNICATING THERMOSTAT

OPTIONAL OUTDOOR AIR SENSOR

OPTIONAL DISCHARGE AIR SENSOR
OPTIONAL OUTDOOR AIR SENSOR
COMMUNICATING THERMOSTAT

COMMUNICATING FURNACE

NON-COMMUNICATING OUTDOOR AIR
CONDITIONING UNIT 1 OR 2 STAGE

DOOR AIR CONDITIONING OR HEAT PUMP UNIT

CLIP ON-BOARD LINK W915 (Y1 TO Y2) FOR TWO-STAGE OPERATION

Outdoor Unit

Indoor Unit Controller
Single wire to terminal C

Single wire to terminal C
Unused wires

COMMUNICATING THERMOSTAT

Unused wires
Communicating systems using the Communicating thermostat require four thermostat wires between the thermostat and the furnace/air handler control and four wires between the outdoor unit and the furnace/air handler control. When a thermostat cable with more than four wires is used, the extra wires must be properly connected to avoid electrical noise. The wires must not be left disconnected.
Use wire nuts to bundle the four unused wires at each end of the cable. A single wire should then be connected to the indoor unit end of the wire bundle and attached to the “C” terminals as shown above.

FIGURE 57

Page 39

Communicating Wiring – Ignition Control 103130-XX

Optional Accessories for use with any Communicating System

NOTE: ICOMMUNICATING THERMOSTAT SENSES HUMIDITY & CONTROLS HUM CONTACTS TO CYCLE HUMIDIFIER BASED QUIRED.
TIONS. BUILT INTO ALL COMMUNICATING ENABLED OUT DOOR UNITS).

120V CONNECTIONS
“HUM” CONTACT IS CLOSED ANYTIME HUMIDITY DEMAND IS PRESENT

sor (Required for even heat)

COMMUNICATING ENABLED FURNACE

ICOMMUNICATING THERMOSTAT

RSBus
Maximum total
tions on the RSBus is limited to 1500ft. Wire gauge of RSBus wire is 18.

24V HUMIDIFIER CONNECTIONS
CS 7000 THERMOSTAT
CONVENTIONAL NONCOMMUNICATING SYSTEM
COMMUNICATING SYSTEM

24V IN jumper not used in noncommunicating configuration
24V IN JUMPER

NOTE: 24V UV LIGHT APPLICATIONS
In a communicating system, neither furnace nor air handler transformer will have adequate VA to power 24V UV light applications. An additional transformer for UV light applications is required.

COMMUNICATING ENABLED FURNACE
ICOMMUNICATING THERMOSTAT

COMMUNICATING ENABLED FURNACE

HEPA BYPASS FILTER X2680 HEPA INTERLOCK KIT
TOR COMMON WIRE THROUGH CURRENT LOOP. SEE HEPA INTERLOCK KIT FOR INSTALLATION DETAILS
LVCS VENTILATION CONTROL SYSTEM
SEE LVCS VENTILATION INSTRUCTIONS FOR DAMPER & SENSOR WIRING

DEHUMIDIFIER CONTROL
HVAC EQUIPMENT

HVAC EQUIP Rf Cf Gs Gh W DH

COMMUNICATING ENABLED FURNACE

FIGURE 58

Page 40

Communicating Wiring – Ignition Control 103130-XX
LENNOX COMMUNICATING INDOOR UNIT

LENNOX COMMUNICATING INDOOR UNIT

LENNOX COMMUNICATING THERMOSTAT OR DAMPER
CONTROL MODULE
CONVENTIONAL OUTDOOR UNIT (1 OR 2 STAGE)

FLOAT SWITCH

LENNOX COMMUNICATING FURNACE EL296V, SL280V, SL280VN, SL297V, SLP99V
cutting DS to R will not cause communication interuption
or error code
DS
CUT* R-DS W914
R

CONVENTIONAL TERMINALS

FIGURE 59

LENNOX COMMUNICATING OUTDOOR UNIT

Page 41

DIP Switch Settings and Field Wiring Ignition Control 103130-XX Field Wiring Applications With Conventional Thermostat

Thermostat

DIP Switch Settings and On-Board Links

DIP Switch 1 Thermostat
Heating Stages

On Board Links Must Be Cut To Select System Options

1 Heat / 1 Cool

ON

NOTE – Use DIP switch 2 to set second-stage heat ON delay. OFF-7 minutes. ON-12 minutes.

DO NOT CUT ANY ON-BOARD LINKS

Wiring Connections

S1 T’STAT

FURNACE TERM. STRIP

OUTDOOR UNIT

1 Heat / 2 Cool

ON

NOTE – Use DIP switch 2 to set second-stage heat ON delay. OFF-7 minutes. ON-12 minutes.

CUT ON-BOARD LINK W915
2 STAGE COMPR

1 Heat / 2 Cool

ON

with t’stat with

humidity control

NOTE – Use DIP switch 2 to set second-stage heat ON delay. OFF-7 minutes. ON-12 minutes.

  • Not required on all units.

CUT ON-BOARD LINK W915
2 STAGE COMPR
CUT ON-BOARD LINK W914
DEHUM OR
HARMONY

S1 T’STAT

FURNACE TERM. STRIP

OUTDOOR UNIT

S1 T’STAT

FURNACE OUTDOOR TERM. STRIP UNIT

o

Page 42

DIP Switch Settings and Field Wiring Ignition Control 103130-XX Field Wiring Applications With Conventional Thermostat

Thermostat 2 Heat / 2 Cool

DIP Switch Settings and On-Board Links

DIP Switch 1 Thermostat
Heating Stages

On Board Links Must Be Cut To Select System Options

OFF

CUT ON-BOARD LINK W915
2 STAGE COMPR

Wiring Connections

S1 T’STAT

FURNACE TERM. STRIP

OUTDOOR UNIT

2 Heat / 2 Cool

OFF

with t’stat with

humidity control

CUT ON-BOARD LINK W915
2 STAGE COMPR

2 Heat / 1 Cool

OFF

with t’stat with

humidity control

CUT ON-BOARD LINK W914
DEHUM OR
HARMONY
CUT ON-BOARD LINK W914
DEHUM OR
HARMONY

2 Heat / 1 Cool

OFF

DO NOT CUT ANY ON-BOARD LINKS

  • Not required on all units.

S1 T’STAT

FURNACE OUTDOOR TERM. STRIP UNIT

S1 T’STAT

o
FURNACE OUTDOOR TERM. STRIP UNIT

o

S1 T’STAT

FURNACE TERM. STRIP

OUTDOOR UNIT

Page 43

Thermostat
Dual Fuel Single Stage Heat Pump
ComfortSense thermostat w/
bilities Capable of 2 stage gas heat control

DIP Switch Settings and Field Wiring Ignition Control 103130-XX Field Wiring Applications With Conventional Thermostat

DIP Switch Settings and On-Board Links

DIP Switch 1 Thermostat
Heating Stages

On Board Links Must Be Cut To Select System Options

OFF

Wiring Connections

T’STAT

FURNACE TERM. STRIP

HEAT PUMP

CUT ON-BOARD LINK W951 HEAT PUMP

H 67M41*

L

L

Y

Y2

D

B

Y2

Dual Fuel Two Stage Heat Pump
ComfortSense thermostat w/
bilities Capable of 2 stage gas heat control

OFF

CUT ON-BOARD LINK W915
2 STAGE COMPR
CUT ON-BOARD LINK W951 HEAT PUMP

T T T’STAT
H

FURNACE TERM. STRIP

outdoor sensor
HEAT PUMP

67M41*

L

L

Y2

Y2

D out blue
B

T

outdoor

T

sensor

  • Connect W1 to W1 ONLY if using defrost tempering kit 67M41 NOTE – Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the furnace integrated control.

Page 44

Thermostat
Dual Fuel Single Stage Heat Pump
ComfortSense thermostat w/
bilities Capable of 2 stage gas heat
midification control

DIP Switch Settings and Field Wiring Ignition Control 103130-XX Field Wiring Applications With Conventional Thermostat

DIP Switch Settings and On-Board Links

DIP Switch 1 Thermostat
Heating Stages

On Board Links Must Be Cut To Select System Options

OFF

Wiring Connections

T’STAT

FURNACE TERM. STRIP

HEAT PUMP

CUT ON-BOARD LINK W951 HEAT PUMP

H 67M41*

CUT ON-BOARD LINK W914
DEHUM OR
HARMONY

L

L

Y

Y2

D

B

Y2

Dual Fuel Two Stage Heat Pump
ComfortSense thermostat w/
bilities Capable of 2 stage gas heat
midification

OFF

CUT ON-BOARD LINK W915
2 STAGE COMPR
CUT ON-BOARD LINK W951 HEAT PUMP
CUT ON-BOARD LINK W914
DEHUM OR
HARMONY

T T T’STAT
H

outdoor sensor

FURNACE TERM. STRIP

HEAT PUMP

67M41*

L

L

Y2

Y2

D

B

Y2

out blue

T

outdoor

T

sensor

  • Connect W1 to W1 ONLY if using defrost tempering kit 67M41 NOTE – Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the furnace integrated control.

Page 45

120V ACC

G

(IF USED)

N L1
8

HUMIDIFIER

S1

S51

ROOM THERMOSTAT

W2 W1 G R C Y1 Y2

OUTDOOR UNIT
Y1
Y2
C L

DOOR INTERLOCK 3 21 654 98 7 12 11 10

S10

PRIMARY

GAS LIMIT

J84

P84

B6

COMBUSTION AIR INDUCER MOTOR

BURNERS

6 S47
FLAME ROLLOUT SWITCH

FLAME SENSOR

IGNITOR

R33
J159 P159

C

GV1

HI

GAS VALVE

M

S47 FLAME ROLLOUT SWITCH

S102
HIGH HEAT PRESSURE SWITCH
S128 LOW HEAT PRESSURE SWITCH

SEE HUM VIEWS HUM
1 2 3 45 6 7 8

L1

J3

ACC SEVEN SEGMENT LED

A92

NEUTRALS

INTEGRATED CONTROL

T1 TRANSFORMER

9 10 1112 13 14 15

DIAGNOSTIC PUSH BUTTON

TB78 8 SENSOR DISCHARGE OUTDOOR AIR

P79 J2

CB8
CIRCUIT BREAKER

4
L13 POWER CHOKE

l+

TB82

RS BUS

l-

LINK

R l+ l- C R l+ l- C

10

W1 W2 G Y2 Y1 C C R DH L O DS

TERMINAL BOARD

TB1

B3

P48 INDOOR

P49

BLOWER

MOTOR

UNIT

BLOWER SPEED CHART FACTORY SHIPPED SETTINGS

SECONDARY 7

HEAT

COOL

ADJUST LIMITS USED

045XV36B

070XV48B FACTORY HIGH FACTORY

1

090XV60C DEFAULT

DEFAULT

110XV60C

Program unit capacity/size

Character on 7- Furnace

Circulator

segment LED

Model

Motor Size

(w dot ON)

8

045XV36B

1/2 HP

9

070XV48B

3/4 HP

11

090XV60C

1 HP

U

110XV60C

1 HP

HUMIDIFIER

HUM AT IFC

TO C TO R OR H ON CS7000

HUMIDIFIER

HUM AT IFC

TO N TO L1
5

1 CUT W914 JUMPER LABELED “DEHUM OR

HARMONY” FROM DS TO R, AT A92 CONTROL

6

BOARD, WHEN USED WITH Comfortsense R

7

7000 THERMOSTAT

2 CUT W951 JUMPER FROM O TO R, LABELED

8

“HEAT PUMP”, AT A92 CONTROL BOARD, WHEN

USED FOR DUAL FUEL APPLICATIONS

9

3 JUMPER W915 FROM Y1 TO Y2 IS FACTORY INSTALLED AT A92 CONTROL BOARD. LEAVE IN FOR ONE STAGE COOL THERMOSTAT. CUT JUMPER Y1 TO Y2 FOR TWO STAGE COOL THERMOSTAT.

DIP SWITCH FACTORY DEFAULT IS FOR A TWO STAGE THERMOSTAT
FIELD SUPPLIED ACC WIRE
USE COPPER CONDUCTORS ONLY
DISCHARGE AND OUTDOOR AIR TERMINALS ARE FOR icomfort USE ONLY
THERMOSTAT CONNECTIONS ARE FOR NON-COMMUNICATING SYSTEM ONLY. REFER TO icomfort INSTALLATION INSTRUCTIONS FOR COMMUNICATING SYSTEMS.

4 L13 USED ON 3/4 AND 1 HP ONLY

10 DH AND L TERMINALS ARE ONLY USED

THERMOSTAT HEAT ANTICIPATION SETTING

WITH icomfort THERMOSTAT

.65 AMP HONEYWELL VALVE .43 AMP WHITE RODGERS VALVE

TWO STAGE HEAT,COOL R

S1 ROOM THERMOSTAT 9

AUTO

NOTE: SEE INSTALLATION INSTRUCTIONS FOR PROCEDURE

ON

TO SET CORRECT BLOWER SPEED FOR SPECIFIC COOLING

TONNAGE BEING APPLIED, AND HEATING TEMPERATURE

FAN

RISE REQUIRED.

TYPICAL SYSTEM SHOWN FOR 2 HEAT/2 COOL WITH A CONVENTIONAL THERMOSTAT. SEE INSTALLATION INSTRUCTIONS FOR CONNECTIONS TO OTHER EQUIPMENT

HEAT COOL 22

COOL

W2 Y2 W1 Y1

G

C

AND ACCESSORIES.

24V

S51 DOOR INTERLOCK L1
7

A92 INTEGRATED CONTROL

LINE

L1

K7 K4

CIRC

K5 K1 K11

P3

P3

J3 2 3 J3 1

BLK RED WHT
HUM

P84 J84 2 3
B6

P159 1 J159

ACC FLAME WHT/PINK SENSE BLK

BLUE

BLUE

TH

BRW

PURPLE S102 HIGH HEAT PRESSURE SWITCH
BRW

MV COM MVL

HOT

24VAC

SEC

K8

P2

5 J2 8

7

2

PS2 MVH

PS1 HLI RO(OUT)

1

12

6

11

4 10

9

3

BRW

(2) S47

GND GND 24VAC COM TR RO(IN)

GRN/YEL GRN/YEL
YEL BRW

PINK S128 LOW HEAT PRESSURE SWITCH
BRW W / YEL STRIPE

YEL ORG

GV1

M

GAS

NO

NO

VALVE C

CB8

HI

C

C

(1) S47 P135 1 J135

A92
INTEGRATED CONTROL

R W2

Y2 W1 Y1 O G DS C

HEAT PUMP W951

W915 3

2
1 W914

C

INDOOR

l-

EQUIPMENT

l+

R

C

OUTDOOR EQUIPMENT

l-

l+

R

RS BUS

l+

8

LINK

l-

PINK PURPLE BLUE BLUE

FLAME SENSOR
120V

120V

T1

ACC

OUTDOOR DISCHARGE SENSOR AIR SENSOR

Page 46

FIGURE 60

WHT COMBUSTION AIR BLOWER MOTOR R33
IGNITOR

Unit Diagram With Igniton Control 103130-XX

J84 1 P84

J159 2 P159

WHT

J3 4 P3

J3 5 P3

A92 INTEGRATED CONTROL

N

N NNN N

WHT WHT

2 J135 P135 S10
YEL

LENNOX

HEATING UNITS-GAS

EL297DF045XV36B EL297DF090XV60C EL297DF070XV48B EL297DF110XV60C

POWER 4 CHOKE

P79 1 2 3 4 5 6 J79

L13

1

2 3 4 J49

P49 5

4

B3

INDOOR

3

BLOWER

2

MOTOR

1

J48 P48

7 EQUIPMENT GROUND

LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD WIRING
DENOTES OPTIONAL COMPONENTS

C 2011

2 HEAT 2 COOL

Supersedes

Litho U.S.A.

WARNINGELECTRIC SHOCK HAZARD,CAN CAUSE INJURY OR DEATH.UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES.
NOTEIF ANY WIRE IN THIS APPLIANCE IS REPLACED,IT MUST BE REPLACED WITH WIRE OF LIKE SIZE, RATING, INSULATION THICKNESS, AND TERMINATION

Ignition Control 103130-XX
HUM

ACC

HS/ CAI

LINE 1 7 SEGMENT LED FLAME SENSE
DIAGNOSTIC PUSH BUTTON

NEUTRAL
INDOOR BLOWER CONNECTOR

DIP SWITCHES

OUTDOOR AIR SENSOR
TERMINALS

12 PIN LOW VOLTAGE CONNECTOR

DISCHARGE AIR SENSOR
TERMINALS
TB83 COMMUNICATING
OUTDOOR EQUIPMENT
TB84 COMMUNICATING
INDOOR THERMOSTAT

R I + I – C R I + I – C W1 W2 G Y2 Y1 C C R DH L O DS
NON-COMMUNICATINGNG 24V TERMINALS

W915 Y1 TO Y2 2 STAGE COMPR
W951 R TO O HEAT PUMP
W914 R TO DS DEHUM OR HARMONY

RS-BUS LINK (TB82, future use)
I+ = DATA HIGH CONNECTION I – = DATA LOW CONNECTION
RS-BUS OUTDOOR (TB83) R = 24VAC I + = DATA HIGH CONNECTION I – = DATA LOW CONNECTION C = 24VAXC COMMON
RS-BUS INDOOR (TB84) R = 24VAC I + = DATA HIGH CONNECTION I – = DATA LOW CONNECTION C = 24VAXC COMMON
1/4″ QUICK CONNECT TERMINALS HUM = UNPOWERED NORMALLY OPEN (DRY) CONTACTS
XMFR = 120 VAC OUTPUT TO TRANSFORMER
LI = 120 VAC INPUT TO CONTROL
ACC = 120 VAC OUTPUT TO OPTIONAL ACCESSORY NEUTRALS = 120 VAC NEUTRAL

THERMOSTAT CONNECTIONS (TB1) DS = DEHUMIDIFICATION SIGNAL W2 = HEAT DEMAND FROM 2ND STAGE T/STAT W1 = HEAT DEMAND FROM 1ST STAGE T/STAT R = CLASS 2 VOLTAGE TO THERMOSTAT G = MANUAL FAN FROM T’STAT C = THERMOSTAT SIGNAL GROUND CONNECTED TO TRANSFORMER GRD (TR) & CHASIS GROUND (GRD)
Y1 = THERMOSTAT 1ST STAGE COOL SIGNAL
Y2 = THERMOSTAT 2ND STAGE COOL SIGNAL
O = THERMOSTAT SIGNAL TO HEAT PUMP REVERSING VALVE
DH = DEHUMIDIFICATION OUTPUT COMMUNICATING THERMOSTAT ONLY
L = USE ONLY WITH A COMMUNICATING THERMOSTAT AND A NON-COMMUNICATING OUTDOOR UNIT

FIGURE 61

Page 47

Integrated Control DIP Switch Settings Conventional Thermostat (non- communicating)
EL297DFV units are equipped with a two-stage, variable speed integrated control. This control manages ignition timing, heating mode fan off delays and indoor blower speeds based on selections made using the control dip switches and jumpers. The control includes an internal watchguard feature which automatically resets the ignition control when it has been locked out. After one hour of continuous thermostat demand for heat, the watchguard will break and remake thermostat demand to the furnace and automatically reset the control to relight the furnace. Note: All communicating settings are set at the communicating therrmostat. See thermostat installation instruction. In a communication system all DIP switch and clippable link settings are ignored. For conventional thermostats proceed with DIP switch and clippable link settings as outlined in the following.
Heating Operation DIP Switch Settings
Switch 1 — Thermostat Selection — This unit may be used with either a single- stage or two-stage thermostat. The thermostat selection is made using a DIP switch which must be properly positioned for the particular application. The DIP switch is factory-positioned for use with a twostage thermostat. If a single-stage thermostat is to be used, the DIP switch must be repositioned.
a. Select “OFF” for two-stage heating operation controlled by a two-stage heating thermostat (factory setting);
b. Select “ON” for two-stage heating operation controlled by a single-stage heating thermostat. This setting provides a timed delay before second-stage heat is initiated.
Switch 2 — Second Stage Delay (Used with SingleStage Thermostat Only) — This switch is used to determine the second stage on delay when a single-stage thermosta is being used. The switch is factory-set in the OFF position, which provides a 7-minute delay before secondstage heat is initiated. If the switch is toggled to the ON position, it will provide a 12-minute delay before secondstage heat is initiated. This switch is only activated when the thermostat selector jumper is positioned for single stage thermostat use.
Switches 3 and 4 — Blower-Off Delay — The blower-on delay of 30 seconds is not adjustable. The blower-off delay (time that the blower operates after the heating demand has been satisfied) can be adjusted by moving switches 3 and 4 on the integrated control. The unit is shipped from the factory with a blower- off delay of 90 seconds. The blower off delay affects comfort and is adjustable to satisfy individual applications. Adjust the blower off delay to achieve a supply air temperature between 90° and 110°F at the exact moment that the blower is de-energized. Longer off delay settings provide lower supply air temperatures; shorter settings provide higher supply air temperatures.TABLE 13 provides the blower off timings that will result from different switch settings.

TABLE 13

Blower Off Delay Switch Settings

Blower Off Delay Seconds

Switch 3

Switch 4

60

On

Off

90 (factory)

Off

Off

120

Off

On

180

On

On

Indoor Blower Operation DIP Switch Settings
Switches 5 and 6 — Cooling Mode Blower Speed — The unit is shipped from the factory with the dip switches positioned for high speed (4) indoor blower motor operation during the cooling mode. TABLE 14 provides the cooling mode blower speeds that will result from different switch settings. Switches 5 and 6 set the blower cfm for secondstage cool. The integrated control automatically ramps down to 70% of the second-stage cfm for first-stage cfm. Refer to tables for corresponding cfm values.

TABLE 14

Cooling Mode Blower Speeds

Speed

Switch 5

Switch 6

Low

On

On

Medium Low

Off

On

Medium High

On

Off

High (factory)

Off

Off

Switches 7 and 8 — Cooling Blower Speed Adjustment

— The unit is shipped from the factory with the dip switches positioned for NORMAL (no) adjustment. The dip switches may be positioned to adjust the blower speed by +10% or -10% to better suit the application. TABLE 15 below provides blower speed adjustments that will result from different switch settings. Refer to tables for corresponding cfm values.

TABLE 15

Cooling Blower Speed Adjustment

Adjustment

Switch 7

Switch 8

+10% (approx)

On

Off

Factory Default

Off

Off

-10% (approx)

Off

On

Switches 9 and 10 — Cooling Mode Blower Speed
Ramping — Blower speed ramping may be used to enhance dehumidification performance. The switches are factory set at option A which has the greatest effect on dehumidification performance. TABLE 16 provides the cooling mode blower speed ramping options that will result from different switch settings. The cooling mode blower speed ramping options are detailed on the next page.
NOTE – The off portion of the selected ramp profile also applies during heat pump operation in dual fuel applications.

Page 48

TABLE 16

Cooling Mode Blower Speed Ramping

Ramping

Switch 9

Switch 10

A (Factory)

Off

Off

B

Off

On

C

On

Off

D

On

On

Ramping Option A (Factory Selection)

· Motor runs at 50% for 30 seconds.

· Motor then runs at 82% for approximately 7-1/2 minutes.

· If demand has not been satisfied after 7-1/2 minutes, motor runs at 100% until demand is satisfied.

· Once demand is met, motor runs at 50% for 30 seconds then ramps down to stop.

OFF

1/2 MIN 50% CFM

7 1/2 MIN 82% CFM

100% CFM

COMPRESSOR DEMAND

1/2 MIN 50% CFM

OFF

Ramping Option B
· Motor runs at 82% for approximately 7-1/2 minutes. If demand has not been satisfied after 7-1/2 minutes, motor runs at 100% until demand is satisfied.
· Once demand is met, motor ramps down to stop.

OFF

7 1/2 MIN 82%CFM

100% CFM

COMPRESSOR DEMAND

OFF

Ramping Option C · Motor runs at 100% until demand is satisfied.
· Once demand is met, motor runs at 100% for 45 seconds then ramps down to stop.

OFF

100% CFM
COMPRESSOR DEMAND

100% CFM 45 SEC.

OFF

Ramping Option D · Motor runs at 100% until demand is satisfied. · Once demand is met, motor ramps down to stop.

OFF

100% CFM
COMPRESSOR DEMAND

OFF

Switches 11, 12 and 13 — Heating Mode Blower Speed –The switches are factory set to the OFF position which provides factory default heat speed. Refer to TABLE 17 for switches 11, 12 and 13 that provided the corresponding increases or decrease to both high and low heat demand. See TABLE 25 on page 58 for allowable heating speeds.

TABLE 17

Heating Mode Blower Speeds

Heat Speed Switch 11 Switch 12

Increase 24%

On

On

Increase 18%

On

On

Increase 12%

On

Off

Increae 6%

On

Off

Factory

Off

Off

Default

Decrease 6%

Off

Off

Decrease

Off

On

12%

Decrease

Off

On

18%

Switch 13 On Off On Off Off
On Off
On

Switches 14 and 15 — Continuous Blower Speed —

TABLE 18 provides continuous blower speed adjustments that will result from different switch settings.

TABLE 18

Continuous Blower Speed

Coninuous Blower Speed

Switch 14

28% of High Cool Speed

Off

38% of High Cool Speed Off
(Factory Setting)

Switch 15 On
Off

Switch 16 – Not Used

Page 49

On-Board Links Note: In a communicating systems with a conventional outdoor unit (non-communicating), the on-board clippable links must be set to properly configure the system.
WARNING
Carefully review all configuration information provided. Failure to properly set DIP switches, jumpers and onboard links can result in improper operation!
On-Board Link W914 Dehum or Harmony (R to DS) Onboard link W914, is a clippable connection between terminals R and DS on the integrated control. W914 must be cut when the furnace is installed with either the Harmony III zone control or a thermostat which features humidity control. If the link is left intact the PMW signal fromHarmony III control will be blocked and also lead to controldamage.

Refer to TABLE 19 for operation sequence in applications including EL297DFV, a thermostat which features humidity control and a single-speed outdoor unit. TABLE 20 gives the operation sequence in applications with a twospeed outdoor unit.
On-Board Link W951 Heat Pump (R to O)
On-board link W951 is a clippable connection between terminals R and O on the integrated control. W951 must be cut when the furnace is installed in applications which include a heat pump unit and a thermostat which features dual fuel use. If the link is left intact, terminal “O” will remain energized eliminating the HEAT MODE in the heat pump.
On-Board Link W915 2 Stage Compr (Y1 to Y2)
On-board link W915 is a clippable connection between terminals Y1 and Y2 on the integrated control. W915 must be cut if two-stage cooling will be used. If the Y1 to Y2 link is not cut the outdoor unit will operate in second-stage cooling only.

TABLE 19 OPERATING SEQUENCE Non-Communicating Thermostat with Humidity Control Feature and Single-Speed Outdoor Unit

OPERATING SEQUENCE

SYSTEM DEMAND

SYSTEM RESPONSE

System Condition

Step

Thermostat Demand

Y1

O

G

W1

NO CALL FOR DEHUMIDIFICATION

Relative Humidity

Status

D

Compre ssor

Blower CFM (cool)

Comments

Normal Operation 1

On On On

BASIC MODE (only active on a Y1 thermostat demand)

Acceptable

24 VAC

High

100%

Compressor and indoor blower follow thermostat demand

Normal Operation 1

On On On

Dehumidification call

2

On On On

PRECISION MODE (operates independent of a Y1 demand)

Acceptable

24 VAC

Demand 0 VAC

High High

100% 70%

ComfortSense® 7500 thermostat energizes Y1 and de-energizes
D on a call for dehumidification

Normal Operation 1

Dehumidification Call

2

On On On On On On

Acceptable

24 VAC

Demand 0 VAC

High High

100% 70%

Dehumidification mode begins when humidity is greater
than set point

Dehumidification Call Only

1

On On On

Demand 0 VAC High

70%

ComfortSense® 7500 thermostat will try to maintain room humidity setpoint by
allowing the room space to maintain
a cooler room thermostat setpoint**

Jumpers at indoor unit with a single stage outdoor unit. With Condensing unit – Cut W914 (R to DS) on SureLight® control With Heat Pump – Cut W914 (R to DS) & W951 (R to O) on SureLight® control
Dave Lennox ComfortSense® 7000 thermostat to use for this application – Y2081 4 heat / 2 cool *Dehumidification blower speed is 70% of COOL speed for all units . **In Precision mode, ComfortSense® 7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.

Page 50

TABLE 20 OPERATING SEQUENCE Non-Communicating Thermostat with Humidity Control Feature and Two-Speed Outdoor Unit

OPERATING SEQUENCE

SYSTEM DEMAND

SYSTEM RESPONSE

System Condition

Thermostat Demand

Step Y1 Y2 O

G W1 W2

Relative Humidity

Status

D

Compre ssor

Blower CFM (cool)

Comments

NO CALL FOR DEHUMIDIFICATION

Normal Operation Y1

1

On

On On

Normal Operation Y2

2

On On On On

Acceptable

24 VAC

Acceptable

24 VAC

Low High

70% 100%

Compressor and indoor blower follow thermostat demand

ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On

On On

Dehumidification call

2 On On On On

Acceptable

24 VAC

Demand

0 VAC

Low High

70% 70%

ComfortSense® 7500 thermostat energizes Y1 and de-energizes D on a call for de-humidification

PRECISION MODE (operates independent of a Y1 demand)

Normal Operation 1 On

On On

Dehumidification Call

2 On On On On

Acceptable

24 VAC

Demand

0 VAC

Low High

70% 70%

Dehumidification mode begins when humidity is
greater than set point

Dehumidification Call Only

1 On On On On

Demand

0 VAC

High

70%

ComfortSense® 7500 thermostat will try to maintain room humidity setpoint by allowing the room space to maintain a cooler room thermostat setpoint**

ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Operation 1 On On On On

Dehumidification Call

2 On On On On

Acceptable

24 VAC

Demand

0 VAC

High High

100% 70%

ComfortSense® 7500 thermostat energizes Y2 and de-energizes D on a call for de-humidification

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Operation 1 On

On On

Dehumidification Call

2 On On On On

Acceptable

24 VAC

Demand

0 VAC

Low High

70% 70%

Dehumidification mode begins when humidity is
greater than set point

Dehumidification Call ONLY

1 On On On On

Demand

0 VAC

High

70% ComfortSense® 7500 thermostat will try to

Jumpers at indoor unit with a two stage outdoor unit Cut factory jumper from Y1 to Y2 or cut W915 (Y1 to Y2) With Condensing unit – Cut W914 (R to DS) on SureLight® control

maintain room humidity setpoint by allowing the room space to maintain a cooler room thermostat

With Heat Pump – Cut W914 (R to DS) & W951 (R to O) on SureLight® control

setpoint***

Dave Lennox ComfortSense® 7000 thermostat to use for this application – Y2081 4 heat / 2 cool

*Normal operation first stage cooling blower speed is 70% COOL speed.

**Dehumidification blower speed is, reduced to 70% of COOL.

***In Precision mode, ComfortSense® 7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.

Page 51

BLOWER DATA

EL297DF045XV36B BLOWER PERFORMANCE (less filter) BOTTOM RETURN AIR 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1 Heating Speed DIP Switch Settings

First Stage Heating Speed – cfm

Second Stage Heating Speed – cfm

+24%

910

1150

+18%

855

1095

+12%

820

1040

+6%

770

990

Factory Default

745

935

­6%

700

880

­12%

665

820

­18%

635

755

COOLING

1 Cooling Speed DIP Switch Settings

First Stage Cooling Speed – cfm Low Medium-Low Medium-High 2 High

Second Stage Cooling Speed – cfm Low Medium-Low Medium-High 2 High

640

755

850

975

895

1050

1210

1360

Factory Default 580

695

780

880

805

965

1105

1250

­

545

645

720

795

735

865

1000

1130

1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specific DIP Switch Settings.
2 Factory default setting.
NOTES – The effect of static pressure is included in air volumes shown. First stage HEAT is approximately 91% of the same second stage HEAT. First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position. Continuous Fan Only speed is selectable at 28%, and 38%, of the selected second stage cooling speed – minimum 380 cfm. Lennox iHarmony® Zoning System Applications – Minimum blower speed is 380 cfm.

Page 52

BLOWER DATA

EL297DF070XV48B BLOWER PERFORMANCE (less filter) BOTTOM RETURN AIR 0 through 0.8 in. w.g. (Heating) and 0 through 1.0 in. w.g. (Cooling) External Static Pressure Range

HEATING

1 Heating Speed DIP Switch Settings

First Stage Heating Speed – cfm

Second Stage Heating Speed – cfm

+24%

1085

1635

+18%

1030

1525

+12%

950

1450

+6%

910

1365

Factory Default

850

1310

­6%

790

1225

­12%

740

1135

­18%

680

1060

COOLING

1 Cooling Speed DIP Switch Settings

First Stage Cooling Speed – cfm Low Medium-Low Medium-High 2 High

Second Stage Cooling Speed – cfm Low Medium-Low Medium-High 2 High

740

915

1055

1255 1110

1340

1575

1800

Factory Default 660

820

940

1120

995

1230

1420

1650

­

575

735

850

995

880

1085

1290

1460

1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control. Refer to Installation Instructions for specific DIP Switch Settings.
2 Factory default setting.
NOTES – The effect of static pressure is included in air volumes shown. First stage HEAT is approximately 91% of the same second stage HEAT. First stage COOL (two-stage air conditioning units only) is approximately 70% of the same second stage COOL speed position. Continuous Fan Only speed is selectable at 28% and 38% of the selected second stage cooling speed – minimum 380 cfm. Lennox iHarmony® Zoning System Applications – Minimum blower spe

References

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