LENNOX ML193DFE Merit Series Gas Furnace Downflow Air Discharge Instruction Manual

ML193DFE Merit Series Gas Furnace Downflow Air Discharge

© 2022 Lennox Industries Inc. Dallas, Texas USA

INSTALLATION INSTRUCTIONS ML193DFE
MERIT® SERIES GAS FURNACE DOWNNFLOW AIR DISCHARGE
507865-02 03/2022 Supersedes 10/2021
THIS MANUAL MUST BE LEFT WITH THE HOMEOWNER FOR FUTURE REFERENCE
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.
CAUTION
As with any mechanical equipment, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.
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.

Contents
Unit Dimensions – inches (mm) ………………………………..2 ML193DFE Gas Furnace…………………………………………3 Shipping and Packing List ………………………………………. 3 Safety …………………………………………………………………..3 Use of Furnace as a Construction Heater …………………. 4 General ………………………………………………………………… 5 Combustion, Dilution, Ventilation Air………………………….5 Setting Equipment …………………………………………………. 8 Filters …………………………………………………………………. 12 Duct System ……………………………………………………….. 12 Pipe Fittings Specifications…………………………………….12 Joint Cementing Procedure ……………………………………14

Venting Practices………………………………………………….15 Gas Piping …………………………………………………………..31 Electrical ……………………………………………………………..33 Unit Start-Up………………………………………………………..38 Gas Pressure Measurement…………………………………..39 Proper Combustion……………………………………………….40 High Altitude ………………………………………………………..40 Testing Non Direct Appliances for Proper Air…………….41 Other Unit Adjustments………………………………………….42 Service……………………………………………………………….. 43 Repair Parts List …………………………………………………..44 Start Up Checklist…………………………………………………45 Blower Data …………………………………………………………49

Page 1

Unit Dimensions – inches (mm)

9/16 (14)

Flue Condensate Trap Assembly Furnished for external field installation on either side of unit. (See installation instructions for additional information.)

COMBUSTION
7 AIR INTAKE (178)
EXHAUST AIR OUTLET

B

RETURN AIR OPENING

2-1/16 (52)

5 (127)

2-1/4

9/16

(57)

(14)

TOP VIEW

A
B
AIR FLOW

9/16 (14)

1 (25) Front Panel

27-3/4 (705)

19-7/16

9/16

(494)

(14)

33 (838)

2 (51) Either Side GAS PIPING INLET (Either Side)
9-1/8 (232) Right 6-9/16 (167) Left

3/4 (19)

Supply C Air

3/4 (19)

FRONT VIEW

ELECTRICAL INLET (Either Side)

CONDENSATE TRAP CONNECTION
(Either Side)

9 (229) 6-7/16 (163) Either Side Either Side

19-1/4 Supply

3/4

(489) Air

(19)

SIDE VIEW

ML193DFE Model No.
045XE36B 070XE6B 090XE48C

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

ML193DFE Gas Furnace
The ML193DFE 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 ML193DFE 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 ML193DFE 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 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 – Propane/LP changeover kit
Safety Information
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.
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, contact with sharp sheet metal edges can result in personal injury. Take care while handling this equipment and wear gloves and protective clothing.
Use only the type of gas approved for use with this furnace. Refer to unit nameplate. ML193DFE units are CSA International certified to ANSI Z21.47 and CSA 2.3 standards. 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:

Page 3

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 ML193DFE 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 ML193DFE 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.
· Return air temperature range between 60°F (16°C) and 80°F (27°C) must be maintained.

Page 4

· 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 ML193DFE 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.
CAUTION
ML193DFE unit should not be installed in areas normally subject to freezing temperatures.

Combustion, Dilution & Ventilation Air
If the ML193DFE 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 ML193DFE furnaces to ensure efficient and safe operation. You must consider combustion air needs and requirements for exhaust vents and gas piping. A portion of this information has been reprinted with permission from the National Fuel Gas Code (ANSIZ223.1/ 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.

Page 5

CAUTION
Do not install the furnace in a corrosive or contaminated atmosphere. Meet all combustion and ventilation air requirements, as well as all local codes.
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 (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

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.
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
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.

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

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)

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 and 3/4 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.
Units with 1/2 or 3/4 HP Blower Motor
RIGID LEG remove shipping bolt and washe
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.

Page 8

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

Back

Front

Horizontal

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

FIGURE 12

Page 9

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.
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

Left Side

Right Side

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.
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.

FURNACE

PROPERLY SIZED FLOOR
OPENING

SUPPLY AIR PLENUM

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

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 plenum is 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 filter size.
A filter must be in place whenever the unit is operating.
IMPORTANT
If a high efficiency filter is being installed as part of this system to ensure better indoor air quality, the filter must be properly sized. High efficiency filters have a higher static pressure drop than standard efficiency 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 19 for proper duct installation.
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. 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 0.5 inches w.c. Operation at these conditions may result in improper limit operation.

Duct Installation Down-Flow Unit
SUPPLY AIR
FIGURE 19 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.

Page 12

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.

TABLE 4

PIPING AND FITTINGS SPECIFICATIONS

Schedule 40 PVC (Pipe)

D1785

Schedule 40 PVC (Cellular Core Pipe)

F891

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 Cellular Core DWV (Pipe)

F628

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
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.

Page 13

Input Size
045 070 090

Vent Pipe Dia. in.
61-1/2 2
2-1/2 3
61-1/2 2
2-1/2 3 2
2-1/2 3

Flush Mount Kit
51W11 (US)
51W12 (CA) 3YES 3YES 3YES 3YES 3YES 3YES 3YES 3YES 3YES 3YES 3YES

TABLE 5

OUTDOOR TERMINATION USAGE*

STANDARD

Wall Kit

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

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

Field Fabricated

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

1YES

5YES

YES

5YES

YES

5YES

YES

5YES

CONCENTRIC

1-1.2 inch 2 inch

3 inch

71M80 (US)
444W92 (CA)

69M29 (US)
444W92 (CA)

60L46 (US) 444W93 (CA)

2YES 2YES 2YES 2YES 2YES 2YES 2YES 2YES

YES YES YES

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 uses with 045 and 070 input models. When using 1-1/2 inch vent pipe, transistion to 2″ pipe before installing 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. When using 1-1/2″ vent pipe, transition to 2″ pipe before installing 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 Requires field provided 2″ to 1-1/2″ reducer.

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.
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.

Page 14

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 20
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 21
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.
Exhaust Piping (FIGURE 23 and FIGURE 24)
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.
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 9. The ML193DFE can be installed as either a Non-Direct Vent or a 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. Intake and exhaust pipe sizing — Size pipe according to TABLE 6 (minimum) and TABLE 7 (maximum). Count all elbows inside and outside the home.

Page 15

TABLE 6

MINIMUM VENT PIPE LENGTHS

ML193DFE MODEL

MIN. VENT LENGTH*

045, 070, 090

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.

Use the following steps in the Piping Size Process to correctly size vent pipe diameter. NOTE – Lennox offers a glueless vent adapter kit 17H92 as an option for exhaust exiting at the furnace top cap coupling.

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?

6

What is the altitude of the furnace installation?

Find max intake or

7

exhaust pipe length. Includes all vent pipe and

elbows inside and outside

the house.

FIGURE 22
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 back toward unit. A minimum of 1/4″ (6mm) drop for each 12″ (305mm) of horizontal run is mandatory for drainage. 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.

Page 16

TABLE 7
Maximum Allowable Intake or Exhaust Vent Length in Feet *InStiazkeeinatnadkeExahnaduesxt hmauusstt bpeipseamlenegpthipesespizaera. tely. Values in table are for Intake OR Exhaust, not combined total. Both NtoOtaTl Eve-nAt ldednigtiothnacal lvceunlat tpioipne. and elbows used to terminate the vent pipe outside the structure must be included in the
Standard Termination at Elevation 0 – 10,000 ft.

Number Of 90° Elbows Used
1 2 3 4 5
6
7
8
9 10
Number Of 90° Elbows Used
1 2
3
4
5 6 7 8 9
10

1-1/2″ Pipe

Model

045

070 090

20

15

15

10

10

n/a

n/a

n/a

1-1/2″ Pipe

Model

045

070 090

15

10

10

n/a

n/a

n/a

2″ Pipe Model

2-1/2″ Pipe Model

045

070

090

045

070

090

61

46

24

100

80

43

56

41

19

95

75

38

51

36

14

90

70

33

46

31

85

65

28

41

26

80

60

23

36

21

75

55

18

31

16

n/a

70

50

13

26

11

65

45

21

n/a

16

60

40

n/a

55

35

Concentric Termination Elevation 0 – 10,000 ft.

2″ Pipe Model

2-1/2″ Pipe Model

045

070

090

045

070

090

53

38

22

90

70

39

48

33

17

85

65

34

43

28

12

80

60

29

38

23

75

55

19

33

18

70

50

14

28

13

65

45

23

n/a

60

40

18

13

n/a

55

35

n/a

50

30

n/a

45

25

3″ Pipe Model

045

070

090

127

127

108

122

122

103

117

117

98

112

112

93

107

107

88

102

102

83

97

97

78

92

92

73

87

87

68

82

82

63

3″ Pipe Model

045

070

090

111

111

104

106

106

99

101

101

94

96

96

89

91

91

84

86

86

79

81

81

74

76

76

69

71

71

64

66

66

59

TABLE 8

Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement 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 Of 90° Elbows
Used

1-1/2″ Pipe

Model

045

070

090

2″ Pipe

Model

045

070

2-1/2″ Pipe

Model

090

045

070

090

3″ Pipe

Model

045

070

090

1

15

10

51

36

14

85

65

28

107

107

88

2

10

46

31

9

80

60

23

102

102

83

3

41

26

4

75

55

18

97

97

78

4

36

21

70

50

8

92

92

73

5

31

16

n/a

6

n/a

26

11

n/a

7

21

6

65

45

3

87

60

40

82

55

35

77

87

68

82

63

77

58

8

16

1

50

30

n/a

72

72

53

9

11

45

25

67

67

48

n/a

10

6

40

20

62

62

43

Page 17

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.

Exhaust

3″

TRANSITION *2″

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 23
  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 24

Page 18

Intake Piping The ML193DFE 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 to secure the intake pipe to the inlet air connector.
2 – 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.
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 25 Follow the next two steps when installing the unit in NonDirect 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 25. 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 – If intake air is drawn from a ventilated attic (FIGURE 26) or ventilated crawlspace (FIGURE 27) the exhaust vent length must not exceed those listed in TABLE 8. If 3″ diameter pipe is used, reduce to 2″ diameter pipe at the termination point to accommodate the debris screen.
3 – Use cement to secure the intake pipe to the connector, if desired.
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 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 26

Page 19

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 27
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 ML193DFE 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 ML193DFE 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 29 or FIGURE 30. 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 9 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 20

TABLE 9

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

Winter Design

Unit Input Size

Vent Pipe

Temperatures1 Diameter °F (°C)

045

070

090

PVC

2PP

PVC

2PP

PVC

2PP

1-1/2″

25

N/A

20

N/A

N/A

N/A

32 to 21

2 in

18

16

31

28

50

48

(0 to -6)

2-1/2 in

13

N/A

24

N/A

42

N/A

3 in

9

9

18

18

35

35

1-1/2″

15

N/A

20

N/A

N/A

N/A

20 to 1

2 in

9

8

18

16

32

29

(-7 to -17)

2-1/2 in

5

N/A

13

N/A

24

N/A

3 in

1

1

8

8

19

19

1-1/2″

10

N/A

15

N/A

N/A

N/A

0 to -20

2 in

5

3

12

10

22

19

(-18 to -29)

2-1/2 in

1

N/A

7

N/A

15

N/A

3 in

N/A

N/A

2

2

10

10

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.

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 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 28.

Conditioned Space

Conditioned Space

Pipe Insulation
Unconditioned Space

FIGURE 28

Exhaust Pipe
Intake Pipe

Page 21

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

D E B

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

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.”

FIGURE 29

Page 22

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 pliances > 10,000 Btuh (3kw) and <50,000
pliances > 50,000 Btuh (15kw)

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″

• 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

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

E =

Clearance to unventilated soffit

• 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 = 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
K = ply inlet

6 inches (152mm) for appliances <10,000
pliances > 10,000 Btuh (3kw) and <50,000
pliances > 50,000 Btuh (15kw) 3 feet (.9m) above if within 10 feet
(3m) horizontally

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)
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.”

FIGURE 30

Page 23

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 39.
Intake and 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. FIGURE 33 through FIGURE 38 show typical terminations.
1 – Intake and exhaust 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 31). You may exit the exhaust out the roof and the intake out the side of the structure (FIGURE 32).
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 33).
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 he velocity of exhaust away from the intake piping. See TABLE 10.

TABLE 10

Exhaust Pipe Termination Size Reduction

ML193DF Model

Termination Pipe Size

045, 070

1-1/2″ (38mm)

*090

2″ (51mm)

*ML193DFE-045, -070 and -090 units with the flush mount termination must use the 1-1/2″ accelerator supplied with the kit.

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 39. NOTE – Care must be taken to avoid recirculation of exhaust back into intake pipe.
Exiting Exhaust and Intake Vent (different pressure zone)

Exhaust Pipe

Furnace

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

FIGURE 31

Exiting Exhaust and Intake Vent (different pressure zone)

Roof Terminated Exhaust Pipe

Furnace

Inches(mm)

FIGURE 32
3″(76mm) MAX.

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

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 33

Page 24

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 39, 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 36.

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 34

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)

FIGURE 35

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 36

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 37

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

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 38

Page 25

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

D
E B
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

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

6″ (152mm) Max

B 1

E

D

B 12″

Front View of Intake and Exhaust

C

12″

2

A

C

Intake

Exhaust

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 39

Page 26

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. FIGURE 40 and FIGURE 41 show 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, 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.
12″ (305mm) ABOVE AVE.
SNOW ACCUMULATION

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.
Crawl Space and Extended Horizontal Venting
Lennox provides kit 51W18 to install 2″ or 3″ PVC exhaust piping through the floor joists and into the crawl space. See FIGURE 42.
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

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

UNCONDITIONED ATTIC SPACE

NON-DIRECT VENT ROOF TERMINATION KIT (15F75 or 44J41)
FIGURE 40
NON-DIRECT VENT APPLICATION USING EXISTING CHIMNEY
STRAIGHT-CUT OR ANGLE-CUT IN DIRECTION
OF ROOF SLOPE

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 41

Basement Floor

KIT 51W18 (USA) KIT 15Z70 (CANADA)

FIGURE 42

Page 27

Condensate Piping
This unit is designed for either right- or left-side exit of condensate piping. Refer to FIGURE 43 and FIGURE 45 for condensate trap locations.
CONDENSATE TRAP AND PLUG LOCATIONS

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

Plug (same on left
side)
Rubber Grommet

FIGURE 43
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. NOTE – Do not remove the rubber grommet used to seal the cabinet on the side not used when installing the condensate trap.

2 – Use a large flat head screw driver or a 1/2″ drive socket extension and remove plug (figure 43) 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 49.
4 – Install drain trap using appropriate PVC fittings, glue all joints. Glue the provided drain trap as shown in FIGURE 49. Route the condensate line to an open drain.
5 – FIGURE 46 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 47 and FIGURE 48. 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 44.
Field Provided Drain Components

Elbow Tubing

Barbed Fitting Hose Clamp

FIGURE 44

Page 28

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 and 24 ft. (7.3m) – kit no. 26K69.
CONDENSATE TRAP LOCATION (shown with right side exit of condensation)

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.
IMPORTANT
Do not use copper tubing or existing copper condensate lines for drain line.
Furnace with Evaporator Coil Using a Common Drain

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 45
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

Field Provided Vent 1″ min. 2″ max. above
condensate drain.
Condensate Drain Connection

Evaporator Drain Line (vent required)

FIGURE 47

Condensate Trap With Optional Overflow Switch

From Evaporator Coil

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

Optional

FurnaceCondensate Drain Connection

FIGURE 46

FIGURE 48

Page 29

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 49

To Drain

Page 30

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 51.Connect the gas supply piping into the gas valve. The maximum torque is 800 in lbs and minimum torque is 350 in lbs 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 51.
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 55.
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 50
IMPORTANT
When testing pressure of gas lines, gas valve must be disconnected and isolated. See FIGURE 50. 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 31

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

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

AUTOMATIC GAS VALVE (with manual shut-off valve)

GROUND JOINT UNION
DRIP LEG

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

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

FIGURE 51

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 32

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.
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. A field-provided make-up box can be installed on the exterior of 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 and install on the outside of the cabinet. See FIGURE 52. The excess wire must be pulled into the blower compartment. Secure the excess wire to the existing harness to protect it from damage. Seal unused openings on left side with plugs removed from right side.
EXTERIOR MAKE-UP BOX
(FIELD PROVIDED RIGHT SIDE)
MAKE-UP BOX
OUTSIDE CABINET
Right Side
FIGURE 52

Page 33

Refer to FIGURE 53 for field wiring, schematic wiring diagram and troubleshooting.
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.
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.
NOTE – Unit nameplate states maximum current draw. Maximum Over-Current Protection allowed is 15 AMP. 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 unitw wiring diagram and the field wiring diagram shown in FIGURE 53. 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) for the USA and current Canadian Electric Code part 1 (CSA standard C22.1) for Canada. A green ground wire is provided in the field make-up box. NOTE – The ML193DFE furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.
Accessory Terminals
One line voltage “EAC” 1/4″ spade terminal is provided on the furnace integrated control. This terminal is energized when the indoor blower is operating. Any accessory rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. If an accessory rated at greater than one amp is connected to this terminal, it is necessary to use an external relay.

One line voltage 120V “HUM” 1/4″ spade terminal is provided on the furnace integrated control. This terminal is energized in the heating mode when the combustion air inducer is operating. Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to one of the provided neutral terminals. If a humidifier rated at greater than one amp is connected to this terminal, it is necessary to use an external relay.
One 24V “HUM” 1/4″ spade terminal is provided on the furnace integrated control. The terminal is energized in the heating mode when the combustion air inducer is operating and the pressure switch is closed. Any humidifier rated up to 0.5 amp can be connected to this terminal with the ground leg of the circuit connected to ground or the “C” terminal.
Thermostat
Install the room thermostat according to the instructions provided with the thermostat. See FIGURE 53 for thermostat designations. If the furnace is being matched with a heat pump, refer to the thermostat installation instruction for set up.
Indoor Blower Speeds
1 – When the thermostat is set to “FAN ON,” the indoor blower will run continuously on the (FAN) speed when there is no cooling or heating demand. See TABLE 19 on page 48 for allowable continuous circulation speeds.
2 – When the ML193DFE is running in the heating mode, the indoor blower will run on the heating speed (HEAT).
3 – When there is a cooling demand, the indoor blower will run on the cooling speed (COOL).
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 + 10% (Range: 108 volts to 132 volts)
· The furnace operates at 60 Hz + 5% (Range: 57 Hz to 63 Hz)
· The furnace integrated control requires both 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 34

FIGURE 53 Page 35

Integrated Control 103217-03 IGNITION CONTROL 103217-03

RED LED RECALL BUTTON

BLOWER OFF DELAY

1/4″ QUICK CONNECT TERMINALS

120V HUM

POWER FOR HUMIDIFIER (120 VAC

LINE

INCOMING POWER LINE (120 VAC)

XFMR

TRANSFORMER PRIMARY (120 VAC)

CIRC

INDOOR BLOWER MOTOR (120 VAC)

EAC

ELECTRONIC AIR CLEANER (120 VAC)

HUM24

POWER FOR HUMIDIFIER (24 VAC)

NEUTRALS (5) NEUTRAL

3/16″ QUICK CONNECT TERMINALS

COOL

COOL SPEED FROM INDOOR BLOWER MOTOR (24 VAC)

HEAT

HEAT SPEED FROM INDOOR BLOWER MOTOR (24 VAC)

FAN

CONTINUOUS FAN SPEED FROM

INDOOR BLOWER MOTOR (24 VAC)

PARK (3)

TERMINALS FOR UNUSED MOTOR SPEED TAPS

FS

FLAME SENSOR ELECTRODE (120 VAC)

24 COM

COMMON (24 VAC)

FIGURE 54
RED LED Flash Code 2 Off
Heartbeat1 Continuous Rapid Flash
1 2 3 4 5 6 7 8 9 10 11 12 13
Note – 1 Note – 2
Note – 3

Diagnostic Codes / Status of Furnace
No power to control or board fault detected
Normal Operation – Idle, Continuous Fan, Cool Call For Heat / Burner Operation Reverse Line Voltage Polarity Improper Earth Ground Burner failed to light, or lost flame during heat demand Low Flame Signal – check flame sensor Watchguard – burner failed to light, exceeded maximum number of retries or recycles. Not Used Primary or Secondary Limit Open or Watchguard Mode – Limit Switch Open longer than 3 minutes Rollout Switch Open Pressure Switch failed to close or opened during heat demand
Watchguard – Pressure Switch opened 5 times during one heat demand
Pressure Switch stuck closed prior to activation of combustion air inducer Flame Sensed without gas valve energized Low Line Voltage
Notes A “Heartbeat” is indicated by a “Slow Flash” – 1 sec on 1 sec off, repeating Error codes are indicated by a “rapid flash” – the LED flashes X times at ½ second on ½ second off, remains off for 3 seconds then repeats. Last 10 error codes are stored in memory including when power is shut off to the unit. – To recall, press and release button, most recent will be displayed first, LED off for 3 sec, then next error code is displayed, etc. To clear error codes, depress and hold button longer than 5 seconds.

Page 36

Integrated Control 107163-01
IGNITION CONTROL 107163-01
PARKS

HUM24 24VCOM COOL HEAT FAN

Push Button Error Recall

Diagnostic LED

RED LED Flash Code Off On
Fast Heartbeat3 Slow Heartbeat1
1 Flash2 2 Flashes2 3 Flashes2 4 Flashes2
5 Flashes2
6 Flashes2
7 Flashes2
8 Flashes2 9 Flashes2 10 Flashes2 11 Flashes2 12 Flashes2 13 Flashes2

Note – 1 Note – 2 Note – 3
Note – 4

Heating Blower Off Delay Selector Switch
Diagnostic Codes / Status of Furnace No Power to Control or Board Fault Detected Board Fault Detected Call for Heat / Burner Operation Normal Operation ­ Idle, Continuous Fan, or Cool Reverse Line Voltage Polarity or Phasing of 120V power Improper earth ground Burner failed to light, or lost flame during heat demand Low flame signal ­ check flame sensor Watchguard ­ burner failed to light, exceeded maximum number of retries/recycles, 1 hour lockout Not used Primary or Secondary limit switch open or Watchguard mode ­ Limit Switch open longer than 3 minutes Roll-out Switch Open Pressure Switch failed to close or opened during heat demand, inducer on Watchguard – Pressure switch opened 5 times during a single heating demand Pressure switch stuck closed prior to activation of Combustion Air Inducer Flame sensed without gas valve energized Low line voltage
Notes A slow heartbeat is indicated by 1s on / 1s off. It is used for idle, continuous fan and cool modes. Error codes are indicated by a “rapid flash” – the LED flashes X times at ½ second on ½ second off, remains off for 3 seconds then repeats. A fast heartbeat is indicated by 0.5s on / 0.5s off. It is only used during a heat call. Last 10 error codes are stored in memory including when power is shut off to the unit. – To recall, press, and release button, most recent will be displayed first, LED off for 3 sec, then next error code is displayed, etc. To clear error codes, depress and hold button longer than 5 seconds.

Page 37

Unit Start Up
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING
Electric shock hazard. Can cause injury or death. Do not use this unit if any part has been under water. Immediately call a qualified service technician to inspect the unit and to replace any part of the control system and any gas control which has been under water.
CAUTION
Before attempting to perform any service or maintenance, turn the electrical power to unit OFF at disconnect switch.
WARNING
Danger of explosion. Can cause injury or product or property damage. Should the gas supply fail to shut off or if overheating occurs, shut off the gas valve to the furnace before shutting off the electrical supply.
BEFORE LIGHTING the unit, smell all around the furnace area for gas. Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor. The gas valve on the ML193DFE is equipped with a gas control switch. Use only your hand to move switch. Never use tools. If the switch will not move by hand, do not try to repair it. Force or attempted repair may result in a fire or explosion.
Placing the furnace into operation:
ML193DFE units are equipped with an automatic hot surface ignition system. Do not attempt to manually light burners on this furnace. Each time the thermostat calls for heat, the burners will automatically light. The ignitor does not get hot when there is no call for heat on these units.
Priming Condensate Trap
The condensate trap should be primed with water prior to start-up to ensure proper condensate drainage. Either pour 10 fl. oz. (300 ml) of water into the trap, or follow these steps to prime the trap:
1 – Follow the lighting instructions to place the unit into operation.
2 – Set the thermostat to initiate a heating demand. 3 – Allow the burners to fire for approximately 3 minutes. 4 – Adjust the thermostat to deactivate the heating
demand.
5 – Wait for the combustion air inducer to stop. Set the thermostat to initiate a heating demand and again allow the burners to fire for approximately 3 minutes.

6 – Adjust the thermostat to deactivate the heating demand and wait for the combustion air inducer to stop. At this point, the trap should be primed with sufficient water to ensure proper condensate drain operation.

WARNING
If you do not follow these instructions exactly, a fire or explosion may result causing property damage, personal
injury or death.

Gas Valve Operation (FIGURE 55)
1 – STOP! Read the safety information at the beginning of this section.
2 – Set the thermostat to the lowest setting. 3 – Turn off all electrical power to the unit. 4 – This furnace is equipped with an ignition device
which automatically lights the burners. Do not try to light the burners by hand.
5 – Remove the upper access panel.
6 – Move gas valve switch to OFF. See FIGURE 55. 7 – Wait five minutes to clear out any gas. If you then
smell gas, STOP! Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions. If you do not smell gas go to next step.
8 – Move gas valve switch to ON. See FIGURE 55.
9 – Replace the upper access panel.
10- Turn on all electrical power to the unit.
11- Set the thermostat to desired setting. NOTE – When unit is initially started, steps 1 through 11 may need to be repeated to purge air from gas line.

MANIFOLD PRESSURE ADJUSTMENT
SCREW

MANIFOLD PRESSURE
OUTLET PORT

INLET PRESSURE
PORT GAS VALVE SHOWN IN ON POSITION
FIGURE 55 12- If the appliance will not operate, follow the
instructions “Turning Off Gas to Unit” and call your service technician or gas supplier.
Turning Off Gas to Unit 1 – Set the thermostat to the lowest setting.
2 – Turn off all electrical power to the unit if service is to be performed.
3 – Remove the upper access panel.
4 – Move gas valve switch to OFF.
5 – Replace the upper access panel.

Page 38

Failure To Operate
If the unit fails to operate, check the following:
1 – Is the thermostat calling for heat?
2 – Are access panels securely in place?
3 – Is the main disconnect switch closed?
4 – Is there a blown fuse or tripped breaker?
5 – Is the filter dirty or plugged? Dirty or plugged filters will cause the limit control to shut the unit off.
6 – Is gas turned on at the meter?
7 – Is the manual main shut-off valve open? 8 – Is the internal manual shut- off valve open? 9 – Is the unit ignition system in lockout? If the unit locks
out again, inspect the unit for blockages.
Heating Sequence Of Operation
1 – When thermostat calls for heat, combustion air inducer starts.
2 – Combustion air pressure switch proves blower operation. Switch is factory- set and requires no adjustment.
3 – After a 15-second prepurge, the hot surface ignitor energizes.
4 – After a 20-second ignitor warm-up period, the gas valve solenoid opens. A 4-second Trial for Ignition period begins.”
5 – Gas is ignited, flame sensor proves the flame, and the combustion process continues.
6 – If flame is not detected after first ignition trial, the ignition control will repeat steps 3 and 4 four more times before locking out the gas valve (“WATCHGUARD” flame failure mode). The ignition control will then automatically repeat steps 1 through 6 after 60 minutes. To interrupt the 60-minute “WATCHGUARD” period, move thermostat from “Heat” to “OFF” then back to “Heat”. Heating sequence then restarts at step 1.

Gas Pressure Adjustment Gas Flow (Approximate)

TABLE 12

GAS METER CLOCKING CHART

Seconds for One Revolution

ML193 Unit

Natural

1 cu ft Dial

2 cu ft Dial

LP

1 cu ft Dial

2 cu ft Dial

-045

80

160

200

400

-070

55

110

136

272

-090

41

82

102

204

Natural-1000 btu/cu ft LP-2500 btu/cu ft

NOTE – To obtain accurate reading, shut off all other gas appliances connected to meter.
Furnace should operate at least 5 minutes before checking gas flow. Determine time in seconds for two revolutions of gas through the meter. (Two revolutions assures a more accurate time). Divide by two and compare to time in TABLE 12. If manifold pressure matches TABLE 13 and rate is incorrect, check gas orifices for proper size and restriction. Remove temporary gas meter if installed.
Supply Pressure Measurement

A threaded plug on the inlet side of the gas valve provides access to the supply pressure tap. Remove the threaded plug, install a field-provided barbed fitting and connect a manometer to measure supply pressure. See TABLE 13 for proper supply line pressure. Replace the threaded plug after measurements have been taken.

TABLE 13

Supply Line and Manifold Pressure (inches w.c.)

Unit

Fuel

Manifold Pressure

Line Pressure

All

Nat. Gas

3.5

4.5 – 10.5

All

L.P. Gas

10.0

11.0 – 13.0

NOTE – A natural to L.P. propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.

Manifold Pressure Measurement

1 – Connect the test gauge positive side “+” to manifold pressure tap on gas valve. Connect the test gauge positive side “+” to manifold pressure tap on gas valve.
2 – Tee into the gas valve regulator vent hose and connect to test gauge negative “-“.
3 – Start unit and let run for 5 minutes to allow for steady state conditions.
4 – After allowing unit to stabilize for 5 minutes, record manifold pressure and compare to value given in TABLE 13.
5 – Shut unit off and remove manometer as soon as an accurate reading has been obtained. Take care to replace pressure tap plug.
6 – Start unit and perform leak check. Seal leaks if found.

Page 39

Proper Combustion
Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking combustion. Take combustion sample beyond the flue outlet and compare to the table below. The maximum carbon monoxide reading should not exceed 100 ppm.

TABLE 14

ML193 Unit 045

CO2 Nat

CO2 LP

070

7.0 – 9.0

8.0 – 10.0

090

The maximum carbon monoxide reading should not exceed 100 pm.

High Altitude Information NOTE – In Canada, certification for installations at elevations over 4500 feet (1372 m) is the jurisdiction of local authorities.
Units may be installed at altitudes up to 10,000 ft. above sea level. See TABLE 15 for de-rate manifold values. Units installed at altitude of 7501 – 10,000 feet require an orifice change. Units installed at altitude of 4501 – 10,000 feet require a pressure switch change which can be ordered separately. TABLE 16 lists conversion kit and pressure switch requirements at varying altitudes.
The combustion air pressure switch is factory-set and requires no adjustment. NOTE – A natural to LP/propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.

TABLE 15

Manifold and Supply Line Pressure 0-10,000ft.

ML193E Unit

Gas

0 – 4500 ft

Manifold Pressure in. wg. 4501 – 5500 ft 5501 – 6500 ft 6501 – 7500 ft

7501 – 10,000 ft

Supply Line Pressure in. w.g.
0 – 10000 ft.

All

Natural

3.5

3.3

3.2

3.1

3.5

4.5

13.0

Sizes L.P. Propane

10.0

9.4

9.1

8.9

10.0

11.0

13.0

NOTE – A natural to L.P. Propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation instruction for the conversion procedure.

TABLE 16

Conversion Kit and Pressure Switch Requirements at Varying Altitudes

ML193E Unit

Natural to LP/ Propane
0 – 7500 ft

High Altitude Natural Burner
Orifice Kit
7501 – 10,000 ft

LP/Propane to Natural
0 – 7500 ft

High Altitude LP/ Propane Burner
Orifice Kit
7501 – 10,000 ft

High Altitude Pressure Switch 4501 – 7500 ft 7501 -10,000 ft

(0 – 2286m) (2286 – 3038m) (0 – 2286m) (2286 – 3038m) (1373 – 2286m) (2286 – 3048m)

-045

-070

*11K49

73W37

*73W81

*11K44

11U65

11U66

-090

• Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit. Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1370 m).

Page 40

Testing of Non-Direct Vent Applications for Proper Venting and Sufficient Combustion Air
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.
After the ML193DFE gas furnace has been started, the following test should be conducted to ensure proper venting and sufficient combustion air has been provided to the ML193DFE as well as to other gas-fired appliances which are separately vented.
If a ML193DFE furnace replaces a Category I 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.
The test should be conducted while all appliances (both in operation and those not in operation) are connected to the venting system being tested. If the venting system has been installed improperly, or if provisions have not been made for sufficient amounts of combustion air, corrections must be made as outlined in the previous section.
1 – Seal any unused openings in the venting system.
2 – Visually inspect the venting system for proper size and

Horizontal pitch. Determine there is no blockage or restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
3 – To the extent that it is practical, close all building doors and windows and all doors between the space in which the appliances connected to the venting system are located and other spaces of the building.
4 – Close fireplace dampers.
5 – Turn on clothes dryers and any appliances not connected to the 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.
6 – Follow the lighting instruction to place the appliance being inspected into operation. Adjust thermostat so appliance will operate continuously.
7 – Use the flame of match or candle to test for spillage of flue gases at the draft hood relief opening after 5 minutes of main burner operation.
8 – If improper venting is observed during any of the above tests, the venting system must be corrected or sufficient combustion/make-up air must be provided. The venting system should be re-sized to approach the minimum size as determined by using the appropriate tables in appendix G in the current standard of the National Fuel Gas Code ANSI-Z223.1/ NPFA 54 in the U.S.A., and the appropriate Natural Gas and Propane appliances venting sizing tables in the current standard of the CSA-B149 Natural Gas and Propane Installation Codes in Canada.
9 – After determining that each appliance remaining connected to the common venting system properly vents when tested as indicated in step 3, return doors, windows, exhaust fans, fireplace dampers and any other gas-burning appliance to their previous condition of use.

Page 41

Other Unit Adjustments

Primary Limit

The primary limit is located on the heating compartment vestibule panel. This limit is factory set and requires no adjustment.
Flame Rollout Switches (Two)

These manually reset switches are located on the front of the burner box.
Pressure Switch

The pressure switch is located in the heating compartment on the cold end header box. This switch checks for proper combustion air inducer operation before allowing ignition trial. The switch is factory-set and must not be adjusted.
Temperature Rise

After the furnace has been started and supply and return air temperatures have been allowed to stabilize, check the temperature rise. If necessary, adjust the blower speed to maintain the temperature rise within the range shown on the unit nameplate. See TABLE 18 on page 48 for allowable heating speeds.Increase the blower speed to decrease the temperature. Decrease the blower speed to increase the temperature rise. Failure to adjust the temperature rise may cause erratic limit operation.
Fan Control

Ignition Control 103217-03

The fan on time of 30 seconds is not adjustable. The fan off delay (amount of time that the blower operates after the heat demand has been satisfied) may be adjusted by changing the jumper position across the five pins on the integrated control. The unit is shipped with a factory fan off setting of 120 seconds. The fan off delay affects comfort and is adjustable to satisfy individual applications. Adjust the fan off delay to achieve a supply air temperature between 90° and 110°F at the moment that the blower is de- energized. Longer off delay settings provide lower return air temperatures; shorter settings provide higher re-
turn air temperatures. See FIGURE 56.
Ignition Control 107163-01

The heat fan-on time of 30 seconds is not adjustable The
heat fan-off delay (amount of time that the blower operates after the heat demand has been satisfied) may be adjusted by changing the two position dip switch on the
integerated control, to one of four slections. Blower off delay is factory set at 90 seconds. For other blower off delay settings, please refer to the following chart:

Blower Delay Select

SW2-1

SW2-2

60

OFF

ON

90

OFF

OFF

120

ON

OFF

180

ON

ON

Factory Setting is 90

HEAT FAN-OFF TIME IN SECONDS

NO JUMPER
To adjust fan-off timing, reposition jumper across pins to achieve desired setting.

60 Second off Time

90 Second off Time

120 Second off Time

180 Second off Time

60 90 120 180 60 90 120 180 60 90 120 180 60 90 120 180

Blower Speeds

FIGURE 56

Follow the steps below to change the blower speeds. 1 – Turn off electrical power to furnace. 2 – Remove blower access panel.
3 – Disconnect existing speed tap at integrated control speed terminal.
NOTE – Termination of any unused motor leads must be insulated. 4 – Place unused blower speed tap on integrated control “PARK” terminal or insulate.
5 – Refer to blower speed selection chart on unit wiring diagram for desired heating or cooling speed. See Product Specifications bulletin for blower performance tables. See TABLE 18 on page 48 for allowable heating speeds.
6 – Connect selected speed tap at integrated control speed terminal.
7 – Re-secure blower access panel.
8 – Turn on electrical power to furnace.
9 – Recheck temperature rise.
Exhaust and Air Intake Pipe

1 – Check exhaust and air intake connections for tightness and to make sure there is no blockage.
2 – Is pressure switch closed? Obstructed exhaust pipe will cause unit to shut off at pressure switch. Check termination for blockages.
3 – Obstructed pipe or termination may cause rollout switches to open. Reset manual flame rollout switches on burner box assembly if necessary.
Electrical

1 – Check all wiring for loose connections. 2 – Check for the correct voltage at the furnace (furnace
operating). 3 – Check amp-draw on the blower motor. Motor Nameplate__Actual__ Thermostat Heat Anticipation

Set the heat anticipator setting (if adjustable) according to the amp draw listed on the wiring diagram that is attached to the unit.

Page 42

Service
WARNING
. ELECTRICAL SHOCK, FIRE, OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result in dangerous operation, serious injury, death or property damage. Improper servicing could result in dangerous operation, serious injury, death, or property damage. Before servicing, disconnect all electrical power to furnace. When servicing controls, label all wires prior to disconnecting. Take care to reconnect wires correctly. Verify proper operation after servicing.
WARNING
The blower access panel must be securely in place when the blower and burners are operating. Gas fumes, which could contain carbon monoxide, can be drawn into living space resulting in personal injury or death.
Annual Furnace Maintenance
At the beginning of each heating season, and to comply with the Lennox Limited Warranty, your system should be checked as follows:
1 – Check wiring for loose connections, voltage at indoor unit and amperage of indoor motor.
2- Check the condition of the belt and shaft bearings if applicable.
3- Inspect all gas pipe and connections for leaks. 4- Check the cleanliness of filters and change if
necessary (monthly).
5- Check the condition and cleanliness of burners andeat exchanger and clean if necessary.
6- Check the cleanliness of blower assembly and clean the housing, blower wheel and blower motor if necessary
7- Inspect the condensate drain and trap for leaks and cracks. The drain and trap must also be cleaned and the trap must be primed with water. Inspect the rubber hoses connected to the pressure switches for cracks or loose connections, replace as necessary. Remove the rubber hoses from the cold end header box and inspect for any blockage, clean as needed. If strainers are installed in the hoses remember to remove and clean before reinstalling the hoses.

8- Evaluate the heat exchanger integrity by inspecting the heat exchanger per the AHRI heat exchanger inspection procedure. This procedure can be viewed at www.ahrinet.org
9- Ensure sufficient combustion air is available to the furnace. Fresh air grilles and louvers (on the unit and in the room where the furnace is installed) must be properly sized, open and unobstructed to provide combustion air.
10-Inspect the furnace intake and exhaust pipes to make sure they are in place, structurally sound, without holes, blockage or leakage and the exhaust pipe is sloped toward he furnace. Inspect terminations to ensure they are free of obstructions and are structurally sound. Inspect the furnace return air duct connection to ensure the duct is sealed to the furnace. Check for air leaks on supply and return ducts and seal where necessary.
11- Inspect the furnace return air duct connection to ensure the duct is sealed to the furnace. Check for air leaks on supply and return ducts and seal where necessary.
12- Check the condition of the furnace cabinet insulation and repair if necessary.
13- Perform a complete combustion analysis during the furnace inspection to ensure proper combustion and operation. Consult Service Literature for proper combustion values.
14- Verify operation of CO detectors and replace batteries as required.
Perform a general system test. Turn on the furnace to check operating functions such as the start-up and shutoff operation.
1 – Check the operation of the ignition system, inspect and clean flame sensor. Check microamps before and after. Check controls and safety devices (gas valve, flame sensor, temperature limits). Consult Service Manual for proper operating range. Thermal Limits should be checked by restricting airflow and not disconnecting the indoor blower. For additional details, please see Service and Application Note H049.
2 – Verify that system total static pressure and airflow settings are within specific operating parameters.
3 – Clock gas meter to ensure that the unit is operating at the specified firing rate. Check the supply pressure and the manifold pressure. If manifold pressure adjustment is necessary, consult the Service Literature for unit specific information on adjusting gas pressure. Not all gas valves are adjustable. Verify correct temperature rise.

Page 43

Winterizing and Condensate Trap Care
1 – Turn off power to the furnace. 2 – Have a shallow pan ready to empty condensate
water.
3 – Remove the clean out cap from the condensate trap and empty water. Inspect the trap then reinstall the drain plug.
Cleaning the Burner Assembly
1 – Turn off electrical and gas power supplies to furnace. Remove upper and lower furnace access panels.
2 – Disconnect the 2-pin plug from the gas valve.
3 – Remove the burner box cover.
4 – Disconnect the gas supply line from the gas valve. Remove gas valve/manifold assembly.
5 – Mark and disconnect sensor wire from the sensor. Disconnect 2-pin plug from the ignitor at the burner box.
6 – Remove four screws which secure burner box assembly to vest panel. Remove burner box from the unit.
7 – Use the soft brush attachment on a vacuum cleaner to gently clean the face of the burners. Visually inspect the inside of the burners and crossovers for any blockage caused by foreign matter. Remove any blockage.
8 – Reconnect the sensor wire and reconnect the 2-pin plug to the ignitor wiring harness.
9 – Reinstall the burner box assembly using the existing four screws. Make sure that the burners line up in the center of the burner ports.
10 – Reinstall the gas valve manifold assembly. Reconnect the gas supply line to the gas valve. Reinstall the burner box cover.
11 – Reconnect 2-pin plug to gas valve.
12 – Replace the blower compartment access panel.
13 – Refer to instruction on verifying gas and electrical connections when re- establishing supplies.
14 -Follow lighting instructions to light and operate furnace for 5 minutes to ensure that heat exchanger is clean and dry and that furnace is operating properly.
15 – Replace heating compartment access panel

Repair Parts List The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model number listed on the CSA nameplate — Example: ML193DF045XE36B. All service must be performed by a licensed professional installer (or equivalent), service agency, or gas supplier. Cabinet Parts
Upper access panel Blower access panel Top Cap Control Panel Parts
Transformer Integrated control board Door interlock switch Blower Parts
Blower wheel Motor Motor mounting frame Motor capacitor Blower housing cutoff plate Heating Parts
Flame Sensor Heat exchanger assembly Gas manifold Combustion air inducer Gas valve Main burner cluster Main burner orifices Pressure switch Ignitor Primary limit control Flame rollout switches

Page 44

Start-Up & Performance Check List

2 2

UNIT SET UP (typical)
Furnace: Model Number_
Serial Number___
Line Voltage

SUPPLY AIR

4

1 GAS SUPPLY

Natural Gas LP Propane Gas

Piping Connections Tight

Leak Tested

Supply Line Pressure “W.C.____

1 Gas Supply Pressure
1

3
Flter RETURN AIR

2 INTAKE / EXHAUST PIPE All Joints Primed and Glued Terminations Installed Properly Horizontal Pipes Sloped (if applicable) Condensate Trap Primed / Line Sloped Pipes Supported Heat Cable Installed and Operable (if applicable)

3 DUCT SYSTEM SUPPLY AIR DUCT Sealed
Insulated (if necessary)
RETURN DUCT Sealed
Filter Installed and Clean
Grilles Unobstructed 4 VOLTAGE CHECK
Supply Voltage _____

Page 45

HEATING MODE

UNIT OPERATION

1 GAS MANIFOLD PRESSURE “W.C._____

COOLING MODE 3 INDOOR BLOWER AMPS__

2 COMBUSTION SAMPLE CO2%__CO PPM_
3 INDOOR BLOWER AMPS__
4 TEMPERATURE RISE Supply Duct Temperature ____ Return Duct Temperature ____ Temperature Rise = ____
5 TOTAL EXTERNAL STATIC Supply External Static _ Return External Static

• __ Total External Static = ___
  6 CONDENSATE LINE Leak Free
  7 VENT PIPE Leak Free Combustion CO2

4 TEMPERATURE DROP Return Duct Temperature Supply Duct Temperature ___ Temperature Drop = _
5 TOTAL EXTERNAL STATIC (dry coil) Supply External Static _ Return External Static + __ Total External Static = _
8 DRAIN LINE Leak Free
9 THERMOSTAT Adjusted and Programmed Explained Operation to Owner

2

7

SUPPLY AIR

9 Blower Motor Amps
3

Thermostat 6

8 Gas Manifold Pressure 1

Temperatures
4

Duct Static High + 5
RETURN AIR
Low –

Contractor’s: Name____TelephoneChecklist Completed____ Job Address_- ____Technician’s Name___

Page 46

Requirements for Commonwealth of Massachusetts
Modifications to NFPA-54, Chapter 10
Revise NFPA-54 section 10.8.3 to add the following requirements:
For all side wall, horizontally vented, gas-fueled equipment installed in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet above the finished grade in the area of the venting, including but not limited to decks and porches, the following requirements shall be satisfied:
1 – INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation of the side wall, horizontally vented, gas-fueled equipment, the installing plumber or gasfitter shall observe that a hard-wired carbon monoxide detector with an alarm and battery backup is installed on the floor level where the gas equipment is to be installed. In addition, the installing plumber or gasfitter shall observe that a battery-operated or hard-wired carbon monoxide detector with an alarm is installed on each additional level of the dwelling, building or structure served by the side wall, horizontally vented, gas-fueled equipment. It shall be the responsibility of the property owner to secure the services of qualified licensed professionals for the installation
a. In the event that the side wall, horizontally vented, gas-fueled equipment is installed in a crawl space or an attic, the hardwired carbon monoxide detector with alarm and battery backup may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision cannot be met at the time of completion of installation, the owner shall have a period of thirty (30) days to comply with the above requirements; provided, however, that during said thirty (30) day period, a battery-operated carbon monoxide detector with an alarm shall be installed.
2 – APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as required in accordance with the above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.
3 – SIGNAGE. A metal or plastic identification plate shall e permanently mounted to the exterior of the building at a minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented, gas-fueled heating appliance or equipment. The sign shall read, in print size no less than one-half (1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS.”

4 – INSPECTION. The state or local gas inspector of the side wall, horizontally vented, gas-fueled equipment shall not approve the installation unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with the provisions of 248 CMR 5.08(2)(a) 1 through 4.
EXEMPTIONS: The following equipment is exempt from 24 CMR 5.08(2)(a) 1 through 4:
1 – The equipment listed in Chapter 10 entitled “Equipment Not Required to Be Vented” in the most current edition of NFPA 54 as adopted by the Board; and
2 – Product Approved side wall, horizontally vented, gasfueled equipment installed in a room or structure separate from the dwelling, building or structure used in whole or in part for residential purposes.
MANUFACTURER REQUIREMENTS – GAS EQUIPMENT VENTING SYSTEM PROVIDED.
When the manufacturer of Product Approved side wall, horizontally vented, gas- fueled equipment provides a venting system design or venting system components with the equipment, the instructions provided by the manufacturer for installation of the equipment and the venting system shall include:
1 – Detailed instructions for the installation of the venting system design or the venting system components: and
2 – A complete parts list for the venting system design or venting system.
MANUFACTURER REQUIREMENTS – GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED.
When the manufacturer of Product Approved side wall, horizontally vented, gas- fueled equipment does not provide the parts for venting the flue gases, but identifies “special venting systems,” the following requirements shall be satisfied by the manufacturer:
1 – The referenced “special venting system” instructions shall be included with the appliance or equipment installation instructions; and
2 – The “special venting systems” shall be Product Approved by the Board, and the instructions for that system shall include a parts list and detailed installation instructions.
A copy of all installation instructions for all Product Approved side wall, horizontally vented, gas-fueled equipment, all venting instructions, all parts lists for venting instructions, and/or all venting design instructions shall remain with the appliance or equipment at the completion of the installation.

Page 47

FOR THE PROVINCE OF ONTARIO, HORIZONTAL SIDE-
WALL VENT APPLICATIONS ONLY
For exterior horizontal venting applications, the 2″ X 1.5″ reducer for 2″ venting at the point where the exhaust pipe exits the structure is not required in direct or non-direct vent applications in the Province of Ontario. In these applications, the vent should be oriented such that the exhaust plume is unobjectionable. If the installation requires more separation between the flue gases and the building structure, a reducer may be installed on the exhaust pipe to increase the flue gas velocity.

ADDENDUM FOR ALL PROVINCES OF CANADA
See below for venting in all provinces of Canada. Lennox approves the following termination for use in all provinces of Canada.

C
D B
12″

A

A – Clearance above grade or average snow accumulation

2″ (51MM) Vent Pipe

3″ (76MM) Vent Pipe

12″ (305 mm) Min. 12″ (305 mm) Min.

B – Horizontal separation between 6″ (152 mm) Min. 6″ (152 mm) Min.

intake and exhaust

24″ (610 mm) Max. 24″ (610 mm) Max.

C – Exhaust pipe length

Per: Saskatchewan Code of Practice

D – Wall support distance from top of each pipe (intake/exhaust)

6″ (152 mm) Max.

6″ (152 mm) Max.

NOTE – Flue gas may be acidic and may adversely affect some building materials. If flue gases impinge on the building materials, a corrosion- resistant shield should be used to protect the wall surface. 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.

Page 48

Blower Data

ML193DF045XE36B PERFORMANCE (Less Filter)

External Static
Pressure in. w.g.

High (Black)

cfm

Watts

Air Volume / Watts at Various Blower Speeds

Medium-High (Brown)

Medium (Blue)

Medium-Low (Yellow)

cfm

Watts

cfm

Watts

cfm

Watts

0.00

1430

353

1305

270

1180

199

890

107

0.10

1395

364

1270

279

1145

207

845

113

0.20

1365

375

1245

291

1105

212

795

121

0.30

1330

383

1215

298

1070

221

740

126

0.40

1305

391

1180

310

1025

228

700

136

0.50

1275

400

1140

320

980

237

660

143

0.60

1245

406

1110

328

950

250

615

147

0.70

– – –

– – –

1080

335

910

252

585

151

0.80

– – –

– – –

1030

332

870

264

545

160

ML193DF070XE36B PERFORMANCE (Less Filter)

External Static
Pressure in. w.g.

High (Black)

cfm

Watts

Air Volume / Watts at Various Blower Speeds

Medium-High (Brown)

Medium (Blue)

Medium-Low (Yellow)

cfm

Watts

cfm

Watts

cfm

Watts

0.00

1415

340

1295

269

1175

191

905

101

0.10

1380

351

1265

276

1140

202

860

109

0.20

1345

360

1240

285

1090

208

810

119

0.30

1325

371

1215

291

1060

218

770

124

0.40

1295

380

1175

302

1025

228

710

132

0.50

1260

392

1135

318

985

236

670

138

0.60

1235

402

1105

320

955

247

620

146

0.70

1185

411

1080

333

910

254

585

152

0.80

– – –

– – –

1040

342

865

261

540

157

ML193DF090XE48C PERFORMANCE (Less Filter)

External Static
Pressure in. w.g.

High (Black)

cfm

Watts

Air Volume / Watts at Various Blower Speed

References

• Air-Conditioning, Heating, and Refrigeration Institute | AHRI

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