HRIA MG1E Series Gas Furnace Instruction Manual

MG1E Series Gas Furnace

Product Information

Product Name:

MG1 Series Downflow, Direct Vent (Sealed Combustion) Forced Air Gas
Furnaces

Important Safety Information:

– This product should be installed according to the provided
instructions to prevent fire or explosion hazards. – If you smell
gas, follow the recommended steps provided in the user manual. –
Non-certified air conditioning or heat pump equipment should not be
used with this furnace in HUD Manufactured Homes. – Cutting,
splicing, or modifying internal electrical wiring may void product
warranties and create hazardous conditions.

Requirements & Codes:

– The use of Nortek Global HVAC manufactured housing air
conditioning components is strongly recommended to meet HUD
Manufactured Home Construction and Safety Standards (3280.714). –
Failure to comply with these standards may result in inadequate
heating or cooling performance and structural damage to a
manufactured home.

Circulating Air Requirements:

– Return air and supply air requirements are outlined in the user
manual.

Furnace Installation:

– General information on furnace installation is provided. –
Instructions for locating and cutting duct openings are included. –
Different methods for duct connector installation are explained. –
Detailed steps for installing the furnace are provided.

Roof Jack Installation:

– Instructions for selecting and installing the roof jack are
given. – Steps for locating and cutting roof/ceiling openings are
included.

Electrical Information:

– Information on line voltage wiring and connecting power supply
wires is provided. – Instructions for low voltage wiring and
connecting thermostat wires are given. – Verifying the anticipator
setting and grounding instructions are included.

Startup & Adjustments:

– Operating instructions for the furnace are provided. – Steps for
shutting off gas in direct ignition models are explained. –
Instructions for verifying input rate, adjusting temperature rise,
and burner adjustments are included. – Guidelines for checking gas
pressure are provided.

Product Usage Instructions

1. Installation: – Follow the provided instructions carefully to
install the MG1 Series Downflow, Direct Vent Forced Air Gas
Furnace. – Ensure that the furnace is installed with the
recommended clearances and in compliance with relevant codes. – Pay
attention to the specific requirements for unit location, return
air, and supply air. 2. Circulating Air Requirements: – Refer to
the user manual for detailed information on circulating air
requirements, including return air and supply air. 3. Furnace
Installation: – Review the general information on furnace
installation. – Follow the instructions for locating and cutting
duct openings. – Choose the appropriate method for duct connector
installation (standard or alternate attachment method). – If round
duct connectors are used, follow the instructions provided for
their installation. – Install the furnace according to the provided
steps. 4. Roof Jack Installation: – Select the appropriate roof
jack based on the instructions provided. – Follow the steps for
locating and cutting roof/ceiling openings. – Install the roof jack
as per the provided instructions. 5. Electrical Information: –
Review the information on line voltage wiring and ensure proper
connection of power supply wires. – Follow the instructions for low
voltage wiring and connecting thermostat wires. – Verify the
anticipator setting as directed. – Ground the furnace according to
the provided guidelines. 6. Startup & Adjustments: –
Familiarize yourself with the operating instructions for the
furnace. – If applicable, follow the steps for shutting off gas in
direct ignition models. – Verify the input rate and adjust the
temperature rise accordingly. – Make necessary burner adjustments
based on the instructions provided. – Check and adjust gas pressure
following the guidelines given. Note: For any assistance or further
help, contact your local distributor or refer to the directory of
Nortek Global HVAC factory authorized servicers located in the
furnace homeowner packet.

MG1 Series
INSTALLATION INSTRUCTIONS

Downflow, Direct Vent (Sealed Combustion) Forced Air Gas Furnaces
For installation in:
· Manufactured Homes · Recreational Vehicles, Park Models, &
Manufactured Buildings · Modular Homes / Buildings

WARNING / AVERTISSEMENT
FIRE OR EXPLOSION HAZARD
· Failure to follow safety warnings exactly could result in serious injury, death or property damage.
· Installation and service must be performed by a qualified installer, service agency or the gas supplier.
· Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
RISQUE D’INCENDIE OU D’EXPLOSION
· Le non-respect des avertissements de sécurité pourrait entraîner des blessures graves ou des dommages matériels importants.
· L’installation et l’entretien doivent être effectués par un installateur qualifié, un organisme de service ou le fournisseur de gaz.
· N’entreposez pas ni n’utilisez de l’essence ni d’autres vapeurs ou liquides inflammables dans le voisinage de cet appareil, ni de tout autre appareil.
WHAT TO DO IF YOU SMELL GAS
· Do not try to light any appliance. · Do not touch any electrical switch; do not use
any phone in your building. · Leave the building immediately. · Immediately call your gas supplier from a
neighbors phone. Follow the gas suppliers instructions. · If you cannot reach your gas supplier, call the fire department.
QUE FAIRE S’IL Y A UNE ODEUR DE GAZ
· N’essayez d’allumer aucun appareil. · Ne touchez à aucun interrupteur électrique; n’utilisez
aucun téléphone dans le bâtiment. · Évacuez l’immeuble immédiatement. · Appelez immédiatement le fournisseur de gaz en employant
le téléphone d’un voisin. Respectez les instructions du fournisseur de gaz.
DO NOT DESTROY. PLEASE READ CAREFULLY & KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

CAUTION
HUD Manufactured Home Construction and Safety Standards (3280.714) prohibit the use of noncertified air conditioning or heat pump equipment with this furnace. It is strongly recommended that manufactured housing air conditioning components from Nortek Global HVAC be selected to provide a matched system specifically designed to meet these requirements.
The cutting, splicing or modifying of any internal electrical wiring may void product warranties and create a hazardous condition. Failure to comply with these standards could also provide inadequate heating or cooling performance and cause structural damage to a manufactured home.
Please contact your local distributor for help. A directory of Nortek Global HVAC factory authorized servicers is located in the furnace homeowner packet.
Reference: HUD Manufactured Home Construction and Safety Standards 3280.714.

TABLE OF CONTENTS
IMPORTANT SAFETY INFORMATION………………… 2
REQUIREMENTS & CODES ………………………………. 3
GENERAL INFORMATION…………………………………. 4 Minimum Clearances ……………………………………….. 4 Applications ……………………………………………………. 5 Unit Location…………………………………………………… 5
CIRCULATING AIR REQUIREMENTS…………………. 5 Return Air……………………………………………………….. 5 Supply Air ………………………………………………………. 6
FURNACE INSTALLATION………………………………… 6 General Information …………………………………………. 6 Locating & Cutting Duct Openings……………………… 6 Standard Duct Connector Installation …………………. 8 Alternate Attachment Method………………………….. 8 Round Duct Connector Installation …………………….. 9 Installing the Furnace ………………………………………. 9
ROOF JACK INSTALLATION …………………………….. 9 Roof Jack Selection …………………………………………. 9 Locating & Cutting Roof / Ceiling Openings ………… 9 Installing The Roof Jack …………………………………… 11
ELECTRICAL INFORMATION ……………………………. 12 Line Voltage Wiring………………………………………….. 12 Connecting Power Supply Wires……………………… 13 Low Voltage Wiring………………………………………….. 14 Connecting Thermostat Wires…………………………. 14 Verifying Anticipator Setting ……………………………. 14 Grounding ………………………………………………………. 14
FUEL SUPPLY & PIPING …………………………………… 14 Leak Check…………………………………………………….. 16 Flue Gas Sampling ………………………………………….. 16 High Altitude Conversion ………………………………….. 16 Conversion to Propane (LP) Gas……………………….. 17 Atmospheric & Direct Ignition Furnaces ……………. 17 Measuring the Supply Gas Pressure………………… 18 Measuring the Manifold Pressure…………………….. 18
STARTUP & ADJUSTMENTS …………………………….. 18 Operating Instructions………………………………………. 19 How to Shut Off Gas – Direct Ignition Models…….. 19 Verifying Input Rate …………………………………………. 19 Verifying & Adjusting Temperature Rise ……………… 19 Burner Adjustments …………………………………………. 20 Gas Pressure ……………………………………………….. 20
OPERATING SEQUENCE ………………………………….. 20 Direct Ignition Furnaces……………………………………. 20

FIGURES & TABLES…………………………………………. 23 Gas Information ………………………………………………. 23 Table 8. Gas Flow Rates………………………………… 23 Table 9. Gas Pipe Capacities………………………….. 23 Table 10. Natural Gas Heating Values……………… 24 Table 11. High Altitude Deration Chart for Natural Gas – High Heating Value……… 24 Table 12. High Altitude Deration Chart for Natural Gas – Low Heating Value ……… 24 Table 13. High Altitude Deration Chart for Propane Gas………………………………….. 24 Electrical Information ……………………………………….. 25 Figure 31. Gas Direct Ignition Furnace, Heating & A/C Ready – All MG1 Models………… 25 Airflow Data ……………………………………………………. 26 Table 14. Heating Airflow (CFM) & Temperature Rise (°F)………………………………………… 26 Table 15. Cooling Airflow (CFM) ……………………… 27
INSTALLATION CHECKLIST……………………………… 28
IMPORTANT SAFETY INFORMATION
Safety markings are used frequently throughout this manual to designate a degree or level of seriousness and should not be ignored. WARNING indicates a potentially hazardous situation that if not avoided, could result in personal injury or death. CAUTION indicates a potentially hazardous situation that if not avoided, may result in minor or moderate injury or property damage.
WARNING:
The safety information listed below must be followed during the installation, service, and operation of this furnace. Failure to follow safety recommendations could result in possible damage to the equipment, serious personal injury or death.
AVERTISSEMENT :
Les renseignements de sécurité indiqués ci-dessous doivent être respectés pendant l’installation, l’entretien et le fonctionnement de cette fournaise. Le non-respect des recommandations de sécurité peut causer des dommages à l’équipement ou des blessures graves, voire mortelles.

TROUBLESHOOTING ……………………………………….. 20
FURNACE CONTROLS & FUNCTIONS ………………. 22
MAINTENANCE ………………………………………………… 22 Installer Information …………………………………………. 22
OPTIONAL ACCESSORIES……………………………….. 22 Optional Add-On Air Conditioning………………………. 22

WARNING:
Do not install this furnace if any part has been submerged under water. A flood damaged furnace is extremely dangerous. Attempts to use the furnace may result in fire or explosion. A qualified service agency should be contacted to inspect the furnace and to replace any electrical or control system parts that have been wet or under water.

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AVERTISSEMENT :
N’installez pas cette fournaise si l’une de ses pièces a été immergée dans de l’eau. Une fournaise endommagée par une inondation est extrêmement dangereuse. Toute tentative d’utiliser la fournaise peut entraîner un incendie ou une explosion. Il faut communiquer avec un organisme de service qualifié pour l’inspection de la fournaise et le remplacement de toutes pièces électriques ou parties du système de commande qui ont été mouillées ou immergées.
CAUTION:
Operating gas furnaces in construction environments can cause a variety of problems within the furnace and may significantly reduce the life or the performance of the furnace. Therefore operating the furnace during construction is not permitted and will void the warranty.
REQUIREMENTS & CODES
· This furnace must be installed in accordance with these instructions, all applicable local building codes and the current revision of the National Fuel Gas Code (NFPA54/ANSI Z223.1) or the Natural Gas and Propane Installation Code, CAN/CSA B149.1.
· Use only with type of gas approved for this furnace. Refer to the furnace rating plate.
· Install this furnace in accordance to the minimum clearances to combustible materials listed in Table 1, (page 5).
· Provide adequate combustion and ventilation air to the furnace space as specified on page 5. Do not block or obstruct air openings on the furnace, air openings to the area where the furnace is installed, or the space around the furnace.
· Combustion products must be discharged outdoors. Connect this furnace to an approved vent system, as specified on page 9.
· Never test for gas leaks with an open flame. Use a commercially available soap solution to check all connections. See page 16.
· This furnace is designed to operate with a maximum external pressure rise of 0.3 inches of water column. NOTE 1: The static pressure measurement should not include the coil (if applicable). Consult the rating plate for the proper circulating air flow and temperature rise. NOTE 2: It is important that the duct system be designed to handle the desired flow rate and external pressure rise. An improperly designed duct system can result in nuisance shutdowns, and comfort or noise issues.
· When supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air shall also be handled through the front door

of the furnace. Make sure there is sufficient return air through the door. See return air connections page 6. · Additional information listed below is for reference purposes only and does not necessarily have jurisdiction over local or state codes. Always consult with local authorities before installing any gas appliance.
Combustion & Ventilation Air · US: National Fuel Gas Code (NFGC), Air for Combustion and
Ventilation · CANADA: Natural Gas and Propane Installation Codes
(NSCNGPIC), Venting Systems and Air Supply for Appliances
Duct Systems · US and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning Contractors National Association (SMACNA), or American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) Fundamentals Handbook
Electrical Connections · US: National Electrical Code (NEC) ANSI/NFPA 70 · CANADA: Canadian Electrical Code CSA C22.1
Gas Piping & Gas Pipe Pressure Testing · US: NFGC and National Plumbing Codes · CANADA: NSCNGPIC
General Installation · US: Current edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association Inc., Batterymarch Park, Quincy, MA 02269; or American Gas Association, 400 N. Capitol, N.W., Washington DC 20001 or www.NFPA.org · CANADA: NSCNGPIC. For a copy, contact Standard Sales, CSA International, 178 Rexdale Boulevard, Etobicoke (Toronto), Ontario, M9W 1R3 Canada
Safety · US: (NFGC) NFPA 54­1999/ANSI Z223.1 and the Installation
Standards, Warm Air Heating and Air Conditioning Systems ANSI/NFPA 90B. · Federal Manufactured Home Constructions & Safety Standard (H.U.D. Title 24, Part 3280.707[a][2]) · The Standard for Manufactured Home Installations (Manufactured Home Sites, Communities, and Set-Ups) ANSI A225.1 and/or CAN/CSA-2240 MH Series). · American National Standard (ANSI-119.2/NFPA-501C) for all recreational vehicle installations. · CANADA: CAN/CSA-B149.1 and .2­M00 National Standard of Canada. (NSCNGPIC)
· The Commonwealth of Massachusetts requires compliance with regulation 248 CMR 4.00 and 5.00 for installation of through ­ the ­ wall vented gas appliances as follows:
1. For direct-vent appliances, mechanical-vent heating appliances or domestic hot water equipment, where the bottom of the vent terminal and the air intake is installed below four feet above grade the following requirements must be satisfied: a.) A carbon monoxide (CO) detector and alarm shall be placed on each floor level where there are bedrooms. The detector shall comply with NFPA 720 (2005 Edition) and be mounted in the living area outside the bedroom(s). b.) A (CO) detector shall be located in the room that houses the appliance or equipment and shall:

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· Be powered by the same electrical circuit as the appliance or equipment.Only one service switch shall power the appliance and the (CO) detector;
· Have battery back-up power; · Meet ANSI/UL 2034 Standards and comply with
NFPA 720 (2005 Edition); and Approved and listed by a Nationally Recognized Testing Laboratory as recognized under 527 CMR.

6″ (152 mm) Top Clearance
0″ Side Clearance to Furnace Cabinet

Removable access panel should be installed above furnace door frame to access roof jack

(45718m”m)

Nearest Wall or Partition

Figure 1. Alcove Installation

6″ (152 mm) Top Clearance
0″ Side Clearance to Furnace Cabinet

Provide min. 235 sq. in. (1516 cm 2 ) open free area in front or side wall
or In closet door located at top, center or bottom
(1526m” m)

CLOSET DOOR

Figure 2. Closet Installation

6″ (152 mm) Top Clearance
0″ Side Clearance to Furnace Cabinet

Provide min. 250 sq. in. (1613 cm 2) open free area in front or side wall
or in closet door
a fully louvered door may be used

(25

1″ mm)

CLOSET DOOR
Figure 3. Special 1″ Clearance

c.) A Product-approved vent terminal must be used, and if applicable, a product-approved air intake must be used.Installation shall be in strict compliance with the manufacturer’s instructions.A copy of the installation instructions shall remain with the appliance or equipment at the completion of the installation.
d.) A metal or plastic identification plate shall be mounted at the exterior of the building, 4 feet directly above the location of vent terminal. The plate shall be of sufficient size, easily read from a distance of eight feet away, and read “Gas Vent Directly Below”.
2. For direct-vent appliances, mechanical vent heating appliances or domestic hot water equipment where the bottom of the vent terminal and the air intake is installed above four feet above grade the following requirements must be satisfied: a.) A (CO) detector and alarm shall be placed on each floor level where there are bedrooms. The detector shall comply with NFPA 720 (2005 Edition) and be mounted in the living area outside the bedroom(s). b.) The (CO) detector shall: · Be located in the room that houses the appliance or equipment; · Be hard-wired, battery powered or both. · Shall comply with NFPA 720 (2005 Edition). c.) A product-approved vent terminal must be used, and if applicable, a product-approved air intake must be used.Installation shall be in strict compliance with the manufacturer’s instructions.A copy of the installation instructions shall remain with the appliance or equipment at the completion of the installation.
GENERAL INFORMATION
CAUTION:
· Do Not alter or modify this furnace or any of its components.
· Never attempt to repair damaged or inoperable components. This may cause unsafe operation, explosion, fire and/or asphyxiation.
· If furnace malfunctions or does not operate properly, contact a qualified service agency or gas utility for assistance.
Minimum Clearances
This heating appliance must be installed with clearances not less than the minimums listed in Table 1, (page 5). This furnace must be installed with ample clearance for easy access to the air filter, blower assembly, burner assembly, controls, and vent connections. See Figure 1, Figure 2, and Figure 3. · The dimensions of the room or alcove must be able to
accommodate the overall size of the furnace and the installation clearances listed in Table 1 and in Figure 4 (page 5). · Alcove installations: minimum 18″ clearance at front of furnace shall be provided for future servicing. A removable access panel should be installed between top of the furnace door frame and the ceiling.

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special requirements for incorporation of air conditioning equipment to the MG1 furnaces.

“N”- 56″
“A” Model w/o Coil Cabinet
“B/C” Model w/Coil Cabinet

“C”- 76″

19 3/4″

23 3/4″

Figure 4. Overall Dimensions

ALL MODELS

CLOSET

Front

6″

Back

0″

Sides

0″

Roof Jack

0″

Top

6″

Top and Sides of Duct

0″

Bottom of Duct

—

A Cabinet (w/ coil box)

0″

A Cabinet (w/o coil box)

1/4″

B Cabinet

0″

Table 1. Minimum Clearances

ALCOVE
18″ 0″ 0″ 0″ 6″ 0″ — 0″ 1/4″ 0″

· Closet installations must use a louvered door having a minimum free area of 235 in2 when located 6″ from furnace or 390 in2 for 5 ton MG1 furnaces. For special clearance between 1″ – 6″, requirements are a louvered door with a minimum of 250 in2 free area, with the openings in the closet door in line with the louvered openings in the furnace door. A fully louvered closet door may be used. See Circulating Air Requirements section (page 5).
· The furnace must be kept free and clear of insulating material. Examine the furnace area when the furnace is installed or when insulation is added. Insulating material may be combustible.
Applications
MG1 series gas furnaces are classified as a Category
I (Catégorie I) appliance and listed as a direct vent (sealed combustion), downflow heating appliance for manufactured (mobile) homes and recreational vehicles. The furnace must be located so that venting can be properly achieved.
Air conditioning may be added to structures with MG1 series furnaces using air conditioning or conventional units. This Installation Instruction manual includes

Unit Location
· The furnace shall be appropriately located to the supply and return air distribution system (page 5). Sides and back of the furnace may be enclosed by wall framing. See Minimum Clearances section on page 4.
· The furnace installation is only intended for free air return through the furnace door louvers. DO NOT connect a ducted return air system directly to the furnace. Improper installation may create a hazard and damage equipment, as well as void all warranties.
· Furnace may be installed on combustible flooring when using manufacturer approved duct connectors. See page 5.
· When installed in a residential garage, the furnace must be positioned so the burners and the source of the ignition are located no less than 18 inches above the floor and protected from physical damage by vehicles.
CIRCULATING AIR REQUIREMENTS
WARNING:
Do not allow combustion products to enter the circulating air supply. Failure to prevent the circulation of combustion products into the living space can create potentially hazardous conditions including carbon monoxide poisoning that could result in personal injury or death.
The surface that the furnace is mounted on must provide sound physical support of the furnace with no gaps, cracks or sagging between the furnace and the floor or platform.
Circulating air ductwork must not be connected to any other heat producing device such as a fireplace insert, stove, etc. This may result in fire, explosion, carbon monoxide poisoning, personal injury, or property damage.
Return Air
U.S.A. home manufacturers shall comply with all of the following conditions to have acceptable return air systems for closet installed forced air heating appliances:
· The return air opening into the closet shall not be less than specified in the appliance’s listing.
· The cross-sectional area of the return duct system leading into the closet, when located in the floor or ceiling shall not be less than 235 in2.
CAUTION:
HAZARD OF ASPHYXIATION: Do not cover or restrict return air opening.

5

· Means shall be provided that prevent inadvertent closure of flat objects placed over the return air opening located in the floor of the closet (versus the vertical front or side wall).
· The total free area of openings in the floor or ceiling registers serving the return air duct system must be at least 235 in2. At least one register should be located where it is not likely to be covered by carpeting, boxes and other objects.
· Materials located in the return duct system must have a flame spread classification of 200 or less. This includes a closet door if the furnace is in a closet.
· Noncombustible pans having 1″ upturned flanges are located beneath openings in a floor duct system.
· Wiring materials located in the return duct system shall conform to Articles 300-22 of the National Electrical Code (ANSI C1/NFPA-70).
· Gas piping is not run in or through the return duct system.
CAUTION:
HAZARD OF ASPHYXIATION: Negative pressure inside the closet, with closet door closed and the furnace blower operating on high speed, shall be no more negative than minus 0.05 inch water column.
· Test the negative pressure in the closet with the aircirculating fan operating at high speed and the closet closed. The negative pressure is to be no more negative than minus 0.05 inch water column.
· Air conditioning systems may require more duct register and open louver area to obtain necessary airflow.
Supply Air
For proper air distribution, the supply duct system must be designed so that the static pressure measured external to the furnace does not exceed the listed static pressure rating shown on the furnace rating plate.
Location, size, and number of registers should be selected on the basis of best air distribution and floor plan of the home. The supply air must be delivered to the conditioned space by duct(s) secured to the furnace casing, running full size and without interruption. Three typical distribution systems are shown in Figure 5
A Single trunk duct

B

Dual trunk duct w/crossover connector

Transition duct

C

w/branches

Figure 5. Typical Supply Duct System

FURNACE INSTALLATION
NOTE: These Installation procedures are suggested for typical furnace installations. Since each installation is different, the sequence of instructions may differ from the actual installation. Only qualified HVAC technicians should install this furnace.
The installer must be familiar with and comply with all codes and regulations applicable to the installation of these heating appliances and related equipment. In the absence of local codes, the installation must be in accordance with the current provisions of one or more of the following standards.
· Federal Manufactured Home Constructions & Safety Standard (H.U.D. Title 24, Part 3280.707[a][2])
· American National Standard (ANSI-119.2/NFPA-501C) for all recreational vehicle installations.
· American National Standard (ANSI-Z223.1/NFPA-54) and/or CAN/CSA B149 for all gas-fired furnace models.
· American National Standard (ANSI-Z95.1/NFPA-31) and/or CSA B139 for all oil- fired furnace models.
· American National Standard (ANSI-C1/NFPA-70) and/or CSA 22.1 Canadian Electric Code Part 1 for all electrical field wiring.
· Units have been certified under standards UL 307A & B, UL727-1999, ANSI Z21.47/CSA 2.3, and CSA B140.10.
General Information
· The furnace must be leveled at installation and attached to a properly installed duct system. Do not use the back of the furnace for return air. See page 5 for circulating requirements.
· The furnace must be installed so that all electrical components are protected from water
· The dimensions of the room or alcove must be able to accommodate the overall size of the furnace and the installation clearances listed in Table 1, (page 5)
and Figure 1 (page 4) · The furnace must be installed upstream from a
refrigeration system. · MG1 series gas furnaces are certified for use on wood
flooring or supports, but must be installed on top of a duct connector. This factory supplied accessory must be installed in the floor cavity and attached to the supply air duct before the furnace is installed.
Locating & Cutting Duct Openings
Floor cut-outs and fuel line holes must be carefully located to avoid misalignment of the furnace, and vent piping. To locate standard ducts see Figure 6 (page 7). For round ducts, see Figure 7 (page 7). 1. Measure 10″ from the rear wall or alcove and mark the
centerline of the cut-out on the floor. 2. Using the centerline as a starting point, draw the rest
of the duct cut-out to the dimensions shown in Figure 6 or Figure 7. 3. Cut out the floor opening 1/16″ larger than the actual cutout drawn. This will allow some clearance when installing the duct connector. 4. Measure from the top of the floor down to the top of the supply air duct to obtain the depth of the floor cavity. NOTE: The depth of the floor cavity shown as “X” in

6

24″ 23 1/4″ 21 3/4″
FURNACE OUTLINE
10″ Fold Flap Here
Cut Here Cut Here
Fold Flap Here Fold Flap Here
Cut Here Fold Flap Here

20″ 14 1/2″
CL
REAR WALL OF CLOSET OR ALCOVE
2 1/4″

2 3/4″

24″ 23 1/4″
21 3/4″ 14 1/2″
FURNACE OUTLINE
10″

FLOOR CUT-OUT

FOR STANDARD

CL

DUCT CONNECTORS

CL CL

CUT-OUT FOR OPTIONAL

CL 1 3/4″

COOLING COIL

3/4″

CL

CL

1 3/4″ 3/4″ 1 7/8″
2 7/8″

ALT FUEL-LINE ENTRY 1 1/4″ Dia.

FUEL 2″
LINE

FURNACE OUTER DOOR

Figure 6. Cut-Out Dimensions for Standard Duct Connectors

20″
CL
10″
REAR WALL OF CLOSET OR ALCOVE

FLOOR

CUT-OUT FOR ROUND DUCT

CL

(14 1/4″ DIAMETER)

CL CL
CL
1 3/4″ 3/4″ 1 7/8″ 2 7/8″

1 3/4″

CUT-OUT FOR CL

OPTIONAL COOLING COIL

3/4″

CL

ALT FUEL-LINE ENTRY 1 1/4″ Dia.

FUEL 2″
LINE

FURNACE OUTER DOOR

Figure 7. Cut-Out Dimensions for Round Duct Connectors

Hole for Gas Line

Wood Floor ConTnaebcstor

Duct Connector

SAuiprpDlyuct

Bend tabs up 90°
Mounting Plate

Figure 8. Standard Duct Connector Installed

“X”
FLOOR CAVITY

FLOOR OPENING
SUPPLY AIR DUCT
Figure 9. Floor Cavity

DUCT CONNECTOR

SUPPLY AIR DUCT

BEND TABS TIGHTLY AGAINST SUPPLY AIR DUCT

Figure 10. Duct Connector Tabs

OPTION 1
Remove this Flap
Cut Here

Supply Air Duct

OPTION 2
Cut Here

Cut Here Cut Here

Cut Here
Remove this Flap

Cut Here

Figure 11. Narrow Air Duct Openings

Duct connector tabs Staples or sheet metal screws

Narrow Duct Duct Flap

Sheet metal screws

Duct Connector
Narrow Duct

Narrow Duct

Figure 12. Narrow Ducts

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IF FLOOR CAVITY “X” IS:
7/8″ / (22) 2″ / (51) 4-1/4″ / (108) 6-1/4″ / (159) 8-1/4″ / (210) 10-1/4″ / (260) 12-1/4″ / (311)

DUCT CONNECTOR TYPE & PART NUMBER

STANDARD DUCT
901987A 901988A 901989A 901990A 901991A 901992A 901993A

ROUND DUCT
904008 N/A
904010 904011 904012 904013 904014

NOTE: If Option 1 is selected, cut out the metal from the shaded area. 2. Fold the two flaps (Options 1 or 2) up to form the opening for the duct connector. 3. Install the duct connector with the bottom tabs extending into the supply air duct. 4. Bend the tabs on the bottom of the duct connector upwards and as tight as possible against the supply air duct. See Figure 12 (page 7). 5. Form the flaps (Options 1 or 2) up against the duct connector as tight as possible. 6. Secure the duct connector flaps to the supply air duct

NOTE: Dimensions shown as Inches / (Millimeter)
Table 2. Duct Connector Sizes
Figure 9 (page 7) will determine the correct duct connector. 5. Determine which duct connector to use from Table 2, (page 8). 6. Measure and drill gas hole and cut out for cooling coil (if applicable). See Figure 6 or Figure 7.
Standard Duct Connector Installation
The standard duct connector is designed for use on ducts 12″ in width. Ducts narrower than 12″ may not allow sufficient clearances for this type of installation. See Alternate Attachment Method section below.
1. Center the duct connector in the floor opening with bottom tabs resting on top of the supply air duct.
2. Mark the cut-out area on the supply air duct by tracing around the connector tabs of the duct connector. See Figure 8 (page 7).
3. Remove the duct connector and cut out the marked area of the supply air duct 1/4″ larger the actual cutout drawn.
4. Install the duct connector back in the floor opening with the bottom tabs extending into the supply air duct.
5. Install the optional mounting plate under the back side of the duct connector as shown in Figure 8. Align the screw holes in both components.
6. Secure the duct connector and the mounting plate to the wood floor with appropriate size screws.
7. Bend the connector tabs on the bottom of the duct connector upwards and as tight as possible against the supply air duct.
8. Bend both tabs up 90° on the mounting plate. See Figure 10 (page 7).
9. Seal all connections with industrial grade sealing tape or liquid sealant. See HUD Code 3280.715 for acceptable standards for tape and sealants.
NOTE: Requirements for sealing ductwork vary from region to region. Consult with local codes for requirements specific to your area.
Alternate Attachment Method
The standard duct connector is designed for use on ducts 12″ in width. However if there is insufficient clearance to bend the duct connector tabs, this alternate attachment method may be used. 1. Score and cut the top of the supply air duct as indicated
in Option 1 or Option 2. See Figure 11 (page 7).

DUCT CONNECTOR

SCREWS

MOUNTING PLATE

FUEL LINE HOLE

FUEL LINE HOLE

14″ SUPPLY CONNECTION
Figure 13. Round Duct Connector Installed

MTG. PLATE TABS
SECURE FURNACE WITH 2 FASTENERS AT FRONT
CORNER HOLES

SLIDE FURNACE ALL THE WAY BACK ONTO MTG. PLATE

Knockout Over Holes SUPPLY AIR DUCT

Figure 14. “A” & “B” Cabinet Furnaces

MTG. PLATE TABS
SECURE FURNACE WITH 2 FASTENERS AT FRONT CORNER HOLES

SLIDE FURNACE BACK AGAINST
MTG. PLATE
SUPPLY AIR DUCT

FUEL LINE HOLES
Figure 15. “A” Cabinet Furnace on Coil Cabinet

8

with staples (3 minimum) or if a 2x block/joist is not provided, use sheet metal screws (2 minimum).
NOTE: The duct connector tabs may be attached to the air duct with sheet metal screws or other suitable fasteners as long as the duct connector and the air duct are securely attached.
7. Seal all connections with industrial grade sealing tape or liquid sealant.
NOTE: Requirements for sealing ductwork vary from region to region. Consult with local codes for requirements specific to your area.
Round Duct Connector Installation
1. Apply a bead of caulking, mastic, or other approved sealant around bottom side of connector.
2. Install and center the duct connector in the floor opening. 3. Install the mounting plate under the back side of the
duct connector. See Figure 13 (page 8). NOTE: Align the screw holes in both components. 4. Secure the duct connector and the mounting plate to the wood floor with appropriate size screws. 5. Connect the round supply duct to the underside of the duct connector and secure them with field supplied sheet metal screws. 6. Seal all connections with industrial grade sealing tape or liquid sealant.
NOTE: Requirements for sealing ductwork vary from region to region. Consult with local codes for requirements specific to your area.
Installing the Furnace
Sides and back of the furnace may be enclosed by wall framing such as in a closet or alcove. The dimensions of the room or alcove must be able to accommodate the overall size of the furnace shown in Figure 4 (page 5) and the installation clearances outlined on page 4. The furnace shall be appropriately connected to the supply distribution system as shown in Figure 14 (page 8) & Figure 15 (page 8).
1. Remove furnace outer door(s) and bottom fuel line knockout.
2. Place furnace onto duct connector and center with floor opening.
3. Slide onto mounting plate. (Bottom rear slots on furnace should engage with mounting plate tabs.)
4. Secure front with one (1) fastener at each corner. See Figure 14 & Figure 15.
NOTE: Additional fasteners may be used at rear, sides or through door frame, as desired, to secure furnace to closet or alcove framing.

ROOF JACK INSTALLATION
Required ceiling and roof cut-out openings must be carefully located to avoid misalignment of the furnace and Roof Jack. NOTE: Install only roof jack assemblies listed in Table 3, (page 10) on this heating appliance.
Roof Jack Selection
1. Determine depth of ceiling cavity from center of roof opening to center of ceiling opening noted as “Dimension A” in Figure 16 (page 10).
2. Determine ceiling height and subtract height of furnace noted as “Dimension B” in Figure 16.
3. Add dimensions “A” & “B” (and X from Table 4, (page 10) if slant deck flashing is used). The total length of [A] + [B] + [X] must be within the minimum and maximum range of the roof jack listed in Table 3.
Application Notes
· FAW, FAWT, SAW and SAWT series roof jacks with a 5″ diameter inner vent pipe may be used with all models of MG1 Series gas furnaces.
F = Flat Flashing: flexes from 0/12 to 1/12 roof slope. See Figure 17 (page 10). S = Slant Flashing: 2.5/12 Slope flexes from 1/12 to 4/12 roof slope, 4/12 flexes from 3/12 to 5/12. See Figure 18 (page 10).
· MG1 furnaces may be used with roof jack systems and extension accessories as tall as 170″ (except MG1-056 models, which are limited to 120″). An internal roof jack extension (p/n 901935 – 10″, p/n 903107 – 18″) can be used to increase roof jack height. All connections inside the home must be made below the ceiling.
· This furnace must never be connected to a chimney flue servicing a fireplace or other appliance designed to burn solid fuel.
· If the roof jack crown is covered or blocked with snow, the furnace will not operate properly. If the home is located in regions where snow accumulation exceeds 7″ (HUD snowload zones) use an external roof jack extension (p/n 901937). A maximum of 2 extensions per roof jacks can be used. Extensions are optional accessories and may be purchased through your distributor.
Locating & Cutting Roof / Ceiling Openings
IMPORTANT NOTE: Do not allow debris to fall into the furnace. This could cause unsafe operation and void the furnace warranty. Use the top cap that comes with the furnace packaging (or alternate protector) to prevent debris from falling into the furnace before the final roof jack connection is made.
NOTE: Refer to the installation instructions provided with optional air conditioning packages when installing furnaces with optional cooling coil cabinet or with optional C* series indoor coils.
1. Locate center of Roof Jack opening, measure 13 1/2″ from the rear wall of closet or alcove along the center line of furnace and floor opening. See Figure 19.
2. Cut ceiling and roof holes: · Ceiling = 8 3/4″ (222 mm) diameter · Roof = 9 3/8″ (238 mm) diameter

9

ROOF JACK CROWN
CEILING CAVITY
“A” CEILING “B”

SLANT DECK FLASHING

“X” (SEE TABLE 5)

Roof Opening

PITCHED ROOF

Flue Pipe

Combustion Air Pipe

56″
Furnace or
76″

Figure 16. Ceiling Cavity Depth

ROOF JACK CROWN

SLANT DECK FLASHING

CEILING CAVITY

CEILING

CEILING OPENING

ROOF OPENING

“X” (SEE TABLE 5)
PITCHED ROOF

Figure 17. Example of Flat Jack with Flashing

MODEL NUMBER

APPROX. LENGTH BELOW FLASHING

(F,S)AW1523-(0,2,4)(A,S) (F,S)AW2135-(0,2,4)(A,S) (F,S)AW2747-(0,2,4)(A,S) (F,S)AW3563-(0,2,4)(A,S) (F,S)AW5195-(0,2,4)(A,S)

15″ – 23″ 21″ – 35″ 27″ – 47″ 35″ – 63″ 51″ – 95″

NOTE: Not all models are available. Check with your local distributor for available models.
S AW 27 47 – 2 S

F = FLAT FLASHING S = SLANT FLASHING
AW= ALL WEATHER

MIN. ADJ. LENGTH

FLUE STEEL TYPE A= ALUMINIZED S=STAINLESS
FLASHING PITCH/12″ RISE 0=FLAT 2=2.5/12 4=4/12

MAX. ADJ. LENGTH

Table 3. Roof Jack Assemblies

ROOF JACK SERIES

IF ROOF PITCH IS:

SLANT DECK FLASHING NUMBER

“X”

“F Series
“S” Series (2.5 / 12 Pitch only)

2″ in 12″ 2-1/2″ in 12″
3″ in 12″ 3-1/2″ in 12″
4″ in 12″ 4-1/2″ in 12″
5″ in 12″ 5-1/2″ in 12″
6″ in 12″ 6-1/2″ in 12″

903893 (2.5/12) 903893 (2.5/12) 903894 (3/12) 903894 (3/12) 903895 (4/12) 903895 (2.5/12) 903895 (2.5/12) 903894 (3/12) 903894 (3/12) 903895 (4/12)

2-1/8″ 2-1/2″ 2-7/8″ 3-1/4″ 3-5/8″ 2-1/8″ 2-1/2″ 2-7/8″ 3-1/4″ 3-5/8″

Optional deck flashings for flat and 2.5/12 pitch roof jacks. 4/12 pitch roof jacks not applicable.
Table 4. Slant Deck Flashings

20″
CL
10″
REAR WALL OF CLOSET OR ALCOVE

ROOF JACK WITH 2 1 2 /12 SLANT
FLASHING

5/12 ROOF SLOPE

2 1 2 /12 SLANT DECK

Figure 18. Example of 2½ / 12 Slant Jack with Flashing

FURNACE OUTLINE
13 1/2″

24″

CEILING CUT-OUT FOR
FLUE AND ROOF JACK

CL
FURNACE OUTER DOOR

Figure 19. Cut-Out Dimensions for Flue & Roof Jack

10

Secure roof jack with appropriate fasteners
after connecting to furnace

Caulk under roof flashing to prevent
water leakage
Optional 2-piece ceiling ring #902521
Figure 20. Flat Roof

Roof Ceiling

Secure lower roof jack section with no. 10 S.M. screws
Caulk under roof flashing to prevent
water leakage

Upper Roof Jack Section
Optional Slant Deck Flashing
Secure flashing with appropriate
fasteners
Ceiling

Figure 21. Pitched Roof

CONNECT OUTER FLUE SHIELD
INNER FLUE PIPE VENT COLLAR
MOUNTING FLANGE

Installing The Roof Jack
1. Apply caulking compound on underside of roof flashing to form a continuous strip at least 3/8″ wide around the underside of the perimeter of the flashing. For flat roof, see Figure 20 or see Figure 21 if roof is pitched.
2. Connect roof jack assembly to the furnace. Insert telescoping roof jack assembly through the opening cut on the roof.
3. Connect inner flue pipe to vent collar of the furnace. See Figure 22.
4. Connect combustion air pipe to furnace collar with sheet metal screw. See Figure 22.
NOTES: · It is recommended that the connection of the combustion
air pipe to the furnace be made before the flashing is secured to the roof to maintain alignment of roof jack and furnace connections. · For replacement furnaces, be sure the inner flue pipe connects over the furnace vent collar. DO NOT use a smaller diameter inner flue pipe which could slide inside the furnace vent collar and restrict the flow of furnace flue products.
5. Attach roof flashing. If necessary, shift roof flashing slightly in the roof opening so that assembly is in alignment with furnace.
NOTE: If flashing is mounted on 12 degree angle, it may be necessary to adjust the angle to match the roof pitch; (1/12 – 4/12 maximum).
6. Press down firmly on roof flashing (over caulking) to make the seal with roof water tight.
7. Secure flashing with appropriate fasteners. NOTE: For added protection against leaks, coat the exposed flashing plate and fasteners with approved roofing compound.
NOTE: Upper roof jack crown to be stored in a prominent location inside manufactured home until on-site installation.
Installing Transit-Mode Venting System (Before Home is Moved to Site)
NOTE: For transit purposes, the transit kit (P/N 903838) should be installed before home is moved to site.
1. Furnace must be installed in accordance to furnace installation manual.
2. Select appropriate roof jack from Table 3, (page 10)
3. Roof jack (less upper roof jack crown), with weather cap to be installed as described in Installing The Roof Jack section.
4. Install the four warning tags (factory supplied) on these items: · Weather cap · Fuel line connection point · Furnace flame observation door · Furnace wall thermostat

Figure 22. Combustion Air Pipe Connection
11

Removing the Transit-Mode Venting System (After home is moved to site)
WARNING:
Failure to properly secure the flue pipe to the furnace may result in fire, explosion or asphyxiation when operating the furnace.
1. Transit-mode weather cap to be removed and upper roof jack crown installed. Do not discard the screws. See Figure 23.
2. Place upper roof jack (crown) on the flue pipe assembly.
NOTE: Make sure inside flue pipe attaches over inner flue pipe and outer Roof Jack pipe fits over outer pipe.
3. Secure in place using three sheet metal screws (#10 x 1/2″) removed in step 1. Do not use the same holes which secured the rain cap in place.
4. Remove and discard all 4 venting system warning tags.

ELECTRICAL INFORMATION
WARNING:
ELECTRICAL SHOCK, FIRE OR EXPLOSION HAZARD
Failure to follow safety warnings exactly could result in 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. Reconnect wires correctly.
· Verify proper operation after servicing.

COMPLETED ASSEMBLY

UPPER ROOF JACK (CROWN)

WEATHER CAP

SCREWS

FLASHING OUTER PIPE

INNER FLUE PIPE FLUE ASSEMBLY

TO FURNACE

Figure 23. Roof Jack Crown

12

AVERTISSEMENT :
RISQUE DE DÉCHARGE ÉLECTRIQUE, D’INCENDIE OU D’EXPLOSION
Le non-respect des avertissements de sécurité pourrait entraîner des blessures graves ou des dommages matériels importants.
Un entretien inapproprié peut provoquer un fonctionnement dangereux, des blessures graves, la mort ou des dommages matériels.
· Avant toute intervention, coupez l’alimentation électrique de la fournaise.
· Pour l’entretien des commandes, étiquetez tous les fils avant de les débrancher. Rebranchez les fils correctement.
· Vérifiez le bon fonctionnement après l’intervention.
Line Voltage Wiring
WARNING:
To avoid electric shock, personal injury, or death, turn off the electric power at the disconnect or the main service panel before making any electrical connections.
· Electrical connections must be in compliance with all applicable local codes with the current revision of the National Electric Code (ANSI/NFPA 70).
· For Canadian installations the electrical connections and grounding shall comply with the current Canadian Electrical Code (CSA C22.1 and/or local codes).
It is recommended that 115VAC line voltage be supplied to the furnace from a dedicated branch circuit containing the correct fuse or circuit breaker for the furnace as listed in Table 5, (page 13).

IMPORTANT NOTE: Refer to the wiring diagram inside the control box cover or Figure 31 (page 25) for the wiring of your particular unit. Any other wiring methods must be acceptable to authority having jurisdiction.
CAUTION:
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing.
IMPORTANT NOTE: Proper line voltage polarity must be maintained in order for the control system to operate correctly. Verify the incoming neutral line is connected to the white wire and the incoming “hot” line is connected to the black wire. The furnace will not operate unless the polarity and ground are properly connected as shown in Figure 25 (page 13).
For installation of A-size Cabinet furnaces, allow sufficient slack in the wiring if an optional cooling coil cabinet is added at a later time. Use of copper conductors is recommended.
Connecting Power Supply Wires
1. Remove the furnace control panel cover. 2. Route wires (115 VAC) through the strain relief on the
left side of the furnace control box. See Figure 24. 3. Connect the hot wire to the black pigtail lead, and
the neutral wire to the white pigtail lead. Secure all connections with suitable wire nuts. 4. Connect the ground wire to the grounding screw. 5. Reinstall the control panel cover and secure with the original mounting screws.

On-Off Switch
Blower Plug Power Entry

Thermostat Wires
Furnace Control Box
To combustion Blower or Flame Roll-out Switch

To Gas Valve On-Auto Switch or Burner (Heating Models Only)
Figure 24. Control Panel (All Models)

THERMOSTAT

Rc

Red

FURNACE Red
R

RH
White
W

ECM Blower Motor

G Y
Yellow

White
W

Yellow

G

Grey
C

To AC Contactor
Figure 25. Thermostat Wiring

FURNACE MODEL
NUMBER-

FURNACE INPUT (BTUH)

CABINET WIDTH (IN.)

NOMINAL ELECTRICAL
SUPPLY

MINIMUM OPERATING
VOLTAGE

MAXIMUM OPERATING
VOLTAGE

MAXIMUM FURNACE AMPERES

MAXIMUM FUSE OR CIRCUIT BREAKER AMPS*

MINIMUM CIRCUIT AMPACITY1

MG1E-056

56,000

19 3/4

115-1-60

103

127

9.4

MG1E-070

70,000

19 3/4

115-1-60

103

127

9.4

MG1E-077

77,000

19 3/4

115-1-60

103

127

9.4

MG1E-090

85,000

19 3/4

115-1-60

103

127

9.4

15

11.8

15

11.8

15

11.8

15

11.8

NOTE: Minimum wire gauge and maximum fuse/circuit breaker amperage are based on MCA and MOP calculations. This furnace is approved for installation with a 15 amp fuse/circuit breaker however. Wire sizing must adhere to current version of the NEC and/or applicable local codes depending upon the overcurrent protection.

• Non-time-delay fuses or circuit breakers are required.

THERMOSTAT WIRE GAUGE
24 22 20 18

RECOMMENDED THERMOSTAT WIRE LENGTH (TOTAL LENGTH)

2 – WIRE – HEATING

4 OR 5 WIRE – COOLING

55 ft. 90 ft. 140 ft. 225 ft.

25 ft. 45 ft. 70 ft. 110 ft.

Total wire length includes wire from furnace to the thermostat, from thermostat to outdoor unit, & from outdoor unit back to the furnace.

Table 5. Voltage Specifications & Thermostat Wire Gauge

13

Low Voltage Wiring
· The furnace is designed to be controlled by a 24 VAC thermostat. The thermostat’s wiring must comply with the current provisions of the NEC (ANSI/NFPA 70) and with applicable local codes having jurisdiction.
· The thermostat must be installed according to the instructions supplied by the thermostat manufacturer. Low voltage connections (24 VAC) from the thermostat are wired to the terminal strip on the integrated control in the furnace.
· The thermostat should be mounted about 5 feet above the floor on an inside wall. DO NOT install the thermostat on an outside wall or any other location where its operation may be adversely affected by radiant heat from fireplaces, sunlight, or lighting fixtures, and convective heat from warm air registers or electrical appliances. Refer to the thermostat manufacturer’s instruction sheet for detailed mounting information.
· The nominal anticipator setting is 0.4. Refer to the thermostat literature for additional information.
· Best practice is to use five-wire conductor thermostat wire for 24 volt low- voltage circuit (2-wire is required for furnace only; 5-wire for heating and optional cooling systems). Refer to Table 6, (page 16) for thermostat wire information.
Connecting Thermostat Wires
1. Insert 24 volt wires through the plastic grommet just above the control panel.
2. Connect the thermostat wires to the furnace low voltage pigtails (dependent on the installation application). See Figure 25 (page 13). NOTE: If AC is installed with the furnace, a Y connection is required to be made at the furnace. See Figure 31 (page 25).
3. Connect low-voltage circuit to the wall thermostat. 4. A hole may be made in the furnace cabinet to ease
thermostat wiring. Make sure that the wiring is protected from the sharp edge of the added hole.
Verifying Anticipator Setting
After the furnace is installed, check the thermostat anticipator against the nominal setting of 0.4. 1. Connect the milliamp meter in series with one of the
gas valve’s low voltage terminals. 2. Energize the gas valve. 3. Read the value of the milliamps. 4. Adjust the heat anticipator of the thermostat to the
value on the milliamp meter. If the heat anticipator is set too high, the furnace may delay turning on. If set too low, the furnace may cycle frequently and not provide comfort to the homeowner.
Grounding

FUEL SUPPLY & PIPING
WARNING:
FIRE OR EXPLOSION HAZARD · Failure to follow safety warnings exactly could
result in serious injury, death or property damage. · Installation and service must be performed by a qualified installer, service agency or the gas supplier. · Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS · Do not try to light any appliance. · Do not touch any electrical switch; do not
use any phone in your building. · Leave the building immediately. · Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s instructions. · If you cannot reach your gas supplier, call the fire department.
AVERTISSEMENT :
RISQUE D’INCENDIE OU D’EXPLOSION · Le non-respect des avertissements de sécurité pourrait
entraîner des blessures graves ou des dommages matériels importants. · L’installation et l’entretien doivent être effectués par un installateur qualifié, un organisme de service ou le fournisseur de gaz. · N’entreposez pas ni n’utilisez de l’essence ni d’autres vapeurs ou liquides inflammables dans le voisinage de cet appareil, ni de tout autre appareil.
QUE FAIRE S’IL Y A UNE ODEUR DE GAZ · N’essayez d’allumer aucun appareil. · Ne touchez à aucun interrupteur électrique; n’utilisez
aucun téléphone dans le bâtiment. · Évacuez l’immeuble immédiatement. · Appelez immédiatement votre fournisseur de gaz à l’aide
du téléphone d’un voisin. Respectez les instructions du fournisseur de gaz. · Si personne ne répond, appelez le service des incendies.

WARNING:
To minimize personal injury, the furnace cabinet must have an uninterrupted or unbroken electrical ground. The controls used in this furnace require an earth ground to operate properly. Acceptable methods include electrical wire or conduit approved for ground service. Do not use gas piping as an electrical ground!

WARNING:
All piping must conform with local building codes, or in the absence of local codes, with the most recent edition of the National Fuel Gas Code ANSI Z223.1 or (CAN/CSA B149.1). Failure to follow all safety warnings could result in serious injury, death or property damage.

14

This furnace may be installed with left, right, or bottom gas entry. When connecting the gas supply, provide clearance between the gas supply line and the entry hole in the furnace casing to avoid unwanted noise and/or damage to the furnace. Typical gas service hookup for this furnace is shown in Figure 26. Table 9, (page 23) lists gas flow capacities for standard pipe sizes as a function of length in typical applications based on nominal pressure drop in the line.
IMPORTANT NOTES: · Some local regulations require the installation of a
manual main shut-off valve and ground joint union external to the furnace. See Figure 26. The shutoff valve should be readily accessible for service and/or emergency use. Consult the local utility or gas supplier for additional requirements regarding placement of the manual main gas shut-off. · Per ANSI 21.47, A 1/8-inch NPT plugged tapping, accessible for test gauge connection, must be installed immediately upstream of the gas supply connection to the furnace external to the cabinet. If local codes allow the use of a flexible gas appliance connector, always use a new listed connector. Do not use a connector that has previously serviced another gas appliance. · Gas piping must never run in or through air ducts, chimneys, gas vents, or elevator shafts. · Compounds used on threaded joints of gas piping must be resistant to the actions of -liquefied petroleum gases.
On-Off-Fan Switch
Control Panel

· The main gas valve and main power disconnect to the furnace must be properly labeled by the installer in case emergency shutdown is required.
· Flexible gas connectors are not recommended for this furnace but may be used if allowed by local jurisdiction. Only new flexible connectors may be used. DO NOT reuse old flexible gas connectors.
· Best practice is to use a drip leg for a vertical run to the unit.
· All piping shall be black iron pipe. Internally tinned copper tubing may be used for gas supply systems.
· Fuel line installations other than typical installations shown in Figure 26 must comply with the fuel piping provisions stated in the Federal Manufactured Home Standard (H.U.D. TITLE 24, PART 3280) and the National Fuel Gas Code (ANSI-Z223.1/NFPA-54).
· Shut-off valve must be designed and listed for use with liquid petroleum (L.P. gas).
· Plugged tappings (1/8″ NPT) for test gauge connection are present on the gas valve. See Figure 27 for locations.
NOTE: Optional fuel inlet lines are available for all gas furnace models to permit the addition of a 1/2″ F.P.T. shut-off valve above the floor.
The gas supply to your home will either be Natural Gas or L.P. Your furnace is factory equipped to operate on Natural Gas. If your gas supply is L.P., you must contact a qualified serviceman or gas supplier to convert the furnace. Instructions for conversion to propane are shown on page 17. Factory installed orifice sizes are listed in Table 6, (page 16).
For natural gas operation, the maximum inlet pressure for the valve is 7″ W.C and the minimum inlet pressure is 4.5″ W.C. Pressure is reduced to 3 1/2″ W.C. by the pressure regulator in the gas valve.
For LP gas, pressure to the gas valve must be more than 11″ W.C. but not more than 13″ W.C. Pressure is reduced to 10″ W.C. by the pressure regulator in the gas valve.

NA

T

OR

L

P

OTHER SIDE

P

T

OF CAP

PRESSURE REGULATOR
CAP

INLET PRESSURE

T

NA

TAP (1/8 NPT)

OUTLET PRESSURE TAP (1/8 NPT)

L
NA
NA

T

Floor To Gas Supply Floor Cavity

Alt. Fuel Line Entry

Some codes may require installation of a manual main shut-off valve and ground joint union external to the furnace. The shut-off valve should be readily accessible for service and/or emergency use. Consult the local utility or gas supplier for additional requirements regarding placement of the manual main gas shut-off.
Figure 26. Typical Gas Piping

Figure 27. Honeywell Gas Valve
15

FURNACE MODEL #
MG1E-056 MG1E-070 MG1E-077 MG1E-090

INPUT MBTU/H
56 70 77 85

OUTPUT MBTU/H
45 57 62 68

ORIFICE NO
NAT. LP 29 45 24 42 21 40 17 36

E.S.P. IN WC
0.3 0.3 0.3 0.3

IGNITOR DIRECT
Y Y Y Y

COMB. BLOWER
Y Y Y Y

MOTOR HP
3/4 3/4 3/4 3/4

NOTES:

·
· ·

Electrical Supply: 120 volts, 60HZ, 1 Ph. Fuse or Breaker – 15 amps Temperature Rise: 45° F to 75° F High Altitude for US and Canadian installations: See High Altitude section on page 16.

· · · ·

Thermostat Circuit: 24 volts, 60HZ, 30 vac Normal Anticipator Setting: 0.4 Manifold Pressure for Natural Gas: 3.5″ w.c. Manifold Pressure for LP Gas: 10″ w.c.

Table 6. MG1 Furnace Specifications – Factory Settings

A/C READY TONS
4 4 4 4

Leak Check
WARNING:
FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in serious injury, death or property damage.
Never test for gas leaks with an open flame. Use a commercially available soap solution made specifically for the detection of leaks to check all connections. A fire or explosion may result causing property damage, personal injury or loss of life.
AVERTISSEMENT :
RISQUE D’INCENDIE OU D’EXPLOSION Le non-respect des avertissements de sécurité pourrait entraîner des blessures graves ou des dommages matériels importants.
N’effectuez jamais d’essai d’étanchéité des gaz avec une flamme nue. Utilisez une solution savonneuse offerte sur le marché conçue spécialement pour la détection des fuites pour vérifier tous les raccordements. Un incendie ou une explosion pourrait survenir et causer des dommages matériels, des blessures ou des pertes de vie.
After the gas piping to the furnace is complete, all connections must be tested for gas leaks. This includes all fittings, pipe connections at the main gas valve, emergency shutoff valve, and flexible gas connectors (if applicable). The soap and water solution can be applied on each joint or union using a small paintbrush. If any bubbling is observed, the connection is not sealed adequately and must be retightened. Repeat the tightening and soap check process until bubbling ceases.

CAUTION:
When pressure testing gas supply lines at pressures greater than 1/2 psig (14 inch W.C.), the gas supply piping system must be disconnected from the furnace to prevent damage to the gas control valve. If the test pressure is less than or equal to 1/2 psig (14 inch W.C.), close the manual shut-off valve
Flue Gas Sampling
It may be necessary to take flue gas sampling in order to check the performance after furnace installation. A flue gas sample may be taken from the heat exchanger, which is located behind the hole of the top-front of blower compartment.
1. Turn off all electric power to the appliance. 2. Remove the black plastic cap located above the blower.
Do not discard cap. 3. Drill a hole through the top of the blower compartment.
NOTE: Hole diameter should be same size as sampling tube. 4. Insert sampling tube through the drilled hole and into the heat exchanger. 5. After a complete check and adjustment of furnace performance, seal the drilled hole with a screw larger than the hole. NOTE: Seal the screw threads with silicon sealant – rated at least 500° F. 6. Plug the outside hole with the plastic cap removed in step 3.
High Altitude Conversion
WARNING:
The reduction of input rating necessary for high altitude installation may only be accomplished with factory supplied orifices. Do not attempt to drill out orifices in the field. Improperly drilled orifices may cause fire, explosion, carbon monoxide poisoning, personal injury or death.

High altitude conversion with this furnace depends on the installation altitude and the heating value of the gas. The installation of this furnace at altitudes above 2,000 feet must meet the requirements of the National Fuel Gas

16

Code or local jurisdiction. In Canada, the requirements for high altitude are different and governed by CSA B149.1. Always consult your local code authority.
This furnace is shipped from the factory with orifices and gas regulator settings for natural gas operation at sea level altitudes. At 2,000 feet, the NFGC requires that this appliance be derated 4% for each 1000 feet of altitude. For example, the input needs to be reduced 8% at 2,000 feet, 12% at 3,000 feet and etc. This deration is in reference to the input rate and gas heating value at sea level.
To derate the furnace requires knowing the heating value of the gas at the installation site. Heating values at particular job sites vary for two reasons:

Conversion to Propane (LP) Gas
WARNING:
This furnace was shipped from the factory equipped to operate on natural gas. Conversion to LP/propane gas must be performed by qualified service personnel using factory supplied conversion parts. Failure to use the proper conversion kit can cause fire, explosion, property damage, carbon monoxide poisoning, personal injury, or death.

1. The chemical mixture of the gas varies from region to region and is expressed as the “sea level heating value”.
2. The heating value varies by altitude. For this reason, especially in high altitude areas, the local gas utility specifies the heating value at the residence’s gas meter as the “local value”.
For added flexibility, two tables have been provided for natural gas installations with high or low heating values at sea level. Table 11, (page 24) & Table 12, (page 24) contain the manifold pressure and orifice sizes to use at various altitudes. Table 11 (HIGH) is for natural gas installations with a heating value of more than 1,000 Btu per cubic foot and Table 12 (LOW) is for less than 1,000 Btu per cubic foot. To determine which table to use:
1. Consult the local utility for the local heating value at your installation site.
2. From Table 10, (page 24), find your local heating value as supplied by the utility company. Follow down the column and stop at your altitude level.
3. If your sea level heating value is HIGH, use Table 11 or if it’s LOW, use Table 12. See Example.
After changing the orifices, it is required that you measure the gas input rate. This may be accomplished in the usual way, by clocking the gas meter and using the local gas heating value. See Verifying Input Rate (page 19).
IMPORTANT NOTE: Observe the action of the burners to make sure there is no yellowing, lifting or flashback of the flame.

WARNING:
Shut off the gas supply at the manual gas shutoff valve, before disconnecting the electrical power. A fire or explosion may result causing property damage, personal injury or loss of life. Failure to follow the safety warnings exactly could result in serious injury, death or property damage.
WARNING:
To avoid electric shock, personal injury, or death, turn off the electric power at the disconnect or the main service panel before making any electrical connections.
This furnace can be converted from factory-equipped natural gas to liquid propane gas. Conversion of this valve requires replacement of the burner orifice and flipping the regulator cap to the side marked LP. The orifice required for conversion is supplied with the furnace. See Figure 27.
For altitudes between 0 and 1,999 feet, use the factory supplied LP orifice as shown in Table 6, (page 16).
Altitudes between 2,000 and 10,000 feet require the orifice to be changed. Table 13, (page 24) lists the correct orifice size and manifold pressure at different altitudes.

Installation Example
Elevation: …………………………………………… 5,000 feet Type of Gas:……………………………………..Natural Gas Local Heating Value of Gas: ………………………….750
Determine which natural gas table to use. From Table 10, (page 24), find 750 and follow down the column, stop at the 5,000 feet row. The heating value listed is LOW. Table 12, (page 24) will be used to determine orifice size and verify manifold pressure.

Atmospheric & Direct Ignition Furnaces
1. Follow the instructions in “How to Shut Off Gas – Direct Ignition” on page 19.
2. Disconnect the gas pipe union and the electrical wires connected to the gas valve.
3. Remove the gas valve assembly: 4. Remove screw(s) from gas valve bracket. Gas valve and
spud may be removed. Orifice is located at the end of the spud. 5. Replace the main orifice with the L.P. gas orifice supplied in the envelope located by the gas valve. Verify the orifice size matches the nameplate or Table 6, (page 16). 6. Unscrew the pressure regulator cap and check for the letters NAT or LP. See Figure 27 (page 15). 7. Invert the cap and tighten until snug. 8. Reassemble the burner assembly into the furnace.

17

9. Reconnect the gas piping and electrical wires to the gas valve.
10.Open the manual shut-off valve and follow the Operating Instructions on page 19.
Measuring the Supply Gas Pressure
To obtain an accurate pressure reading, turn off all gas appliances (i.e. Dryers, water heaters, stoves, etc.) at their ON/OFF control or individual gas valves. 1. Remove the inlet pressure plug from the INLET side
of the gas valve with a 3/16 Allen wrench. See Figure 27. 2. Install a 1/8 NPT fitting, which is compatible with a manometer or similar pressure gauge. 3. Connect the manometer or pressure gauge to the inlet pressure tap. 4. Turn on all electrical power to the furnace. 5. Turn the main gas supply valve (on the outside of the unit) to the ON position. 6. Start the furnace by adjusting the thermostat to it’s highest setting. Allow the furnace to run for 10 minutes. 7. Check the incoming gas line pressure. Propane gas furnaces must be between 11.0″-14.0″ W.C. Natural gas installations must be between 4.5″-10.0″ W.C. If the pressure is not between these specified ranges, contact your local gas supplier for adjustment. 8. Adjust the thermostat to it’s lowest setting and allow the unit to cycle off. 9. Turn the main gas supply valve (on the outside of the unit) to the OFF position. 10.Turn off all electrical power to the furnace. 11.Disconnect the manometer or pressure gauge. 12.Remove the NPT fitting and reinstall the inlet pressure plug. NOTE: To prevent cross threading, hand tighten the plug first, then tighten with 3/16 Allen wrench.
Measuring the Manifold Pressure
The manifold pressure must be measured by installing a pressure gauge (Manometer, Magnehelic Meter, etc.) to the outlet end of the gas valve.
1. Remove the manifold pressure plug from the outlet side of the gas valve with a 3/16 Allen wrench.See Figure 27 (page 15).
2. Install a 1/8 NPT fitting, which is compatible with a Manometer or similar pressure gauge.
3. Connect the manometer or pressure gauge to the pipe thread fitting.
4. Start the furnace by adjusting the thermostat 5 degrees above room temperature. Allow the furnace to operate for 3 minutes.
5. Measure the manifold pressure on the manometer or pressure gauge. Compare the measured value to the value in Table 11, (page 24), Table 12, (page 24), or Table 13, (page 24).
6. Replace the cap so that the letters facing up represent the type of gas being used for the furnace. See Figure 27 (page 15).
7. Adjust the thermostat to its lowest setting. 8. Turn off the main gas supply to the unit at the manual
shut-off valve, which is located outside of the unit.

9. Turn off all of the electrical power to the furnace. 10.Disconnect the manometer or pressure gauge. 11.Remove the 1/8 NPT fitting and reinstall the manifold
pressure plug. NOTE: To prevent cross threading, hand tighten the plug first then tighten with 3/16 Allen wrench.
STARTUP & ADJUSTMENTS
PLEASE READ ALL SAFETY INFORMATION BEFORE LIGHTING THE FURNACE
WARNING:
FIRE OR EXPLOSION HAZARD · Failure to follow safety warnings exactly could
result in serious injury, death or property damage. · Installation and service must be performed by a qualified installer, service agency or the gas supplier. · Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS · Do not try to light any appliance. · Do not touch any electrical switch; do not
use any phone in your building. · Leave the building immediately. · Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s instructions. · If you cannot reach your gas supplier, call the fire department.
AVERTISSEMENT :
RISQUE D’INCENDIE OU D’EXPLOSION · Le non-respect des avertissements de sécurité pourrait
entraîner des blessures graves ou des dommages matériels importants. · L’installation et l’entretien doivent être effectués par un installateur qualifié, un organisme de service ou le fournisseur de gaz. · N’entreposez pas ni n’utilisez de l’essence ni d’autres vapeurs ou liquides inflammables dans le voisinage de cet appareil, ni de tout autre appareil.
QUE FAIRE S’IL Y A UNE ODEUR DE GAZ · N’essayez d’allumer aucun appareil. · Ne touchez à aucun interrupteur électrique; n’utilisez
aucun téléphone dans le bâtiment. · Évacuez l’immeuble immédiatement. · Appelez immédiatement votre fournisseur de gaz à l’aide
du téléphone d’un voisin. Respectez les instructions du fournisseur de gaz. · Si personne ne répond, appelez le service des incendies.

18

WARNING:
Before placing the furnace in service, it must be checked to ensure it is equipped for the type of gas being used. The burner flame must be observed and adjusted if necessary. Failure to observe this caution may result in unsafe operation, explosion and/or fire, or asphyxiation. See the Gas Supply and Combustion Air sections.
· The first operation of the furnace after any home setup must be performed by a qualified service technician.
· BEFORE STARTUP: Smell all around the furnace for gas and next to the floor. Some gas is heavier than air and may settle on the floor.
· Do not use this furnace if any part has been under water. Immediately call a service technician to inspect the furnace and to replace any part of the gas valve or control system which has been under water.
WARNING:
Close the hinged fire door. If door is left open or spring is broken it may allow products of combustion into the living space by the furnace blower, resulting in possible asphyxiation.
WARNING:
Should overheating occur, or the gas supply fails to shut off, shut off the manual gas valve to the furnace before shutting off the electrical supply.
AVERTISSEMENT :
En cas de surchauffe, ou si l’alimentation de gaz omet de s’arrêter, fermez le robinet de gaz manuel à la fournaise avant de couper l’alimentation électrique.
Operating Instructions (Direct Ignition Furnaces)
Direct ignition furnaces do not have a pilot. Ignition is accomplished by a hot surface ignitor. A circuit board takes care of all timing functions. After lighting, the circuit board uses the ignitor as a flame sensor, shutting off gas should the flame go out. There are no external relays or timing devices. Do not try to light this furnace by hand. The circuit board is not field serviceable.
1. Set the thermostat to the lowest setting. 2. Turn off all electric power to the appliance. 3. Remove the furnace door and turn off the gas valve.
Push in and turn the gas control knob clockwise to OFF. See Figure 28 (page 20). 4. Wait ten (10) minutes to clear out any gas. If you smell gas, STOP! and follow the Safety Information. If you do not smell gas, proceed to step 5.

5. Set the thermostat MODE the ON position. 6. Turn the gas valve ON. Push in and turn gas control
knob counter-clockwise to ON (Figure 28). 7. Replace the furnace door. 8. Turn on all electric power to the appliance. 9. Change the thermostat mode to HEAT and the
temperature selector to a desired temperature level. The igniter should light in approximately 75 seconds. If the appliance will not operate, see “How to Shut Off Gas – Direct Ignition” on page 19 and call your service technician or gas supplier.
NOTE: In the event of any flashback or explosion, immediately shut off the furnace and call your service technician.
How to Shut Off Gas – Direct Ignition Models
1. Set the thermostat to the lowest setting. 2. Turn off all electric power to the appliance before
servicing unit. 3. Set the furnace On-Off Switch to OFF. 4. Turn gas control knob clockwise to OFF (Figure 28). 5. Replace the furnace door.
Verifying Input Rate
IMPORTANT NOTE: The input rate must not exceed the rate shown on the furnace rating plate. At altitudes above 2,000 feet, it must not exceed that on the rating plate less 4% for each 1,000 feet.
The input rate must be verified for each installation to prevent over-firing of the furnace. To determine the exact input rate, perform the following procedures:
1. Shut off all other gas fired appliances. 2. Start the furnace and run it for at least 3 minutes. 3. Measure the time (in seconds) required for the gas
meter to complete one revolution. 4. Convert the time per revolution to cubic feet of gas per
hour using Table 8, (page 23). 5. Multiply the gas flow rate in cubic ft per hr by the heating
value of the gas in Btu per cubic ft to obtain the input rate in Btuh. See example.
Example: · Time for 1 revolution of a gas meter with a 1 cubic ft
dial = 40 seconds. · From Table 8 read 90 cubic ft gas per hr. · Local heating value of the gas (obtained from gas
supplier) = 1,040 Btu per cubic ft. · Input rate = 1,040 x 90 = 93,600 Btuh.
6. The manifold pressure must be verified for each installation by a qualified installer, service agency or the gas supplier. See page 18.
Verifying & Adjusting Temperature Rise
Confirm the temperature rise through the furnace is within the limits specified on the furnace rating plate. Any temperature rise outside the specified limits could result in premature failure of the heat exchanger. 1. Place thermometers in the return and supply air stream
as close to the furnace as possible. To avoid false

19

GAS CONTROL KNOB
Figure 28. Direct Ignition Gas Valve – Honeywell
readings, the thermometer on the supply air side must be shielded from direct radiation from the heat exchanger. 2. Adjust all registers and duct dampers to the desired position and run the furnace for 10 to 15 minutes in high fire before taking any temperature readings. The temperature rise is the difference between the supply and return air temperatures.
For typical duct systems, the temperature rise will fall within the limits specified on the rating plate with the blower speed at the factory recommended setting. If the measured temperature rise is outside the specified limits, it may be necessary to change the speed of the blower. NOTE: Lowering the blower speed increases the temperature rise and a higher blower speed will decrease the temperature rise.
The furnace is equipped with a multi-tap ECM motor. For alternate motor tap selections see Table 14, (page 26) & Table 15, (page 27).
Burner Adjustments
CAUTION:
· Adjustment must be made only by a qualified technician. Improper air adjustment may cause unsafe operation, explosion and/or fire asphyxiation.
· If the input to the furnace is too great because of excessive gas pressure, wrong size nozzle or orifice, high altitude, etc., the burner flame will be sooty and can produce carbon monoxide, which could result in unsafe operation, explosion and/or fire or asphyxiation.
Burner settings are made at the factory. However, these settings may change during shipping, handling, and installation. The following items should be checked and readjusted if necessary.
Gas Pressure
The gas pressure can be checked with a manometer at the pressure tap located on the top of the gas valve. Natural gas manifold pressure should be 3.5″ W.C. and L.P. gas manifold pressure should be 10″ W.C. Replace the gas pressure tap plug on the gas valve. See Figure 27 (page 15).

OPERATING SEQUENCE
Direct Ignition Furnaces
1. On a call for heat, the thermostat contacts close, supplying 24 VAC between terminals C and W of the control module.
2. When the inducer starts, the air pressure switch closes at -0.30 W.C. differential pressure and energizes the gas valve.
3. After a 45 second purge, the ignitor is energized for a 30 second warm-up period. After warm up, the gas valve opens. NOTE: The time for ignition is approximately 6 seconds, after which the gas valve either remains open if flame is sensed, or closes if flame is not sensed.
4. If flame is not sensed, the sequence repeats four more times before a lockout occurs. To reset, wait 30 seconds and then interrupt the 24 VAC power by turning the room thermostat below room temperature, then returning it to the original set point.
5. If flame does not establish on the 5th attempt (initial fire + 4 re- tries), the control de-energizes the gas valve, the red LED flashes 4 times, and the furnace locks out heat operation for 1 hour. See Table 7, (page 21).
6. If a flame is present, the control energizes the main blower on heat speed 30 seconds after the gas valve opens.
WARNING:
Should overheating occur or the gas supply fails to shut off, shut off the manual gas valve to the furnace before shutting off the electrical supply.
7. When call for heat is satisfied the thermostat contacts open, the gas valve shuts off gas flow and the combustion blower remains on for a 30 second post-purge period.
8. The main blower is de-energized after a 120 second blower off delay.
TROUBLESHOOTING
High Gas Bills
a. Verify the proper orifice is being used. See Table 6, (page 16).
b. Check the return air system. Is it clear and free of blockage?
c. Check the furnace filter. Is it clean or need replacing? d. Verify the home is insulated, windows and doors fit tightly,
and there are no leaks in the heating duct system. e. Check the room thermostat. Is the setting higher than
necessary? Low humidity requires higher temperatures for the same level of comfort. Check for proper humidity level in the home.
Burner Motor won’t Run – T-stat Calls for Heat
1. Check the electrical supply to the furnace. 2. Verify the furnace On-Off switch is in the ON position.
See Figure 27 (page 15) or Figure 28 (page 20). 3. Defective thermostat circuit – white and red thermostat
low voltage leads. If the combustion fan runs, check: · Thermostat connections · Thermostat

20

CONTROL MODULE STATUS INDICATORS – MG1 SERIES

RED LED INDICATOR

STATUS

Steady ON Steady OFF Rapid flash One flash Two flashes Three flashes Four flashes
Five flashes

Control OK No power False flame or internal control fault Limit switch is open Pressure switch is open Pressure switch is stuck closed Lockout due to failed ignition
L1 neutral reversed or L1 voltage not present on L1

Flame Status – A Yellow LED labeled “Flame” is provided to indicate flame status. When flame is sensed, the flame LED is lit. If flame sense is weak, yellow LED will flash.
Table 7. Control Module Status Indicators
4. No voltage to control module – determine if 24 volts (or 120 volts) is available to the control module. If voltage is not available check for: · Blown fuse, defective transformer, circuit breaker, no electrical supply. · Limit switch open. · Loose connections.
Combustion Blower Runs, Ignitor Heats Up But No Flame
1. Defective pressure switch – check air tube and electrical connections.
2. Burner in purge mode – allow 75 seconds for flame establishing period.
3. Check for proper electrical connections at purge timer, control box, or gas valve.
4. Check for gas supply – gas line valve on, control lever on.
5. Check for blockage in combustion / vent pipe or heat exchanger.
120 VAC Is Available At AMP Plug Ignitor Does Not Heat Up
1. Disconnect power to the furnace. 2. Disconnect AMP plug to the ignitor, and check ignitor
resistance with an ohm meter. Set on RX1 scale. · Cold resistance reading should be 8-16 Ohms. · If above or below this rating at room temperature
change ignitor. 3. Check for continuity from ignitor receptacle to burner. 4. Disconnect ignitor leads at AMP receptacle and check
for 120 volts at the plug during ignition sequence. 5. Replace ignition control if 120 volts is not available at
AMP plug during ignition sequence.
Main Flame Ignites – Burner Locks Out
· Ignition control is not properly grounded. · Defective ignition control. · Improper polarity of 120 volt power supply. · Ignitor has hairline crack. · Improper gas pressure or burner air adjustment is not
allowing flame to contact ignitor tip for flame rectification. · Misaligned ignitor does not allow flame to contact ignitor
tip for flame rectification.

Burner Short Cycling – Thermostat Calls for Heat, Limit Switches Closed
· Check for polarity. · Check ground. · Check flue. · Check combustion air. · Check gas pressure. · Check orifice.
24 Volts Supplied To Gas Valve During Ignition – No Main Gas Flow
· Gas valve may be defective. Replace if necessary. · Gas piping may be plugged. Check for adequate gas
supply to gas valve at union.
Burner Operates – Insufficient Heat
· Check thermostat for proper setting and location. Thermostat should not be located where it will be affected by another heat source.
· Check for clean filter and proper air flow. · Check burner for proper gas firing rate. · Be sure unit is not undersized for its thermal load. · Check thermostat anticipator. The nominal setting is
0.4.
Burner Flame Without Motor Running
· Gas valve stuck open, check gas valve for proper operation (replace if necessary) and inspect heat exchanger.
· Check for 115 volts to the combustion blower motor; replace if necessary.
· If no power to combustion blower then check wiring and control module; replace if necessary.
Circulation Air Blower Will Not Operate Even Though The Burner Does Operate
· Check thermostat G connection to the motor. · Check 115 Volts wiring to motor. · Check for a defective motor.

21

FURNACE CONTROLS & FUNCTIONS
Furnace On / Off Switch: This switch turns electrical power to the furnace on and off. The switch must be set in the ON position for the furnace to operate. If blower operation is not desired, the furnace On-Off switch may be set in the Off position to cut the electrical power to the furnace. See Figure 26 (page 15).
Limit Control: This furnace is protected by two high temperature safety limit switches. The auxiliary (upper) limit switch and the high temperature (lower) limit switch are automatic reset types. If either limit trips, the burner will shut off. If either limit switch trips off again soon after resetting, set the furnace furnace On-Off switch to the Off position and call your authorized serviceman. See Figure 26.
Blower Off Delay: When the blower fan operates under cooling mode, there is a 40 second delay after the call for cooling (from the thermostat) is satisfied before the blower turns off.
Gas Valve: The gas valves for the gas furnaces are a 100% shut-off type and will fail safe, if for some reason the gas is turned off. The valve is a “slow-open” for MG1 models which means it opens to a low-fire position, and after a few seconds, “steps-open” to high-fire.
Summer Cooling : The unit is equipped to use a 4-wire thermostat. When using a 5-wire thermostat, RC and RH should be jumped (see instructions included with thermostat). NOTE: The MG1 furnace requires a Y connection to the furnace. See Figure 31 (page 25).
MAINTENANCE
Installer Information
All furnaces need periodic service at the beginning of each heating season. Call your qualified service contractor for these items: · Remove the air circulator and clean all dust and lint
from the unit with a stiff bristle brush. · Inspect the combustion chamber blower compartment,
flue collar and Roof Jack. · Check the gas valve (if applicable) and fuel line
connections for leaks. · Make any adjustments necessary for good operation.

OPTIONAL ACCESSORIES
Necessary when the furnace is used with packaged air conditioners If an air conditioner is installed that does not use the furnace blower for air distribution and operates independently of the furnace, the thermostat system must have an interlock to prevent the furnace and air conditioner from operating at the same time. This interlock system usually contains either a “Heat-Cool” switch which must be turned to one of the positions to activate heat or cool operation, or a positive “OFF” switch on the cooling thermostat.
The furnace must also be equipped with an automatic damper to prevent cold air from being discharged up around the heat exchanger (p/n 901996 for furnaces without coil cavity, or p/n 901083 with coil cavity). See Figure 29 or Figure 30. Cold air may cause condensation inside the heat exchanger which can rust and lead to early failure.
Optional Add-On Air Conditioning
Whether split system or single package, an energysaving air conditioner is available that has been designed specifically for manufactured housing applications and can best handle your home comfort needs. Ask your dealer or contractor about add-on central air conditioning systems.
Single package unit includes cooling coils, compressor, and vertical discharge fan. This type of unit connects with the existing home air duct system (an optional close-off damper is required with the furnace).
Split system unit with vertical discharge for quiet operation connects with cooling coil furnace (optional coil cavity required with “A” model furnaces).

WARNING:
Use of furnace or air conditioning components that are not included in the certification of this appliance may create a hazard, invalidate the certification, and in many states, make installations illegal. Listed air conditioning components are specified on the furnace label.

Figure 29. With Coil Cavity Damper

Figure 30. Without Coil Cavity Damper
22

FIGURES & TABLES

Gas Information

GAS FLOW RATES (CUBIC FEET PER HOUR)

TIME FOR ONE REVOLUTION
(SECONDS)
10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64

CUBIC FEET PER REVOLUTION OF GAS METER

1

5

10

360

1,800

300

1,500

257

1,286

225

1,125

200

1,000

180

900

164

818

150

750

138

692

129

643

120

600

113

563

106

529

100

500

95

474

90

450

86

429

82

409

78

391

75

375

72

360

69

346

67

333

64

321

62

310

60

300

58

290

56

281

3,600 3,000 2,571 2,250 2,000 1,800 1,636 1,500 1,385 1,286 1,200 1,125 1,059 1,000 947 900 857 818 783 750 720 692 667 643 621 600 581 563

GAS FLOW RATES (CUBIC FEET PER HOUR)

TIME FOR ONE REVOLUTION
(SECONDS)
66 68 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 100 102 104 106 108 110 112 114 116 118 120

CUBIC FEET PER REVOLUTION OF GAS METER

1

5

10

55

273

545

53

265

529

51

257

514

50

250

500

49

243

486

47

237

474

46

231

462

45

225

450

44

220

439

43

214

429

42

209

419

41

205

409

40

200

400

39

196

391

38

191

383

38

188

375

37

184

367

36

180

360

35

176

353

35

173

346

34

170

340

33

167

333

33

164

327

32

161

321

32

158

316

31

155

310

31

153

305

30

150

300

Table 8. Gas Flow Rates

CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR) FOR NATURAL GAS (SPECIFIC GRAVITY – 0.60)

NOMINAL PIPE

LENGTH OF PIPE RUN (FEET)

DIAMETER (IN.)

10

20

30

40

50

60

70

80

1/2

130

90

75

65

55

50

45

40

3/4

280

190

150

130

115

105

95

90

1

520

350

285

245

215

195

180

170

1 1/4

1,050

730

590

500

440

400

370

350

1 1/2

1,600

1,100

890

760

670

610

Input To Furnace (Btu/hr) Cubic Feet Per Hour Required =
Heating Value of Gas (Btu/Cu. Ft.)

NOTE: The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas flow required by the furnace. To determine the cubic feet per hour of gas flow required by the furnace, divide the input rate of the furnace by the heating value (from gas supplier) of the gas.
Table 9. Gas Pipe Capacities

23

ALTITUDE ABOVE
SEA LEVEL
2,000 FT 3,000 FT 4,000 FT 5,000 FT 6,000 FT 7,000 FT 8,000 FT 9,000 FT 10,000 FT

650 LOW LOW LOW LOW LOW LOW LOW LOW LOW

LOCAL HEATING VALUES FOR NATURAL GAS

BTU PER CUBIC FOOT

700 LOW LOW LOW LOW LOW LOW LOW LOW LOW

750 LOW LOW LOW LOW LOW LOW LOW LOW HIGH

800
LOW LOW LOW LOW LOW LOW HIGH HIGH HIGH

850
LOW LOW LOW LOW HIGH HIGH HIGH HIGH HIGH

900
LOW LOW HIGH HIGH HIGH HIGH HIGH HIGH HIGH

Table 10. Natural Gas Heating Values

950 HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH

1,000 HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH

1,050 HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH HIGH

ALTITUDE ABOVE SEA LEVEL
0 to 1,999 FT 2,000 to 2,999 FT 3,000 to 3,999 FT 4,000 to 4,999 FT 5,000 to 5,999 FT 6,000 to 6,999 FT 7,000 to 7,999 FT 8,000 to 8,999 FT 9,000 to 9,999 FT

MG1-056
29 29 30 30 30 30 31 31 32

NATURAL GAS – HIGH HEATING VALUE

FURNACE MODELS

MG1-070

MG1-077

MG1-090

24

21

17

26

23

18

26

24

19

27

25

20

28

26

21

28

27

22

29

27

23

29

28

24

30

29

25

MANIFOLD PRESSURE IS 3.5 IN WC (GAS VALVE SETTINGFOR NAT. GAS)
Factory Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size

Table 11. High Altitude Deration Chart for Natural Gas – High Heating Value

ALTITUDE ABOVE SEA LEVEL
0 to 1,999 FT 2,000 to 2,999 FT 3,000 to 3,999 FT 4,000 to 4,999 FT 5,000 to 5,999 FT 6,000 to 6,999 FT 7,000 to 7,999 FT 8,000 to 8,999 FT 9,000 to 9,999 FT

MG1-056
29 29 29 29 30 30 30 31 31

NATURAL GAS – LOW HEATING VALUE

FURNACE MODELS

MG1-070
24 24 25 26 27 27 28 29 29

MG1-077
21 20 21 22 23 24 25 26 27

MG1-090
17 17 18 19 20 21 22 23 24

MANIFOLD PRESSURE IS 3.5 IN WC (GAS VALVE SETTINGFOR NAT. GAS)
Factory Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size

Table 12. High Altitude Deration Chart for Natural Gas – Low Heating Value

ALTITUDE ABOVE SEA LEVEL
0 to 1,999 FT 2,000 to 2,999 FT 3,000 to 3,999 FT 4,000 to 4,999 FT 5,000 to 5,999 FT 6,000 to 6,999 FT 7,000 to 7,999 FT 8,000 to 8,999 FT 9,000 to 9,999 FT

MG1-056
45 47 47 47 48 48 49 49 50

PROPANE GAS

FURNACE MODELS

MG1-070
42 42 43 43 44 44 44 45 46

MG1-077
40 41 42 42 43 43 43 44 45

MG1-090
36 37 38 39 40 41 42 42 43

MANIFOLD PRESSURE IS 10 IN WC (GAS VALVE SETTINGFOR LP GAS)
Conversion Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size Service Orifice Size

NOTES: Includes 4% Input Reduction for Each 1,000 Feet. Reference Sources: ANSI Z223.1, CSA B149.1, NFPA 54, National Fuel Gas Code.
Table 13. High Altitude Deration Chart for Propane Gas

24

RED YELLOW WHITE BLACK
GRAY

RED GRAY

COM 24V

BLACK BLACK

BLACK BLACK

Electrical Information
Figure 31. Gas Direct Ignition Furnace, Heating & A/C Ready – All MG1 Models
25

WIRING DIAGRAM

Gas Direct Ignion Furnace, Heang & A/C Ready.
NOTES: 1. Incoming power must be polarized. Observe color coding. (See furnace data label for electrical informaon.) 2. If any of the original wires (as supplied with the appliance) must be replaced, use 105C Thermoplasc type wire or its equivalent. 3. A wire from “Y” on the thermostat to the furnace is required.

ON/OFF SWITCH

ECM

W

BLOWER

MOTOR

Y

R

1 2 3 45NL CG

C

G

GREEN

WHITE YELLOW RED GRAY GREEN

BLUE
AUX. LIMIT BLUE

GREEN

BLUE

HI-LIMIT

CONTROL LIGHT STATUS

RED
Steady ON Steady OFF Rapid Flash 1 Flash 2 Flashes 3 Flashes 4 Flashes 5 Flashes

Control OK
No Power False eam or internal control fault Limit switch is open
Pressure switch is open with inducer on Pressure switch is closed with inducer off Lockout due to failed ignion 115 vac & neutral reversed

YELLOW Steady ON Blinking Steady OFF

Good Flame Signal Weak Flame Signal No Flame Signal

YELLOW YELLOW

WIRE NUTS SUPPLIED
BY INSTALLER
L1 NEUTRAL

WHITE

GROUND SCREW

IGNITOR
LEGEND: FIELD WIRING LOW VOLTAGE HIGH VOLTAGE

1 1 BLACK 2 2 BLACK

GAS VALVE

96 3

R

852

G W

74 1

C

CONTROL LIGHTS

321 6 54

BLACK

WHITE RED YELLOW

MOTOR CHOKE (ON SELECT MODELS)
BLACK

123456 123456

NEU XFRM L1 H C
GRAY

GROUND SCREW

TRANS-

FORMER

24V

R

C

L

N

115V

WHITE

BLACK
BLACK BLACK FURNACE ELECTRICAL BOX

COMBUSTION FAN
12 12
ORANGE
ORANGE
PRESSURE SWITCH

*Refer to blower table for factory heang speed.
1039357A
(Replaces 10393570)
04/22

MODEL NAME/ HEATING INPUT

MOTOR SPEED

MG1E-056F1AAM1 56,000 BTU/Hr

5 – High 4 – Alternate 3 – Med-Hi* 2 – Med-Low 1 – Low

Airflow Data

MG1E-056F1A(A,B)M1

0.1 CFM RISE

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.2

0.3

0.4

CFM RISE CFM RISE CFM RISE

0.5 CFM RISE

928

45

876

47

829

50

890

47

843

49

790

53

735

56

683

61

798

52

749

55

695

60

629

66

MODEL NAME/ HEATING INPUT

MOTOR SPEED

MG1E-070F1AAM1 70,000 BTU/Hr

5 – High 4 – Alternate 3 – Med-High* 2 – Med-Low 1 – Low

MG1E-070F1A(A,B)M1

0.1 CFM RISE

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.2

0.3

0.4

CFM RISE CFM RISE CFM RISE

0.5 CFM RISE

1,212

43

1,178

44

1,148

45

1,114

47

1,079

48

931

56

886

59

836

62

782

66

732

71

MODEL NAME/ HEATING INPUT

MOTOR SPEED

MG1E-077F1AAM1 77,000 BTU/Hr

5 – High 4 – Alternate 3 – Med-High* 2 – Med-Low 1 – Low

MG1E-077F1AAM1

0.1 CFM RISE

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.2

0.3

0.4

CFM RISE CFM RISE CFM RISE

0.5 CFM RISE

1,212

47

1,178

48

1,148

50

1,114

51

1,079

53

996

57

960

59

924

62

885

64

848

67

MODEL NAME/ HEATING INPUT

MOTOR SPEED

MG1E-090F1AAM1 85,000 BTU/Hr

5 – High 4 – Med-High 3 – Med-Low* 2 – Alternate 1 – Low

MG1E-090F1AAM1

0.1 CFM RISE

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.2

0.3

0.4

CFM RISE CFM RISE CFM RISE

0.5 CFM RISE

1,188

56

1,154

58

1,119

60

1,091

61

1,054

63

1,015

66

978

68

956

70

917

73

NOTES:
1. To comply with government mandated efficiency standards, two openings are required for airflows above 1,600 CFM. 2. Data is shown without filter. 3. Temperature rises in the table are approximate. Actual temperature rises may vary. 4. Individual cells shaded in gray indicate a temperature rise outside of the recommended range. 5. To comply with government mandated efficiency standards, speed settings shaded in gray are not allowed in HEAT mode. 6. The “*” denotes the factory heat and cool setting. If a different motor speed is needed, the appropiate wire from the “HEAT” or “COOL” tap
on the control board must be connected to the desired Tap (1-5) at the motor.

Table 14. Heating Airflow (CFM) & Temperature Rise (°F)

26

MODEL NAME/ HEATING INPUT
MG1E-056F1AAM1 56,000 BTU/Hr

MOTOR SPEED
5 – High* 4 – Alternate 3 – Med-High 2 – Med-Low 1 – Low

MG1E-056F1AAM1

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

CFM CFM CFM CFM CFM CFM CFM

1,524 1,199 1,013 890 798

1,491 1,160 972 843 749

1,458 1,122 928 790 695

1,421 1,080 876 735 629

1,385 1,037 829 683 442

1,348 993 780 615 369

1,308 946 728 566

0.8 CFM 1,270 899 675 510

MODEL NAME/ HEATING INPUT
MG1E-070F1AAM1 70,000 BTU/Hr

MOTOR SPEED
5 – High* 4 – Alternate 3 – Med-High 2 – Med-Low 1 – Low

MG1E-070F1AAM1

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

CFM CFM CFM CFM CFM CFM CFM

1,573 1,387 1,212 931 640

1,541 1,353 1,178 886 599

1,511 1,321 1,148 836 562

1,479 1,289 1,114 782 513

1,452 1,254 1,079 732 476

1,419 1,216 1,036 670 425

1,388 1,183 1,005 620

0.8 CFM 1,358 1,148 964 565

MODEL NAME/ HEATING INPUT
MG1E-077F1AAM1 77,000 BTU/Hr

MOTOR SPEED
5 – High* 4 – Alternate 3 – Med-High 2 – Med-Low 1 – Low

MG1E-077F1AAM1

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

CFM CFM CFM CFM CFM CFM CFM

1,573 1,333 1,212 996 683

1,541 1,300 1,178 960 642

1,511 1,268 1,148 924 599

1,479 1,236 1,114 885 540

1,452 1,201 1,079 848 498

1,419 1,162 1,036 814 451

1,388 1,129 1,005 772 386

0.8 CFM 1,358 1,093 964 734

MODEL NAME/ HEATING INPUT
MG1E-085F1AAM1 85,000 BTU/Hr

MOTOR SPEED
5 – High* 4 – Med-High 3 – Med-Low 2 – Alternate 1 – Low

MG1E-090F1AAM1

EXTERNAL STATIC PRESSURE (IN. W.C.)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

CFM CFM CFM CFM CFM CFM CFM

1,590 1,337 1,188 1,015 779

1,555 1,306 1,154 978 742

1,521 1,274 1,119 956 698

1,493 1,243 1,091 917 654

1,458 1,210 1,054 871 617

1,426 1,182 1,023 834 564

1,397 1,142 984 792 516

0.8 CFM 1,371 1,104 941 740 472

NOTES:
1. To comply with government mandated efficiency standards, two openings are required for airflows above 1,600 CFM. 2. Data is shown without filter. 3. The “*” denotes the factory heat and cool setting. If a different motor speed is needed, the appropiate wire from the “HEAT” or “COOL”
tap on the control board must be connected to the desired Tap (1-5) at the motor.

Table 15. Cooling Airflow (CFM)

27

INSTALLATION CHECKLIST

INSTALLATION ADDRESS: CITY:

STATE:

UNIT MODEL #

UNIT SERIAL #

Unit Installed Minimum clearances per Table 1, (page 5)?

YES

NO

INSTALLER NAME: CITY:

STATE:

Has the owner’s information been reviewed with the customer?

YES

NO

Has the Literature Package been left with the unit?

YES

NO

ATTENTION INSTALLERS:
It is your responsibility to know this product better than your customer. This includes being able to install the product according to strict safety guidelines and instructing the customer on how to operate and maintain the equipment for the life of the product. Safety should always be the deciding factor when installing this product and using common sense plays an important role as well. Pay attention to all safety warnings and any other special notes highlighted in the manual. Improper installation of the furnace or failure to follow safety warnings could result in serious injury, death, or property damage.
These instructions are primarily intended to assist qualified individuals experienced in the proper installation of this appliance. Some local codes require licensed installation/service personnel for this type of equipment. Please read all instructions carefully before starting the installation. Return these instructions to the customer’s package for future reference.

ELECTRICAL SYSTEM

Electrical connections tight?

YES

NO

Line voltage polarity correct?

YES

NO

Supply Voltage: ____ VOLTS

Has the thermostat been calibrated?

YES

NO

Is the thermostat level?

YES

NO

Is the heat anticipator setting correct?

YES

NO

GAS SYSTEM

Gas Type: (circle one) Gas pipe connections leak-tested?

Natural Gas
YES

Propane NO

Gas Line Pressure: ……………………………………………….. (in – W.C.)

Installation Altitude:……………………………………………………(FT.)

Deration Percentage:…………………………………………………(%)

Furnace Input:…………………………………………………………..(Btuh)

Supply Air Temperature: ……………………………………………(° F)

Return Air Temperature: ……………………………………………(° F)

Temperature Rise: ……………………………………………………(° F)

COMBUSTION AIR & VENTING SYSTEM

Is there adequate fresh air supply for combustion & ventilation?

YES

NO

Vent free from restrictions?

YES

NO

Filter(s) secured in place?

YES

NO

Filter(s) clean?

YES

NO

Flue connections tight?

YES

NO

Is there proper draft?

YES

NO

Specifications & illustrations subject to change without notice or incurring obligations (04/22). O’Fallon, MO, © Nortek Global HVAC LLC 2022. All Rights Reserved.

1034914B (Replaces 1034914A)

References

• NFPA | The National Fire Protection Association

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