International Comfort Products G9MAC0601714, G9MAC0602120, G9MAC0801714, G9MAC0802120, G9MAC1002122 Installation Manual

INSTALLATION INSTRUCTIONS

Modulating Gas Valve, Variable Speed Motor

35” Tall High Efficiency Condensing Gas Furnace

(F/G)9MAC

These instructions must be read and understood completely before attempting installation.

Safety Labeling and Signal Words

DANGER, WARNING, CAUTION, and NOTE

The signal words DANGER, WARNING,
CAUTION, and NOTE are used to identify levels of

hazard seriousness. The signal word DANGER is
only used on product labels to signify an immediate
hazard. The signal words WARNING, CAUTION,
and NOTE will be used on product labels and
throughout this manual and other manual that may
apply to the product.

DANGER − Immediate hazards which will result in
severe personal injury or death.

WARNING − Hazards or unsafe practices which
could result in severe personal injury or death.

CAUTION − Hazards or unsafe practices which
may result in minor personal injury or product or
property damage.

NOTE − Used to highlight suggestions which will
result in enhanced installation, reliability, or
operation.

Signal Words in Manuals

The signal word WARNING is used throughout
this manual in the following manner:

!

WARNING

The signal word CAUTION is used throughout
this manual in the following manner:

!

CAUTION

Signal Words on Product Labeling

Signal words are used in combination with
colors and/or pictures or product labels.

Safety−alert symbol

When you see this symbol on the unit and in
instructions or manuals, be alert to the
potential for personal injury.

TABLE OF CONTENTS

SAFETY CONSIDERATIONS 3..............................

INTRODUCTION 4.........................................

CODES AND STANDARDS 4................................

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS 5.......

DIMENSIONS 6...........................................

LOCATION 7..............................................

LOCATION RELATIVE TO COOLING EQUIPMENT 9...........

AIR FOR COMBUSTION AND VENTILATION 9................

CONDENSATE TRAP 10....................................

INSTALLATION 17..........................................

UPFLOW INSTALLATION 17.................................

DOWNFLOW INSTALLATION 19..............................

HORIZONTAL INSTALLATION 21.............................

FILTER ARRANGEMENT 23.................................

AIR DUCTS 25.............................................

GAS PIPING 25.............................................

ELECTRICAL CONNECTIONS 27.............................

J−BOX INSTALLATION 28...................................

VENTING 32...............................................

SPECIAL VENTING REQUIREMENTS

FOR INSTALLATIONS IN CANADA 32........................

DIRECT VENT / 2−PIPE SYSTEM 33..........................

VENTILATED COMBUSTION AIR SYSTEMS 33................

TERMINATION REQUIREMENTS FOR THE PROVINCES

OF ALBERTA AND SASKATCHEWAN 38......................

INSTALLING THE VENT TERMINATION 43....................

Portions of the text and tables are reprinted from NFPA 54 /ANSI Z223.1−2009©, with permission of National Fire Protection Association, Quincy, MA 02269 and American Gas Association, Washington, DC

20001. This reprinted material is not the complete and official position of the NFPA or ANSI, on the referenced subject, which is represented only by the standard in its entirety.

MAXIMUM EQUIVALENT VENT LENTH 47.....................

MAXIMUM LENGTH OF UNINSULATED AND

INSULATED VENT PIPE-FT (M) 49...........................

Use of the AHRI Certified TM Mark indicates a
manufacturer’s participation in the program.
For verification of certification for individual
products, go to www.ahridirectory.org .

INSTALLER: Affix these instructions on or adjacent to the
furnace.
CONSUMER: Retain these instructions for future
reference.

Printed in U.S.A. 440 01 4201 02 Dec. 2011

Required Notice for Massachusetts Installations

Important

The Commonwealth of Massachusetts requires compliance with regulation 248 CMR as follows:

5.08: Modifications to NFPA−54, Chapter 10

2) Revise 10.8.3 by adding the following additional requirements:

(a) For all side wall horizontally vented gas fueled equipment installed in every dwelling, building or structure used in whole or in part for residential

purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet
above finished grade in the area of the venting, including but not limited to decks and porches, the following requirements shall be satisfied:

1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation of the side wall horizontal vented gas fueled equipment, the
installing plumber or gasfitter shall observe that a hard wired carbon monoxide detector with an alarm and battery back−up is installed on the floor
level where the gas equipment is to be installed. In addition, the installing plumber or gasfitter shall observe that a battery operated or hard wired
carbon monoxide detector with an alarm is installed on each additional level of the dwelling, building or structure served by the side wall
horizontal vented gas fueled equipment. It shall be the responsibility of the property owner to secure the services of qualified license professionals
for the installation of hard wired carbon monoxide detectors.

a. In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the hard wired carbon

monoxide detector with alarm and battery back−up may be installed on the next adjacent floor level.

b. In the event that the requirements of this subdivision can not be met at the time of completion of installation, the owner shall have a period of

thirty (30) days to comply with the above requirement; provided, however, that during said thirty (30) day period, a battery operated carbon
monoxide detector with an alarm shall be installed.

2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as required in accordance with the above provisions shall
comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.

3. SIGNAGE. A metal or plastic identification plate shall be permanently mounted to the exterior of the building at a minimum height of eight (8) feet
above grade directly in line with the exhaust vent terminal for the horizontally vented gas fueled heating appliance or equipment. The sign shall
read, in print size no less than one−half (1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS”.

4. INSPECTION. The state of local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve the installation unless,
upon inspection, the inspector observes carbon monoxide detectors and signage installed in accordance with the provisions of 248 CMR

5.08(2)(a) 1 through 4.

(b) EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a) 1 through 4:

1. The equipment listed in Chapter 10 entitled “Equipment Not Required To Be Vented” in the most current edition of NFPA 54 as adopted by the
Board; and

2. Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate from the dwelling, building or
structure used in whole or in part for residential purposes.

(c) MANUFACTURER REQUIREMENTS − GAS EQUIPMENT VENTING SYSTEM PROVIDED. When the manufacturer of Product Approved side wall

horizontally vented gas equipment provides a venting system design or venting system components with the equipment, the instructions provided by
the manufacturer for installation of the equipment and the venting system shall include:

1. Detailed instructions for the installation of the venting system design or the venting system components; and

2. A complete parts list for the venting system design or venting system.

(d) MANUFACTURER REQUIREMENTS − GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED. When the manufacturer of a Product Approved side

wall horizontally vented gas fueled equipment does not provide the parts for venting the flue gases, but identifies “special venting systems”, the
following requirements shall be satisfied by the manufacturer:

1. The referenced “special venting system” instructions shall be included with the appliance or equipment installation instructions; and

2. The “special venting systems” shall be Product Approved by the Board, and the instructions for that system shall include a parts list and detailed
installation instructions.

(e) A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled equipment, all venting instructions, all parts lists

for venting instructions, and/or all venting design instructions shall remain with the appliance or equipment at the completion of the installation.

For questions regarding these requirements, please contact the Commonwealth of Massachusetts Board of State Examiners of Plumbers and Gas

Fitters, 239 Causeway Street, Boston, MA 02114. 617−727−9952

2

Specifications are subject to change without notice.

440 01 4201 02

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Safety Considerations

!

FIRE, EXPLOSION, ELECTRICAL SHOCK, AND
CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in dangerous
operation, personal injury, death, or property damage.

Improper installation, adjustment, alteration, service,
maintenance, or use can cause carbon monoxide
poisoning, explosion, fire, electrical shock, or other
conditions which may cause personal injury or property
damage. Consult a qualified service agency, local gas
supplier, or your distributor or branch for information or
assistance. The qualified service agency must use
only factory−authorized and listed kits or accessories
when modifying this product.

!

FURNACE RELIABILITY HAZARD

Failure to follow this caution may result in unit
component damage.

Application of this furnace should be indoors with
special attention given to vent sizing and material, gas
input rate, air temperature rise, unit leveling, and unit
sizing.

Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock,
or other conditions which may cause death, personal injury or
property damage. Consult a qualified installer, service agency,
local gas supplier, or your distributor or branch for information
or assistance. The qualified installer or agency must use only
factory−authorized kits or accessories when modifying this
product. Refer to the individual instructions packaged with the
kits or accessories when installing.

Installing and servicing heating equipment can be hazardous
due to gas and electrical components. Only trained and

qualified personnel should install, repair, or service
heating equipment. Untrained personnel can perform basic

maintenance functions such as cleaning and replacing air
filters. All other operations must be performed by trained
service personnel. When working on heating equipment,
observe precautions in literature, on tags, and on labels
attached to or shipped with furnace and other safety
precautions that may apply.

These instructions cover minimum requirements and conform
to existing national standards and safety codes. In some
instances, these instructions exceed certain local codes and
ordinances, especially those that may not have kept up with
changing residential construction practices. We require these
instructions as a minimum for a safe installation.

Follow all safety codes. Wear safety glasses, protective
clothing, and work gloves. Have a fire extinguisher available.
Read these instructions thoroughly and follow all warnings or
cautions included in literature and attached to the unit.

WARNING

CAUTION

!

CAUTION

CUT HAZARD

Failure to follow this caution may result in personal
injury.

Sheet metal parts may have sharp edges or burrs. Use
care and wear appropriate protective clothing, safety
glasses and gloves when handling parts, and servicing
furnaces.

This is the safety−alert symbol . When you see this symbol
on the furnace and in instructions or manuals, be alert to the

potential for personal injury.
Understand the signal words DANGER, WARNING, and

CAUTION. These words are used with the safety−alert symbol.
DANGER identifies the most serious hazards which will result
in severe personal injury or death. WARNING signifies a
hazard which could result in personal injury or death.
CAUTION is used to identify hazards which may result in minor
personal injury or product and property damage. NOTE is used
to highlight suggestions which will result in enhanced
installation, reliability, or operation.

1. Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.

2. Install this furnace only in a location and position as
specified in the “Location” section of these instructions.

3. Provide adequate combustion and ventilation air to the
furnace space as specified in “Air for Combustion and
Ventilation” section.

4. Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only,
as specified in the “Venting” section of these
instructions.

5. 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, as
specified in the “Gas Piping” section.

6. Always install furnace to operate within the furnace’s
intended temperature−rise range with a duct system
which has an external static pressure within the
allowable range, as specified in the “Start−Up,
Adjustments, and Safety Check” section. See furnace
rating plate.

7. When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space
containing the furnace, the return air shall also be
handled by duct(s) sealed to the furnace casing and
terminating outside the space containing the furnace.
See “Air Ducts” section.

8. A gas−fired furnace for installation in a residential
garage must be installed as specified in the warning box
in the “Location” section. (See Figure 4)

9. The furnace may be used for construction heat provided
that the furnace installation and operation complies with
the first CAUTION in the LOCATION section on page 7
of these instructions.

10. These Multipoise Gas−Fired Furnaces are CSA
design−certified for use with natural and propane gases
(see furnace rating plate) and for installation in alcoves,
attics, basements, closets, utility rooms, crawlspaces,
and garages. The furnace is factory−shipped for use
with natural gas. A CSA (A.G.A. and C.G.A.) listed
accessory gas conversion kit is required to convert
furnace for use with propane gas.

11. See Table 1 for required clearances to combustible

construction.

440 01 4201 02 3

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

12. Maintain a 1−in. (25 mm) clearance from combustible
materials to supply air ductwork for a distance of 36−in.
(914 mm) horizontally from the furnace. See NFPA 90B
or local code for further requirements.

Table 1

POSITION

Minimum Clearances to

Combustible Materials for All Units

CLEARANCE

In(mm)

REAR 0

FRONT (Combustion air openings in

furnace and in structure)

1 (25)

Required for service 24 (610)

All Sides of Supply Plenum 1 (25)

Sides 0

Vent 0

Top of Furnace 1 (25)

13. These furnaces SHALL NOT be installed directly on
carpeting, tile, or any other combustible material other
than wood flooring. In downflow installations, factory
accessory floor base MUST be used when installed on
combustible materials and wood flooring. Special base
is not required when this furnace is installed on
manufacturer’s Coil Assembly is used. See Table 1 for
clearance to combustible construction information.

Introduction

The 4−way multipoise Category IV condensing furnace is CSA
design−certified as a direct−vent (2−pipe) and ventilated
combustion air venting installations. (See Figure 3) The
furnace is factory−shipped for use with natural gas. The
furnace can be converted in the field for use with propane gas
when a factory−supplied conversion kit is used. Refer to the
furnace rating plate for conversion kit information.

This furnace is not approved for installation in mobile homes,
recreational vehicles, or outdoors.

This furnace is designed for minimum continuous return−air
temperature of 60°F (15°C) db or intermittent operation down to
55°F (15°C) db such as when used with a night setback
thermostat. Return−air temperature must not exceed 80°F
(27°C) db. Failure to follow these return−air temperature limits
may affect reliability of heat exchangers, motors, and controls
(See Figure 1)

The furnace should be sized to provide 100 percent of the
design heating load requirement plus any margin that occurs
because of furnace model size capacity increments. Heating
load estimates can be made using approved methods available
from Air Conditioning Contractors of America (Manual J);
American Society of Heating, Refrigerating, and
Air−Conditioning Engineers; or other approved engineering
methods. Excessive oversizing of the furnace could cause the
furnace and/or vent to fail prematurely.

For accessory installation details, refer to the applicable
instruction literature.

NOTE: Remove all shipping materials, parts assemblies and
literature before operating the furnace.

Figure 1

Freeze Protection and Return Air
Temperature

SUPPLY

MAX 80°F/27°C

AIR

MIN 60°F/16°C

32° F/0° C MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED

Codes and Standards

Follow all national and local codes and standards in
addition to these instructions. The installation must comply

with regulations of the serving gas supplier, local building,
heating, plumbing, and other codes. In absence of local codes,
the installation must comply with the national codes listed
below and all authorities having jurisdiction.

In the United States and Canada, follow all codes and
standards for the following:

Safety

 US: National Fuel Gas Code (NFGC) NFPA

54−2009/ANSI Z223.1−2009 and the Installation
Standards, Warm Air Heating and Air Conditioning
Systems ANSI/NFPA 90B

 CANADA: National Standard of Canada, Natural Gas

and Propane Installation Code (NSCNGPIC)
CAN/CSA B149.1−2010

General Installation

 US: NFGC and the NFPA 90B. For copies, contact the

National Fire Protection Association Inc.,
Batterymarch Park, Quincy, MA 02269; or for only the
NFGC contact the American Gas Association, 400 N.
Capitol, N.W., Washington DC 20001.

 CANADA: NSCNGPIC. For a copy, contact Standard

Sales, CSA International, 178 Rexdale Boulevard,
Etobicoke (Toronto), Ontario, M9W 1R3, Canada.

Combustion and Ventilation Air

 US: Section 9.3 of the NFPA54/ANSI Z223.1−2009,

Air for Combustion and Ventilation

 CANADA: Part 8 of the CAN/CSA B149.1−2010,

Venting Systems and Air Supply for Appliances

4 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

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)
2005 Fundamentals Handbook Chapter 35.

Acoustical Lining and Fibrous Glass
Duct

 US and CANADA: current edition of SMACNA, NFPA

90B as tested by UL Standard 181 for Class I Rigid Air
Ducts

Gas Piping and Gas Pipe Pressure
Testing

 U.S.A.: NFPA 54/ANSI Z223.1−2009, NFGC; Chapters

5, 6, 7, and 8 and national plumbing codes.

 CANADA: CAN/CSA−B149.1−2010, Parts 4, 5, 6 and

9.

In the state of Massachusetts:

 This product must be installed by a licensed plumber or

gas fitter.

 When flexible connectors are used, the maximum

length shall not exceed 36−in. (914 mm).

 When lever type gas shutoffs are used they shall be

T−handle type.

 The use of copper tubing for gas piping is not

approved by the state of Massachusetts.

Electrical Connections

 U.S.A.: National Electrical Code (NEC) ANSI/NFPA

70−2011

 CANADA: Canadian Electrical Code CSA C22.1

Electrostatic Discharge (ESD)
Precautions Procedure

!

FURNACE RELIABILITY HAZARD

Failure to follow this caution may result in unit com­ponent damage.

Electrostatic discharge can affect electronic compon­ents. Take precautions during furnace installation and
servicing to protect the furnace electronic control. Pre­cautions will prevent electrostatic discharges from per­sonnel and hand tools which are held during the pro­cedure. These precautions will help to avoid exposing
the control to electrostatic discharge by putting the
furnace, the control, and the person at the same elec­trostatic potential.

CAUTION

1. Disconnect all power to the furnace. Multiple
disconnects may be required. DO NOT TOUCH THE
CONTROL OR ANY WIRE CONNECTED TO THE
CONTROL PRIOR TO DISCHARGING YOUR BODY’S
ELECTROSTATIC CHARGE TO GROUND.

2. Firmly touch the clean, unpainted, metal surface of the
furnace chassis which is close to the control. Tools held
in a person’s hand during grounding will be satisfactorily
discharged.

3. After touching the chassis, you may proceed to service
the control or connecting wires as long as you do nothing
to recharge your body with static electricity (for example;
DO NOT move or shuffle your feet, do not touch
ungrounded objects, etc.).

4. If you touch ungrounded objects (and recharge your
body with static electricity), firmly touch a clean,
unpainted metal surface of the furnace again before
touching control or wires.

5. Use this procedure for installed and uninstalled
(ungrounded) furnaces.

6. Before removing a new control from its container,
discharge your body’s electrostatic charge to ground to
protect the control from damage. If the control is to be
installed in a furnace, follow items 1 through 4 before
bringing the control or yourself in contact with the
furnace. Put all used and new controls into containers
before touching ungrounded objects.

7. An ESD service kit (available from commercial sources)
may also be used to prevent ESD damage.

Accessories

See Specification Sheets for a list of accessories for this
product.

Table 2

QUANTITY COMPONENT NAME

1 Air Intake Pipe Flange
1 Vent Pipe Flange
2 Coupling Flange Gaskets

10 Sharp Tip Screws (Vent and Inlet Flanges)

1 Vent Pipe Coupling
2 Vent Pipe Coupling Clamps
1 Rubber Drain Tube
4 Drain Tube Clamps
1 1/2” CPVC to 3/4” PVC Pipe Adapter
1 Gas Line Grommet
1 Junction Box Cover
1 Junction Box Base
1 Green Ground Screw
3 Blunt Tip Screws (Junction Box)
1 Thermostat Wire Grommet

Provided separately in furnace

1 Drain Extension Tube − “Z” Pipe

Loose Parts Bag Contents
(shipped in blower compartment)

440 01 4201 02 5

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Figure 2 Dimensions

(F/G9MAC)

FURNACE SIZE

0601714 17−1/2 (445) 15−7/8 (403) 16 (406) 8 3/4 (222) 154 (69)
0602120 21 (533) 19−3/8 (492) 19−1/2 (495) 10 1/2 (267) 159 (72)
0801714 17−1/2 (445) 15−7/8 (403) 16 (406) 8 3/4 (222) 164 (74)
0802120 21 (533) 19−3/8 (492) 19−1/2 (495) 10 1/2 (267) 169 (77)
1002122 21 (533) 19−3/8 (492) 19−1/2 (495) 10 1/2 (267) 179 (80)
1202422 24−1/2 (622) 22−7/8 (581) 23 (584) 12 1/4 (311) 203 (91)

A B C D

CABINET WIDTH OUTLET WIDTH

BOTTOM

INLET WIDTH

AIR INTAKE

NOTE:

1. Doors may vary by model.

2. Recommended air duct dimensions and configurations:
a. For 800 CFM 16−in. (406 mm) round or 14 ½ x 12−in. (368 x 305 mm) rectangle.
b. For 1200 CFM 20−in. (508mm) round or 14 ½ x 19 ½−in. (368 x 495 mm) rectangle.

c. For 1600 CFM 22−in. (559 mm) round or 14 ½ x 22 1/16−in. (368 x 560 mm) rectangle.

d. For airflow requirements above 1800 CFM, see Air Delivery table in Installation Instructions for specific use of single side

inlets. The use of both side inlets, a combination of 1 side and the bottom, or the bottom only return air openings may be
required for airflow requirements above 1800 CFM at 0.5 in. w.c. ESP

SHIP WT.

LB (KG)

6 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Location

!

PERSONAL INJURY AND/OR PROPERTY DAMAGE
HAZARD

Improper use or installation of this furnace may result in
premature furnace component failure. This gas furnace
may be used for heating buildings under construction
provided that:

−The furnace is permanently installed with all electrical
wiring, piping, venting and ducting installed according to
these installation instructions. A return air duct is
provided, sealed to the furnace casing, and terminated
outside the space containing the furnace. This prevents
a negative pressure condition as created by the
circulating air blower, causing a flame rollout and/or
drawing combustion products into the structure.

−The furnace is controlled by a thermostat. It may not be
“hot wired” to provide heat continuously to the structure
without thermostatic control.

−Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and
other construction materials. It also prevents the
entrainment of drywall dust into combustion air, which
can cause fouling and plugging of furnace components.

−The temperature of the return air to the furnace is
maintained between 55°F (13°C) and 80°F (27°C), with
no evening setback or shutdown. The use of the furnace
while the structure is under construction is deemed to be
intermittent operation per our installation instructions.

−The air temperature rise is within the rated rise range on
the furnace rating plate, and the gas input rate has been
set to the nameplate value.

−The filters used to clean the circulating air during the
construction process must be either changed or
thoroughly cleaned prior to occupancy.

−The furnace, ductwork and filters are cleaned as
necessary to remove drywall dust and construction
debris from all HVAC system components after
construction is completed.

−Verify proper furnace operating conditions including
ignition, gas input rate, air temperature rise, and venting
according to these installation instructions.

General

These furnaces are shipped with materials to assist in proper
furnace installation. These materials are shipped in the main
blower compartment.

See Table 2 for loose parts bag contents.
This furnace must:

• be installed so the electrical components are protected
from water.

• not be installed directly on any combustible material other
than wood flooring (refer to SAFETY
CONSIDERATIONS).

CAUTION

• be located close to the chimney or vent and attached to an
air distribution system. Refer to Air Ducts section.

• be provided ample space for servicing and cleaning.
Always comply with minimum fire protection clearances
shown in Table 1 or on the furnace clearance to
combustible construction label.

! WARNING

CARBON MONOXIDE POISONING / COMPONENT
DAMAGE HAZARD

Failure to follow this warning could result in personal in­jury or death and unit component damage.

Corrosive or contaminated air may cause failure of parts
containing flue gas, which could leak into the living
space. Air for combustion must not be contaminated by
halogen compounds, which include fluoride, chloride,
bromide, and iodide. These elements can corrode heat
exchangers and shorten furnace life. Air contaminants
are found in aerosol sprays, detergents, bleaches, clean­ing solvents, salts, air fresheners, and other household
products. Do not install furnace in a corrosive or contam­inated atmosphere. Make sure all combustion and circu­lating air requirements are met, in addition to all local
codes and ordinances.

The following types of furnace installations may require
OUTDOOR AIR for combustion due to chemical exposures:

• Commercial buildings

• Buildings with indoor pools

• Laundry rooms

• Hobby or craft rooms, and

• Chemical storage areas

If air is exposed to the following substances, it should not be
used for combustion air, and outdoor air may be required for
combustion:

• Permanent wave solutions

• Chlorinated waxes and cleaners

• Chlorine based swimming pool chemicals

• Water softening chemicals

• De−icing salts or chemicals

• Carbon tetrachloride

• Halogen type refrigerants

• Cleaning solvents (such as perchloroethylene)

• Printing inks, paint removers, varnishes, etc.

• Hydrochloric acid

• Cements and glues

• Antistatic fabric softeners for clothes dryers

• Masonry acid washing materials

All fuel−burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal must
be made between the furnace cabinet and the return−air duct
to prevent pulling air from the burner area.

440 01 4201 02 7

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Figure 3 Multipoise Orientations

THE BLOWER IS

LOCATED BELOW THE

BURNER SECTION, AND

CONDITIONED AIR IS

THE BLOWER IS LOCATED

TO THE RIGHT OF THE

BURNER SECTION, AND

AIR CONDITIONED AIR IS

DISCHARGED TO THE LEFT.

DISCHARGED UPWARD.

THE BLOWER IS

LOCATED ABOVE THE

BURNER SECTION, AND

CONDITIONED AIR IS

DISCHARGED DOWNWARD

!

WARNING

FIRE, INJURY OR DEATH HAZARD

Failure to follow this warning could result in personal in­jury, death and/or property damage.

When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least
18−in. (457 mm) above the floor. The furnace must be
located or protected to avoid damage by vehicles. When
the furnace is installed in a public garage, airplane
hangar, or other building having a hazardous atmo­sphere, the furnace must be installed in accordance with
the NFPA 54/ANSI Z223.1−2009 or CAN/CSA
B149.1−2010. (See Figure 4)

Figure 4 Installation in a Garage

THE BLOWER IS

LOCATED TO THE LEFT

OF THE BURNER SECTION,

AND CONDITIONED AIR IS

DISCHARGED TO THE RIGHT.

!

WARNING

FIRE HAZARD

Failure to follow this warning could result in personal in­jury, death and/or property damage.

Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect re­turn−air ducts to the back of the furnace. (See Figure 5)

Figure 5 Prohibited Installations

A10494

A93044

8 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Location Relative to Cooling
Equipment

The cooling coil must be installed parallel with, or on the
downstream side of the unit to avoid condensation in the heat
exchangers. When installed parallel with the furnace, dampers
or other flow control must prevent chilled air from entering the
furnace. If the dampers are manually operated, they must be
equipped with means to prevent operation of either unit unless
the damper is in the full−heat or full−cool position.

Air for Combustion and
Ventilation

Introduction

Direct Vent (2−Pipe) Applications

When the furnace is installed as a direct vent (2-pipe) furnace,
no special provisions for air for combustion are required.
However, other gas appliances installed in the space with the
furnace may require outside air for combustion. Follow the
guidelines below to insure that other gas appliances have
sufficient air for combustion.

Ventilated Combustion Air Applications

When the furnace is installed using the ventilated combustion
air option, the attic or crawlspace must freely communicate with
the outdoor to provide sufficient air for combustion. The
combustion air pipe cannot be terminated in attics or
crawlspaces that use ventilation fans designed to operate
during the heating season. If ventilation fans are present in
these areas, the combustion air pipe must terminate outdoors
as a Direct Vent/ 2-Pipe system.

All air for combustion is piped directly to the furnace from a
space that is well ventilated with outdoor air (such as an attic or
crawlspace) and the space is well isolated from the living space
or garage. In addition, other gas appliances installed in the
space with the furnace may require outside air for combustion.
Follow the guidelines below to insure that the roof or
crawlspace walls have sufficient free area to provide sufficient
air for combustion and ventilation for the furnaces. The
guidelines below can be used to insure that other gas
appliances have sufficient air for combustion.

Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:

• U.S. Installations: Section 9.3 of the NFPA 54/ANSI

Z223.1−2009 , Air for Combustion and Ventilation and
applicable provisions of the local building codes.

• Canadian Installations: Part 8 of

CAN/CSA−B149.1−2010, Venting Systems and Air
Supply for Appliances and all authorities having
jurisdiction.

!

FURNACE CORROSION HAZARD

Failure to follow this caution may result in furnace
damage.

Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide,
and iodide. These elements can corrode heat
exchangers and shorten furnace life. Air contaminants
are found in aerosol sprays, detergents, bleaches,
cleaning solvents, salts, air fresheners, and other
household products.

CAUTION

!

WARNING

CARBON MONOXIDE POISONING HAZARD

Failure to follow this warning could result in personal
injury or death.

The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could
create a NEGATIVE PRESSURE CONDITION at the
furnace. Make−up air MUST be provided for the
ventilation devices, in addition to that required by the
furnace. Refer to the Carbon Monoxide Poisoning
Hazard warning in the venting section of these
instructions to determine if an adequate amount of
make−up air is available.

Figure 6

*Minimum dimensions of 3‐in.

NOTE: Use any of the following combinations

of openings:
A & B C & D D & E F & G

Air for Combustion, Ventilation,
and Dilution for Outdoors

A03174

Outdoor Combustion Air Method

1. Provide the space with sufficient air for proper
combustion, ventilation, and dilution of flue gases using
permanent horizontal or vertical duct(s) or opening(s)
directly communicating with the outdoors or spaces that
freely communicate with the outdoors.

2. Figure 6 illustrates how to provide TWO OUTDOOR
OPENINGS, one inlet and one outlet combustion and
ventilation air openings to the outdoors.

a. One opening MUST commence within 12-in.

(300 mm) of the ceiling and the second opening
MUST commence within 12-in. (300 mm) of the floor.

b. Size openings and ducts per Figure 6 and Table 3.
c. TWO HORIZONTAL DUCTS require 1 square inch

(25.4 square mm) of free area per 2,000 Btuh (1,100

2

mm

/kW) of combined input for all gas appliances in

the space per Figure 6 and Table 3.

440 01 4201 02 9

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

d. TWO OPENINGS OR VERTICAL DUCTS require 1

square inch (25.4 square mm)of free area per 4,000
Btuh (550 mm
appliances in the space per Figure 6 and Table 3.

3. ONE OUTDOOR OPENING requires:
a. 1 sq. in. (25.4 square mm)of free area per 3,000 Btuh

(734 mm
appliances in the space per Table 3 and

2

/kW) for combined input of all gas

2

/kW) for combined input of all gas

b. Not less than the sum of the areas of all vent

connectors in the space.

The opening shall commence within 12-in. (300 mm) of the
ceiling. Appliances in the space shall have clearances of at
least 1-in. (25 mm) from the sides and back and 6-in. (150 mm)
from the front. The opening shall directly communicate with the
outdoors or shall communicate through a vertical or horizontal
duct to the outdoors or spaces (crawl or attic) that freely
communicate with the outdoors.

Table 3 Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors

TWO OPENINGS OR

VERTICAL DUCTS

(1 SQ. IN./4,000 BTUH)

(550 SQ. MM/KW)

Free Area of Open-

ing and Duct

Sq. In (mm)

Round Duct

In. (mm)

FURNACE

INPUT

(BTUH)

60,000

80,000
100,000
120,000

140,000 *

TWO HORIZONTAL DUCTS

(1 SQ. IN./2,000 BTUH)

(1,100 SQ. MM/KW)

Free Area of

Opening and Duct

Sq. In (Sq. mm)

30 (19355) 6 (152) 20 (13043) 5 (127) 15 (9678) 5 (127)
40 (25807) 7 (178) 27 (17391) 6 (152) 20 (12904) 5 (127)
50 (32258) 8 (203) 34 (21739) 7 (178) 25 (16130) 6 (152)
60 (38709) 9 (229) 40 (26087) 7 (178) 30 (19355) 6 (152)
70 (45161) 10 (254) 47 (30435) 8 (203) 35 (22581) 7 (178)

Round

Duct

In. (mm)

Dia

SINGLE DUCT OR OPENING

(1 SQ. IN./3,000 BTUH)

(734 SQ. MM/KW)

Free Area of Open-

ing and Duct

Sq. In (Sq. mm)

Round

Duct

In. (mm)

Dia

EXAMPLE: Determining Free Area

FURNACE WATER HEATER TOTAL INPUT

100,000 + 30,000 = (130,000 divided by 4,000) = 32.5 Sq. In. for each two Vertical Ducts or Openings

60,000 + 40,000 = (100,000 divided by 3,000) = 33.3 Sq. In. for each Single Duct or Opening
80,000 + 30,000 = (110,000 divided by 2,000) = 55.0 Sq. In. for each two Horizontal Ducts

Dia.

Table 4 Minimum Space Volumes for 100% Combustion, Ventilation and Dilution Air from Outdoors

OTHER THAN FAN‐ASSISTED TOTAL

(1,000'S BTUH GAS INPUT RATE)

ACH

0.60

0.50

0.40

0.30

0.20

0.10

0.00

NP = Not Permitted

30 40 50 40 60 80 100 120 140

1,050
(29.7)

1,260
(35.6)

1,575
(44.5)

2,100
(59.4)

3,150
(89.1)

6,300

(178.0)

NP NP NP NP NP NP NP NP NP

1,400
(39.6)

1,680
(47.5)

2,100
(59.4)

2,800
(79.2)

4,200

(118.9)

8,400

(237.8)

CONDENSATE TRAP

!

CAUTION

1,750

(49.5)

2,100
(59.4)

2,625
(74.3)

3,500
(99.1)

5,250

(148.6)
10,500

(297.3)

Space Volume Ft

1,400
(39.6)

1,680
(47.5)

2,100
(59.4)

2,800
(79.2)

4,200

(118.9)

8,400

(237.8)

1,500
(42.5)

1,800
(51.0)

2,250
(63.7)

3,000
(84.9)

4,500

(127.3)

9,000

(254.6)

PROPERY DAMAGE HAZARD

FAN‐ASSISTED TOTAL

(1,000'S BTUH GAS INPUT RATE)

3

3

(M

)

2,000

(56.6)

2,400

(67.9)

3,000

(84.9)

4,000

(113.2)

6,000

(169.8)
12,000

(339.5)

!

2,500
(70.8)

3,000
(84.9)

3,750

(106.1)

5,000

(141.5)

7,500

(212.2)
15,000

(424.4)

CAUTION

3,000
(84.9)

3,600

(101.9)

4,500

(127.3)

6,000

(169.8)

9,000

(254.6)
18,000

(509.2)

Failure to follow this caution may result in burst water

FROZEN AND BURST WATER PIPE HAZARD

Failure to protect against the risk of freezing may result
in property damage.

Special precautions MUST be made if installing furnace
in an area which may drop below freezing. This can
cause improper operation or damage to equipment. If
furnace environment has the potential of freezing, the
drain trap and drain line must be protected. The use of
electric heat tape or RV antifreeze is recommended for
these installations.

pipes and/or property damage.
If a condensate pump is installed, a plugged condensate

drain or a failed pump may cause the furnace to shut
down. Do not leave the home unattended during freezing
weather without turning off water supply and draining
water pipes or otherwise protecting against the risk of
frozen pipes.

DO NOT trap the drain line in any other location than at the
condensate drain trap supplied with the furnace. If possible, DO
NOT route the drain line where it may freeze. The drain line

3,500
(99.1)

4,200

(118.9)

5,250

(148.6)

7,000

(198.1)
10,500

(297.1)
21,000

(594.1)

10 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

must terminate at an inside drain to prevent freezing of the
condensate and possible property damage.

Special precautions MUST be made if installing furnace in an
area which may drop below freezing. This can cause improper
operation or damage to the equipment. If the furnace
environment has the potential of freezing, the drain trap and
drain line must be protected. Use 3 to 6 watt per foot of 115
volt, 40° F (4° C) self−regulating shielded and water proof heat
tape. Wrap the drain trap and drain line with the heat tape and
secure with the ties. Follow the heat tape manufacturer’s
recommendations. Prime the trap before furnace operation.

Condensate Trap − Upflow Orientation

When the furnace is installed in the upflow position, it is not
necessary to relocate the condensate trap or associated
tubing. Refer to Figure 7 for upflow condensate trap
information. Refer to Condensate Drain section for information
how to install the condensate drain.

Figure 7 Upflow Trap Configuration

Condensate Trap

Relief Port

Collector Box

Plugs

Condensate Trap − Downflow
Orientation

When the furnace is installed in the downflow position, the
factory-installed trap will be located at the upper left corner of
the collector box. When the furnace is installed in the downflow
orientation, the factory-installed trap must be relocated for
proper condensate drainage.

To Relocate the Condensate Trap:

 Orient the furnace in the downflow position.
 Figure 8 shows the condensate trap and tubing before and

after relocation. Refer to Figure 8 to begin the trap conversion.

 Refer to Condensate Drain section for information how to install

the condensate drain.

Vent Pipe Clamp

Vent Elbow Clamp

Vent Elbow

Pressure Switch

Port

Collector Box

Plug

Condensate Trap

Relief Port

Condensate Trap

Outlet

A11306Representative drawing only, some models may vary in appearance.

440 01 4201 02 11

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Figure 8 Unconverted Factory Configuration as viewed in the Downflow Orientation

Remove pressure switch tube from
pressure switch port.

Remove relief tube from relief
port on condensate trap.

Remove trap from
collector box.

Loosen clamp on inlet
to vent elbow.

Install plugs on
open ports on
collector box.

Connect relief tube to
port on collector box.

Rotate elbow to
desired position and

9

tighten clamp to
15 lb.−in.

Slide tube in stand−offs
to adjust length.

Representative drawing only, some models may vary in appearance.

Downflow Trap Configuration

Remove tube from
relief port.

Remove middle and bottom plugs.
DO NOT DISCARD.

Trim excess tube.

7

Connect pressure switch
tube to port on collector
box.

Attach condensate trap
with screw to collector
box.

Connect relief tube to
relief port on condensate
trap.

Align condensate trap
over middle and bottom
ports of collector box.

A11585A

Representative drawing only, some models may vary in appearance.

Condensate Trap − Horizontal
Orientation

When the furnace is installed in the horizontal right position, the
factory-installed trap will be located at the bottom of the collector
box. When the furnace is installed in the horizontal left position,
the factory-installed trap will be located at the top of the collector
box. The trap must be repositioned on the collector box for proper
condensate drainage.

When the furnace is installed as a direct−vent furnace, a field
supplied, accessory Horizontal Installation Kit (trap grommet) is
required for all direct−vent horizontal installations (only). The kit
contains a rubber casing grommet designed to seal between the
furnace casing and the condensate trap. (See Figure 16)

NOTE: The Horizontal Installation Kit (trap grommet) is NOT
required for single−pipe, ventilated combustion air, or other
non−direct vent applications.

NOTE: The condensate trap extends below the side of the
casing in the horizontal position. A minimum of 2 in. (51 mm) of
clearance is required between the casing side and the furnace
platform for the trap to extend out of the casing in the horizontal
position. Allow at least 1/4−in. (6 mm) per foot of slope away
from the furnace in horizontal sections of drain line.

To Relocate the Condensate Trap:

 Remove the knockout in the casing for the condensate trap.
 Install the grommet in the casing when required.

NOTE: This grommet is only required for direct−vent
applications

A11585B

 Orient the furnace in the desired position.

12 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

 Allow for 2 in. (51 mm) of clearance underneath the furnace for

the condensate trap and drain line.

 Figure 9 shows the condensate trap and tubing before and

after relocation in the horizontal right position.

after relocation in the horizontal left position.

 Refer to the appropriate figure to begin the trap conversion.
 Refer to Condensate Drain section for information how to install

the condensate drain.

 Figure 10 shows the condensate trap and tubing before and

Figure 9 Unconverted Factory Configuration as viewed in the Horizontal Left Orientation

Remove trap from

If alternate vent position
is required, loosen clamp
on vent elbow inlet.

collector box.

Remove relief tube
from relief port on
condensate trap.

Remove pressure switch tube
from port on collector box.

Remove relief tube
from port on collector
box.

Representative drawing only, some models may vary in appearance.

Rotate elbow to
desired position and
torque clamp on inlet
15 lb.−in.

Slide relief tube in
stand−offs to adjust
length.

Attach condensate
trap to collector box
with screw.

Align trap over middle
and right−hand port on
collector box.

Representative drawing only, some models may vary in appearance.

Horizontal Left Trap Configuration

Remove middle and right
plug from collector box.
DO NOT DISCARD

Install plugs in open
ports on collector box.

Connect relief tube to
port on collector box.

Trim excess tube.
Route pressure switch tube
underneath relief tube and
connect to port on collector box.

Connect relief tube to
relief port on condensate
trap.

A11586A

A11586B

440 01 4201 02 13

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Figure 10 Unconverted Factory Configuration as viewed in the Horizontal Right Orientation

Remove plug from
collector box.
DO NOT DISCARD.

If alternate vent position
is required, loosen clamp
on inlet of vent elbow.

Remove trap from
collector box.

Representative drawing only, some models may vary in appearance.

Horizontal Right Trap Configuration

Attach condensate trap
to collector box with
screw.

Install plug in open
port on collector box.

Representative drawing only, some models may vary in appearance.

Slide relief tube in
stand-offs to adjust
length.

Vent elbow shown in alternate
orientation. Tighten clamp on
inlet to vent elbow 15 lb.-in.

Align trap over middle and
right-hand port on collector box.

A11281

14 440 01 4201 02

Specifications subject to change without notice.

INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC

Condensate Drain Connection

!

FROZEN AND BURST WATER PIPE HAZARD

Failure to protect against the risk of freezing may result
in property damage.

Special precautions MUST be made if installing furnace
in an area which may drop below freezing. This can
cause improper operation or damage to equipment. If
furnace environment has the potential of freezing, the
drain trap and drain line must be protected. The use of
electric heat tape or RV antifreeze is recommended for
these installations.

!

PROPERY DAMAGE HAZARD

Failure to follow this caution may result in burst water
pipes and/or property damage.

If a condensate pump is installed, a plugged condensate
drain or a failed pump may cause the furnace to shut
down. Do not leave the home unattended during freezing
weather without turning off water supply and draining
water pipes or otherwise protecting against the risk of
frozen pipes.

DO NOT trap the drain line in any other location than at the
condensate drain trap supplied with the furnace. If possible, DO
NOT route the drain line where it may freeze. The drain line
must terminate at an inside drain to prevent freezing of the
condensate and possible property damage.

Special precautions MUST be made if installing furnace in an
area which may drop below freezing. This can cause improper
operation or damage to the equipment. If the furnace
environment has the potential of freezing, the drain trap and
drain line must be protected. A self−regulating, shielded and
waterproof heat tape rated at 3 to 6 watt per foot of 115 volt,
40° F (4° C) may be used to help provide freeze protection.
Wrap the drain trap and drain line with the heat tape and
secure with the ties. Follow the heat tape manufacturer’s
recommendations. Prime the trap before furnace operation.

Upflow/Downflow Orientation

In the Upflow or Downflow orientation, the condensate trap is
inside the furnace casing. The condensate drain must be
routed from the trap through the furnace casing. The
condensate drain can be routed through the left or right side of
the casing. (The left or right side is as you are viewing/facing
the furnace from the front.) The furnace condensate drain can
be connected to the Air Conditioning condensate drain as
shown in Figure 11.

NOTE: On narrower casings, it may be easier to remove the
condensate trap, connect the drain line components and
re-install the condensate trap. Read the steps thoroughly to
familiarize yourself with the required steps.

For Right Side Condensate Drain:

1. Remove the 7/8−in. knock−out from the right side of the

casing. (See Figure 12)

2. Remove the pre−formed rubber drain tube and two
spring clamps from the loose parts bag.

3. Slide a spring clamp 1 in. (25 mm) down the plain end
(the end without the formed grommet) of the drain tube.

CAUTION

CAUTION

4. From inside the casing, insert the formed grommet end
of the elbow through the 7/8−in. knockout in the casing.

5. Pull the grommet through the casing from the outside
until it is seated in the knockout

6. Attach the plain end of the drain tube to the outlet stub
on the drain trap. Secure the drain tube to the trap with
the spring clamp.

The remaining drain line can be constructed from field supplied
1/2−in. CPVC or 3/4−in. PVC pipe in compliance with local
building codes. A factory−supplied 1/2−in. CPVC to 3/4−in PVC
adapter is supplied in the loose parts bag for use as required.

7. Install the adapter or connect the 1/2−in. CPVC pipe by
sliding a spring clamp over the open end of the grommet
on the outside of the furnace casing.

8. Open the spring clamp and insert the long end of the
adapter of the 1/2−in. CPVC pipe into the outlet stub on
the drain tube.

9. Connect additional condensate piping to a
code−approved drain, or to a condensate pump
approved for use with acidic furnace condensate and
compatible with mineral and vegetable oils, such as
canola oil.

NOTE: Allow at least 1/4−in. (6mm) per foot of slope away
from the furnace in horizontal sections of drain line.

Figure 11 Example of Field Drain Attachment

OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN

TEE

TO OPEN
DRAIN

A11276

For Left Side Condensate Drain Connection:

1. For left side condensate drainage, the drain line is routed
from the condensate trap, behind the inducer (upflow) or
gas valve (downflow) and out through the left side of the
furnace casing. A pre-formed 1/2−in. CPVC “Z” pipe is
provided with the furnace. The “Z“ pipe is long enough to
extend across the casing for drain connections.

2. The “Z” pipe is connected to the condensate trap and the
outside of the furnace by modifying the formed rubber

drain tube as shown in Figure 13.

3. Locate the “Z” pipe. Remove the pre-formed drain tube
and four spring clamps from the loose parts bag.

4. Remove the formed grommet from the rubber drain tube
by cutting the elbow along the vertical line located about
1 3/8−in. (35 mm) away from the formed grommet. See
Figure 12. DO NOT DISCARD THE FORMED
GROMMET OR THE RUBBER ELBOW. Both of these
pieces will be used.

440 01 4201 02 15

Specifications subject to change without notice.