Page 1
Printed in U.S.A. 440 01 4201 01 Sept. 2011
INSTALLATION INSTRUCTIONS
Modulating, 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.
!
WARNING
Signal Words in Manuals
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.
The signal word WARNING is used throughout
this manual in the following manner:
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 PROCEDURE 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 18.....................................
HORIZONTAL INSTALLATION 20.....................................
FILTER ARRANGEMENT 23........................................
AIR DUCTS 25..................................................
GAS PIPING 25.................................................
ELECTRICAL CONNECTIONS 27.....................................
J−BOX INSTALLATION 27.........................................
VENTING 31...................................................
SPECIAL VENTING REQUIREMENTS FOR INSTALLATIONS IN CANADA 31.......
DIRECT VENT / 2−PIPE SYSTEM 32..................................
VENTILATED COMBUSTION AIR SYSTEMS 32...........................
TERMINATION REQUIREMENTS FOR THE
PROVINCES OF ALBERTA AND SASKATCHEWAN 37......................
INSTALLING THE VENT TERMINATION 42..............................
MAXIMUM EQUIVALENT VENT LENTH - FEET (METERS) 46.................
MAXIMUM ALLOWABLE EXPOSED VENT LENGTHS IN UNCONDITIONED SPACE 47
MAXIMUM
LENGTH OF UNINSULATED AND INSULATED VENT PIPE-FT (M) 47....
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.
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.
Page 2
440 01 4201 01
Specifications are subject to change without notice.
2
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
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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 01 3
Specifications subject to change without notice.
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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 (2−pipe) furnace. (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:
MAX 80°F/27°C
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 01
Specifications subject to change without notice.
Page 5
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 Pressure Switch Tube
1
1 Drain Tube Elbow
1 Drain Extension Tube
2 Drain Tube Clamps
1 Drain Line Grommet
1 Gas Line Grommet
1 Gas Line Knockout Plug
1 Junction Box Cover
1 Junction Box Base
1 Green Ground Screw
3 Blunt Tip Screws (Junction Box)
1 Thermostat Wire Grommet
Loose Parts Bag Contents
(shipped in blower compartment)
Outlet Choke Plate (used with 40k BTUH
furnaces, only)
440 01 4201 01 5
Specifications subject to change without notice.
Page 6
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 2 Dimensions
(F/G9MAC)
FURNACE SIZE
60,000 17−1/2 (445) 15−7/8 (403) 16 (406) 8 3/4 (222) 154 (69)
80,000 17−1/2 (445) 15−7/8 (403) 16 (406) 8 3/4 (222) 164 (73)
100,000 21 (533) 19−3/8 (492) 19−1/2 (495) 10 1/2 (267) 179 (80)
120,000 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: Doors may vary by model.
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 of 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 01
Specifications subject to change without notice.
Page 7
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 the following 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 01 7
Specifications subject to change without notice.
Page 8
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
8 440 01 4201 01
A10494
A93044
Specifications subject to change without notice.
Page 9
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 01 9
Specifications subject to change without notice.
Page 10
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
2
/kW) for combined input of all gas
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
2
/kW) for combined input of all gas
appliances in the space per Table 3 and
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 HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH)
FURNACE
INPUT
(BTUH)
(1,100 SQ. MM/KW)
Free Area of
Opening and Duct
Sq. In (Sq. mm)
40,000 *
60,000
80,000
100,000
120,000
140,000 *
20 (12904) 5 (127) 14 (8696) 5 (127) 10 (6452) 4 (102)
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)
* Not all families have these models.
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
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)
EXAMPLE: Determining Free Area
Round Duct
In. (mm)
Dia.
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
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
Space Volume Ft
1,050
(29.7)
1,260
(35.6)
1,575
(44.5)
2,100
(59.4)
3,150
(89.1)
6,300
(178.0)
1,400
(39.6)
1,680
(47.5)
2,100
(59.4)
2,800
(79.2)
4,200
(118.9)
8,400
(237.8)
1,750
(49.5)
2,100
(59.4)
2,625
(74.3)
3,500
(99.1)
5,250
(148.6)
10,500
(297.3)
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)
NP NP NP NP NP NP NP NP NP
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)
3,000
(84.9)
3,600
(101.9)
4,500
(127.3)
6,000
(169.8)
9,000
(254.6)
18,000
(509.2)
CONDENSATE TRAP
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.
1. Loosen the clamp around the inlet of the vent elbow on
the inducer.
2. Rotate the vent elbow to the desired position and tighten
the clamp 15 in.−lbs.
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.
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 01
Specifications subject to change without notice.
Page 11
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 7 Upflow Trap Configuration
Condensate Trap
Vent Pipe Clamp
Relief Port
Vent Elbow Clamp
Collector Box
Plugs
To Relocate the Condensate Trap:
1. Orient the furnace in the downflow position.
2. Figure 8 shows the condensate trap and tubing before
and after relocation.
3. Refer to the appropriate figure to begin the trap
conversion.
4. Remove the relief tube from the condensate trap.
5. Remove the screw that secures the condensate trap to
the collector box.
6. Remove the trap.
7. Remove the relief tube from of the port on the collector
box. It is not necessary to remove the hose from the
inducer assembly.
8. Remove the pressure switch tube from the port on the
collector box.
9. Remove the pressure switch tube from the stand−offs on
the inducer assembly
10. Loosen the clamp around the inlet of the vent elbow on
the inducer.
11. Remove the middle and bottom plugs from the lower
right side of the collector box and set aside. Do Not
Discard Plugs.
Vent Elbow
Collector Box
Plug
Condensate Trap
Relief Port
Condensate Trap
Pressure Switch
Port
Outlet
A11306Representative drawing only, some models may vary in appearance.
12. Refer to the appropriate figure to begin the trap
conversion.
13. Install the two (2) plugs previous removed from the
collector box in the ports where the condensate trap was
removed.
14. Install the trap over the ports on the lower right side of
the collector box.
15. Secure the trap to the collector box with the screw.
16. Connect the relief tube to the condensate trap to the
relief port of the condensate trap.
17. If necessary, slide the relief tube in the inducer
stand−offs to adjust the position of the tube.
18. Connect the relief tube to the relief port of the
condensate trap.
19. Route the pressure switch tube to the port on the
collector box next to the condensate trap. Trim off any
excess tube to avoid sags or kinks in the tube.
20. Rotate the vent elbow to the desired position and tighten
the clamp 15 in.−lbs.
21. Refer to Condensate Drain section for information how to
install the condensate drain.
440 01 4201 01 11
Specifications subject to change without notice.
Page 12
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 8 Unconverted Factory Configuration as viewed in the Downflow orientation
Remove pressure switch tube from
front of pressure switch.
Remove relief tube from relief
port on condensate trap.
Remove trap from
collector box.
Loosen clamp on inlet
to vent elbow.
Remove tube from
relief port.
Remove middle and bottom plugs.
DO NOT DISCARD.
Representative drawing only, some models may vary in appearance.
Downflow Trap Configuration
Condensate Trap−Horizontal
Orientation
When the furnace is installed in the horizontal right position, the
factory−installed trap will be located at the bottom left corner of
the collector box. When the furnace is installed in the horizontal
left position, the factory−installed trap will be located at the top
12 440 01 4201 01
Representative drawing only, some models may vary in appearance.
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 is required for all
horizontal installations. The kit contains a rubber casing
grommet designed to seal between the furnace casing and the
condensate trap. (See Figure 9)
Specifications subject to change without notice.
A11277
Page 13
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 9 Drain Trap Grommet
Remove knockout
Install grommet before
relocating condensate
trap
Horizontal Drain Trap Grommet
A11348
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. In areas where the ambient temperature will fall below
32° F. (0°C), a field−supplied condensate freeze protection kit is
required. See Product Data for current kit offering. Follow the
instructions included in the kit.
To Relocate the Condensate Trap:
1. Remove the knockout in the casing for the casing
grommet.
2. Install the grommet in the casing.
NOTE: This grommet is only required for direct−vent
applications.
3. Orient the furnace in the desired position.
4. Allow for 2−in. (51 mm) of clearance underneath the
furnace for the condensate trap and drain line.
5. Figure 10 shows the condensate trap and tubing before
and after relocation in the horizontal left position.
6. Figure 11 shows the condensate trap and tubing before
and after relocation in the horizontal right position.
7. Refer to the appropriate figure to begin the trap
conversion.
8. Remove the relief tube from the condensate trap.
9. Remove the screw that secures the condensate trap to
the collector box.
10. Remove the trap.
Horizontal Left only:
1. Remove the relief tube from of the port on the collector
box. It is not necessary to remove the hose from the
inducer assembly.
2. Remove the pressure switch tube from the port on the
collector box.
3. Remove the pressure switch tube from the stand−offs on
the inducer assembly.
For Horizontal Right only:
1. The pressure switch tube location is not modified.
2. Loosen the clamp around the inlet of the vent elbow on
the inducer.
3. Remove the plugs from the collector box and set aside.
Do Not Discard Plugs.
For Horizontal Left only:
1. Remove the middle and right plug from the ports at the
bottom of the collector box.
For Horizontal Right only:
1. Remove the plug to the right of the condensate trap.
2. Refer to the appropriate figure to begin the trap
conversion.
3. Install the plugs previous removed from the collector box
in the ports where the condensate trap was removed.
4. Install the trap over the ports on the lower side of the
collector box.
5. Secure the trap to the collector box with the screw.
6. Connect the relief tube to the condensate trap to the
relief port of the condensate trap.
7. If necessary, slide the relief tube in the inducer
stand−offs to adjust the position of the tube.
For Horizontal Left only:
1. Connect the relief tube to the relief port of the
condensate trap.
2. Connect the pressure switch tube to the port on the
collector box next to the condensate trap. Trim off any
excess tube to avoid sags or kinks in the tube.
3. Rotate the vent elbow to the desired position and tighten
the clamp 15 in.−lbs.
4. Refer to Condensate Drain section for information how to
install the condensate drain.
440 01 4201 01 13
Specifications subject to change without notice.
Page 14
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 10 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.
Remove relief tube
from port on collector
box.
collector box.
Remove relief tube
from relief port on
condensate trap.
Remove pressure switch tube
from port on collector box.
Remove middle and right
plug from 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
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.
A11282
14 440 01 4201 01
Specifications subject to change without notice.
Page 15
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 11 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.
Condensate Drain Protection
Freezing condensate left in condensate trap and drain line may
cause cracks, and possible water damage may occur. Freeze
protection of the condensate trap is required when the furnace
is installed in the horizontal position and the attic temperature is
below 32° F (0° C).
If freeze protection for the condensate trap is required, use
condensate freeze protection accessory.
See Product Data for current kit offering.
The remaining condensate drain line can be protected by using
a 3 to 6 watt per ft. (.3M) at 120v and 40°F (4.4°C)
self-regulating, shielded, and waterproof heat tape. Wrap field
drain pipe with heat tape, approximately 1 wrap per ft. (.3M).
Follow manufacturer’s recommendations and installation
instructions supplied with heat tape.
440 01 4201 01 15
Align trap over middle and
right-hand port on collector box.
Representative drawing only, some models may vary in appearance.
Condensate Drain Connection
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 the
furnace.) The furnace condensate drain can be connected to
the Air Conditioning condensate drain as shown in Figure 12.
NOTE: On narrower casing, 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.
Specifications subject to change without notice.
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.
A11281
Page 16
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 12 Example of Field Drain Attachment
OPEN STAND
PIPE FOR
A/C OR
HUMIDIFIER
DRAIN
TEE
TO OPEN
DRAIN
A11276
For Right Side Condensate Drain:
1. Remove the 7/8−in. knock−out from the right side of the
casing. (See Figure 15)
2. Remove the pre−formed drain tube and two spring
clamps from the loose parts bag.
3. Slide a spring clamp 1−in. down the plain end of the
drain tube.
4. From inside the casing, insert the formed grommet end
of the tube through the 7/8−in. knockout in the casing.
5. Pull the tube 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.
7. Slide a spring clamp over the open end of the drain tube
outside the casing.
8. Open the spring clamp and connect a field−supplied
1/2−in. CPVC street elbow to the open end of the drain
tube.
9. Connect additional 1/2−in. CPVC piping to a condensate
pump approved for use with acidic furnace condensate
or to a code−approved drain.
For Left Side Condensate Drain Connection:
1. For left side condensate drainage, the drain line is routed
from the condensate trap, behind the inducer and out
through the left side of the casing. A pre-formed “Z” pipe
is provided in the loose parts bag shipped with the
furnace. The “Z” pipe is long enough to extend out of the
casing on the 14 3/16-in. (360 mm) wide furnace. Larger
casings will require a field supplied CPVC pipe and to
extend the drain line out of the furnace.
2. The “Z” pipe is connected to the condensate trap by
modifying the formed rubber drain tube. Connect the
drain line as shown below:
3. Remove the knock−out from the left side of the casing.
(See Figure 15)
4. Install the grommet for the 1/2−in. CPVC drain line in the
7/8−in. knockout in the casing.
5. Remove the pre−formed drain tube, the offset 1/2−in.
CPVC pipe and two spring clamps from the loose parts
bag.
6. Remove the formed grommet on the tube by cutting the
tube along the vertical line located about 1−in. away from
the formed grommet. (See Figure 13)
Figure 13 Modify Drain Tube
Cut and remove formed end of
drain tube for left side and horizontal
drain connection
RIGHT SIDE DRAIN ELBOW
A11388
7. Slide a spring clamp 1−in. down the plain end of the
drain tube
8. With the bend in the tube oriented horizontally and plain
end of the tube pointing away from you, insert the 1/2−in
CPVC pipe into the other end of the drain tube. Rotate
the tube so the offset in the tube points away from you.
Slide a spring clamp over the open end of the 1/2−in.
CPVC tube and secure the cut end of drain tube to the
pipe. (See Figure 14)
Figure 14 Drain Trap Connection and Routing
Attach tube to condensate trap
Cut formed end o
condensate drain tube
Field supplied 1/2” CPVC
coupling & drain extension
17 1/2“, 21” and 24 1/2” casing
Field supplied 1/2”
CPVC to drain
Casing grommet from
loose parts bag
9. Prime the bare end of the pipe with CPVC primer.
10. Route the offset pipe behind the inducer assembly and
through the grommet in the casing, if the “Z” pipe is long
enough. If the “Z” pipe is not long enough, continue with
installation.
11. 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.
Connect short end
of “Z” pipe to modied
drain tube
TRAP, DRAIN ELBOW WITH DISCHARGE PIPE
Modied drain tube connect to
condensate trap and “Z” pipe
Field-supplied 1/2” CPVC coupling & drain
pipe 17 1/2“, 21” and 24 1/2” casings
LEFT SIDE DRAIN ROUTED BEHIND INDUCER
A11344
16 440 01 4201 01
Specifications subject to change without notice.
Page 17
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
12. If the “Z” pipe does not extend through the casing, slide a
piece of field supplied CPVC through the grommet in the
casing, otherwise, go to Step 17.
13. Cement a 1/2-in. CPVC coupling to the end of the CPVC
pipe.
14. Apply cement to the end of the “Z” pipe connected to the
condensate trap.
15. Connect the field-supplied CPVC pipe to the CPVC pipe
connected to the condensate trap.
16. Cut off excess CPVC pipe outside the casing.
17. Connect additional 1/2-in. CPVC piping to a condensate
pump approved for use with acidic furnace condensate
or to a code-approved drain.
18. When a condensate pump is not used, slope the pipe
away from the furnace to allow for proper drainage.
Figure 15 Knockout Removal
7. Slide the other spring clamp down the plain end of the
drain tube.
8. Connect additional 1/2−in. CPVC piping to the open end
of the tube.
9. Slide the spring clamp down over the 1/2−in. CPVC pipe.
10. Connect additional 1/2−in. CPVC piping to a condensate
pump approved for use with acidic furnace condensate
or to a code−approved drain.
11. When a condensate pump is not used, slope the pipe
away from the furnace to allow for proper drainage.
Figure 16 Formed Tube Grommet
INSTALL CLAMPS ON DRAIN TUBE
ATTACH DRAIN TUBE TO CONDENSATE
DRAIN TRAP
PULL DRAIN STUB
THROUGH CASING
A11305
!
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.
Horizontal Orientation
1. In the Horizontal orientation, a field supplied accessory
drain trap grommet is required to seal the gap between
the casing and the condensate trap for direct vent
applications only. The condensate trap outlet extends 2
inches (51 mm) below the furnace casing. To allow for
servicing the trap, the condensate drain tube in the loose
parts bag can be modified to make a coupler to allow for
future service of the condensate trap and drain line.
2. Remove the knock-out for the condensate trap in the
side of the casing.
3. Install the drain trap grommet in the casing (for direct
vent applications). If necessary, remove the trap, install
the grommet and re-install the trap.
4. Remove the pre-formed drain tube, the offset 1/2-in.
CPVC pipe and two spring clamps from the loose parts
bag.
5. Remove the formed grommet on the tube to create an
elbow or straight connector. (See Figure 16)
6. Connect the cut tube to the outlet of the condensate trap
with 1 spring clamp.
A11342
INSTALLATION
UPFLOW INSTALLATION
NOTE: The furnace must be pitched forward as shown in
Figure 17 for proper condensate drainage.
Figure 17 Furnace Pitch Requirements
LEVEL 0-IN. (0 MM) TO
1/2-IN. (13 MM) MAX
MIN 1/4-IN. (6 MM) TO
1/2-IN. (13 MM) MAX
UPFLOW OR
DOWNFLOW
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct
shall be provided with a removable access panel. This opening
shall be accessible when the furnace is installed and shall be of
such a size that the heat exchanger can be viewed for possible
HORIZONTAL
A11237
440 01 4201 01 17
Specifications subject to change without notice.
Page 18
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
openings using light assistance or a probe can be inserted for
sampling the air stream. The cover attachment shall prevent
leaks.
Connect supply−air duct to flanges on furnace supply−air
outlet. Bend flange upward to 90 with wide duct pliers. (See
Figure 21) The supply−air duct must be connected to ONLY
the furnace supply−outlet−air duct flanges or air conditioning
coil casing (when used). DO NOT cut main furnace casing side
to attach supply air duct, humidifier, or other accessories. All
accessories MUST be connected to duct external to furnace
main casing.
Return Air Connections
!
FIRE HAZARD
A failure to follow this warning could cause personal
injury, death and/or property damage.
Never connect return−air ducts to the back of the
furnace. Follow instructions below.
The return−air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Figure 26, Figure 27 and Figure 28.
Bypass humidifier may be attached into unused return air side
of the furnace casing.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. Remove this panel when bottom
return air is used. This panel may be used as the bottom
closure of an accessory bottom return air box or discarded. To
remove bottom closure panel, perform the following:
1. Tilt or raise furnace and remove four (4) screws holding
bottom plate. (See Figure 18)
2. Remove bottom plate.
3. Remove bottom closure panel.
4. Reinstall bottom plate and screws.
Figure 18 Removing Bottom Closure Panel
WARNING
Leveling Legs (If Desired)
In upflow position with side return inlet(s), leveling legs may be
used. (See Figure 19) Install field−supplied, 5/16 x 1−1/2 in. (8
x 38 mm) (max) corrosion−resistant machine bolts, washers
and nuts.
Figure 19 Leveling Legs
A89014
NOTE: Bottom closure must be used when leveling legs are
used. It may be necessary to remove and reinstall bottom
closure panel to install leveling legs. To remove bottom closure
panel, see Step 1 in Bottom Return Air Inlet section.
To install leveling legs:
1. Position furnace on its back. Locate and drill a hole in
each bottom corner of furnace.
2. For each leg, install nut on bolt and then install bolt with
nut in hole. (Install flat washer if desired.)
3. Install another nut on other side of furnace base. (Install
flat washer if desired.)
4. Adjust outside nut to provide desired height, and tighten
inside nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
DOWNFLOW INSTALLATION
NOTE: The furnace must be pitched forward as shown in
Figure 17 for proper condensate drainage.
BOTTOM
PLATE
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. This panel MUST be in place
when only side return air is used.
NOTE: Side return−air openings can be used in UPFLOW and
most HORIZONTAL configurations. Do not use side return−air
openings in DOWNFLOW configuration. (See Figure 26,
Figure 27 and Figure 28)
18 440 01 4201 01
Supply Air Connections
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following
three accessories are used (see Specification sheets for list of
approved accessories):
• Special Base − NAHA01101SB
L11F004
Specifications subject to change without notice.
• Cased Coil Assembly − END4X, ENW4X
1. Determine application being installed from Table 5.
2. Construct hole in floor per Table 5 and Figure 20.
3. Construct plenum to dimensions specified in Table 5
4. Install as shown in Figure 22. If Coil Assembly Part is
and Figure 20.
used, install as shown in Figure 23 .
Page 19
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 20
NOTE: It is recommended that the perforated supply−air duct
flanges be completely removed from furnace when installing
the furnace on a factory−supplied cased coil. To remove the
supply−air duct flange, use wide duct pliers or hand seamers to
bend flange back and forth until it breaks off. Be careful of
sharp edges. (See Figure 21)
!
Floor and Plenum Opening
Dimensions
A96283
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.
Figure 21 Duct Flanges
UPFLOW DOWNFLOW HORIZONTAL
PERFORATED
DISCHARGE DUCT
FL ANGE
90 90
Connect supply−air duct to supply−air outlet on furnace. Bend
flange inward past 90 with wide duct pliers (See Table 1
Figure 21) The supply−air duct must be connected to ONLY
the furnace supply outlet or air conditioning coil casing (when
used). When installed on combustible material, supply−air duct
must be connected to ONLY the factory−approved accessory
subbase, or a factory−approved air conditioning coil casing. DO
NOT cut main furnace casing to attach supply side air duct,
humidifier, or other accessories. All accessories MUST be
connected to duct external to furnace casing.
Return Air Connections
!
FIRE HAZARD
A failure to follow this warning could cause personal
injury, death and/or property damage.
Never connect return−air ducts to the back of the
furnace. Follow instructions below.
The return−air duct must be connected to return−air opening
(bottom inlet) as shown in Figure 26. DO NOT cut into casing
sides (left or right). Bypass humidifier connections should be
made at ductwork or coil casing sides exterior to furnace. (See
Figure 26)
WARNING
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. Remove and discard this panel
when bottom return air is used in downflow applications. To
remove bottom closure panel, perform the following:
1. Tilt or raise furnace and remove four (4) screws holding
bottom plate panel. (See Figure 18)
2. Remove bottom plate.
3. Remove bottom closure panel.
4. Reinstall bottom plate and screws.
440 01 4201 01 19
YES
120
MIN
Specifications subject to change without notice.
YES
NO
120
MIN
YES
YES
NO
120
MIN
YES
YES
NO
A10493
Page 20
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Table 5 Opening Dimensions − in. (mm)
FURNACE
CASING WIDTH
IN. (mm)
17–1/2
(445)
21
(533)
24−1/2
(622)
APPLICATION
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow applications on combustible flooring (subbase required)
Downflow Applications on Combustible Flooring with Coil Assembly or coil
box (subbase not required)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow applications on combustible flooring
(subbase required)
Downflow Applications on Combustible Flooring with Coil Assembly or coil
box (subbase not required)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow applications on Combustible flooring
(subbase required)
Downflow Applications on Combustible Flooring with Coil Assembly or
coil box (subbase not required)
PLENUM OPENING FLOOR OPENING
A B C D
16
(406)
15−7/8
(403)
15−1/8
(384)
15−1/2
(394)
19−1/2
(495)
19−3/8
(492)
18−5/8
(473)
19
(483)
23
(584)
22−7/8
(581)
22−1/8
(562)
22−1/2
(572)
21−5/8
(549)
19
(483)
19
(483)
19
(483)
21−5/8
(549)
19
(483)
19
(483)
19
(483)
21−1/8
(537)
19
(483)
19
(483)
19
(483)
16−5/8
(422)
16−1/2
(419)
16−3/4
(425)
16−1/2
(419)
20−1/8
(511)
20
(508)
20−1/4
(514)
20
(508)
23−5/8
(600)
23−1/2
(597)
23−3/4
(603)
23−1/2
(597)
22−1/4
19−5/8
20−5/8
22−1/4
19−5/8
20−5/8
22−1/4
19−5/8
20−5/8
(565)
(498)
(600)
20
(508)
(565)
(498)
(600)
20
(508)
(565)
(498)
(600)
20
(508)
Figure 22
Furnace, Plenum, and Subbase
Installed on a Combustible Floor
A96285
Figure 23
Furnace, Plenum, and Coil
Assembly on a Combustible Floor
A96284
HORIZONTAL INSTALLATION
NOTE: The furnace must be pitched forward as shown in
Figure 17 for proper condensate drainage.
The furnace can be installed horizontally in an attic or
crawlspace on either the left−hand (LH) or right−hand (RH)
side. The furnace can be hung from floor joists, rafters or
trusses or installed on a non−combustible platform, blocks,
bricks or pad.
20 440 01 4201 01
Specifications subject to change without notice.
Page 21
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
! WARNING
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, 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.
Figure 24 Suspended Furnace Installation
Suspended Furnace Support
The furnace may be supported under the entire length of the
furnace with threaded rod and angle iron. (See Figure 24)
Secure angle iron to bottom of furnace as shown.
Platform Furnace Support
Construct working platform at location where all required
furnace clearances are met. (See Table 1 and Figure 25) For
furnaces with 1−in. (25 mm) clearance requirement on side, set
furnace on non−combustible blocks, bricks or angle iron. For
crawlspace installations, if the furnace is not suspended from
the floor joists, the ground underneath furnace must be level
and the furnace set on blocks or bricks.
COMBUSTION − AIR PIPE
(SEE VENTING SECTION)
2−in.
(51 mm)
A11155
440 01 4201 01 21
Specifications subject to change without notice.
Page 22
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 25 Working Platform for Attic Installation
COMBUSTION − AIR PIPE
(SEE VENTING SECTION)
2−in.
(51 mm)
ROLLOUT PROTECTION REQUIRED
Install 1.2” x 22” (305 x 559 mm) sheet
metal in front of burner compartment
area.
Roll−Out Protection
Provide a minimum 12−in. x 22−in. (305 x 559 mm) piece of
sheet metal for flame roll−out protection in front of burner area
for furnaces closer than 12−in. (305 mm) above the
combustible deck or suspended furnaces closer than 12−in.
(305mm) to joists. The sheet metal MUST extend underneath
the furnace casing by 1−in. (25mm) with the door removed.
The bottom closure panel may be used for flame roll−out
protection when bottom of furnace is used for return air
connection. See Figure 25 for proper orientation of roll−out
shield.
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct
shall be provided with a removable access panel. This opening
shall be accessible when the furnace is installed and shall be of
such a size that the heat exchanger can be viewed for possible
openings using light assistance or a probe can be inserted for
sampling the air stream. The cover attachment shall prevent
leaks.
Connect supply−air duct to flanges on furnace supply−air
outlet. Bend flange upward to 90 with wide duct pliers. (See
Figure 21) The supply−air duct must be connected to ONLY
the furnace supply−outlet−air duct flanges or air conditioning
coil casing (when used). DO NOT cut main furnace casing side
to attach supply air duct, humidifier, or other accessories. All
accessories MUST be connected to duct external to furnace
main casing.
A11154
Return Air Connections
The return−air duct must be connected to bottom of the
furnace. The side of casing that faces downward may also be
used for return air connection. A combination of the bottom
and downward facing side may also be used. Bypass
humidifier may be attached into unused return air side of the
furnace casing. (See Figure 28)
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. Remove this panel when bottom
return air is used. This panel may be used for rollout protection
or discarded. To remove bottom closure panel, perform the
following:
1. Tilt or raise furnace and remove four (4) screws holding
bottom plate. (See Figure 18)
2. Remove bottom plate.
3. Remove bottom closure panel.
4. Reinstall bottom plate and screws.
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed
in bottom return−air opening. This panel MUST be in place
when side return air inlet(s) are used without a bottom return air
inlet.
Not all horizontal furnaces are approved for side return air
connections (See Figure 28)
22 440 01 4201 01
Specifications subject to change without notice.
Page 23
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Filter Arrangement
!
FIRE, CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in personal
injury, or death.
Never operate a furnace without a filter or filtration device
installed. Never operate a furnace with filter or filtration
device access doors removed.
Furnaces shipped without a filter rack:
There are no provisions for an internal filter in these furnaces.
An external filter rack is required and is purchased separately.
A field supplied accessory air cleaner may also be used in
place of the filter rack.
For upflow applications, the filter can be installed on either side
of the furnace, the bottom of the furnace or any combination of
side and bottom of the furnace. (See Figure 27, Figure 29, and
Figure 30)
For downflow applications, the filter rack (or field supplied
accessory air cleaner) must only be connected to the bottom
opening on the furnace (See Figure 26 and Figure 30 and
Table 7).
For horizontal applications, the filter rack (or field supplied
accessory air cleaner) can be connected to the bottom opening
on the furnace. For side return use in the horizontal position,
refer to Figure 28. If both side and bottom openings are used in
Figure 28, each opening used will require a filter.
A filter rack or any field supplied accessory air cleaner can also
be installed in the common return duct prior to entering the
return air opening in any orientation.
See Table 6 for recommended filter size details.
Table 6 Filter Size Information − inch (mm)
FURNACE
CASING
WIDTH
17-1/2
(445)
21 (533)
24-1/2
(622)
* Recommended to maintain air filter face velocity. See Product Data for part
number.
Refer to the instructions supplied with the Filter Rack or
accessory air filter for additional assembly and installation
options.
WARNING
FILTER SIZE
SIDE RETURN
16 x 25 x 3/4
(406 x 635 x 19)
16 x 25 x 3/4
(406 x 635 x 19)
16 x 25 x 3/4
(406 x 635 x 19)
(406 x 635 x 19)
(508 x 635 x 19)
(610 x 635 x 19)
BOTTOM
RETURN
16 x 25 x 3/4
20 x 25 x 3/4
24 x 25 x 3/4
FILTER
TYPE
Washable*
Washable*
Washable*
Figure 26
Figure 27
Figure 28
Downflow Return Air
Configurations and Restrictions
L10F033
Upflow Return Air Configurations
and Restrictions
L10F032
Horizontal Return Air
Configurations and Restrictions
HORIZONTAL TOP
RETURN NOT
PERMITTED FOR
ANY MODEL
440 01 4201 01 23
Specifications subject to change without notice.
SIDE RETURN AIR NOT
PERMITTED FOR 2000 CFM
AND ABOVE OF AIR FLOW
L10F034
Page 24
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
External Filter Cabinet Configurations
Figure 29 Accessory Side Filter Rack
FURNACE
FILTER
FRAME
1
(TYP.)
1
1
/
1
4”
DOOR
/
4”
25
FILTER
1
/
8”
3
/
8”
TABS
TABS
L10F027
1
/
2”
Figure 30 Accessory Bottom Filter Rack
L10F031
B
A
3
/
2
8”
3
/
4”
A
17
22−5/16
(566.4)
1
/
23
8”
1
/
8”
OPENING
14
OPENING
1
/
16
8”
1
/
2”
28−7/16
(722.2)
2−3/16
(55.5)
Table 7 Dimensional Drawing − inch (mm)
KIT NO.
NAHB00601FF
NAHB00701FF
NAHB00801FF
FURNACE
WIDTH
17−1/2
(444.5)
21
(533.4)
24−1/2
(622.3)
A B
14−5/8
(371.5)
18−1/8
(460.4)
21−5/8
(549.3)
17−5/8
(447.7)
21−1/8
(536.6)
24−5/8
(625.5)
24 440 01 4201 01
Specifications subject to change without notice.
Page 25
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Air Ducts
General Requirements
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA)
or American Society of Heating, Refrigerating and Air
Conditioning Engineers (ASHRAE) or consult The Air Systems
Design Guidelines reference tables available from your local
distributor. The duct system should be sized to handle the
required system design CFM at the design external static
pressure. The furnace airflow rates are provided in the Service
and Technical Manual, Air Delivery−CFM (with filter). When a
furnace is installed so that the 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.
Secure ductwork with proper fasteners for type of ductwork
used. Seal supply− and return−duct connections to furnace
with code approved tape or duct sealer.
NOTE: Flexible connections should be used between ductwork
and furnace to prevent transmission of vibration.
Ductwork passing through unconditioned space should be
insulated to enhance system performance. When air
conditioning is used, a vapor barrier is recommended.
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.
Ductwork Acoustical Treatment
NOTE: Metal duct systems that do not have a 90 degree elbow
and 10 ft. (3 M) of main duct to the first branch take−off may
require internal acoustical lining. As an alternative, fibrous
ductwork may be used if constructed and installed in
accordance with the latest edition of SMACNA construction
standard on fibrous glass ducts. Both acoustical lining and
fibrous ductwork shall comply with NFPA 90B as tested by UL
Standard 181 for Class 1 Rigid air ducts.
NOTE: For horizontal applications, the top most flange may be
bent past 90 to allow the evaporator coil to hang on the
flange temporarily while the remaining attachment and sealing
of the coil are performed.
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Use proper length of pipe to avoid stress on gas control manifold and a gas leak.
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Gas valve inlet and/or inlet pipe must remain capped
until gas supply line is permanently installed to protect
the valve from moisture and debris. Also, install a sediment trap in the gas supply piping at the inlet to the
gas valve.
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC in the U.S.A.
Refer to current edition of CAN/CSA B149.1 in Canada.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
NOTE: Use a back−up wrench on the inlet of the gas valve
when connecting the gas line to the gas valve.
NOTE: In the state of Massachusetts:
1. Gas supply connections MUST be performed by a
licensed plumber or gas fitter.
2. When flexible connectors are used, the maximum length
shall not exceed 36−in. (915 mm).
3. When lever handle type manual equipment shutoff
valves are used, they shall be T−handle valves.
4. The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.
Refer to Table 8 for recommended gas pipe sizing. Risers must
be used to connect to furnace and to meter. Support all gas
piping with appropriate straps, hangers, etc. Use a minimum of
one hanger every 6 ft. (1.8 M). Joint compound (pipe dope)
should be applied sparingly and only to male threads of joints.
Pipe dope must be resistant to the action of propane gas.
WARNING
WARNING
GAS PIPING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber.
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.
440 01 4201 01 25
WARNING
FIRE OR EXPLOSION HAZARD
A failure to follow this warning could result in personal injury, death, and/or property damage.
If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not use
a connector which has previously served another gas appliance. Black iron pipe shall be installed at the furnace
gas control valve and extend a minimum of 2−in. (51 mm)
outside the furnace.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace damage.
Connect gas pipe to furnace using a backup wrench to
avoid damaging gas controls and burner misalignment.
Specifications subject to change without notice.
!
!
WARNING
CAUTION
Page 26
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Table 8 Maximum Capacity of Pipe
NOMINAL
IRON PIPE
SIZE
IN. (MM)
1/2 (13)
3/4 (19)
1 ( 25)
1‐1/4 (32)
1‐1/2 (39)
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-In. W.C.) or less and
a pressure drop of 0.5-In. W.C. (based on a 0.60 specific gravity gas). Ref: Table 8
above, and 6.2 of NFPA54/ANSI Z223.1-2009.
INTERNAL
DIA.
IN. (MM)
0.622
(158)
0.824
(20.9)
1.049
(26.6)
1.380
(35.0)
1.610
(40.9)
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. (1.8 M) of
furnace.
Install a sediment trap in riser leading to furnace as shown in
Figure 31. Connect a capped nipple into lower end of tee.
Capped nipple should extend below level of furnace gas
controls. Place a ground joint union between furnace gas
control valve and exterior manual equipment gas shutoff valve.
LENGTH OF PIPE − FT (M)
10
(3.0)20(6.0)30(9.1)40(12.1)
(15.2
175 120 97 82 73
360 250 200 170 151
680 465 375 320 285
140
950 770 660 580
0
2100146
1180 990 900
0
50
)
Figure 31 Typical Gas Pipe Arrangement
L10F030
A 1/8−in. (3 mm) NPT plugged tapping, accessible for test
gauge connection, MUST be installed immediately upstream of
gas supply connection to furnace and downstream of manual
equipment shutoff valve.
Piping should be pressure and leak tested in accordance with
the current addition of the NFGC in the United States, local,
and national plumbing and gas codes before the furnace has
been connected. Refer to current edition of NSCNGPIC in
Canada. After all connections have been made, purge lines
and check for leakage at furnace prior to operating furnace.
NOTE: The furnace gas control valve inlet pressure tap
connection is suitable to use as test gauge connection
providing test pressure DOES NOT exceed maximum 0.5 psig
(14−in. w.c.) stated on gas control valve. (See Figure 32)
Figure 32
Inlet
Pressure Tap
ON/OFF Switch
Redundant Automatic Control
Valve (Modulating)
MODULATING
Min/Max Heat Adust
(Under Cap)
Turn screw 1 click per
second to adjust rate.
Clockwise to increase
rate, counter clockwise
to decrease rate.
GAS FLOW
Manifold
Pressure Tap
1/2” NPT Outlet
A10496
If pressure exceeds 0.5 psig (14−in. w.c.), gas supply pipe must
be disconnected from furnace and capped before and during
supply pipe pressure test. If test pressure is equal to or less
than 0.5 psig (14−in. w.c.), turn off electric shutoff switch
located on furnace gas control valve and accessible manual
equipment shutoff valve before and during supply pipe
pressure test. After all connections have been made, purge
lines and check for leakage at furnace prior to operating
furnace.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON and OFF.
Some installations require gas entry on right side of furnace (as
viewed in upflow). (See Figure 33)
Gas Pipe Grommet
For direct vent (2-pipe) applications, the knockout for the gas
pipe must be sealed to prevent air leakage. Remove the
knockout, install the grommet in the knockout, then insert the
gas pipe. The grommet is included in the loose parts bag. (See
Figure 33)
26 440 01 4201 01
Specifications subject to change without notice.
Page 27
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 33 Gas Entry
Left Side Gas Entry. Gas Pipe
Grommet Required For Direct
Vent Applications.
Gas Pipe Grommet Required
For Direct Vent Applications
ELECTRICAL CONNECTIONS
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Blower door switch opens 115−v power to control. No
component operation can occur. Do not bypass or close
switch with blower door removed.
WARNING
115−V Wiring
Furnace must have a 115-v power supply properly connected
and grounded.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control status indicator light flashes rapidly
and furnace does NOT operate.
Verify that the voltage, frequency, and phase correspond to that
specified on unit rating plate. Also, check to be sure that
service provided by utility is sufficient to handle load imposed
by this equipment. Refer to rating plate or Table 9 for
equipment electrical specifications.
U.S.A. Installations: Make all electrical connections in
accordance with National Electrical Code (NEC) ANSI/NFPA 70
and any local codes or ordinances that might apply.
Canadian Installations: Make all electrical connections in
accordance with the current edition of the Canadian Electrical
Code CSA C22.1 and any local codes or ordinances that might
apply.
! WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not connect aluminum wire between disconnect
switch and furnace. Use only copper wire.
See Figure 34 for field wiring diagram showing typical field
115−v wiring. Check all factory and field electrical connections
for tightness.
Field−supplied wiring shall conform with the limitations of 63°F
(33°C) rise.
!
WARNING
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
The cabinet MUST have an uninterrupted or unbroken
ground according to NEC ANSI/NFPA 70−2011 or local
codes to minimize personal injury if an electrical fault
should occur. In Canada, refer to Canadian Electrical
Code CSA C22.1. This may consist of electrical wire,
conduit approved for electrical ground or a listed,
grounded power cord (where permitted by local code)
when installed in accordance with existing electrical
codes. Refer to the power cord manufacturer’s ratings
for proper wire gauge.
Do not use gas piping as an electrical ground.
!
CAUTION
FURNACE MAY NOT OPERATE HAZARD
Failure to follow this caution may result in intermittent
furnace operation.
Furnace control must be grounded for proper operation
or else control will lock out. Control must remain
grounded through green/yellow wire routed to gas
valve and manifold bracket screw.
SWITCH
Use a separate, fused branch electrical circuit with a properly
sized fuse or circuit breaker for this furnace. See Table 9 for
wire size and fuse specifications. A readily accessible means of
electrical disconnect must be located within sight of the
furnace.
COPPER
WIRE ONLY
ALUMINUM
WIRE
A11146
J−Box Installation
!
FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
If field−supplied manual disconnect switch is to be
mounted on furnace casing side, select a location where
a drill or fastener cannot damage electrical or gas
components.
The J-Box is used when field line voltage electrical connections
are made to the furnace wiring harness inside the furnace
casing. The J-Box is not required if a field-supplied electrical
box is attached to the outside of the furnace casing and the box
is grounded to the green ground wire of the main wiring
harness and the earth ground of the field electrical supply.
WARNING
440 01 4201 01 27
Specifications subject to change without notice.
Page 28
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
The J−Box cover, mounting bracket and screws are shipped in
the loose parts bag included with the furnace. The J−Box can
Figure 34 Typical 2−Stage Field Wiring Diagram
NOTE 2
WC Y RG
W2
COM
W/W1
NOTE 1
Y/Y2
R
G
NOTES: 1.
BLOWER
DOOR
SWITCH
BLK
WHT
GND
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
BLK
WHT
JUNCTION
BOX
FIVE
WIRE
THREE-WIRE
HEATING-
ONLY
FURNACE
C
O
N
T
R
O
L
24-VOLT
TERMINAL
BLOCK
be mounted on the left or right side of the casing, as viewed
from the upflow position. (See Figure 35)
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
1-STAGE
THERMOSTAT
TERMINALS
CONDENSING
UNIT
Connect Y/Y2-terminal as shown for proper operation.
Some thermostats require a "C" terminal connection as shown.
2.
If any of the original wire, as supplied, must be replaced, use
3.
same type or equivalent wire.
FIELD-SUPPLIED
FUSED DISCONNECT
GND
208/230- OR
460-VOLT
THREE
PHASE
208/230VOLT
SINGLE
PHASE
Figure 35 J−Box Location
J BOX LOCATIONS
Representative drawing only, some models may vary in appearance.
Remove the J−Box cover and mounting bracket from the loose
parts bag. Select a 7/8−in. (22 mm) knock-out on the desired
side of the casing. Remove the knock-out from the casing. Drill
two 1/8−in. (3 mm) pilot holes in the casing dimples by the
desired 7/8−in. (22 mm) knock-out.
Align the J−Box mounting bracket against the inside of the
casing and secure the mounting bracket with the screws. (See
Figure 36)
Electrical Box on Furnace Casing Side
NOTE: Check that duct on side of furnace will not interfere with
installed electrical box.
1. Fasten a field-supplied external electrical box to the
outside of the casing by driving two field-supplied
screws from inside electrical box into casing. (See
Figure 37)
2. Route field power wiring into external electrical box.
3. Pull furnace power wires through 1/2-in. (12 mm)
diameter hole in J−Box. If necessary, loosen power
wires from strain−relief wire-tie on furnace wiring
harness.
4. Connect any code required external disconnect(s) to
field power wiring.
Figure 36 J−Box Bracket Installation
J−BOX
MOUNTING
SCREWS
J−BOX
MOUNTING
BRACKET
GROUND
SCREW
J−BOX COVER
A11F003
5. Route external field power wires through holes in
electrical box and casing.
6. Connect field ground wire and factory ground wire to
green ground screw on J−Box mounting bracket as
shown in Figure 36.
7. Connect field power and neutral leads to furnace power
leads. as shown in Figure 34.
A11401
28 440 01 4201 01
Specifications subject to change without notice.
Page 29
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
8. Attach furnace J−Box cover to mounting bracket with
screws supplied in loose parts bag. Do not pinch wires
between cover and bracket.
9. Complete external disconnect wiring and installation.
Connect line voltage leads as shown in Figure 37. Use
best practices (NEC in U.S. for wire bushings, strain
relief, etc., and Canadian Electrical Code CSA C22.1.)
Figure 37
LINE VOLTAGE
Field−Supplied Electrical Box on
Furnace Casing
GROUND
NEUTRAL
A10141
Power Cord Installation in Furnace J−Box
NOTE: Power cords must be able to handle the electrical
requirements listed in Table 9. Refer to power cord
manufacturer’s listings.
1. Install J−Box mounting bracket to inside of furnace
casing. (See Figure 36)
2. Route listed power cord through 7/8−in. (22 mm)
diameter hole in casing and J−Box bracket.
3. Secure power cord to J−Box bracket with a strain relief
bushing or a connector approved for the type of cord
used.
4. Pull furnace power wires through 1/2−in. (12 mm)
diameter hole in J−Box. If necessary, loosen power wires
from strain—relief wire−tie on furnace wiring harness.
5. Connect field ground wire and factory ground wire to
green ground screw on J−Box mounting bracket as
shown in Figure 36.
6. Connect power cord power and neutral leads to furnace
power leads as shown in Figure 34.
7. Attach furnace J−Box cover to mounting bracket with
screws supplied in loose parts bag. Do not pinch wires
between cover and bracket.
BX Cable Installation in Furnace J−Box
1. Install J−Box mounting bracket to inside of furnace
casing.
2. Route BX connector through 7/8−in. (22 mm) diameter
hole in casing and J−Box bracket.
3. Secure BX cable to J−Box bracket with connectors
approved for the type of cable used.
4. Connect field ground wire and factory ground wire to
green ground screw on J−Box mounting bracket as
shown in Figure 36.
5. Connect field power and neutral leads to furnace power
leads. as shown in Figure 34.
6. Attach furnace J−Box cover to mounting bracket with
screws supplied in loose parts bag. Do not pinch wires
between cover and bracket.
24−V Wiring
Make field 24−v connections at the 24−v terminal strip. (See
Figure 39) Connect terminal Y/Y2 as shown in Figure 34 for
proper cooling operation. Use only AWG No. 18, color−coded,
copper thermostat wire.
NOTE: Use AWG No. 18 color-coded copper thermostat wire
for lengths up to 100 ft. (30.5 M). For wire lengths over 100 ft.,
use AWG No. 16 wire.
The 24−v circuit contains an automotive−type, 3−amp. fuse
located on the control. Any direct shorts during installation,
service, or maintenance could cause this fuse to blow. If fuse
replacement is required, use ONLY a 3−amp. fuse of identical
size.
Thermostats and Control Settings
For best results, use a communicating wall control to control
this modulating furnace. A single stage or two−stage heating
and cooling thermostat can be used with the furnace. The
furnace control board CPU will control the furnace and outdoor
unit staging. A two stage heating and cooling thermostat can
also be used to control the staging. However, full modulating
capability will not be available when the furnace staging is
controlled by the thermostat. Furnace staging will be limited to
Minimum and Maximum inputs or Intermediate and Maximum
inputs depending on the configuration of set-up switches
SW1-2 and SW4-2. Refer to typical thermostat wiring diagrams
and the Sequence of Operation section for additional details.
Consult the thermostat installation instructions for specific
information about configuring the thermostat.
Accessories (See Figure 38 and Figure 39)
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used)
using 1/4−in female quick connect terminals to the two
male 1/4−in quick−connect terminals on the control
board marked EAC−1 and EAC−2. The terminals are
rated for 115VAC, 1.0 amps maximum and are
energized during blower motor operation.
2. Humidifier (HUM)
The HUM terminal is a 24 VAC output, energized
when the blower is operating during a call for heat.
Connect an accessory 24 VAC, 0.5 amp. Maximum (if
used) to the 1/4−in male quick−connect HUM terminal
and COM−24V screw terminal on the control board
thermostat strip.
NOTE: If the humidifier has its own 24 VAC power supply, an
isolation relay may be required. Connect the 24 VAC coil of the
isolation relay to the HUM and COM/24V screw terminal on the
control board thermostat strip.
3. Communication Connector
This connection is used when the furnace is
controlled by an optional communicating wall control
instead of a standard thermostat. The communication
plug is supplied with the communicating wall control.
Refer to the instructions supplied with the
communicating wall control for complete details.
4. Outside Air Thermistor (OAT)
The OAT connection is used in conjunction with
communicating wall control. It is not required when the
furnace is controlled by a standard type thermostat.
440 01 4201 01 29
Specifications subject to change without notice.
Page 30
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Refer to the instructions supplied with the
communicating wall control for complete details.
Alternate Power Supplies
Power from an alternate power supply that non-sinusoidal may
damage the furnace or cause erratic furnace operation.
Contact the alternate power supply manufacturer for
specifications and details.
This furnace is designed to operate on a utility generated
power which has a smooth sinusoidal waveform. If the furnace
is to be operated on a generator or other alternate power
supply, the alternate power supply must produce a smooth
sinusoidal waveform for compatibility with furnace electronics.
The alternate power supply must generate the same voltage,
phase, and frequency (Hz) as shown in Table 9 or on the
furnace rating plate.
Table 9 Electrical Data − MODULATING (F/G)9MAC
OPERATING VOLTAGE
RANGE* MAXIMUM
Maximum* Minimum*
UNIT
AMPS
UNIT
AMPACITY#
MINIMUM
WIRE SIZE
AWG
UNIT SIZE
VOLTS-
HERTZ-
PHASE
60,000 115-60-1 127 104 9.7 12.7 14 29 (8.8) 15
80,000 115-60-1 127 104 9.7 12.7 14 29 (8.8) 15
100,000 115-60-1 127 104 14.8 19.1 12 30 (9.1) 20
120,000 115-60-1 127 104 14.8 19.1 12 30 (9.1) 20
* Permissible limits of the voltage range at which the unit operates satisfactorily.
# Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier, etc.) full load
amps.
Time−delay type is recommended.
Length shown is as measured one way along wire path between unit and service panel for maximum 2 percent voltage drop.
MAXIMUM
WIRE
LENGTH
FT (M)}
MAXIMUM
FUSE OR CKT
BKR
AMPS{
Figure 38 Isolation Relay for Humidifiers with Internal Power Supply
To Humidifier Leads
24 V
Coil
To Humidifier Leads
Figure 39 Variable Speed Furnace Control − Switch Locations
PL9
SW4
3 2 1
PL4
SW*
A B C D
1
OAT
To HUM Terminal On
Furnace Control Board
To Com/24V Screw Terminal
on Thermostat Strip
A11157
O
N
8 7 6 5 4 3 2 1
SW2 SW3
O
3 2 1
W2
Y1
DHUM
3 2 1
N
30 440 01 4201 01
O
N
Specifications subject to change without notice.
PL7
O
N
Page 31
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
24-V THERMOSTAT
PL2 – HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
115-VAC (L2) NEUTRAL
CONNECTIONS
115-VAC (L1) LINE
VOLTAGE CONNECTIONS
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
PL1 – LOW VOLTAGE MAIN
HARNESS CONNECTOR
PL3 – ECM BLOWER
TRANSFORMER 24-VAC
CONNECTIONS
3-AMP FUSE
STATUS AND COMM
LED LIGHTS
SW1 SETUP
SWITCHES AND
DELAY
MODEL PLUG
CONNECTOR
AIR CONDITIONING
(A/C) AIRFLOW
SETUP SWITCHES
COMMUNICATION
CONNECTOR
CONTINUOUS FAN
(CF) AIRFLOW
SETUP SWITCHES
OUTDOOR
IR TEMP
CONNECTOR
HUMIDIFIER
TERMINAL (24
VAC
0.5 AMP MAX.
FLASH
UPGRADE
CONNECTOR
(FACTORY
ONLY)
SW4 SETUP
SWITCHES
SOFTWARE
VERSION
PART NUMBER AND
DATE CODE WWYY
PL8 - MODULATING
CONNECTOR
Figure 39 (CONT.) Variable Speed Furnace Control for ECM Blower Motor (Modulating)
A
GAS VALVE
BLOWER OFF-
-
TERMINALS
VENTING
Furnace is set in place in the required orientation.
Special Venting Requirements for Installations
in Canada
Installation in Canada must conform to the requirements of
CAN/CSA B149 code. Vent systems must be composed of
pipe, fittings, cements, and primers listed to ULC S636. The
special vent fittings and accessory concentric vent termination
kits and accessory external drain trap have been certified to
ULC S636 for use with those Royal Pipe and IPEX PVC vent
components which have been certified to this standard. In
Canada, the primer and cement must be of the same
manufacturer as the vent system – GVS-65 Primer (Purple) for
Royal Pipe or IPEX System 636, PVC/CPVC Primer, Purple
Violet for Flue Gas Venting and GVS-65 PVC Solvent Cement
for Royal Pipe or IPEX System 636
Gas Venting, rated Class IIA, 65 deg C. must be used with this
venting system - do not mix primers and cements from one
manufacturer with a vent system from a different manufacturer.
Follow the manufacturer’s instructions in the use of primer and
cement and never use primer or cement beyond its expiration
date.
The safe operation, as defined by ULC S636, of the vent
system is based on following these installation instructions, the
vent system manufacturer’s installation instructions, and proper
use of primer and cement. All fire stop and roof flashing used
with this system must be UL listed material. Acceptability under
Canadian standard CAN/CSA B149 is dependent upon full
compliance with all installation instructions. Under this
440 01 4201 01 31
(1)
t, PVC Cement for Flue
Specifications subject to change without notice.
HARNESS
CONNECTOR
L11F061
standard, it is recommended that the vent system be checked
once a year by qualified service personnel.
The authority having jurisdiction (gas inspection authority,
municipal building department, fire department, etc) should be
consulted before installation to determine the need to obtain a
permit.
*IPEX System 636™ is a trademark of IPEX Inc.
Consignes spéciales pour l’installation de
ventilation au Canada
L’installation faite au Canada doit se conformer aux exigences
du code CAN/CSA B149−2010. Ce systême de ventillation doit
se composer de tuyaux, raccords, ciments et apprêts
conformes au ULC S636. La tuyauterie de ventillation des gaz,
ses accessoires, le terminal concentrique mural ainsi que
l’ensemble du drain de condensat extérieur ont été certifiés
ULCS 636 pour l’application des composantes Royal Pipe,
IPEX PVC qui sont certifiées à ce standard. Au Canada,
l’apprêt et le ciment doivent être du même fabricant que le
système d’évacuation. L’apprêt GVS-65 (Purple) et le
ciment-solvant GVS-65 doivent être utilisé avec les Royal Pipe.
Système IPEX 636, apprêt PVC/CPVC, Purple pour
évacuation des gaz de combustion et système IPEX 636(1)t,
ciment PVC pour évacuation des gaz de combustion, coté
classe IIA, 65 deg C. doivent être utilisés avec le système
d’évacuation IPEX 636 – Ne pas combiner l ’apprêt et le ciment
d’un manufacturier avec un système d’évacuation d’un
manufacturier différent.
Page 32
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Bien suivre les indications du manufacturier lors de l’utilisation
de l’apprêt et du ciment et ne pas utiliser ceux-ci si la date
d’expiration est atteinte.
L’opération sécuritaire, tel que définit par ULC S636, du
système de ventilation est basé sur les instructions
d’installation suivantes, ainsi que l’usage approprié de l’apprêt
et ciment. Tout arrët feu et solin de toit utilisés avec ce
système doivent être des matériaux listés UL. L’acceptation du
standard Canadien CAN/CSA B149 est directement relié à
l’installation conforme aux instructions ci- haut mentionnées. Le
standard Canadien recommande l’ inspection par un personel
qualifié et ce, une fois par année.
Les autoritées ayant juridiction (inspecteurs de gas,
inspecteurs en bâtiments, département des incendies, etc)
devraient être consultées avant l’installation afin de déterminer
si un permis est requis.
!
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance connected to the venting system being placed
into operation could result in carbon monoxide poisoning or death.
Failure to follow the steps outlined below for each appliance connected to the venting system being placed
into operation could result in carbon monoxide poisoning or death.
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and horizontal pitch, as required in the National Fuel Gas
Code, NFPA 54/ANSI Z223.1−2009 and these in-
structions. Determine that there is no blockage or restriction, leakage, corrosion and other deficiencies,
which could cause an unsafe condition.
3. As far as practical, close all building doors and windows and all doors between the space in which the appliance(s) connected to the venting system are located and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected to the venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they
are operating at maximum speed. Do not operate a
summer exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected into operation. Adjust the thermostat
so appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances
at the draft hood relief opening after 5 minutes of main
burner operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the
above tests, the venting system must be corrected in
accordance with the National Fuel Gas Code, NFPA
54/ANSI Z223.1−2009.
9. After it has been determined that each appliance connected to the venting system properly vents when
tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other gas−fired
burning appliance to their previous conditions of use.
General
If this furnace replaces a furnace that was connected to a vent
system or chimney, the vent or vent connectors of other
remaining appliances may need to be re−sized. Vent systems
or vent connectors of other appliances must be sized to the
minimum size as determined using appropriate table found in
the current edition of National Fuel Gas Code NFPA 54/ANSI
Z−223.1. In Canada, refer to CAN/CSA−B149.1
An abandoned masonry chimney may be used as a raceway
for properly insulated and supported combustion−air (when
applicable) and vent pipes. Each furnace must have its own set
of combustion−air and vent pipes and be terminated
individually, as shown in Figure 52 for Direct Vent (2−pipe)
system or Figure 53 for ventilated combustion air option.
A furnace shall not be connected to a chimney flue serving a
separate appliance designed to burn solid fuel.
Other gas appliances with their own venting system may also
use the abandoned chimney as a raceway providing it is
permitted by local code, the current edition of the National Fuel
Gas Code and the vent or liner manufacturer’s installation
instructions. Care must be taken to prevent the exhaust gases
from one appliance from contaminating the combustion air of
other gas appliances.
Do not take combustion air from inside the chimney when using
ventilated combustion air or single pipe vent option.
These furnaces can be vented either as direct vent furnace, or
as ventilated combustion air system. Each type of venting
system is described below. Common venting between
furnaces or other appliances prohibited.
Materials
U.S.A.
Combustion air and vent pipe, fittings, primers, and solvents
must conform to American National Standards Institute (ANSI)
standards and American Society for Testing and Materials
(ASTM) standards. See Table 11 for approved materials for use
in the U.S.A.
Canada
Special Venting Requirements for Installations in Canada
Installation in Canada must conform to the requirements of
CAN/CSA B149 code. Vent systems must be composed of
pipe, fittings, cements, and primers listed to ULC S636.
Venting Systems
A factory accessory concentric vent termination kit is available
for direct vent terminations. Concentric vent termination kits are
available for 2−in. and 3−in. pipe. See Table 10 for available
options.
Table 10
Direct Vent (2−pipe)
Termination Kit
2−in (51 mm) Concentric
Vent Kit
3−in (76 mm) Concentric
Vent Kit
Direct Vent / 2−Pipe System
In a direct vent (2−pipe) system, all air for combustion is taken
directly from outdoor atmosphere, and all flue products are
discharged to outdoor atmosphere. Combustion-air and vent
pipes must terminate together in the same atmospheric
pressure zone, either through the roof or a sidewall (roof
termination preferred). See Figure 59 for required clearances.
Ventilated Combustion Air Systems
In a ventilated combustion air option, the vent terminates and
discharges the flue products directly to the outdoors similar to a
direct vent system. See Figure 60 for required clearances.
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
Vent Termination Kit for Direct
Vent (2−pipe) Systems
Termination
System
Single Penetration
of Wall or Roof
Single Penetration
of Wall or Roof
Diam. Of
Combustion Air
and Vent Pipes
in.(mm)
1, 1−1/2, 2, or 2−1/2
(25, 38, 51, 64 mm)
2−1/2, 3 or 4
(64, 76, 102 mm)
32 440 01 4201 01
Specifications subject to change without notice.
Page 33
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
crawl space) and the space is well isolated from the living
space or garage. Combustion air requirements for this option
are the same as the requirements for providing outside air for
combustion for a single pipe vent system. Refer to the “Air For
Combustion and Ventilation Section.”
Provisions for adequate combustion, ventilation, and dilution air
U.S.A. Installations: Section 9.3 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.
must be provided in accordance with:
Table 11 Approved Combustion-Air and Vent Pipe, Fitting and Cement Materials (U.S.A. Installation)
ASTM
SPECIFICATION
(MARKED ON
MATERIAL)
D1527
D1785
D2235
D2241
D2466
D2468
D2564
D2661
D2665
F438
F441
F442
F493
F628
F656
F891
MATERIAL PIPE FITTINGS
ABS Pipe − − Schedule−40
PVC Pipe − − Schedule−40
For ABS − − Solvent Cement For ABS
PVC Pipe − − SDR−21 & SDR−26
PVC − Fittings − Schedule−40
ABS − Fittings − Schedule−40
For PVC − − Solvent Cement For PVC
ABS Pipe Fittings − DWV at Schedule−40 IPS sizes
PVC Pipe Fittings − DWV
CPVC − Fittings − Schedule−40
CPVC Pipe − − Schedule−40
CPVC Pipe − − SDR
For CPVC − − Solvent Cement For CPVC
ABS Pipe − −
For PVC − − Primer For PVC
PVC Pipe − − Cellular Core Schedule−40 & DWV
SOLVENT CEMENT AND
PRIMERS
DESCRIPTION
Cellular Core DWV at Schedule−40 IPS
sizes
Figure 40 Upflow Vertical Vent
Any other unused
knockout may be used
for combustion air
connection.
1
2
3
4
5
6
7
6
Attach vent pipe adapter with gasket to furnace casing.
Align notches in rubber coupling over standoffs on adapter. Slide clamps over the coupling.
Slide vent pipe through adapter and coupling into vent elbow.
Insert vent pipe into vent elbow.
Torque all clamps 15 lb.-in.
Attach combustion air pipe adapter with gasket to furnace.
Attach combustion air pipe to adapter with silicone. Pilot drill a 1/8-in.
hole in adapter and secure with a #7 x 1/2-in sheet metal screw.
Representative drawing only, some models may vary in appearance.
7
3
2
5
1
4
5
A11310
440 01 4201 01 33
Specifications subject to change without notice.
Page 34
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 41 Upflow Right Vent
Any other unused
knockout may be used
for combustion air
connection.
Figure 42 Upflow Left Vent
6
2
1
Rotate vent elbow to
required position.
Attach vent pipe adapter with gasket to furnace casing.
1
Align notches in rubber coupling over standoffs on adapter. Slide clamps over the coupling.
2
Slide vent pipe through adapter and coupling into vent elbow.
3
4
Insert vent pipe into vent elbow.
Torque all clamps 15 lb.-in.
5
6
Attach combustion air pipe adapter with gasket to furnace casing.
Attach combustion air pipe to adapter with silicone. Pilot drill a 1/8-in.
7
hole in adapter and secure with a #7 x 1/2-in. sheet metal screw.
Representative drawing only, some models may vary in appearance.
7
4
5
6
7
5
3
A11308
3
2
&
Attach vent pipe adapter with gasket to furnace casing.
1
Align notches in rubber coupling over standoffs on adapter. Slide clamps over the coupling.
2
Slide vent pipe through adapter and coupling into vent elbow.
3
4
Insert vent pipe into vent elbow.
Torque all clamps 15 lb.-in.
5
Attach combustion air pipe adapter with gasket to furnace.
6
Attach combustion air pipe to adapter with silicone. Pilot drill a 1/8-in.
7
hole in adapter and secure with a #7 x 1/2-in sheet metal screw.
34 440 01 4201 01
4
1
5
Representative drawing only, some models may vary in appearance.
Specifications subject to change without notice.
Any other unused
knockout may be used
for combustion air
connection.
Rotate vent elbow to
5
required position.
A11309
Page 35
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 43 Downflow Left Vent
3
2
7
Attach vent pipe adapter with gasket to furnace casing.
1
Align notches in rubber coupling over standoffs on adapter. Slide clamps over the coupling.
2
Slide vent pipe through adapter and coupling into vent elbow.
3
4
Insert vent pipe into vent elbow.
Torque all clamps 15 lb.-in.
5
6
Attach combustion air pipe adapter with gasket to furnace.
Attach combustion air pipe to adapter with silicone. Pilot drill a 1/8-in.
7
hole in adapter and secure with a #7 x 1/2-in sheet metal screw.
Representative drawing only, some models may vary in appearance.
Rotate vent elbow to
5
1
6
required position.
4
5
A11311
Figure 44 Downflow Right Vent
Any other unused
knockout may be used
for combustion air
connection.
Attach vent pipe adapter with gasket to furnace casing.
1
Align notches in rubber coupling over standoffs on adapter. Slide clamps over the coupling.
2
Slide vent pipe through adapter and coupling into vent elbow.
3
4
Insert vent pipe into vent elbow.
Torque all clamps 15 lb.-in.
5
6
Attach combustion air pipe adapter with gasket to furnace.
Attach combustion air pipe to adapter with silicone. Pilot drill a 1/8-in.
7
hole in adapter and secure with a #7 x 1/2-in sheet metal screw.
Rotate vent elbow to
required position.
4
5
2
1
6
Representative drawing only, some models may vary in appearance.
5
3
7
A11312
440 01 4201 01 35
Specifications subject to change without notice.
Page 36
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 45 Downflow Vertical Vent
Requires Accessory Internal Vent Kit
See Specification Sheets for current kit number
Representative drawing only, some models may vary in appearance.
Figure 47 Vent Pipe Flush with Adaptor
VENT PIPE ADAPTER WITH GASKET
INSTALLED ON FURNACE VENT
PIPE IS CUT FLUSH WITH TOP OF
ADAPTER.
Figure 48 Vent Pipe Flush Showing Coupling
ALIGN NOTCHES IN VENT PIPE
COUPLING OVER STAND−OFF
ON ADAPTER. TORQUE LOWER
CL AMP 15 LB−IN. WHEN REMAINING
VENT PIPE IS INSTALLED, TORQUE
UPPER CL AMP TO 15 LB−IN.
L11F063
Figure 46
Vent Coupling and Adapter with
Gaskets
Vent Coupling and Adapter
Attach gaskets to vent pipe and combustion air adapters
Figure 49 Combustion Air Pipe
Point elbow down towards
back of furnace
12” MINIMUM
256.0 mm
36 440 01 4201 01
CASING SIDE ATTACHMENT
COMBUSTION AIR PIPE
(ATTIC OR CRAWLSPACE ONLY)
Specifications subject to change without notice.
TOP PLATE ATTACHMENT
COMBUSTION AIR PIPE
(ATTIC OR CRAWLSPACE ONLY)
A11376
Page 37
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Locating the Vent Termination
General
NOTE: Termination Requirements for the Provinces of
Alberta and Saskatchewan are located at the end of this
section.
Combustion−air (Direct vent/2−pipe system only) and vent pipe
must terminate outside structure, either through sidewall or
roof.
For vent termination clearance, refer to Figure 59 for Direct
Vent/2−Pipe system and Figure 60 for Non−direct
Vent/Ventilated Combustion Air system. For exterior termination
arrangements, refer to Figure 59 for Direct Vent/2−Pipe system
and Figure 60 for Non−Direct/Ventilated Combustion Air
system.
Roof termination is preferred since it is less susceptible to
damage or contamination, and it has less visible vent vapors.
Sidewall terminations require sealing or shielding of building
surfaces with a corrosive resistance material due to corrosive
combustion products of vent system.
NOTE: (Direct Vent/2−Pipe system ONLY) A factory accessory
termination kit MUST be used.
When determining appropriate location for termination, consider
the following guidelines:
1. Comply with all clearance requirements stated in
Figure 59 or Figure 60 per application.
2. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs or air
conditioning equipment.
3. Termination or termination kit should be positioned so
that it will not be affected by wind eddy, such as inside
building corners, nor by recirculation of flue gases,
airborne leaves, or light snow.
4. Termination or termination kit should be positioned where
it will not be damaged by or subjected to foreign objects
such as stones, balls, etc.
5. Termination or termination kit should be positioned where
vent vapors are not objectionable.
Direct Vent / 2−Pipe System
Direct vent (2−pipe) vent and combustion air pipes must
terminate outside the structure. Follow all clearances as shown
Figure 59. Allowable vent and combustion air terminations are
shown in Figure 52.
Ventilated Combustion Air
The vent pipe for a Ventilated Combustion Air System must
terminate outdoors. Follow all vent termination clearances
shown in Figure 60. Allowable vent terminations are shown in
Figure 53. The combustion air pipe terminates in a
well−ventilated attic or crawl space. When the furnace is
installed in a well ventilated attic or crawlspace, install the
combustion air pipe as shown in Figure 49. Follow the
clearances as shown in Figure 57 and Figure 58.
The combustion air pipe cannot terminate in attics or crawl
spaces that use ventilation fans designed to operate in the
heating season. If ventilation fans are present in these areas,
the combustion air pipe must terminate outdoors as a Direct
Vent System.
Termination Requirements for the
Provinces of Alberta and Saskatchewan
The Provinces of Alberta and Saskatchewan require a
minimum unobstructed distance of 4 ft. (1.2m) from the
foundation to the property line of the adjacent lot for vent
termination of any appliance with an input over 35,000 btuh. If
there is less than 4 ft. (1.2m) of unobstructed distance to the
property line of the adjacent lot, no type of vent termination is
permitted for appliances with inputs greater than 35,000 btuh.
There are no additional restrictions on unobstructed distances
greater than 8 ft. (2.4m). All single, 2-pipe and concentric vents
may be used, providing all other Code and manufacturer’s
requirements in these instructions are adhered to. Refer to the
appropriate Vent Termination section above for locating the
vent termination .
If the unobstructed distance from the foundation to the property
line of the adjacent lot is no less than 4 ft. (1.2m) and no
greater than 8 ft. (2.4m), it will be necessary to re-direct the flue
gas plume. In this situation, a concentric vent kit cannot be
used. A 2-pipe termination (or single pipe termination when
permitted) that re-directs the flue gas away by use of an elbow
or tee, certified to ULC S636
must be used. (See Figure 50 and Figure 51)
The concentric vent kit currently cannot be modified to attach
an elbow to the vent portion of the rain cap. A tee attached to
the rain cap could potentially direct the flue gas plume toward
the intake air stream and contaminate the incoming combustion
air for the furnace.
Refer to Figure 50 and Figure 51 for terminations approved for
use in Alberta and Saskatchewan.
from the adjacent property line
Figure 50 Tee at Termination Outlet
12−in
30.48 cm
12−in
30.48 cm
Above anticipated
snow level
L10F024
440 01 4201 01 37
Specifications subject to change without notice.
Page 38
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 51 Vent Terminations Figure 51 (CONT.) Vent Terminations
Figure 52 Combustion Air and Vent Pipe Termination for Direct Vent (2−Pipe) System
Roof T e rm ination (Pref erred)
V e r tical separation
between comb ustion
air and v ent
8 3/4 in. (222mm)f or 3 in. (76mm)ki t
6 3/4 in. (172mm)f or 2 in. (51mm) ki t
Maintain 12 in. (305mm)min.
clearance abo ve
highest anticipated
sno w le ve l
Maximum of 24 in.(614mm)
abo v e roof
Note: "A" denotes 0 to < 2 in.
Between the first 2 vents
Third vent must be > 36 in. away
18 in. maximu m
90 °
At least 36 in.
(914mm)
(457mm)
A t least 36 in
(51mm)
(914mm)
Concent ri c V ent and Comb ustion Ai r
A
Abandoned masonr y
used as race wa y
(per code)
(914mm)
12
in.
min fro m
ov erhang or roof
(typ)
in.
(305mm)
At least 36 in.
(914mm)
12
in. (305mm)
separation between
A
.
bottom ofcomb ustion air and
bottom of v ent (typ)
Maintain 12
min. clearance abo ve
highest anticipated
sno w le ve l or grade
whiche ve r is greater (typ)
Roof T er mination (pre fe rred)
A
Side wa ll te rm inatio n
in. (305mm)
of less than 12
At least
36 in.
(914mm)
above highest snow level
A
Maintain 12
in.
min. clearance abo ve
highest anticipated
sno w le ve l, maximum of
24 in . abo v e roof
1
in. (25mm)
A
t le
a
3
s t
6
in
.
Concent ri c V ent
and Comb ustion - Air
Side T e rm inatio n
(305mm)
maximum (typ) from wall to inlet
12
in. (305mm)
ov erhang or roof
A
Maintain 12
min. clearance ab ov e
highest anticipated
sno w le v el or grade
which eve r is greate r
minimum fro m
(305mm)
in.
A05090
38 440 01 4201 01
Specifications subject to change without notice.
Page 39
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 53 Vent Pipe Termination for Non−Direct Vent and Ventilated Combustion Air System
Roof Termination (Preferred)
Ven t
(305mm)
Maintain 12 in .
minimum clearance
above highest anticipated
snow level maximum of
24 in. (610mm) above roof.
Abandoned masonry
used as raceway
(per code)
12 in. min. (305 mm)from
overhang or roof
Sidewall Termination
with Straight Pipe (preferred)
Maintain 12 in. (305mm)
minimum clearance
above highest anticipated
snow level or grade
whichever is greater
A05091
90°
Side wall termination
with 2 elbows (preferred)
12 in. (305 mm) min. from
overhang or roof
Maintain 12 in. (305mm)
minimum clearance
above highest anticipated
snow level or grade
whichever is greater.
6 in. (152mm) minimum clearance
between wall and end of vent pipe.
10 in. (254mm) maximum pipe length
Size the Vent and Combustion Air Pipes
General
Furnace combustion air and vent pipe connections are sized
for 2-in. (51 mm) pipe. Any pipe diameter change should be
made outside furnace casing in vertical pipe. Any change is
diameter to the pipe must be made as close to the furnace as
reasonably possible.
The Maximum Vent Length for the vent pipe and combustion air
pipe equals the Maximum Equivalent Vent Length (MEVL) in
Table 12 or Table 13, minus the number of fittings multiplied by
the deduction for each type of fitting used from Table 14.
The measured length of pipe used in a 2−pipe termination is
included in the total vent length. Include a deduction for a Tee
when used for Alberta and Saskatchewan terminations.
Concentric vent terminations, pipe lengths or elbows do not
require a deduction from the Maximum Equivalent Vent Length.
1. Measure the individual distance from the furnace to the
termination for each pipe.
2. Select a Maximum Equivalent Vent Length (MEVL)
longer than the measured distance of the individual vent
and combustion air connections to the vent termination.
3. Count the number of elbows for each pipe.
4. For each pipe, multiply the number of elbows by the
equivalent length for the type of elbow used. Record the
equivalent length of all the elbows for each pipe.
5. If a Tee is used on the termination, record the equivalent
length of the Tee used.
6. Record the equivalent length of the termination to be
used.
7. Subtract the equivalent lengths of the fittings and
terminations from the Maximum Equivalent Vent Length.
8. If the Maximum Vent Length calculated is longer than the
individual measured length of the vent pipe and
combustion air pipe, then the diameter of pipe selected
may be used.
9. If the Maximum Vent Length calculated is shorter than
the individual measured length of either the vent pipe or
440 01 4201 01 39
the combustion air pipe, recalculate the Maximum Vent
Length using the next larger diameter pipe.
NOTE: The vent pipe and combustion air pipe must be the
same diameter.
NOTE: If the Maximum Vent Length for diameter of the pipe
selected is longer than the measured length and the equivalent
length of all the fitting and terminations, recalculate using the
next smaller diameter. If the recalculated Maximum Vent Length
is longer than the measured length of the vent pipe and
combustion air pipe, then that diameter of pipe selected may be
used.
When installing vent systems of short pipe lengths, use the
smallest allowable pipe diameter. Do not use pipe size greater
than required or incomplete combustion, flame disturbance, or
flame sense lockout may occur.
Combustion Air and Vent Piping Insulation
Guidelines
NOTE: Use closed cell, neoprene insulation or equivalent.
The vent pipe may pass through unconditioned areas. The
amount of exposed pipe allowed is shown in Table 15.
1. Using winter design temperature (used in load
calculations), find appropriate temperature for your
application and furnace model.
2. Determine the amount of total and exposed vent pipe.
3. Determine required insulation thickness for exposed pipe
length(s).
4. When combustion air inlet piping is installed above a
suspended ceiling, the pipe MUST be insulated with
moisture resistant insulation such as Armaflex or other
equivalent type of insulation.
5. Insulate combustion air inlet piping when run in warm,
humid spaces.
6. Install the insulation per the insulation manufacturer’s
installation instructions.
NOTE: Pipe length (ft / M) specified for maximum pipe lengths
located in unconditioned spaces (See Table 15) cannot exceed
total allowable pipe length as calculated from Table 12 or
Table 13.
Specifications subject to change without notice.
Page 40
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Configure the Furnace
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury or
death.
To route the vent pipe and combustion air pipe through the
furnace, the manufacturer supplied kit must be used. Failure
to properly seal the blower compartment from the furnace
vestibule could result in the circulation of carbon monoxide
throughout the structure. The vent pipe and combustion air
pipe must be a continuous pipe while passing through the
blower compartment. Seals supplied in this kit must be
installed per the instructions provided. Follow all procedures
outlined in these instructions.
With the furnace installed in the required position, remove the
desired knockouts from the casing. It will be necessary to
remove one knockout for the vent pipe and the other knockout
for the combustion air connection.
Use a flat blade screwdriver and tap on the knockout on
opposite sides, where the knockout meets the casing. Fold the
knockout down with duct pliers and work the knockout back
and forth until it is removed. Trim any excess metal from the
knockout with tin snips.
The vent elbow can be rotated to the required location on the
casing if necessary. See Figure 54 To rotate the vent elbow:
1. Loosen the clamp on the inlet of the vent elbow attached
to the inducer.
2. Rotate the vent elbow to the required position. There are
rounded notches in the vent elbow to align it with the
inducer for each orientation.
3. Tighten the clamp around the vent elbow. Torque the
clamp to 15 lb-in. See Figure 40 through Figure 45,
Figure 55 and Figure 56.
Figure 54 Inducer Vent Elbow − Variable
WARNING
Figure 55 Horizontal Left Vent Configuration
HORIZONTAL LEFT VERTICAL VENT
Representative drawing only, some models may vary in appearance.
MODUL ATING INDUCER ASSEMBLY
Representative drawing only, some models may vary in appearance.
VENT ELBOW CL AMP
TORQUE 15 LB−IN.
INDUCER OUTLET
VENT PIPE CL AMP
TORQUE 15 LB−IN.
VENT ELBOW
HORIZONTAL LEFT, LEFT VENT
Representative drawing only, some models may vary in appearance.
HORIZONTAL LEFT, RIGHT VENT
Representative drawing only, some models may vary in appearance.
40 440 01 4201 01
Specifications subject to change without notice.
Page 41
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 56 Horizontal Right Vent Configuration
HORIZONTAL RIGHT, VERTICAL VENT
Representative drawing only, some models may vary in appearance.
HORIZONTAL RIGHT, LEFT VENT
Representative drawing only, some models may vary in appearance.
HORIZONTAL RIGHT, RIGHT VENT
Representative drawing only, some models may vary in appearance.
Installing the Vent Pipe Adapter and
Combustion Air Pipe Adapter
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury or
death.
To route the vent pipe and combustion air pipe through the
furnace, the manufacturer supplied kit must be used. Failure
to properly seal the blower compartment from the furnace
vestibule could result in the circulation of carbon monoxide
throughout the structure. The vent pipe and combustion air
pipe must be a continuous pipe while passing through the
blower compartment. Seals supplied in this kit must be
installed per the instructions provided. Follow all procedures
outlined in these instructions.
NOTE: The rubber coupling that attaches to the vent pipe
adapter must be used. The adapter seals the vent pipe to the
casing and reduces the strain on the vent elbow attached to the
inducer.
1. Apply the gaskets to the vent pipe and combustion air
pipe adapters. See Figure 46.
NOTE: The vent pipe adapter and combustion air pipe adapter
have the same ID, however, the combustion air pipe adapter
has a pipe stop at the end.
2. Align the screw holes in the plastic vent pipe adapter with
the dimples in the casing.
3. Pilot drill the screw holes for the adapter in the casing
and attach the vent pipe adapter to the furnace with
sheet metal screws
4. Slide the end of the rubber vent coupling with notches in
it over the standoffs on the vent pipe adapter.
5. Insert a length of vent pipe through the coupling into the
outlet of the vent elbow.
6. Tighten the clamp around the outlet of the vent elbow.
Torque the clamp to 15 lb−in.
Install the remaining vent and combustion air pipes as shown
below. It is recommended that all pipes be cut, prepared, and
preassembled before permanently cementing any joint.
1. Working from furnace to outside, cut pipe to required
length(s).
2. Deburr inside and outside of pipe.
3. Chamfer outside edge of pipe for better distribution of
primer and cement.
4. Clean and dry all surfaces to be joined.
5. Check dry fit of pipe and mark insertion depth on pipe.
6. Insert the vent pipe into the vent elbow.
7. Torque clamp on vent elbow 15 lb−in.
8. Torque clamp on vent coupling 15 lb−in.
9. Insert the combustion air pipe into the adapter.
10. Pilot drill a screw hole through the adapter into the
combustion air pipe and secure the pipe to the adapter
with sheet metal screws.
11. Seal around the combustion air pipe with silicone or foil
tape.
12. After pipes have been cut and preassembled, apply
generous layer of cement primer to pipe fitting socket
and end of pipe to insertion mark. Quickly apply
approved cement to end of pipe and fitting socket (over
primer). Apply cement in a light, uniform coat on inside of
socket to prevent buildup of excess cement. Apply
second coat.
WARNING
440 01 4201 01 41
Specifications subject to change without notice.
Page 42
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
13. While cement is still wet, twist pipe into socket with
1/4−in. turn. Be sure pipe is fully inserted into fitting
socket.
14. Wipe excess cement from joint. A continuous bead of
cement will be visible around perimeter of a properly
made joint.
15. Handle pipe joints carefully until cement sets.
16. Horizontal portions of the venting system shall be
supported to prevent sagging. Support combustion air
piping and vent piping a minimum of every 5 ft. (1.5M) [3
ft. (.91M) for SDR−21 or −26 PVC] using perforated
metal hanging strap or commercially available hangars
designed to support plastic pipe.
17. Prevent condensate from accumulating in the pipes by
sloping the combustion air piping and vent piping
downward towards furnace a minimum of 1/4-in. per
linear ft. with no sags between hangers.
18. Complete the vent and combustion air pipe installation
by connecting to the concentric vent or by installing the
required termination elbows as shown in Figure 52 and
Figure 53, Alberta Figure 50 and Figure 51.
19. For ventilated combustion air terminations, refer to
Figure 53, Alberta Figure 50 and Figure 51.
20. Use appropriate methods to seal openings where
combustion air pipe and vent pipe pass through roof or
sidewall.
Optional Installation of the vent pipe
This option provides a disconnect point for the vent pipe. The
vent pipe must be cemented to the plastic vent pipe adapter to
maintain a sealed vestibule. See Figure 47 and Figure 48
1. Insert a length of vent pipe through the casing into the
outlet of the vent elbow.
2. Slide the plastic vent pipe adapter over the length of the
vent pipe down to the furnace casing. Mark the pipe
where it is flush with the outlet of the adapter.
3. Remove the pipe from the furnace and the adapter and
cut off any excess pipe.
4. Clean and prime the end of the pipe that is flush with the
vent adapter with a primer that is appropriate for the type
of pipe being used.
5. Re−insert the pipe through the casing into the vent
elbow.
6. Tighten the clamp around the outlet of the vent elbow.
Torque the clamp to 15 lb−in.
7. Apply cement to the end of the pipe and to the inside of
the plastic vent adapter.
8. Slide the adapter over the vent pipe and align the screw
holes in the adapter with the dimples in the furnace
casing.
9. Pilot drill 1/8−in. screw holes for the adapter in the casing
and secure the adapter to the furnace with sheet metal
screws.
10. Loosen the clamps on the rubber vent coupling.
11. Slide the end of the coupling with notches in it over the
standoffs in the vent pipe adapter.
12. Tighten the clamp of the coupling over the vent pipe
adapter. Torque the lower clamp around the vent pipe
adapter to 15 lb−in.
13. Pilot drill a 1/8−in. hole in the combustion air pipe
adapter.
14. Complete the vent and combustion air pipe as shown in
“Install the Vent and Combustion Air Pipe”
Installing the Vent Termination
Roof Terminations
A roof termination of any type will require a 4-in. (102 mm)
flashing for a 2−in. (51 mm) concentric vent or a 5−in. diameter
(127 mm) flashing for a 3-in. (76 mm) concentric vent kit. For
2-pipe or single pipe vent systems, a flashing for each pipe of
the required diameter will be necessary.
It is recommended that the flashing be installed by a roofer or
competent professional prior to installing the concentric vent.
The terminations can be installed on a flat or pitched roof.
Concentric Vent
Single or multiple concentric vent must be installed as shown in
Figure 52. Maintain the required separation distance between
vents or pairs of vents as shown in Figure 52 and all
clearance shown in Figure 59.
Cut one 4−in. (102 mm) diameter hole for 2−in. (51 mm) kit, or
one 5−in. (127 mm) diameter hole for 3−in. (76 mm) kit in the
desired location.
Loosely assemble concentric vent/combustion air termination
components together using instructions in kit.
Slide assembled kit with rain shield REMOVED through hole in
wall or roof flashing.
NOTE: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
2−Pipe Terminations
Two pipe vent must be installed as shown in Figure 52 and
Figure 53. Maintain the required separation distance between
vents or pairs of vents as shown in Figure 52 and Figure 53
and all clearance shown in Figure 59 or Figure 60.
Cut the required number of holes in the roof or sidewall for vent
and combustion air pipes. Sidewall holes for 2-pipe vent
terminations should be side-by-side, allowing space between
the pipes for the elbows to fit on the pipes.
Holes in the roof for two pipe terminations should be spaced no
more than 18−in. (457 mm) apart.
Termination elbows will be installed after the vent and (if used)
combustion air pipe is installed.
Sidewall Terminations
Concentric Vent Termination
Determine an appropriate location for termination kit using the
guidelines provided in section “Locating The Vent Termination”
in this instruction.
1. Cut one 4−in. diameter hole for 2−in. kit, or one 5−in.
diameter hole for 3−in. kit.
2. Loosely assemble concentric vent/combustion air
termination components together using instructions in kit.
3. Slide assembled kit with rain shield REMOVED through
hole.
NOTE: Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
4. Locate assembly through sidewall with rain shield
positioned no more than 1−in. (25 mm) from wall as
shown in Figure 52.
5. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
Direct Vent (2-Pipe) Termination
Determine an appropriate location for termination kit using the
guidelines provided in section “Locating The Vent Termination”
in this instruction.
1. Cut two holes, one for each pipe, of appropriate size for
pipe size being used.
2. Loosely install elbow on combustion air and vent pipe
and place assembly on combustion−air pipe.
42 440 01 4201 01
Specifications subject to change without notice.
Page 43
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
NOTE: For applications using vent pipe option indicated by
dashed lines in Figure 52 and Figure 53, rotate vent elbow 90
from position.
3. Disassemble loose pipe fittings. Clean and cement using
same procedures as used for system piping.
For Ventilated Combustion Air Terminations, terminate as
shown in Figure 53.
(Direct Vent / 2-Pipe System ONLY)
When two or more furnaces are vented near each other, two
vent terminations may be installed as shown in Figure 52, but
Figure 57 Crawl Space Vent Termination
Ventilated Combustion
Air intake pipe
Pipe hangar
next vent termination must be at least 36−in. (914 mm) away
from first two terminations. It is important that vent terminations
be made as shown in Figure 52 to avoid recirculation of flue
gases.
Inducer Outlet Restrictor
The loose parts bag may contain an inducer outlet restrictor.
The outlet restrictor is NOT used on these furnaces. Discard
restrictor.
3” (76 mm)
Ventilated Combustion Air
intake termination in crawl
space
Figure 58 Attic Vent Termination
12” (305 mm)
CRAWL SPACE
Ventilated Combustion
Air intake pipe
Vent through
roof flashing
12” (305 mm) min. above
higest level of insulation
440 01 4201 01 43
ATTIC
Specifications subject to change without notice.
L11F016
Page 44
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 59 Direct Vent Termination Clearance
V
V
Item Clearance Description Canadian Installation (1)
Clearance above grade, veranda, porch, deck, balcony, or
A
anticipated snow level
B Clearance to a window or door that may be opened
C Clearance to a permanently closed window
Vertical clearance to a ventilated soffit located above the
terminal within a horizontal distance of 2′ (61cm) from the
D
centerline of the terminal
E Clearance to an unventilated soffit
F Clearance to an outside corner
G Clearance to an inside corner
Clearance to each side of the centerline extended above
H
electrical meter or gas service regulator assembly
I Clearance to service regulator vent outlet 3 ft. (.9 m)
Clearance to non-mechanical air supply inlet to building or the
J
combustion air inlet to any other appliance
K Clearance to a mechanical air supply inlet 6 ft. (1.8 m) 3 ft. (.9 m) above if within 10′ (3m) horizontally
L Clearance under a veranda, porch, deck, or balcony
Clearance to each side of the centerline extended above or
below vent terminal of the furnace to a dryer or water heater
M
vent, or other appliance's direct vent intake or exhaust.
Clearance to the vent terminal of a dryer vent, water heater
N
vent, or other appliances direct vent intake or exhaust.
O Clearance from a plumbing vent stack 3 ft. (.9 m) 3 ft. (.9 m)
Clearance above a paved sidewalk or paved driveway located
P
on public property.
u greater than, w greater than or equal to, t less than, v less than or equal to
(1) In accordance with the current CAN/CSA B149.1, Natural Gas and Propane Installation Code
(2) In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code
Notes:
1 The vent for this appliance shall not terminate
a. Over public walkways; or
b. Near soffit vents or crawl space vents or other areas where condensate or vapor could create a nuisance or hazard or property damage; or
c. Where condensate vapor could cause damage or could be detrimental to the operation of regulators, relief valves, or other equipment.
2. When locating vent terminations, consideration must be given to prevailing winds, location, and other conditions which may cause recirculation of the combustion products of adjacent vents.
Recirculation can cause poor combustion, inlet condensate problems, and accelerated corrosion of the heat exchangers.
3. Avoid venting under a deck or large overhang. Recirculation could occur and cause performance or system problems.
12 in. (305 mm). 18 in. (457mm) above roof surface 12 in. (305 mm)
12 in. (305 mm) for appliances u 10,000 Btuh (3 kW) and v
100,000 Btuh (30 kW), 36 in. (914 mm) for appliances u
100,000 Btuh (30 kW)
For clearances not specified in ANSI Z223.1/NFPA 54 or
CAN/CSA B149.1, clearances shall be in accordance with
local installation codes and the requirements of the gas suppli
er and the manufacture's installation instructions.
3 ft. (.9 m) within a height15 feet (4.5 m) above the meter/reg
ulator assembly
12 in. (305 mm) for appliances u 10,000 Btuh (3 kW) and v
100,000 Btuh (30 kW), 36″ (91 cm) for appliances u 100,000
Btuh (30 kW)
12 in. (305 mm) Permitted only if veranda, porch, deck, or
balcony is fully open on a minimum of two sides beneath the
floor.
12 in. (305 mm) 12 in. (305 mm)
3 ft. (.9 m) 3 ft. (.9 m)
7 ft. (2.1 m) A vent shall not terminate directly above a side
walk or paved driveway that is located between two single
family dwellings and serves both dwellings.
9 in. (229 mm) for appliances u 10,000 Btuh (3 kW) and v
50,000 Btuh (14.7 kW), 12″ (30 cm) for appliances u 50,000
Btuh (14.7 kW)
For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/
CSA B149.1, clearances shall be in accordance with local instal
lation codes and the requirements of the gas supplier and the
manufacture's installation instructions.
3 ft. (.9 m) within 15 feet (4.5 m) above the meter/regulator
assembly
3 ft. (.9 m) For clearances not specified in ANSI Z223.1/NFPA
54 or CAN/CSA B149.1, clearances shall be in accordance with
local installation codes and the requirements of the gas supplier
and the manufacture's installation instructions.
9 in. (23 cm) for appliances u 10,000 Btuh (3 kW) and v
50,000 Btuh (15 kW), 12″ (30 cm) for appliances u 50,000
Btuh (14.7 kW)
For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/
CSA B149.1, clearances shall be in accordance with local instal
lation codes and the requirements of the gas supplier and the
manufacture's installation instructions.
For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/
CSA B149.1, clearances shall be in accordance with local instal
lation codes and the requirements of the gas supplier and the
manufacture's installation instructions.
U.S. Installation (2)
44 440 01 4201 01
Specifications subject to change without notice.
Page 45
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Figure 60 Other than Direct Vent Clearance − Ventilated Combustion Air Option
V
V
Item Clearance Descriptions Canadian Installation (1)
Clearance above grade, veranda, porch, deck, balcony, or
A
anticipated snow level
B Clearance to a window or door that may be opened
C Clearance to a permanently closed window
Vertical clearance to a ventilated soffit located above the
terminal within a horizontal distance of 2′ (61cm) from the
D
centerline of the terminal
E Clearance to an unventilated soffit
F Clearance to an outside corner
G Clearance to an inside corner
Clearance to each side of the centerline extended above
H
electrical meter or gas service regulator assembly
I Clearance to service regulator vent outlet 3 ft. (.9 m)
Clearance to non-mechanical air supply inlet to building or the
J
combustion air inlet to any other appliance
K Clearance to a mechanical air supply inlet 6 ft. (1.83 m) 3 ft. (.9 m) above if within 10 ft. (3 m) horizontally
L Clearance under a veranda, porch, deck, or balcony
Clearance to each side of the centerline extended above or
below vent terminal of the furnace to a dryer or water heater
M
vent, or other appliance's direct vent intake or exhaust.
Clearance to the vent terminal of a dryer vent, water heater
N
vent, or other appliances direct vent intake or exhaust.
O Clearance from a plumbing vent stack 3 ft. (.9 m) 3 ft. (.9 m)
Clearance above a paved sidewalk or paved driveway located
P
on public property.
u greater than, w greater than or equal to, t less than, v less than or equal to
(1) In accordance with the current CAN/CSA B149.1, Natural Gas and Propane Installation Code
(2) In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code
Notes:
1 The vent for this appliance shall not terminate
a. Over public walkways; or
b. Near soffit vents or crawl space vents or other areas where condensate or vapor could create a nuisance or hazard or property damage; or
c. Where condensate vapor could cause damage or could be detrimental to the operation of regulators, relief valves, or other equipment.
2. When locating vent terminations, consideration must be given to prevailing winds, location, and other conditions which may cause recirculation of the combustion products of adjacent vents.
Recirculation can cause poor combustion, inlet condensate problems, and accelerated corrosion of the heat exchangers.
3. Avoid venting under a deck or large overhang. Recirculation could occur and cause performance or system problems.
12 in. (305 mm), 18 in. (457 mm) above roof surface 12 in. (305 mm)
12 in. (305 mm) for appliances u 10,000 Btuh (3 kW) and
v 100,000 Btuh (30 kW), 36 in. (914 mm) for appliances u
100,000 Btuh (30 kW)
For clearances not specified in ANSI Z223.1/NFPA 54 or
CAN/CSA B149.1, clearances shall be in accordance with
local installation codes and the requirements of the gas suppli
er and the manufacture's installation instructions.
3 ft. (.9 m) within a height 15ft (4.5 m) above the meter/regu
lator assembly
12 in. (305 mm) for appliances u 10,000 Btuh (3 kW) and
v 100,000 Btuh (30 kW), 36 in. (914 mm) for appliances u
100,000 Btuh (30 kW)
12 in. (305 mm) Permitted only if veranda, porch, deck, or
balcony is fully open on a minimum of two sides beneath the
floor.
12 in. (305 mm) 12 in. (305 mm)
3 ft. (.9 m) 3 ft. (.9 m)
7 ft. (2.1 m) A vent shall not terminate directly above a side
walk or paved driveway that is located between two single
family dwellings and serves both dwellings.
4 ft. (1.2 m) below or to the side of the opening. 1 ft. (.3 m)
above the opening.
For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/
CSA B149.1, clearances shall be in accordance with local instal
lation codes and the requirements of the gas supplier and the
manufacture's installation instructions.
3 ft. (.9 m) within 15 ft. (4.5 m) above the meter/regulator
assembly
3 ft. (.9 m) For clearances not specified in ANSI Z223.1/NFPA
54 or CAN/CSA B149.1, clearances shall be in accordance with
local installation codes and the requirements of the gas supplier
and the manufacture's installation instructions.
4 ft. (1.2 m) below or to the side of opening: 1 ft. (.3 m) above
opening.
For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/
CSA B149.1, clearances shall be in accordance with local instal
lation codes and the requirements of the gas supplier and the
manufacture's installation instructions.
7 ft. (2.1 m)
U.S. Installation (2)
440 01 4201 01 45
Specifications subject to change without notice.
Page 46
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Table 12 MAXIMUM EQUIVALENT VENT LENTH - Feet (Meters)
Note: Maximum Equivalent Vent Length (MEVL) does NOT include elbows or terminations
Use Table 14 − DEDUCTIONS FROM MEVL to determine allowable vent length for each application.
Altitude
FT (M)
Unit Size
BTU/Hr
1-1/2 2 2-1/2 3 4
60,000 55 (16.8) 135 (41.1) 235 (71.6) 265 (80.8) N/A
0 to 2000
(0 to 610)
80,000 35 (10.7) 130 (39.6) 175 (53.3) 235 (71.6) 265 (80.8)
100,000 N/A 50 (15.2) 11 0 (33.5) 235 (71.6) 265 (80.8)
120,000 N/A N/A 15 (4.6) 100 (30.5) 250 (76.2)
60,000 45 (13.7) 127 (38.7) 222 (67.7) 250 (76.2) N/A
2001 to 3000
(610 to 914)
80,000 30 (9.1) 90 (27.4) 165 (50.3) 222 (67.7) 249 (75.9)
100,000 N/A 40 (12.2) 104 (31.7) 223 (68.0) 250 (76.2)
120,000 N/A N/A 11 (3.4) 93 (28.3) 237 (72.2)
60,000 40 (12.2) 119 (36.3) 210 (64.0) 235 (71.6) N/A
3001 to 4000
(914 to 1219)
80,000 25 (7.6) 85 (25.9) 155 (47.2) 210 (64.0) 232 (70.7)
100,000 N/A 40 (12.2) 98 (29.9) 211 (64.3) 236 (71.9)
120,000 N/A N/A 8 (2.4) 86 (26.2) 224 (68.3)
60,000 35 (10.7) 115 (35.1) 204 (62.2) 228 (69.5) N/A
4001 to 4500
(1219 to 1370)
80,000 23 (7.0) 85 (25.9) 150 (45.7) 202 (61.6) 224 (68.3)
100,000 N/A 40 (12.2) 94 (28.7) 205 (62.5) 229 (69.8)
120,000 N/A N/A N/A 83 (25.3) 217 (66.1)
See notes at end of Venting Tables.
See Table 13 for altitudes over 4500 ft (1370m).
Table 13 MAXIMUM EQUIVALENT VENT LENTH - Feet (Meters)
Note: Maximum Equivalent Vent Length (MEVL) does NOT include elbows or terminations.
Use DEDUCTIONS FROM MEVL − Table 14 to determine allowable vent length for each application.
Note: Vent sizing for Canadian installations over 4500 ft. (1370 M) above sea level are subject to acceptance
Altitude
FT (M)
Unit Size
60,000 35 (10.7) 111 (33.8) 198 (60.4) 221 (67.4) N/A
4501 to 5000
(1370 to 1524)
80,000 23 (7.0) 85 (25.9) 146 (44.5) 195 (59.4) 216 (65.8)
100,000 N/A 40 (12.2) 91 (27.7) 200 (61.0) 222 (67.7)
120,000 N/A N/A N/A 80 (24.4) 211 (64.3)
60,000 37 (11.3) 103 (31.4) 186 (56.7) 207 (63.1) N/A
5001 to 6000
(1524 to 1829)
80,000 22 (6.7) 76 (23.2) 137 (41.8) 183 (55.8) 200 (61.0)
100,000 N/A 33 (10.1) 85 (25.9) 188 (57.3) 208 (63.4)
120,000 N/A N/A N/A 74 (22.6) 199 (60.7)
60,000 35 (10.7) 96 (29.3) 174 (53.0) 194 (59.1) N/A
6001 to 7000
(1829 to 2134)
80,000 20 (6.1) 71 (21.6) 120 (36.6) 171 (52.1) 185 (56.4)
100,000 N/A 31 (9.4) 79 (24.1) 178 (54.3) 195 (59.4)
120,000 N/A N/A N/A 68 (20.7) 187 (57.0)
60,000 32 (9.8) 89 (27.1) 163 (49.7) 181 (55.2) N/A
7001 to 8000
(2134 to 2438)
80,000 18 (5.5) 66 (20.1) 120 (36.6) 159 (48.5) 170 (51.8)
100,000 N/A 29 (8.8) 73 (22.3) 167 (50.9) 182 (55.5)
120,000 N/A N/A N/A 62 (18.9) 175 (53.3)
60,000 30 (9.1) 82 (25.0) 152 (46.3) 168 (51.2) N/A
8001 to 9000
(2438 to 2743)
80,000 17 (5.2) 62 (18.9) 111 (33.8) 148 (45.1) 156 (47.5)
100,000 N/A 27 (8.2) 67 (20.4) 157 (47.9) 170 (51.8)
120,000 N/A N/A N/A 56 (17.1) 164 (50.0)
60,000 27 (8.2) 76 (23.2) 142 (43.3) 156 (47.5) N/A
9001 to 10,000
(2743 to 3048)
80,000 15 (4.6) 57 (17.4) 103 (31.4) 137 (41.8) 142 (43.3)
100,000 N/A 24 (7.3) 62 (18.9) 147 (44.8) 157 (47.9)
120,000 N/A N/A N/A 51 (15.5) 153 (46.6)
NOTES:
A. 3- and 4-inch vent pipe systems require long radius elbows.
B. Vent sizing for Canadian installations over 4500 ft. (1370 M) above sea level are subject to acceptance by the local authorities having jurisdiction.
C. N/A - Not Allowed; pressure switch will not close, or flame disturbance may result..
D. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
E. Size both the combustion-air and vent pipe independently, then use the larger diameter for both pipes.
F. Assume two 45° elbows equal one 90° elbow. Wide radius elbows are desirable and may be required in some cases.
G. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
H. The minimum pipe length is 5 ft (1.5 M) for all applications.
I. Use 3-in. (76 mm) diameter concentric vent termination kit for installations requiring 4-in (102 mm) diameter pipe.
by the local authorities having jurisdiction.
1-1/2 2 2-1/2 3 4
DIRECT VENT (2-PIPE) AND VENTILATED COMBUSTION AIR
Vent Pipe Diameter (in.)
DIRECT VENT (2-PIPE) AND VENTILATED COMBUSTION AIR
Vent Pipe Diameter
46 440 01 4201 01
Specifications subject to change without notice.
Page 47
INSTALLATION INSTRUCTIONS Gas Furnace: (F/G)MAC
Table 14 DEDUCTIONS FROM MAXIMUM EQUIVALENT VENT LENGTH - Feet (Meters)
Pipe Diameter (in): 1-1/2 2 2-1/2 3* 4*
Mitered 90° Elbow 8 (2.4) 8 (2.4) 8 (2.4)
Medium Radius 90° Elbow 5 (1.5) 5 (1.5) 5 (1.5)
Long Radius 90° Elbow 3 (0.9) 3 (0.9) 3 (0.9) 3 (0.9) 3 (0.9)
Mitered 45º Elbow 4 (1.2) 4 (1.2) 4 (1.2)
Medium Radius 45° Elbow 2.5 (0.8) 2.5 (0.8) 2.5 (0.8)
Long Radius 45° Elbow 1.5 (0.5) 1.5 (0.5) 1.5 (0.5) 1.5 (0.5) 1.5 (0.5)
Tee 16 (4.9) 16 (4.9) 16 (4.9) 16 (4.9) 16 (4.9)
* Note: 3- and 4-inch vent pipe systems require long radius elbows.
Venting System Length Calculations
The maximum length for each vent pipe (inlet or exhaust) equals the Maximum Equivalent Vent Length (MEVL) from Table 12 and
Table 13 minus the number of elbows multiplied by the deduction for each elbow in Table 14.
Standard vent terminations and concentric vent terminations count for zero deduction.
Example
A Direct-Vent 60,000 BTU/Hr furnace installed at 2100 ft altitude with 2-inch vent piping.
Venting system includes, FOR EACH PIPE, (3) 90º long radius elbows, (2) 45º long radius elbows and a concentric vent kit.
Maximum Equivalent Vent Length = 127 ft Table 12
Deduct (3) 90° long radius elbows 3 x 3 ft = - 9 ft Table 14
Deduct (2) 45° long radius elbows 2 x 1.5 ft = - 3 ft Table 14
Maximum vent length
115 ft (For EACH vent or inlet pipe)
Table 15
(F/G)9MAC
Max. Heat
Input
60000
80000
100000
Winter
Design
Temp °F (°C)
20 (-10)
0 (-20)
-20 (-30)
-40 (-40)
20 (-10)
0 (-20)
-20 (-30)
-40 (-40)
20 (-10)
0 (-20)
-20 (-30)
-40 (-40)
Maximum Allowable Exposed Vent Lengths in Unconditioned Space
Maximum Length of Uninsulated and Insulated Vent Pipe-Ft (M)
No Insulation 3/8-in. (9.5 mm) 1/2-in. (12.7 mm)
Pipe Length
in Ft. & M
Ft. 34.0 29.0 28.0 23.0 N/A 55.0 88.0 79.0 69.0 N/A 55.0 104.0 93.0 81.0 N/A
M 10.4 8.8 8.5 7.0 N/A 16.8 26.8 24.1 21.0 N/A 16.8 31.7 28.3 24.7 N/A
Ft. 14.0 9.0 7.0 0.0 N/A 55.0 49.0 43.0 34.0 N/A 55.0 60.0 52.0 42.0 N/A
M 4.3 2.7 2.1 0.0 N/A 16.8 14.9 13.1 10.4 N/A 16.8 18.3 15.8 12.8 N/A
Ft. 5.0 0.0 0.0 0.0 N/A 41.0 32.0 26.0 18.0 N/A 50.0 40.0 33.0 24.0 N/A
M 1.5 0.0 0.0 0.0 N/A 12.5 9.8 7.9 5.5 N/A 15.2 12.2 10.1 7.3 N/A
Ft. 0.0 0.0 0.0 0.0 N/A 30.0 21.0 16.0 8.0 N/A 37.0 28.0 22.0 13.0 N/A
M 0.0 0.0 0.0 0.0 N/A 9.1 6.4 4.9 2.4 N/A 11.3 8.5 6.7 4.0 N/A
Ft. 35.0 39.0 39.0 33.0 25.0 35.0 118.0 107.0 92.0 76.0 35.0 130.0 125.0 109.0 90.0
M 10.7 11.9 11.9 10.1 7.6 10.7 36.0 32.6 28.0 23.2 10.7 39.6 38.1 33.2 27.4
Ft. 22.0 16.0 14.0 7.0 0.0 35.0 69.0 60.0 49.0 35.0 35.0 83.0 72.0 60.0 45.0
M 6.7 4.9 4.3 2.1 0.0 10.7 21.0 18.3 14.9 10.7 10.7 25.3 21.9 18.3 13.7
Ft. 11.0 5.0 2.0 0.0 0.0 35.0 46.0 39.0 29.0 16.0 35.0 57.0 48.0 37.0 23.0
M 3.4 1.5 0.6 0.0 0.0 10.7 14.0 11.9 8.8 4.9 10.7 17.4 14.6 11.3 7.0
Ft. 4.0 0.0 0.0 0.0 0.0 35.0 33.0 26.0 17.0 4.0 35.0 41.0 34.0 24.0 11.0
M 1.2 0.0 0.0 0.0 0.0 10.7 10.1 7.9 5.2 1.2 10.7 12.5 10.4 7.3 3.4
Ft. N/A 47.0 47.0 41.0 32.0 N/A 50.0 110.0 112.0 93.0 N/A 50.0 110.0 132.0 110.0
M N/A 14.3 14.3 12.5 9.8 N/A 15.2 33.5 34.1 28.3 N/A 15.2 33.5 40.2 33.5
Ft. N/A 21.0 19.0 12.0 1.0 N/A 50.0 74.0 61.0 45.0 N/A 50.0 89.0 74.0 57.0
M N/A 6.4 5.8 3.7 0.3 N/A 15.2 22.6 18.6 13.7 N/A 15.2 27.1 22.6 17.4
Ft. N/A 8.0 6.0 0.0 0.0 N/A 50.0 49.0 38.0 23.0 N/A 50.0 60.0 48.0 32.0
M N/A 2.4 1.8 0.0 0.0 N/A 15.2 14.9 11.6 7.0 N/A 15.2 18.3 14.6 9.8
Ft. N/A 1.0 0.0 0.0 0.0 N/A 42.0 34.0 24.0 10.0 N/A 50.0 43.0 32.0 18.0
M N/A 0.3 0.0 0.0 0.0 N/A 12.8 10.4 7.3 3.0 N/A 15.2 13.1 9.8 5.5
Pipe Diameter-inches (mm) Pipe Diameter-inches (mm) Pipe Diameter-inches (mm)
1.5 2.0 2.5 3.0 4.0 1.5 2.0 2.5 3.0 4.0 1.5 2.0 2.5 3.0 4.0
(38) (51) (64) (76) (102) (38) (51) (64) (76) (102) (38) (51) (64) (76) (102)
20 (-10)
0 (-20)
120000
-20 (-30)
-40 (-40)
Ft. N/A N/A 15.0 49.0 40.0 N/A N/A 15.0 100.0 111.0 N/A N/A 15.0 100.0 131.0
M N/A N/A 4.6 14.9 12.2 N/A N/A 4.6 30.5 33.8 N/A N/A 4.6 30.5 39.9
Ft. N/A N/A 15.0 17.0 6.0 N/A N/A 15.0 75.0 57.0 N/A N/A 15.0 90.0 70.0
M N/A N/A 4.6 5.2 1.8 N/A N/A 4.6 22.9 17.4 N/A N/A 4.6 27.4 21.3
Ft. N/A N/A 10.0 2.0 0.0 N/A N/A 15.0 48.0 32.0 N/A N/A 15.0 59.0 42.0
M N/A N/A 3.0 0.6 0.0 N/A N/A 4.6 14.6 9.8 N/A N/A 4.6 18.0 12.8
Ft. N/A N/A 1.0 0.0 0.0 N/A N/A 15.0 32.0 17.0 N/A N/A 15.0 41.0 25.0
M N/A N/A 0.3 0.0 0.0 N/A N/A 4.6 9.8 5.2 N/A N/A 4.6 12.5 7.6
440 01 4201 01 47
Specifications subject to change without notice.
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