The Signature Series is NOT designed for amateur installation. Installation SHOULD be performed by an authorized technician.
Please read this manual carefully before installation and keep it for future reference.
The Signature Series is NOT designed for amateur installation. Installation SHOULD be performed by an authorized technician.
Please read this manual carefully before installation and keep it for future reference.
Owner & Installation
Manual
MGM*96SE*XA Gas Furnace
Signature Series
Due to updates and constantly improving performance, the information and
instructions within this manual are subject to change without notice. Please visit
www.mrcool.com/documentation to ensure you have the latest version of this manual.
Version Date: 07-29-22
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(P) 507768C05
*P507768C05*
Manufactured By
MRCOOL LLC
Hickory, KY 42051
This manual must be left with the homeowner for future reference.
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to
the potential for personal injury or death.
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional installer (or
equivalent), service agency or the gas supplier.
WARNING
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION
Table of Contents
Unit Dimensions ..........................................................2
Parts Arrangement.......................................................3
Gas Furnace ................................................................4
Shipping and Packing List ...........................................4
Safety Information .......................................................4
General ........................................................................6
Combustion, Dilution & Ventilation Air .........................6
Installation ...................................................................9
Filters .........................................................................13
Duct System ..............................................................13
Venting Practices .......................................................16
Condensate Piping ....................................................34
Gas Piping .................................................................38
Electrical ....................................................................41
Unit Start-Up ..............................................................45
Testing for Proper Venting and Sucient Combustion
Air for Non-Direct Vent Applications ..........................49
Other Unit Adjustments..............................................49
Blower Performance ..................................................51
Service.......................................................................53
Planned Service ........................................................56
Repair Parts List ........................................................56
INSTALLATION INSTRUCTIONS
MGM*96SE*XA
Warm Air Gas Furnace Upow/
Horizontal Left/Right Air Discharge
Direct Vent & Non-Direct Vent
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Front View
Top View
Side View
3/4
(19)
B
33
(838)
A
1
Bottom Return
Air Opening
9/16
(14)
C
3/4
(19)
14-3/4
(375)
16
(406)
2
Optional
Side Return
Air Filter Kit
(either side)
5/8
(16)
19-7/16 (494)
27-3/4 (705)
6-1/2 (165)
(either side)
14
(356)
Condensate
Trap Connection
(either side)
Electrical Inlet
(either side)
9 (229) Right
6-9/16 (167) Left
Gas Piping Inlet
(either side)
2 (51) (either side)
9/16
(14)
1 (25)
Front Panel
1
Bottom Return
Air Opening
3-1/4
(83)
12-5/8 (321)
(either side)
23
(584)
1
Side Return
Air Opening
(either side)
1-15/16 (49)
1-1/2
(38)
23-1/2 (597)
Supply Air
Opening
2 (51)
2-7/8
(73)
Exhaust Air
Outlet
Combustion
Air Intake
2
Optional
Side Return
Air Filter Kit
(either side)
23-3/4 (603)
25 (635)
3-3/8
(86)
D
1
NOTE - (5 Ton) size units installed in upow applications that
require air volumes of 1800 cfm (850 L/s) or greater must have
one of the following:
1. Single side return air with transition, to accommodate 20 x 25
x 1 in. (508 x 635 x 25 mm) cleanable air lter. (Required to
maintain proper air velocity.)
2. Single side return air with optional “RAB” Return Air Base.
3. Bottom return air.
4. Return air from both sides.
5. Bottom and one side return air.
See “Blower Performance Tables” for additional information.
2
Optional External Side Return Air Filter kit is not for use with
optional Return Air Base.
* Consider sizing requirements for optional IAQ equipment before
cutting side return opening.
Unit Dimensions
Capacity
A B C D
in. mm in. mm in. mm in. mm
045-B3
070-B3
17-1/2 446 16-3/8 416 16 406 7-5/8 194
090-C4
110-C5
21 533 19-7/8 505 19-1/2 495 9-3/8 238
135-D5 24-1/2 622 23-3/8 594 23 584 11-1/8 283
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Figure 1.
Parts Arrangement
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Gas Furnace
The MGM*96SE*XA Category IV gas furnace is shipped
ready for installation in the upflow or horizontal
position. The furnace is shipped with the bottom panel
in place. The bottom panel must be removed if the unit
is to be installed in horizontal or upflow applications with
bottom return air.The MGM*96SE*XA can be installed as
either a Direct Vent or a Non-Direct Vent gas central
furnace.
The furnace is equipped for installation in natural
gas applications. A conversion kit (ordered
separately) is required for use in propane/LP gas
applications.
NOTE: In Direct Vent installations, combustion air is
taken from outdoors and flue gases are discharged
outdoors. In Non-Direct Vent installations, combustion air
is taken from indoors or ventilated attic or crawlspace
and flue gases are discharged outdoors. See Figure 2
and Figure 3 for applications involving roof termination.
Figure 2.
Figure 3.
Shipping and Packing List
1 - Assembled Gas Furnace
1 - Bag assembly containing the following:
1 - Snap bushing
1 - Snap Plug
1 - Wire tie
1 - Condensate trap
1 - Condensate trap cap
1 - Condensate trap clamp
1 - 2” diameter debris screen
1 - 3/4” Threaded street elbow
NOTE: The required bellows grommet is eld-provided.
See the Gas Piping section for relevant diagrams.
Check equipment for shipping damage. If you nd any
damage, immediately contact the last carrier.
Please refer to specication sheets for available
accessories.
Safety Information
DANGER OF EXPLOSION!
There are circumstances in which odorant used with
LP/Propane gas can lose its scent. In case of a leak,
LP/Propane gas will settle close to the oor and may be
dicult to smell. An LP/Propane leak detector should be
installed in all LP applications.
DANGER
Use only the type of gas approved for use with this
furnace. Refer to unit nameplate.
MGM*96SE*XA units are CSA International certified to
ANSI Z21.47 and CSA 2.3 standards.
Building Codes
In the USA, installation of gas furnaces must conform with
local building codes. In the absence of local codes, units
must be installed according to the current National Fuel
Gas Code (ANSI Z223.1/NFPA 54). The National Fuel Gas
Code is available from the American National Standards
Institute,Inc., 11 West 42nd Street, New York, NY 10036.
In Canada, installation must conform with current National
Standard of Canada CSA-B149 Natural Gas and Propane
Installation Codes, local plumbing or waste water codes
and other applicable local codes.
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In order to ensure proper unit operation in non-direct vent
applications, combustion and ventilation air supply must
be provided according to the current National Fuel Gas
Code or CSA-B149 standard.
Installation Locations
This furnace is CSA International certied for installation
clearances to combustible material as listed on the unit
nameplate and in the table in Figure 13 and Figure 18.
Accessibility and service clearances must take precedence
over re protection clearances.
NOTE: For installation on combustible oors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood ooring.
For installation in a residential garage, the furnace must be
installed so that the burner(s) and the ignition source are
located no less than 18 inches (457 mm) above the oor.
The furnace must be located or protected to avoid physical
damage by vehicles. When a furnace is installed in a public
garage, hangar, or other building that has a hazardous
atmosphere, the furnace must be installed according to
recommended good practice requirements and current
National Fuel Gas Code or CSA B149 standards.
NOTE: Furnace must be adjusted to obtain a temperature
rise within the range specied on the unit nameplate.
Failure to do so may cause erratic limit operation and
premature heat exchanger failure.
This furnace must be installed so that its electrical
components are protected from water.
Installed in Combination with a Cooling Coil
When this furnace is used with cooling units (Figure 4),
it shall be installed in parallel with, or on the upstream
side of, cooling units to avoid condensation in the heating
compartment. With a parallel ow arrangement, a damper
(or other means to control the ow of air) must adequately
prevent chilled air from entering the furnace. If the damper
is manually operated, it must be equipped to prevent
operation of either the heating or the cooling unit, unless it
is in the full HEAT or COOL setting.
When installed, this furnace must be electrically grounded
according to local codes. In addition, in the United States,
installation must conform with the current National
Electric Code, ANSI/NFPA No. 70. The National Electric
Code (ANSI/NFPA No. 70) is available from the following
address:
National Fire Protection Association
1 Battery March Park
Quincy, MA 02269
In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of
the Canadian Electrical Code Part I (CSA Standard C22.1)
and/or local codes.
Figure 4. Heating Unit Installed Parallel to Air Handler
Unit
NOTE: This furnace is designed for a minimum continuous
return air temperature of 60°F (16°C) or an intermittent
operation down to 55°F (13°C) dry bulb for cases where a
night setback thermostat is used. Return air temperature
must not exceed 85°F (29°C) dry bulb.
This furnace may be installed in alcoves, closets, attics,
basements, garages, and utility rooms in the upow or
horizontal position.
This furnace design has not been CSA certied for
installation in mobile homes, recreational vehicles, or
outdoors.
Use of Furnace as a Construction Heater
Units may be used for heating of buildings or structures
under construction, if the following conditions are met to
ensure proper operation.
DO NOT USE THE UNIT FOR CONSTRUCTION HEAT
UNLESS ALL OF THE FOLLOWING CRITERIA ARE
MET:
a. Furnace must be in its nal location. The vent system
must be permanently installed per these installation
instructions.
b. Furnace must be installed as a two pipe system
and one hundred percent (100%) outdoor air must
be provided for combustion air requirements during
construction.
c. A room thermostat must control the furnace. The use
of xed jumpers that will provide continuous heating is
prohibited.
d. The input rate and temperature rise must be set per
the furnace rating plate.
e. Supply and Return air ducts must be provided and
sealed to the furnace. Return air must be terminated
outside of the space where furnace is installed.
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f. Return air temperature range between 60°F (16°C)
and 80°F (27°C) must be maintained.
g. MERV 11 or greater air lters must be installed in
the system and must be regularly inspected and
maintained (e.g., regular static checks and replaced at
end of life) during construction.
h. Blower and vestibule access panels must be in place
on the furnace at all times.
i. The furnace heat exchanger, components, duct
system, and evaporator coils must be thoroughly
cleaned following nal construction clean−up.
j. Air lters must be replaced upon construction
completion.
k. All furnace operating conditions (including ignition,
input rate, temperature rise and venting) must
be veried in accordance with these installation
instructions.
EQUIPMENT MAY EXPERIENCE PREMATURE
COMPONENT FAILURE AS A RESULT OF FAILURE TO
FOLLOW THE ABOVE INSTALLATION INSTRUCTIONS.
FAILURE TO FOLLOW THE ABOVE INSTALLATION
INSTRUCTIONS VOIDS THE MANUFACTURER’S
EQUIPMENT LIMITED WARRANTY. MRCOOL
DISCLAIMS ALL LIABILITY IN CONNECTION WITH
INSTALLER’S FAILURE TO FOLLOW THE ABOVE
INSTALLATION INSTRUCTIONS.
NOTWITHSTANDING THE FOREGOING, INSTALLER
IS RESPONSIBLE FOR CONFIRMING THAT THE USE
OF CONSTRUCTION HEAT IS CONSISTENT WITH
THE POLICIES AND CODES OF ALL REGULATING
ENTITIES. ALL SUCH POLICIES AND CODES MUST BE
ADHERED TO.
General
These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.
In addition to the requirements outlined previously, the
following general recommendations must be considered
when installing one of these furnaces:
• Place the furnace as close to the center of the air
distribution system as possible. The furnace should
also be located close to the vent termination point.
• When the furnace is installed in non-direct vent
applications, do not install the furnace where drafts
might blow directly into it. This could cause improper
combustion and unsafe operation.
• When the furnace is installed in non-direct vent
applications, do not block the furnace combustion air
opening with clothing, boxes, doors, etc. Air is needed
for proper combustion and safe unit operation.
• When the furnace is installed in an attic or other
insulated space, keep insulation away from the
furnace.
• When the furnace is installed in an unconditioned
space, consider provisions required to prevent freezing
of condensate drain system.
NOTE: The Commonwealth of Massachusetts stipulates
these additional requirements:
• Gas furnaces shall be installed by a licensed plumber
or tter only.
• The gas cock must be “T handle” type.
• When a furnace is installed in an attic, the passageway
to and service area surrounding the equipment shall
be oored.
These units should not be installed in areas normally
subject to freezing temperatures.
CAUTION
Combustion, Dilution & Ventilation Air
If this unit is installed as a Non-Direct Vent Furnace, follow
the guidelines in this section.
NOTE: In Non-Direct Vent Installations, combustion air is
taken from indoors and ue gases are discharged outdoors.
In the past, there was no problem in bringing in sucient
outdoor air for combustion. Inltration provided all the air
that was needed. In today’s homes, tight construction
practices make it necessary to bring in air from outside
for combustion. Take into account that exhaust fans,
appliance vents, chimneys, and replaces force additional
air that could be used for combustion out of the house.
Unless outside air is brought into the house for combustion,
negative pressure (outside pressure is greater than inside
pressure) will build to the point that a down draft can
occur in the furnace vent pipe or chimney. As a result,
combustion gases enter the living space creating a
potentially dangerous situation.
In the absence of local codes concerning air for combustion
and ventilation, use the guidelines and procedures in this
section to install these furnaces to ensure ecient and safe
operation. You must consider combustion air needs and
requirements for exhaust vents and gas piping. A portion
of this information has been reprinted with permission from
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the National Fuel Gas Code (ANSI-Z223.1/NFPA 54). This
reprinted material is not the complete and ocial position
of ANSI on the referenced subject, which is represented
only by the standard in its entirety.
Insucient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine base swimming pool chemicals
• Water softening chemicals
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes, etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
WARNING
Do not install the furnace in a corrosive or contaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.
CAUTION
In Canada, refer to the CSA B149 Installation codes.
All gas-red appliances require air for the combustion
process. If sucient combustion air is not available,
the furnace or other appliance will operate ineciently
and unsafely. Enough air must be provided to meet the
needs of all fuel-burning appliances and appliances such
as exhaust fans which force air out of the house. When
replaces, exhaust fans, or clothes dryers are used at the
same time as the furnace, much more air is required to
ensure proper combustion and to prevent a down draft.
Insucient air causes incomplete combustion which can
result in carbon monoxide.
In addition to providing combustion air, fresh outdoor air
dilutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents
and other contaminants which can corrode furnace
components.
The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is
installed in an unconned or a conned space.
Unconned Space
An unconned space is an area such as a basement
or large equipment room with a volume greater than 50
cubic feet (1.42 m³) per 1,000 Btu (.29 kW) per hour of
the combined input rating of all appliances installed in that
space. This space also includes adjacent rooms which are
not separated by a door. Though an area may appear to
be unconned, it might be necessary to bring in outdoor air
for combustion if the structure does not provide enough air
by inltration. If the furnace is located in a building of tight
construction with weather stripping and caulking around
the windows and doors, follow the procedures in the “Air
from Outside” section.
Conned Space
A conned space is an area with a volume less than 50
cubic feet (1.42 m³) per 1,000 Btu (.29 kW) per hour of
the combined input rating of all appliances installed in that
space. This denition includes furnace closets or small
equipment rooms.
When the furnace is installed so that supply ducts carry
air circulated by the furnace to areas outside the space
containing the furnace, the return air must be handled by
ducts which are sealed to the furnace casing and which
terminate outside the space containing the furnace. This
is especially important when the furnace is mounted on
a platform in a conned space such as a closet or small
equipment room. Even a small leak around the base of the
unit at the platform or at the return air duct connection can
cause a potentially dangerous negative pressure condition.
Air for combustion and ventilation can be brought into the
conned space either from inside the building or from
outside.
Air from Inside
If the conned space that houses the furnace adjoins a
space categorized as unconned, air can be brought in
by providing two permanent openings between the two
spaces. Each opening must have a minimum free area of 1
square inch (645 mm²) per 1,000 Btu (.29 kW) per hour of
total input rating of all gas-red equipment in the conned
space. Each opening must be at least 100 square inches
(64516 mm²). One opening shall be within 12 inches (305
mm) of the top of the enclosure and one opening within 12
inches (305 mm) of the bottom. See Figure 5.
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Figure 5. Equipment in Conned Space - All Air From
Inside
Air from Outside
If air from outside is brought in for combustion and
ventilation, the conned space shall be provided with two
permanent openings. One opening shall be within 12” (305
mm) of the top of the enclosure and one within 12” (305
mm) of the bottom. These openings must communicate
directly or by ducts with the outdoors or spaces (crawl
or attic) that freely communicate with the outdoors or
indirectly through vertical ducts. Each opening shall have
a minimum free area of 1 square inch per 4,000 Btu (645
mm² per .59 kW) per hour of the total input rating of all
equipment in the enclosure (see Figure 6 and Figure 7).
It is also permissible to bring in air for combustion from a
ventilated attic (Figure 9) or ventilated crawl space (Figure
10).
Figure 6. Equipment in Conned Space - All Air from
Outside
(Inlet Air from Crawl Space and Outlet Air to
Ventilated Attic)
When communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1
square inch (645 mm²) per 2,000 Btu (.56 kW) per hour of
the total input rating of all equipment in the enclosure. See
Figure 8.
When ducts are used, they shall be of the same cross-
sectional area as the free area of the openings to which
they connect. The minimum dimension of rectangular
air ducts shall be no less than 3 inches (75 mm). In
calculating free area, the blocking eect of louvers, grilles,
or screens must be considered. If the design and free area
of protective covering is not known for calculating the size
opening required, it may be assumed that wood louvers
will have 20 to 25 percent free area and metal louvers and
grilles will have 60 to 75 percent free area. Louvers and
grilles must be xed in the open position or interlocked
with the equipment so that they are opened automatically
during equipment operation.
Figure 7. Equipment in Conned Space - All Air from
Outside
(All Air through Ventilated Attic)
Figure 8. Equipment in Conned Space - All Air from
Outside
OUTLET AIR
INLET AIR
NOTE−Each air duct opening shall have a free area of at least one
square inch per 2,000 Btu (645mm
2
per .59kW) per hour of the total
input rating of all equipment in the enclosure. If the equipment room
is located against an outside wall and the air openings communi-
cate directly with the out doors, each opening shall have a free area
of at least 1 square inch per 4,000 Btu (645mm
2
per 1.17kW) per
hour of the total input rating of all other equipment in the enclosure.
ROOF TERMINATED
EXHAUST PIPE
SIDE WALL
TERMINATED
EXHAUST PIPE
(ALTERNATE
LOCATION)
FURNACE
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If this unit is being installed in an application with
combustion air coming in from a space serviced by an
exhaust fan, power exhaust fan, or other device which
may create a negative pressure in the space, take care
when sizing the inlet air opening. The inlet air opening
must be sized to accommodate the maximum volume
of exhaust air as well as the maximum volume of
combustion air required for all gas appliances serviced
by this space.
WARNING
Ventilation Louvers
Inlet Air
(Minimum 12 in.
(305mm) above
Attic Floor)
Roof Terminated
Exhaust Pipe
Furnace
*Intake Debris
Screen
(Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
2
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 9. Equipment in Conned Space
(Inlet Air from Ventilated Attic and Outlet Air to
Outside)
Roof Terminated
Exhaust Pipe
Furnace
Ventilation
Louvers
(Crawl Space)
*Intake Debris Screen Provided
Inlet Air
Minimum
12 in. (305mm)
above Crawl
Space Floor
Coupling or
3 in. to 2 in.
Transition
(Field Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
2
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 10. Equipment in Conned Space
(Inlet Air from Ventilated Crawl Space and Outlet Air
to Outside)
Shipping Bolt Removal
Units with 1/2 hp & 3/4 hp blower motor are equipped
with three exible legs and one rigid leg. The rigid leg
is equipped with a shipping bolt and a at white plastic
washer (rather than the rubber mounting grommet used
with a exible mounting leg). See Figure 11. The bolt and
washer must be removed before the furnace is placed into
operation. After the bolt and washer have been removed,
the rigid leg will not touch the blower housing.
Figure 11.
Units with 1/2 HP & 3/4 HP
Blower Motor
Installation
Setting Equipment
Do not connect the return air ducts to the back of the
furnace. Doing so will adversely aect the operation of
the safety control devices, which could result in personal
injury or death.
WARNING
Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into
living space resulting in personal injury or death.
WARNING
Upow Applications
The gas furnaces can be installed as shipped in the upow
position. Refer to Figure 13 for clearances. Select a location
that allows for the required clearances that are listed on
the unit nameplate. Also consider gas supply connections,
electrical supply, vent connection, condensate trap and
drain connections, and installation and service clearances
[24 inches (610 mm) at unit front]. The unit must be level
from side to side. Tilt the unit slightly (maximum 1/2 in.
from level) from back to front to aid in the draining of the
heat exchanger. See Figure 12.
Allow for clearances to combustible materials as indicated
on the unit nameplate.
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Figure 12. Setting Equipment
Tilt the unit slightly (Max. 1/2”) from back to front to aid in the draining of the heat exchanger.
Unit must be level side-to-side in all applications.
Improper installation of the furnace can result in
personal injury or death. Combustion and ue products
must never be allowed to enter the return air system or
air in the living space. Use sheet metal screws and joint
tape to seal return air system to furnace.
In platform installations with furnace return, the furnace
should be sealed airtight to the return air plenum. A door
must never be used as a portion of the return air duct
system. The base must provide a stable support and an
airtight seal to the furnace. Allow absolutely no sagging,
cracks, gaps, etc.
For no reason should return and supply air duct systems
ever be connected to or from other heating devices
such as a replace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
WARNING
Figure 13. Installation Clearances
Upow Applications
Left Side Right Side
Top
Bottom (Floor)
Top/Plenum 1 in. (25 mm)
* Front 0
Back 0
Sides 0†
Vent 0
Floor 0‡
* Front clearance in alcove installation must be 24 in. (610
mm). Maintain a minimum of 24 in. (610 mm) for front service
access.
† Allow proper clearances to accommodate condensate trap.
‡ For installations on a combustible oor, do not install
the furnace directly on carpeting, tile or other combustible
materials other than wood ooring.
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Return Air Guidelines
Return air can be brought in through the bottom or either
side of the furnace installed in an upow application. If the
furnace is installed on a platform with bottom return, make
an airtight seal between the bottom of the furnace and the
platform to ensure that the furnace operates properly and
safely. The furnace is equipped with a removable bottom
panel to facilitate installation.
Markings are provided on both sides of the furnace cabinet
for installations that require side return air. Cut the furnace
cabinet at the maximum dimensions shown on Page 2.
Furnace applications which include side return air and a
condensate trap installed on the same side of the cabinet
(trap can be installed remotely within 5 ft.) require either a
return air base or eld-fabricated transition to accommodate
an optional IAQ accessory taller than 14.5”. See Figure 14.
Figure 14. Side Return Air
(with Transition and Filter)
Return
Air
Plenum
Tr ansition
20” X 25” X 1”
(508mm X 635mm X25mm)
Air Filter
Figure 15. Optional Return Air Base
(Upow Applications Only)
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Figure 16. Removing the Bottom Panel
Removing the Bottom Panel
Remove the two screws that secure the bottom cap to the
furnace. Pivot the bottom cap down to release the bottom
panel. Once the bottom panel has been removed, reinstall
the bottom cap. See Figure 16.
Horizontal Applications
Do not install the furnace on its front or its back. See
Figure 17.
WARNING
Figure 17.
This furnace can be installed in horizontal applications with
either right or left hand air discharge.
Refer to Figure 18 for clearances in horizontal applications.
Figure 18. Installation Clearances
Horizontal Applications
Bottom (Floor)**
Left End
Right End
Air
Flow
Air
Flow
Right-Hand Discharge
Left End
Right End
Air
Flow
Air
Flow
Bottom (Floor)**
Left-Hand Discharge
Top/Plenum 1 in. (25 mm)
* Front 0
Back 0
Sides 0†
Vent 0
Floor 0‡
* Front clearance in alcove installation must be 24 in. (610
mm). Maintain a minimum of 24 in. (610 mm) for front service
access.
† Allow proper clearances to accommodate condensate trap.
‡ For installations on a combustible oor, do not install
the furnace directly on carpeting, tile or other combustible
materials other than wood ooring.
Suspended Installation of Horizontal Unit
This furnace may be installed in either an attic or a crawl
space. Either suspend the furnace from roof rafters or oor
joists, as shown in Figure 19, or install the furnace on a
platform, as shown in Figure 20. A horizontal suspension
kit (51W10) may be ordered from your distributor or use
equivalent.
Figure 19. Typical Horizontal Application
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NOTE: Heavy-gauge sheet metal straps may be used to
suspend the unit from roof rafters or ceiling joists. When
straps are used to suspend the unit in this way, support
must be provided for both the ends. The straps must not
interfere with the plenum or exhaust piping installation.
Cooling coils and supply and return air plenums must be
supported separately.
NOTE: When the furnace is installed on a platform or with
the horizontal suspension kit in a crawl space, it must be
elevated enough to avoid water damage, accommodate
drain trap and to allow the evaporator coil to drain.
Platform Installation of Horizontal Unit
1. Select location for unit keeping in mind service and
other necessary clearances. See Figure 18.
2. Construct a raised wooden frame and cover frame
with a plywood sheet. If unit is installed above nished
space, fabricate an auxiliary drain pan to be installed
under unit. Set unit in drain pan as shown in Figure
20. Leave 8 inches for service clearance below unit for
condensate trap.
3. Provide a service platform in front of unit. When
installing the unit in a crawl space, a proper support
platform may be created using cement blocks.
4. Route auxiliary drain line so that water draining from
this outlet will be easily noticed by the homeowner.
5. If necessary, run the condensate line into a condensate
pump to meet drain line slope requirements. The
pump must be rated for use with condensing furnaces.
Protect the condensate discharge line from the pump
to the outside to avoid freezing.
6. Continue with exhaust, condensate and intake piping
installation according to instructions.
Figure 20.
Return Air - Horizontal Applications
Return air may be brought in only through the end of a
furnace installed in the horizontal position. The furnace
is equipped with a removable bottom panel to facilitate
installation. See Figure 16.
Filters
This unit is not equipped with a lter or rack. A eld provided
lter is required for the unit to operate properly. Table 1 lists
recommended lter sizes.
A lter must be in place whenever the unit is operating.
Furnace Cabinet
Width
Filter Size
Side Return Bottom Return
B (17-1/2”)
16 x 25 x 1 (1)
16 x 25 x 1 (1)
C (21”) 20 x 25 x 1 (1)
D (24-1/2”) 16 x 25 x 1 (2) 24 x 25 x 1 (1)
Table 1.
Duct System
Use industry approved standards to size and install the
supply and return air duct system. This will result in a quiet
and low-static system that has uniform air distribution.
NOTE: This furnace is not certied for operation in heating
mode (indoor blower operating at selected heating speed)
with an external static pressure which exceeds 0.5 inches
w.c. Operation at these conditions may result in improper
limit operation.
Supply Air Plenum
If the furnace is installed without a cooling coil, a removable
access panel should be installed in the supply air duct. The
access panel should be large enough to permit inspection
(by reected light) of the heat exchanger for leaks after the
furnace is installed. The furnace access panel must always
be in place when the furnace is operating and it must not
allow leaks into the supply air duct system.
Return Air Plenum
NOTE: Return air must not be drawn from a room where
this furnace, or any other gas fueled appliance (i.e., water
heater), or carbon monoxide producing device (i.e., wood
replace) is installed.
When return air is drawn from a room, a negative pressure
is created in the room. If a gas appliance is operating in
a room with negative pressure, the ue products can be
pulled back down the vent pipe and into the room. This
reverse ow of the ue gas may result in incomplete
combustion and the formation of carbon monoxide gas.
This raw gas or toxic fumes might then be distributed
throughout the house by the furnace duct system.
Return air can be brought in through the bottom or either
side of the furnace. If a furnace with bottom return air is
installed on a platform, make an airtight seal between the
bottom of the furnace and the platform to ensure that the
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unit operates properly and safely. Use berglass sealing
strips, caulking, or equivalent sealing method between the
plenum and the furnace cabinet to ensure a tight seal. If
a lter is installed, size the return air duct to t the lter
frame.
Pipe & Fittings Specications
All pipe, ttings, primer and solvent cement must conform
with American National Standard Institute and the American
Society for Testing and Materials (ANSI/ASTM) standards.
The solvent shall be free owing and contain no lumps,
undissolved particles or any foreign matter that adversely
aects the joint strength or chemical resistance of the
cement. The cement shall show no gelation, stratication,
or separation that cannot be removed by stirring. Refer to
Table 2 for approved piping and tting materials.
Solvent cements for plastic pipe are ammable liquids
and should be kept away from all sources of ignition.
Do not use excessive amounts of solvent cement when
making joints. Good ventilation should be maintained to
reduce re hazard and to minimize breathing of solvent
vapors. Avoid contact of cement with skin and eyes.
CAUTION
MGM*96SE
*XA exhaust and intake connections are
made of PVC. Use PVC primer and solvent
cement when using PVC vent pipe. When using ABS
vent pipe, use transitional solvent cement to make
connections to the PVC fitting in the unit.
IMPORTANT
Use PVC primer and solvent cement or ABS solvent
cement meeting ASTM specications, refer to Table 2.
As an alternate, use all purpose cement, to bond ABS,
PVC, or CPVC pipe when using ttings and pipe made of
the same materials. Use transition solvent cement when
bonding ABS to either PVC or CPVC.
Low temperature solvent cement is recommended during
cooler weather. Metal or plastic strapping may be used for
vent pipe hangers. Uniformly apply a liberal coat of PVC
primer for PVC or use a clean dry cloth for ABS to clean
inside socket surface of tting and male end of pipe to
depth of tting socket.
Canadian Applications Only
Pipe, ttings, primer and solvent cement used to vent
(exhaust) this appliance must be certied to ULC S636 and
supplied by a single manufacturer as part of an approved
vent (exhaust) system. When bonding the vent system to
the furnace, use ULC S636 approved One-Step Transition
Cement to bond the pipe to the ue collar, or to bond
the 90° elbow or reducing 90° elbow to the ue collar. In
addition, the rst three feet of vent pipe from the furnace
ue collar must be accessible for inspection.
Table 2.
Piping and Fittings Specications
Schedule 40 PVC (Pipe) D1785
Schedule 40 PVC (Cellular Core Pipe) F891
Schedule 40 PVC (Fittings) D2466
Schedule 40 CPVC (Pipe) F441
Schedule 40 CPVC (Fittings) F438
SDR-21 PVC or SDR-26 PVC (Pipe) D2241
SDR-21 CPVC or SDR-26 CPVC (Pipe) F442
Schedule 40 ABS Cellular Core DWV
(Pipe)
F628
Schedule 40 ABS (Pipe) D1527
Schedule 40 ABS (Fittings) D2468
ABS-DWV (Drain Waste & Vent)
(Pipe & Fittings)
D2661
PVC-DWV (Drain Waste & Vent)
Pipe & Fittings)
D2665
PRIMER & SOLVENT CEMENT
ASTM
SPECIFICATION
PVC & CPVC Primer F656
PVC Solvent Cement D2564
CPVC Solvent Cement F493
ABS Solvent Cement D2235
PVC/CPVC/ABS All Purpose Cement For
Fittings & Pipe of the same material
D2564, D2235,
F493
ABS to PVC or CPVC Transition Solvent
Cement
D3138
CANADA PIPE & FITTING & SOLVENT
CEMENT
MARKING
PVC & CPVC Pipe and Fittings
ULCS636PVC & CPVC Solvent Cement
ABS to PVC or CPVC Transition Cement
POLYPROPYLENE VENTING SYSTEM
ULC-S636
PolyPro® by Duravent
InnoFlue® by Centrotherm ULC-S636
ECCO Polypropylene Vent
TM
ULC-S636
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Capacity
Vent Pipe
Dia.
(in.)
Standard Concentric
Flush Mount Kit Wall Kit
Field
Fabricated
1-1/2 inch 2 inch 3 inch
51W11 (US)
51W12 (CA)
2 inch 3 inch
71M80 (US)
4
44W92
(CA)
69M29 (US)
4
44W92
(CA)
60L46 (US)
4
444W93
(CA)
22G44 (US)
4
30G28 (CA)
44J40 (US)
4
81J20 (CA)
045
1
1-1/2
3
YES YES
1
YES
5
YES
2
YES
N/A N/A
2
3
YES YES
1
YES
5
YES
2
YES
2-1/2
3
YES YES
1
YES
5
YES
2
YES
3
3
YES YES
1
YES
5
YES
2
YES
070
1
1-1/2 3YES YES
1
YES
5
YES
2
YES
2 3YES YES
1
YES
5
YES
2
YES
2-1/2
3
YES YES
1
YES
5
YES
2
YES
3
3
YES YES
1
YES
5
YES
2
YES
090
2
3
YES
N/A
YES
5
YES
N/A
YES YES
2-1/2
3
YES YES
5
YES YES YES
3
3
YES YES
5
YES YES YES
110
2 YES YES
5
YES YES YES
2-1/2 YES YES
5
YES YES YES
3 YES YES
5
YES YES YES
135 3 YES YES
5
YES YES YES
NOTE - Standard Terminations do not include any vent pipe or elbows external to the structure. Any vent pipe or elbows external to the structure must be included in total
vent length calculations. See vent length tables.* Kits must be properly installed according to kit instructions.
1Requires eld-provided outdoor 1-1/2” exhaust accelerator.
2Concentric kits 71M80 and 44W92 include 1-1/2” outdoor accelerator, when used with 045 and 070 input models. When using 1-1/2 in. piping, the pipe must transition to
2in. pipe when used with the concentrci kit.
3 Flush mount kits 51W11 and 51W12 includes 1-1/2 in. outdoor exhaust accelerator, required when used with 045, 070 and 090 input models. When using 1-1/2 in. piping,
the pipe must transition to 2in. pipe when used with the ush mount kit.
4 Termination kits 30G28, 44W92, 44W93 and 81J20 are certied to ULC S636 for use in Canada only.
5 See table 10 for vent accelerator requirements
6 2inch to 1-1/2 inch reducer required. must be ed required.
Table 3. Outdoor Termination Kits Usage
Joint Cementing Procedure
All cementing of joints should be done according to the
specications outlined in ASTM D 2855.
NOTE: A sheet metal screw may be used to secure the
intake pipe to the connector, if desired. Use a drill or self
tapping screw to make a pilot hole.
DANGER OF EXPLOSION!
Fumes from PVC glue may ignite during system check.
Allow fumes to dissipate for at least 5 minutes before
placing unit into operation.
DANGER
1. Measure and cut vent pipe to desired length.
2. Debur and chamfer end of pipe, removing any ridges
or rough edges. If end is not chamfered, edge of pipe
may remove cement from tting socket and result in a
leaking joint.
3. Clean and dry surfaces to be joined.
4. Test t joint and mark depth of tting on outside of pipe.
5. Uniformly apply a liberal coat of PVC primer for PVC
or use a clean dry cloth for ABS to clean inside socket
surface of tting and male end of pipe to depth of tting
socket.
NOTE: Time is critical at this stage. Do not allow
primer to dry before applying cement.
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6. Promptly apply solvent cement to end of pipe and
inside socket surface of tting. Cement should be
applied lightly but uniformly to inside of socket. Take
care to keep excess cement out of socket. Apply
second coat to end of pipe.
7. Immediately after applying last coat of cement to pipe,
and while both inside socket surface and end of pipe
are wet with cement, forcefully insert end of pipe into
socket until it bottoms out. Turn PVC pipe 1/4 turn
during assembly (but not after pipe is fully inserted) to
distribute cement evenly. Do not turn ABS or cellular
core pipe.
NOTE: Assembly should be completed within 20
seconds after last application of cement. Hammer
blows should not be used when inserting pipe.
8. After assembly, wipe excess cement from pipe at end
of tting socket. A properly made joint will show a bead
around its entire perimeter. Any gaps may indicate
an improper defective assembly due to insucient
solvent.
9. Handle joints carefully until completely set.
Venting Practices
Figure 21.
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from
a venting system commonly run with separate gas
appliances, the venting system is likely to be too large to
properly vent the remaining attached appliances.
Conduct the following test while each appliance is operating
and the other appliances (which are not operating) remain
connected to the common venting system. If the venting
system has been installed improperly, you must correct the
system as indicated in the general venting requirements
section.
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation.
WARNING
1. Seal any unused openings in the common venting
system.
2. Inspect the venting system for proper size and
horizontal pitch. Determine that there is no blockage,
restriction, leakage, corrosion, or other deciencies
which could cause an unsafe condition.
3. Close all building doors and windows and all doors
between the space in which the appliances remaining
connected to the common venting system are located
and other spaces of the building. Turn ON clothes
dryers and any appliances not connected to the
common venting system. Turn ON any exhaust fans,
such as range hoods and bathroom exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close replace dampers.
4. Follow the lighting instructions. Turn ON the appliance
that is being inspected. Adjust the thermostat so that
the appliance operates continuously.
5. After the main burner has operated for 5 minutes, test
for leaks of ue gases at the draft hood relief opening.
Use the ame of a match or candle.
6. After determining that each appliance connected to
the common venting system is venting properly, (step
3) return all doors, windows, exhaust fans, replace
dampers, and any other gas burning appliances to
their previous mode of operation.
7. If a venting problem is found during any of the
preceding tests, the common venting system must be
modied to correct the problems.
Resize the common venting system to the minimum vent
pipe size determined by using the appropriate tables in
Appendix G. (These are in the current standards of the
National Fuel Gas Code ANSI Z223.1.
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Figure 22.
CHIMNEY
OR GAS
VENT
(Check sizing
for remaining
appliance)
FURNACE
(Removed from
from common
vent system)
WATER
HEATER
OPENINGS
(To Adjacent
Room)
If this gas furnace replaces a furnace which
was commonly vented with another gas appliance,
the size of the existing vent pipe for that gas
appliance must be checked. Without the heat of the
original furnace flue products, the existing vent pipe
is probably oversized for the single water heater or
other appliance. The vent should be checked for
proper draw with the remaining appliance.
REPLACING FURNACE THAT
WAS PART OF A COMMON
VENT SYSTEM
Exhaust Piping
See Figure 25 and Figure 26
1. In areas where piping penetrates joist or interior walls,
hole must be large enough to allow clearance on all
sides of pipe through center of hole using a hanger.
2. When furnace is installed in a residence where unit
is shut down for an extended period of time, such
as a vacation home, make provisions for draining
condensate collection from trap and lines.
3. Route piping to outside of structure. Continue with
installation following instructions given in piping
termination section.
Do not discharge exhaust into an existing stack or
stack that also serves another gas appliance. If vertical
discharge through an existing unused stack is required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.
CAUTION
The exhaust vent pipe operates under positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
Vent Piping Guidelines
This gas furnace can be installed as either a Non-Direct
Vent or a Direct Vent gas central furnace.
NOTE: In non-Direct Vent installations, combustion air is
taken from indoors and ue gases are discharged outdoors.
In Direct Vent installations, combustion air is taken from
outdoors and ue gases are discharged outdoors.
Intake and exhaust pipe sizing - Size pipe according to
Table 4 and Table 5A through Table 5D. Table 4 lists the
minimum vent pipe lengths permitted. Table 5A through
Table 5D list the maximum pipe lengths permitted.
Regardless of the diameter of pipe used, the standard
roof and wall terminations described in the Exhaust Piping
section should be used. Exhaust vent termination pipe is
sized to optimize the velocity of the exhaust gas as it exits
the termination. Refer to Table 8.
In some applications which permit the use of several
dierent sizes of vent pipe, a combination vent pipe may
be used. Contact MRCOOL for assistance in sizing vent
pipe in these applications.
NOTE: It is acceptable to use any pipe size which ts
within the guidelines allowed in Table 5A through Table 5D.
NOTE: The exhaust collar on all models is sized to
accommodate 2” Schedule 40 vent pipe. In horizontal
applications, transition to exhaust pipe larger than 2” must
be made in vertical runs of the pipe. A 2” elbow must be
added before the pipe is transitioned to any size larger
than 2”. This elbow must be added to the elbow count
used to determine acceptable vent lengths. Contact the
Application Department for more information concerning
sizing of vent systems which include multiple pipe sizes.
Figure 23.
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Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT
Table 4. Minimum Vent Pipe Lengths
Capacity Min. Vent Length*
045, 070, 090, 110, 135
15 ft or 5 ft plus 2 elbows or
10 ft plus 1 elbow
*Any approved termination may be added to the minimum
length listed.
045, 070,
090, 110,
135
Standard or
Concentric?
See Table 3
Intake or
Exhaust?
1-1/2”, 2”,
2-1/2”,
or 3”
Furnace capacity?
1
Which termination?
2
Which needs most
elbows?
3
How many?
4
Desired pipe size?
5
What is the altitude?
6
Use Table 5 to find
max pipe length.
7
Figure 24.
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Table 5.
Maximum Allowable Intake or Exhaust Vent Length in Feet
Standard Termination at Elevation 0 - 2,000 ft
Number
of 90°
Elbows
Used
1-1/2” Pipe 2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 20 15
n/a n/a n/a
81 66 44 24
n/a
115 115 93 58
n/a
138 137 118 118 80
2 15 10 76 61 39 19 110 110 88 53 133 132 113 113 75
3 10
n/a
71 56 34 14 105 105 83 48 128 127 108 108 70
4
n/a
66 51 29
n/a
100 100 78 43 123 122 103 103 65
5 61 46 24 95 95 73 38 118 117 98 98 60
6 56 41 19 90 90 68 33 113 112 93 93 55
7 51 36 14 85 85 63 28 108 107 88 88 50
8 46 31
n/a
80 80 58 23 103 102 83 83 45
9 41 26 75 75 53 18 98 97 78 78 40
10 36 21 70 70 48 13 93 92 73 73 35
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 5A.
Maximum Allowable Intake or Exhaust Vent Length in Feet
Standard Termination at Elevation 2,001 - 10,000 ft
Number of
90° Elbows
Used
2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 81 35 20
n/a n/a
115 110 67 53
n/a
138 137 118 118 80
2 76 30 15 110 105 62 48 133 132 113 113 75
3 71 25 10 105 100 57 43 128 127 108 108 70
4 66 20
n/a
100 95 52 38 123 122 103 103 65
5 61 15 95 90 47 33 118 117 98 98 60
6 56 10 90 85 42 28 113 112 93 93 55
7 51
n/a
85 80 37 23 108 107 88 88 50
8 46 80 75 32 18 103 102 83 83 45
9 41 75 70 27 13 98 97 78 78 40
10 36 70 65 22 n/a 93 92 73 73 35
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 5B.
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Maximum Allowable Intake or Exhaust Vent Length in Feet
Concentric Termination at Elevation 0 - 2,000 ft
Number
of 90°
Elbows
Used
1-1/2” Pipe 2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 15 10
n/a n/a n/a
73 58 42 22
n/a
105 105 89 54
n/a
121 121 114 114 70
2 10
n/a
68 53 37 17 100 100 84 49 116 116 109 109 65
3
n/a
63 48 32 12 95 95 79 44 111 111 104 104 60
4 58 43 27
n/a
90 90 74 39 106 106 99 99 55
5 53 38 22 85 85 69 34 101 101 94 94 50
6 48 33 17 80 80 64 29 96 96 89 89 45
7 43 28 12 75 75 59 24 91 91 84 84 40
8 38 23
n/a
70 70 54 19 86 86 79 79 35
9 33 18 65 65 49 14 81 81 74 74 30
10 28 13 60 60 44 n/a 76 76 69 69 25
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 5C.
Maximum Allowable Intake or Exhaust Vent Length in Feet
Concentric Termination at Elevation 2,001 - 10,000 ft
Number of
90° Elbows
Used
2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 73 30 15
n/a n/a
105 96 53 38
n/a
121 121 114 114 70
2 68 25 10 100 91 48 33 116 116 109 109 65
3 63 20
n/a
95 86 43 28 111 111 104 104 60
4 58 15 90 81 38 23 106 106 99 99 55
5 53 10 85 76 33 18 101 101 94 94 50
6 48
n/a
80 71 28 13 96 96 89 89 45
7 43 75 66 23
n/a
91 91 84 84 40
8 38 70 61 18 86 86 79 79 35
9 33 65 56 13 81 81 74 74 30
10 28 60 51 n/a 76 76 69 69 25
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 5D.
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Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated Attic or Crawl
Space For Intake Air in Feet
Standard Termination at Elevation 0 - 2,000 ft
Number
of 90°
Elbows
Used
1-1/2” Pipe 2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 15 10
n/a n/a n/a
71 56 34 14
n/a
100 100 78 43
n/a
118 117 98 98 60
2 10
n/a
66 51 29 9 95 95 73 38 113 112 93 93 55
3
n/a
61 46 24
n/a
90 90 68 33 108 107 88 88 50
4 56 41 19 85 85 63 28 103 102 83 83 45
5 51 36 14 80 80 58 23 98 97 78 78 40
6 46 31 9 75 75 53 18 93 92 73 73 35
7 41 26
n/a
70 70 48 13 88 87 68 68 30
8 36 21 65 65 43
n/a
83 82 63 63 25
9 31 16 60 60 38 78 77 58 58 20
10 26 11 55 55 33 73 72 53 53 15
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 6A.
Maximum Allowable Exhaust Vent Lengths With Furnace Installed in a Closet or Basement Using Ventilated Attic or Crawl
Space For Intake Air in Feet
Standard Termination at Elevation 2,001 - 10,000 ft
Number of
90° Elbows
Used
2” Pipe 2-1/2" Pipe 3" Pipe
Capacity Capacity Capacity
045 070 090 110 135 045 070 090 110 135 045 070 090 110 135
1 71 30 15
n/a n/a
100 96 53 38
n/a
118 117 98 98 60
2 66 25 10 95 91 48 33 113 112 93 93 55
3 61 20
n/a
90 86 43 28 108 107 88 88 50
4 56 15 85 81 38 23 103 102 83 83 45
5 51 10 80 76 33 18 98 97 78 78 40
6 46
n/a
75 71 28 13 93 92 73 73 35
7 41 70 66 23
n/a
88 87 68 68 30
8 36 65 61 18 83 82 63 63 25
9 31 60 56 13 78 77 58 58 20
10 26 55 51 n/a 73 72 53 53 15
NOTE - Size intake and exhaust pipe length separately. Values in table are for Intake OR Exhaust, not combined total. Both Intake
and Exhaust must be same pipe size.
NOTE - Additional vent pipe and elbows used to terminate the vent pipe outside the structure must be included in the total vent length
calculation.
NOTE - Contact your local FTC if more than 85ft of venting is needed.
Table 6B.
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TYPICAL EXHAUST PIPE CONNECTIONS IN UPFLOW DIRECT OR
NON-DIRECT VENT APPLICATIONS
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
NOTE: Exhaust pipe and intake pipe must be the same diameter.
2”
2”
2”
2”
or
or
TRANSITION
3”
*2”
2”
EXHAUST
Pipe size determined in Table 5
DO NOT transition
from smaller to larger
pipe in horizontal runs
of exhaust pipe.
045/070 Only
TRANSITION
1-1/2”
2”
6”
MINIMUM
Figure 25.
TYPICAL EXHAUST PIPE CONNECTIONS IN HORIZONTAL DIRECT OR NON-DIRECT VENT
APPLICATIONS (RIGHT-HAND DISCHARGE SHOWN)
SIDE VIEW
45°
MAX
45°
MAX
2”
2”
2”
2”
or
2”
12” max.
EXHAUST
TRANSITION
3”
*2”
*2”
EXHAUST
TRANSITION
1-1/2”
2”
2”
EXHAUST
or
NOTE: 1-1/2” Vent
Pipe Diameter Allowed
Only on 045/070 Units
.
DO NOT transition
from larger to smaller
pipe in horizontal runs
of exhaust pipe.
EXHAUST
DO NOT transition
from smaller to larger
pipe in horizontal runs
of exhaust pipe.
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
NOTE: Exhaust pipe and intake pipe must be the same diameter.
Figure 26.
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Figure 27.
TYPICAL INTAKE PIPE CONNECTIONS IN UPFLOW DIRECT OR
NON-DIRECT VENT APPLICATIONS
2”
2”
2”
2”
or
AIR
INTAKE
2”
TRANSITION
3”
*2”
Pipe size determined in Table 5
or
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
NOTE: Exhaust pipe and intake pipe must be the same diameter.
Figure 28.
TYPICAL INTAKE PIPE CONNECTIONS IN HORIZONTAL DIRECT OR NON-DIRECT VENT
APPLICATION (RIGHT-HAND DISCHARGE SHOWN)
2”
2”
2”
2”
or
2”
AIR
INTAKE
TRANSITION
3”
*2”
*2”
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
NOTE: Exhaust pipe and intake pipe must be the same diameter.
Intake Piping
Figure 27 through Figure 28
This gas furnace may be installed in either direct vent
or non-direct vent applications. In non-direct vent
applications, when intake air will be drawn into the furnace
from the surrounding space, the indoor air quality must be
considered and guidelines listed in Combustion, Dilution
and Ventilation Air section must be followed.
Follow the next two steps when installing the unit in Direct
Vent applications, where combustion air is taken from
outdoors and ue gases are discharged outdoors. The
provided air intake screen must not be used in direct vent
applications (outdoors).
1. Use transition solvent cement or a sheet metal screw
to secure the intake pipe to the inlet air connector.
2. Route piping to outside of structure. Continue with
installation following instructions given in general
guide lines for piping terminations and in intake and
exhaust piping terminations for direct vent sections.
Refer to Table 5A through Table 5D for pipe sizes.
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Figure 29.
TYPICAL AIR INTAKE PIPE CONNECTIONS
UPFLOW NON-DIRECT VENT APPLICATIONS
Intake
Debris
Screen
(Provided)
NOTE: Debris screen and elbow may be rotated so that the
screen may be positioned to face forward or to either side.
Figure 30.
TYPICAL AIR INTAKE PIPE CONNECTIONS
HORIZONTAL NON-DIRECT VENT APPLICATIONS
Intake
Debris
Screen
(Provided)
OR
PVC Pipe
Coupling
NOTE: Debris screen and elbow may be
rotated so that the screen may be
positioned to face forward or to either side.
(Horizontal Right-Hand Air Discharge Application Shown)
Follow the next two steps when installing the unit in Non–
Direct Vent applications where combustion air is taken
from indoors and ue gases are discharged outdoors.
1. Use eld-provided materials and the factory-provided
air intake screen to route the intake piping as shown in
Figure 29 or Figure 30. Maintain a minimum clearance
of 3” (76 mm) around the air intake opening. The air
intake opening (with the protective screen) should
always be directed forward or to either side in the
upow position, and either straight out or downward in
the horizontal position.
The air intake piping must not terminate too close to
the ooring or a platform. Ensure that the intake air
inlet will not be obstructed by loose insulation or other
items that may clog the debris screen.
2. If intake air is drawn from a ventilated attic (Figure
31) or ventilated crawlspace (Figure 32) the exhaust
vent length must not exceed those listed in Table 5D.
If 3” diameter pipe is used, reduce to 2” diameter pipe
at the termination point to accommodate the debris
screen.
3. Use a sheet metal screw to secure the intake pipe to
the connector, if desired.
If this unit is being installed in an application with
combustion air coming in from a space serviced by an
exhaust fan, power exhaust fan, or other device which
may create a negative pressure in the space, take care
when sizing the inlet air opening. The inlet air opening
must be sized to accommodate the maximum volume
of exhaust air as well as the maximum volume of
combustion air required for all gas appliances serviced
by this space.
CAUTION
Ventilation Louvers
Inlet Air
(Minimum 12 in.
(305mm) above
Attic Floor)
Roof Terminated
Exhaust Pipe
Furnace
*Intake Debris
Screen
(Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
2
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 31. Equipment in Conned Space
(Inlet Air from Ventilated Attic and Outlet Air to
Outside)
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Roof Terminated
Exhaust Pipe
Furnace
Ventilation
Louvers
(Crawl Space)
*Intake Debris Screen Provided
Inlet Air
Minimum
12 in. (305mm)
above Crawl
Space Floor
Coupling or
3 in. to 2 in.
Transition
(Field Provided)
* See Maximum Vent Lengths table
NOTE-The inlet and outlet air openings shall each have a
free area of at least one square inch per 4,000 Btu (645mm
2
per 1.17kW) per hour of the total input rating of all equipment
in the enclosure.
Figure 32. Equipment in Conned Space
(Inlet Air from Ventilated Crawl Space and Outlet Air
to Outside)
General Guidelines for Vent Terminations
In Non–Direct Vent applications, combustion air is taken
from indoors and the ue gases are discharged to the
outdoors. This furnace is then classied as a non–direct
vent, Category IV gas furnace.
In Direct Vent applications, combustion air is taken from
outdoors and the ue gases are discharged to the outdoors.
This furnace is then classied as a direct vent, Category IV
gas furnace.
In both Non–Direct Vent and Direct Vent applications, the
vent termination is limited by local building codes. In the
absence of local codes, refer to the current National Fuel
Gas Code ANSI Z223-1/NFPA 54 in U.S.A., and current
CSA-B149 Natural Gas and Propane Installation Codes in
Canada for details.
Position termination according to location given in Figure
34 or Figure 35. In addition, position termination so it is
free from any obstructions and 12” above the average
snow accumulation.
At vent termination, care must be taken to maintain
protective coatings over building materials (prolonged
exposure to exhaust condensate can destroy protective
coatings). It is recommended that the exhaust outlet not be
located within 6 feet (1.8 m) of a condensing unit because
the condensate can damage the painted coating.
NOTE: See Table 6A through Table 6B for maximum
allowed exhaust pipe length without insulation in
unconditioned space during winter design temperatures
below 32°F (0°C). If required exhaust pipe should be
insulated with 1/2” (13 mm) Armaex or equivalent. In
extreme cold climate areas, 3/4” (19 mm) Armaex or
equivalent may be necessary. Insulation on outside runs
of exhaust pipe must be painted or wrapped to protect
insulation from deterioration. Exhaust pipe insulation may
not be necessary in some specic applications.
NOTE: During extremely cold temperatures, below
approximately 20° F (6.7° C), units with long runs of vent
pipe through unconditioned space, even when insulated,
may form ice in the exhaust termination that prevents the
unit from operating properly. Longer run times of at least 5
minutes will alleviate most icing problems. Also, a heating
cable may be installed on exhaust piping and termination
to prevent freeze-ups. Heating cable installation kits are
available. See unit specication sheets for part numbers.
Do not use screens or perforated metal in exhaust
terminations. Doing so will cause freeze-ups and may
block the terminations.
IMPORTANT
For Canadian Installations Only:
In accordance to CSA International B149 installation
codes, the minimum allowed distance between the
combustion air intake inlet and the exhaust outlet of
other appliances shall not be less than 12 inches (305
mm).
IMPORTANT
507768C05
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Maximum Allowable Exhaust Vent Pipe Length
3
(in ft.) without Insulation in Unconditioned Space For Winter Design
Temperatures Single - Stage High Eciency Furnace
Winter Design
Temperatures
1
ºF (ºC)
Vent Pipe
Diameter
Unit Input Size
045 070 090 110 135
32 to 21
(0 to -6)
PVC
2
PP PVC
2
PP PVC
2
PP PVC
2
PP PVC
2
PP
1-1/2 in. 25 N/A 20 N/A N/A N/A N/A N/A N/A N/A
2 in.
18 16 31 28 50 48 30 30
N/A N/A
2-1/2 in.
13 N/A 24 N/A 42 N/A 56 N/A
N/A N/A
3 in.
9 9 18 18 35 35 47 47 42 42
20 to 1
(-7 to -17)
1-1/2 in. 15 N/A 20 N/A N/A N/A N/A N/A N/A N/A
2 in.
9 8 18 16 32 29 30 30
N/A N/A
2-1/2 in.
5 N/A 13 N/A 24 N/A 34 N/A
N/A N/A
3 in.
1
1
8 8 19 19 26 26 23 23
0 to -20
(-18 to -29)
1-1/2 in. 10 N/A 15 N/A N/A N/A N/A N/A N/A N/A
2 in.
5
3
12 10 22 19 30 27
N/A N/A
2-1/2 in.
1
N/A
7 N/A 15 N/A 22 N/A
N/A N/A
3 in.
N/A
N/A
2 2 10 10 16 16
13 13
1
Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.
2
Poly-Propylene vent pipe (PP) by Duravent and Centrotherm
3
Vent length in table is equivalent length. Each elbow is equivalent to 5ft. of straight pipe and should be included when measuring
total length.
NOTE- Maximum uninsulated vent lengths listed may include the termination (vent pipe exterior to the structure ) and cannot exceed
5 linear feet or the maximum allowable intake or exhaust vent length listed in Table 5A through Table 5D or Table 7.
NOTE - If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace. See Figure 33.
NOTE - Concentric terminations are the equivalent of 5’ and should be considered when measuring pipe length.
Table 7.
Conditioned
Space
Unconditioned
Space
Exhaust
Pipe
Intake
Pipe
Conditioned
Space
Pipe Insulation
Figure 33. Insulating Exhaust Pipe in an Unconditioned Space
507768C05
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VENT TERMINATION CLEARANCES
FOR NON-DIRECT VENT INSTALLATIONS IN THE US AND CANADA
K
D
E
L
B
C
F
G
A
B
J
A
M
I
H
INSIDE CORNER
DETAIL
VENT TERMINAL
AIR SUPPLY INLET
AREA WHERE TERMINAL
IS NOT PERMITTED
Fixed
Closed
Operable
B
Fixed
Closed
Operable
B
B
A =
B =
C =
D =
E =
F =
G =
H =
I =
J =
K =
L =
M =
US Installations
1
Canadian Installations
2
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
Clearance above grade, veranda,
porch, deck or balcony
Clearance to window or
door that may be opened
4 feet (1.2 m) below or to side of opening;
1 foot (30cm) above opening
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
Clearance to permanently
closed window
Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 2 feet (610 mm)
from the center line of the terminal
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
tended above meter / regulator assembly
Clearance to service regulator
vent outlet
Clearance to non-mechanical air
pliance
ply inlet
Clearance above paved sidewalk or
paved driveway located on public property
Clearance under veranda, porch, deck or balcony
* 12”
* Equal to or greater than soffit depth.
*
* 3 feet (.9m)
* 12”
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
3 feet (.9m) above if within 10 feet
(3m) horizontally
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
1
In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code
2
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
† A vent shall not terminate directly above a sidewalk or paved driveway that is
located between two single family dwellings and serves both dwellings.
‡
4 feet (1.2 m) below or to side of opening;
1 foot (30 cm) above opening
7 feet (2.1m)†
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* Equal to or greater than soffit depth.
* No minimum to outside corner *
No minimum to outside corner
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
*12 inches (305mm)‡
**
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the
lation instructions.”
Permitted only if veranda, porch, deck or balcony is fully open on a minimum of
two sides beneath the floor. Avoiding this location is recommended if possible.
Figure 34. Vent Termination Clearances for Non-Direct Installations
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VENT TERMINATION CLEARANCES
FOR DIRECT VENT INSTALLATIONS IN THE USA AND CANADA
K
D
E
L
B
C
F
G
A
B
J
A
M
I
H
INSIDE CORNER
DETAIL
VENT TERMINAL
AIR SUPPLY INLET
AREA WHERE TERMINAL
IS NOT PERMITTED
Fixed
Closed
Operable
B
Fixed
Closed
Operable
B
B
A =
B =
C =
D =
E =
F =
G =
H =
I =
J =
K =
L =
M =
US Installations
1
Canadian Installations
2
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
12 inches (305mm) or 12 in. (305mm)
above average snow accumulation.
Clearance above grade, veranda,
porch, deck or balcony
Clearance to window or
door that may be opened
6 inches (152mm) for appliances <10,000
pliances > 10,000 Btuh (3kw) and <50,000
pliances > 50,000 Btuh (15kw)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
Clearance to permanently
closed window
Vertical clearance to ventilated soffit
located above the terminal within a
horizontal distance of 2 feet (610mm)
from the center line of the terminal
Clearance to unventilated soffit
Clearance to outside corner
Clearance to inside corner
tended above meter / regulator assembly
Clearance to service regulator
vent outlet
Clearance to non-mechanical air
pliance
ply inlet
Clearance above paved sidewalk or
paved driveway located on public property
Clearance under veranda, porch, deck or balcony
* 12”
*
*
* 7 feet (2.1m)
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
6 inches (152mm) for appliances <10,000
pliances > 10,000 Btuh (3kw) and <50,000
pliances > 50,000 Btuh (15kw)
6 inches (152mm) for appliances <10,000
Btuh (3kw), 12 inches (305mm) for
appliances > 10,000 Btuh (3kw) and
<100,000 Btuh (30kw), 36 inches (.9m)
for appliances > 100,000 Btuh (30kw)
3 feet (.9m) above if within 10 feet
(3m) horizontally
6 feet (1.8m)
7 feet (2.1m)†
12 inches (305mm)‡
1
In accordance with the current ANSI Z223.1/NFPA 54 Natural Fuel Gas Code
2
In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA
B149.1, clearance will be in accordance with local installation
codes and the requirements of the gas supplier and these
installation instructions.”
† A vent shall not terminate directly above a sidewalk or paved driveway that is located
between two single family dwellings and serves both dwellings.
* 12”
* Equal to or greater than soffit depth* Equal to or greater than soffit depth
* Equal to or greater than soffit depth * Equal to or greater than soffit depth
* No minimum to outside corner
*
No minimum to outside corner
3 feet (.9m) within a height 15 feet (4.5m)
above the meter / regulator assembly
3 feet (.9m)
*
*12 inches (305mm)‡
Btuh (3kw), 9 inches (228mm) for ap-
Btuh (15kw), 12 inches (305mm) for ap-
Clearance to each side of center line ex-
Btuh (3kw), 9 inches (228mm) for ap-
Btuh (15kw), 12 inches (305mm) for ap-
supply inlet to building or the com-
bustion air inlet to any other ap-
Clearance to mechanical air sup-
‡
Permitted only if veranda, porch, deck or balcony is fully open on a minimum of
two sides beneath the floor. Avoiding this location is recommended if possible.
Figure 35. Vent Termination Clearances for Direct Installations
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Details of Intake and Exhaust Piping
Terminations for Direct Vent Installations
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and ue gases are discharged to outdoors.
NOTE: Flue gas may be slightly acidic and may adversely
aect some building materials. If any vent termination
is used and the ue gases may impinge on the building
material, a corrosion-resistant shield (minimum 24 inches
square) must be used to protect the wall surface. If the
optional tee is used, the protective shield is required.
The shield should be constructed using wood, plastic,
sheet metal or other suitable material. All seams, joints,
cracks, etc. in the aected area should be sealed using an
appropriate sealant. See Figure 39.
Intake and exhaust pipes may be routed either horizontally
through and outside wall or vertically through the roof. In
attic or closet installations, vertical termination through the
roof is preferred. Figure 36 through Figure 44 show typical
terminations.
1. Intake and exhaust terminations are not required to be
in the same pressure zone. You may exit the intake on
one side of the structure and the exhaust on another
side (Figure 37). You may exit the exhaust out the roof
and the intake out the side of the structure (Figure 38).
2. Intake and exhaust pipes should be placed as close
together as possible at termination end (refer to
illustrations). Minimum separation is 3” (76 mm)
on roof terminations and 6” (152 mm) on sidewall
terminations.
3. On roof terminations, the intake piping should terminate
straight down using two 90° elbows (see Figure 36).
4. Exhaust piping must terminate straight out or up as
shown. A reducer may be required on the exhaust
piping at the point where it exits the structure to
improve the velocity of exhaust away from the intake
piping. See Table 8.
Capacity Exhaust Pipe Size
Termination
Pipe Size
045 & 070
2” (51mm),
2-1/2” (64mm),
3” (76mm)
1-1/2” (38mm)
90
2” (51mm)110
135 3” (76mm)
* -045, -070 and -090 Units with the ush mount termination
must use the 1-1/2” accelerator supplied with the kit.
Table 8. Exhaust Pipe Termination Size Reduction
NOTE: Care must be taken to avoid recirculation of
exhaust back into intake pipe.
Figure 36. Direct Vent Roof Termination Kit
(15F75 or 44J41)
UNCONDITIONED
ATTIC SPACE
SIZE PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
3” (76MM) MIN.
12” (305MM) ABOVE
AVERAGE SNOW
ACCUMULATION
3” (76MM) OR
2” (51MM) PVC
PROVIDE SUPPORT
FOR INTAKE AND
EXHAUST LINES
8” (203MM) MIN
Inches (MM)
1/2” (13MM) FOAM
INSULATION IN
UNCONDITIONED
SPACE
Figure 37.
Figure 38.
5. On eld supplied terminations for sidewall exit, exhaust
piping may extend a maximum of 12 inches (305 mm)
for 2” PVC and 20 inches (508 mm) for 3” (76 mm)
PVC beyond the outside wall. Intake piping should be
as short as possible. See Figure 39.
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Figure 39.
* Use wall support every 24” (610 mm). Use two
wall supports if extension is greater than
24” (610 mm) but less than 48” (1219 mm).
NOTE
− One wall support must be within 6” (152 mm)
from top of each pipe (intake and exhaust) to prevent
movement in any direction.
NOTE − FIELD−PROVIDED
REDUCER MAY BE
REQUIRED TO ADAPT
LARGER VENT PIPE SIZE
TO TERMINATION
STRAIGHT
APPPLICATION
EXTENDED
APPLICATION
D
B
D
B
A
2” (51mm)
Vent Pipe
3” (76mm)
Vent Pipe
A− Minimum clearance
above grade or average
snow accumulation
B− Maximum horizontal
separation between
intake and exhaust
D− Maximum exhaust
pipe length
E− Maximum wall support
distance from top of each
pipe (intake/exhaust)
12” (305 mm)
12” (305 mm)
12” (305 mm)
6” (152 mm)6” (152 mm)
6” (152 mm)6” (152 mm)
8” (203 mm)8” (203 mm)
20” (508 mm)
6” (152 mm)6” (152 mm)
A
Intake
Elbow
* WALL
SUPPORT
B
A
D
E
B
D
E
A
ALTERNATE TERMINATIONS (TEE & FORTY−FIVE DEGREE ELBOWS ONLY)
C2 -Minimum from end of
exhaust to inlet of intake
C1 -Minimum from end of
exhaust to inlet of intake
FIELD FABRICATED WALL TERMINATION
C1
C2
C1
C2
Front View of
Intake and Exhaust
Intake
Exhaust
C
B
1
2
D
A
C
3
Intake
Elbow
Exhaust
B
A
D
2” (51MM)
Vent Pipe
3” (76MM)
Vent Pipe
A− Clearance above
grade or average snow
accumulation
B− Horizontal
separation between
intake and exhaust
C− Minimum from
end of exhaust to
inlet of intake
D− Exhaust pipe length
E− Wall support distance
from top of each pipe
(intake/exhaust)
12” (305 mm) Min. 12” (305 mm) Min.
6” (152 mm) Min.
24” (610 mm) Max.
9” (227 mm) Min.
12” (305 mm) Min.
16” (405 mm) Max.
6” (152 mm) Max.
6” (152 mm) Min.
24” (610 mm) Max.
9” (227 mm) Min.
12” (305 mm) Min.
20” (508 mm) Max.
6” (152 mm) Max.
D
C
12”
1
2
E
B
A
1
The exhaust termination tee should be connected to the 2” or 3” PVC flue pipe as shown in the illustration.
Do not use an accelerator in applications that include an exhaust termination tee.
The accelerator is not required.
2
As required. Flue gas may be acidic and may adversely affect some building materials. If a side wall vent
termination is used and flue gases will impinge on the building materials, a corrosion-resistant shield
(24 inches square) should be used to protect the wall surface. If optional tee is used, the protective shield
is recommended. The shield should be constructed using wood, sheet metal or other suitable material.
All seams, joints, cracks, etc. in affected area, should be sealed using an appropriate sealant.
3
Exhaust pipe 45° elbow can be rotated to the side away from the combustion air inlet to direct exhaust
away from adjacent property. The exhaust must never be directed toward the combustion air inlet.
D
C
12”
1
2
E
B
A
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6. On eld supplied terminations, a minimum distance
between the end of the exhaust pipe and the end of
the intake pipe without a termination elbow is 8” and a
minimum distance of 6” with a termination elbow. See
Figure 39.
7. If intake and exhaust piping must be run up a side
wall to position above snow accumulation or other
obstructions, piping must be supported every 24” (610
mm) as shown in Figure 39. When exhaust and intake
piping must be run up an outside wall, the exhaust
piping must be terminated with pipe sized per Table 8.
The intake piping may be equipped with a 90° elbow
turndown. Using turndown will add 5 feet (1.5 m) to the
equivalent length of the pipe.
8. A multiple furnace installation may use a group of up to
four terminations assembled together horizontally, as
shown in Figure 41.
Figure 40.
Figure 41.
Figure 42.
DIRECT VENT CONCENTRIC ROOFTOP TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
Minimum
Above Average
Snow
Accumulation
SHEET METAL STRAP
(Clamp and sheet metal strap
must be field−installed to support
the weight of the termination kit.)
FLASHING
(Not Furnished)
CLAMP
INTAKE
12” (305mm)
FIELD-PROVIDED REDUCER
MAY BE REQUIRED TO
ADAPT DIFFERENT VENT
PIPE SIZE TO TERMINATION
Figure 43.
DIRECT VENT CONCENTRIC WALL TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
12” (305mm) Min.
above grade or
cumulation.
INTAKE
AIR
EXHAUST
AIR
INTAKE
AIR
INTAKE
AIR
EXHAUST
AIR
OUTSIDE
WALL
GRADE
CLAMP
(Not Furnished)
FIELD-PROVIDED REDUCER
MAY BE REQUIRED TO
ADAPT DIFFERENT VENT
PIPE SIZE TO TERMINATION
Figure 44. Direct Vent Application Using Existing
Chimney
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *
EXHAUST VENT
1/2” (13mm)
WEATHERPROOF
INSULATION
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
ALTERNATE
INTAKE PIPE
INTAKE PIPE
INSULATION (optional)
EXTERIOR
PORTION OF
CHIMNEY
INSULATE
TO FORM
SEAL
SHEET
METAL TOP
PLATE
8” - 12”
(203mm - 305mm)
* SIZE TERMINATION
PIPE PER EXHAUST
PIPE TERMINATION
SIZE REDUCTION
TABLE
3” - 8”
(76mm -
203mm)
3” - 8”
(76mm -
203mm)
Minimum 12” (305mm)
above chimney top
plate or average snow
accumulation
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Details of Exhaust Piping Terminations for Non-
Direct Vent Applications
Exhaust pipes may be routed either horizontally through
an outside wall or vertically through the roof. In attic or
closet installations, vertical termination through the roof
is preferred. Figure 45 through Figure 48 show typical
terminations.
1. Exhaust piping must terminate straight out or up as
shown. The termination pipe must be sized as listed
in Table 8. The specied pipe size ensures proper
velocity required to move the exhaust gases away
from the building.
2. On eld supplied terminations for side wall exit,
exhaust piping may extend a maximum of 12 inches
(305 mm) for 2” PVC and 20” (508 mm) for 3” (76 mm)
PVC beyond the outside wall. See Figure 46.
UNCONDITIONED
ATTIC SPACE
3” (76MM) OR
2” (51MM) PVC
PROVIDE SUPPORT
FOR EXHAUST LINES
12” (305MM)
ABOVE AVE.
SNOW
ACCUMULATION
SIZE PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
Figure 45. Non-Direct Vent Roof Termination Kit
(15F75 or 44J41)
Figure 46. Non-Direct Vent Field Supplied Wall
Termination
SIZE TERMINATION
PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO
ADAPT DIFFERENT
VENT PIPE SIZE TO
TERMINATION
3. If exhaust piping must be run up a sidewall to position
above snow accumulation or other obstructions, piping
must be supported every 24” (610 mm) as shown in
Figure 47. When exhaust piping must be run up an
outside wall, any reduction in exhaust pipe size must
be done after the nal elbow.
SIZE TERMINATION
PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
* Use wall support every 24” (610 mm). Use two supports of extension is greater than 24”
(610 mm) but less than 48” (1219 mm).
FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO
ADAPT DIFFERENT
VENT PIPE SIZE TO
TERMINATION
Figure 47. Non-Direct Vent Field Supplied Wall
Termination Extended
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *
EXHAUST VENT
1/2” (13mm)
WEATHERPROOF
INSULATION
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
INTAKE PIPE
INSULATION (optional)
EXTERIOR
PORTION OF
CHIMNEY
INSULATE
TO FORM
SEAL
SHEET
METAL TOP
PLATE
* SIZE TERMINATION PIPE PER EXHAUST
PIPE TERMINATION SIZE REDUCTION TABLE
Minimum 12” (305mm)
above chimney top
plate or average snow
accumulation
Figure 48. Non-Direct Vent Application Using Existing
Chimney
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Exhaust through Crawl Space Vent Option
All 33” condensing gas furnaces (92%+) are now approved
to be vented down through a crawl space. Ensure a vent
pipe drain kit, 51W18 (USA) or 15Z70 (Canada), is used as
directed through the oor joists and into the crawl space.
See the following gures.
Consult the vent tables for vent lengths and approved
materials.
2” or 3”
Sanitary Tee
1/2” PVC
Drain Stub
Drain Trap
Assembly
Rubber Boot (51W18)
Drain Plug (15Z70)
Clamp
(51W18 Only)
From
Furnace
To Vent
Termination
Drain Trap
(assembled)
Figure 49. Kit 51W18 (USA) / 15Z70 (Canada) Parts
Identication and Assembly
Exhaust from
Furnace
To Termination
Exhaust from
Furnace
To Termination
* Kit 51W18 is shown.
Figure 50. Crawl Space Vent Pipe Drain Trap
Assembled Incorrectly
KIT 51W18 (USA)
Basement Floor
To Te rmination
1/2” PVC to
Code-Approved
Drain
24” max.
Downflow Furnace
Exhaust
KIT 15Z70 (Canada)
* Kit 51W18 is shown.
NOTE: Upow furnaces exhaust from the left side. All dimensions shown are typical for upow or downow furnaces.
NOTE: All horizontal runs of exhaust pipe must slope back toward the kit a minimum of 1/4” (6mm) for each 12” (305mm) to ensure drainage.
Figure 51. Upow or Downow Furnace with Exhaust through Crawl Space
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Condensate Piping
This unit is designed for either right or left side exit of
condensate piping in upow applications. In horizontal
applications, the condensate trap must extend below the
unit. An 8” service clearance is required for the condensate
trap. Refer to Figure 52 for condensate trap locations.
Figure 59 shows trap assembly using 1/2” PVC or 3/4”
PVC.
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
Plug
(same on
left side)
Trap
(same on
right side)
1-1/2 in.
NOTE - In upflow applications where side return air
filter is installed on same side as the condensate
trap, filter rack must be installed beyond condensate
trap or trap must be relocated to avoid interference.
Figure 52.
NOTE: If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.
1. Determine which side condensate piping will exit the
unit, location of trap, eld-provided ttings and length
of PVC pipe required to reach available drain.
2. Use a large at head screw driver or a 1/2” drive
socket extension and remove plug (Figure 52) from
the cold end header box at the appropriate location
on the side of the unit. Install provided 3/4 NPT street
elbow tting into cold end header box. Use Teon tape
or appropriate pipe dope.
3. Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See Figure 54.
4. Install drain trap using appropriate PVC ttings, glue
all joints. Glue the provided drain trap as shown in
Figure 59. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward slope
from the furnace to the drain.
5. Figure 55 and Figure 56 show the furnace and
evaporator coil using a separate drain. If necessary
the condensate line from the furnace and evaporator
coil can drain together. See Figure 57 and Figure 58.
Upow furnace (Figure 53) - In upow furnace
applications the eld provided vent must be a minimum
1” to a maximum 2” length above the condensate drain
outlet connection. Any length above 2” may result in a
ooded heat exchanger if the combined primary drain
line were to become restricted.
Horizontal furnace (Figure 55) - In horizontal furnace
applications the eld provided vent must be minimum
4” to a maximum 5” length above the condensate drain
outlet connection. Any length above 5” may result in a
ooded heat exchanger if the combined primary drain
line were to become restricted.
NOTE: In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and
trap assembly.
NOTE: Vinyl tubing may be used for condensate drain.
Tubing must be 1-1/4” o.d. X 1” i.d. and should be
attached to the drain on the trap using a hose clamp.
Do not use copper tubing or existing copper condensate
lines for drain line.
CAUTION
6. If unit will be started immediately upon completion of
installation, prime trap per procedure outlined in Unit
Start-Up section.
Condensate line must slope downward away from the
trap to drain. If drain level is above condensate trap,
condensate pump must be used. Condensate drain line
should be routed within the conditioned space to avoid
freezing of condensate and blockage of drain line. If
this is not possible, a heat cable kit may be used on the
condensate trap and line. Heating cable kit is available in
various lengths; 6 ft. (1.8 m) - kit no. 26K68; 24 ft. (7.3 m) -
kit no. 26K69; and 50 ft. (15.2 m) - kit no. 26K70.
A separate drain line must be run to the drain from the
condensate trap to ensure proper drainage and pressure
switch operation. DO NOT connect the condensate trap
drain into the drain line from the evaporator coil.
CAUTION
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Figure 53. Condensate Trap Locations
(Unit shown in upow position with remote trap)
* Piping from furnace must slope down a minimum of
1/4” per ft. toward trap.
Figure 54. Condensate Trap with Optional Overow
Switch
When combining the furnace and evaporator coil
drains together, the A/C condensate drain outlet must
be vented to relieve pressure in order for the furnace
pressure switch to operate properly.
WARNING
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Figure 55. Condensate Trap Locations
* Piping from furnace must slope down a minimum of 1/4” per ft. toward trap.
Figure 56. Unit with Cooling Coil Using Separate
Drain
Figure 57. Evaporator Coil Using a Common Drain
Figure 58. Evaporator Coil Using a Common Drain
Piping from furnace and evaporator coil must slope down a minimum 1/4” per ft. toward trap.
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Figure 59. Trap / Drain Assembly Using 1/2” PVC or 3/4” PVC
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Gas Piping
If a exible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe shall
be installed at the gas valve and extend outside the
furnace cabinet. The exible connector can then be
added between the black iron pipe and the gas supply
line.
CAUTION
Do not exceed 600 in.-lbs. (50 ft.-lbs.) torque when
attaching the gas piping to the gas valve.
WARNING
1. Gas piping may be routed into the unit through either
the left or right hand side. Supply piping enters into
the gas valve from the side of the valve as shown in
Figure 61. Move Bellows grommet to side which gas
line enters. Ensure opposite gas line hole is plugged
with supplied plug.
A low inlet pressure switch in LP/propane applications
is recommended.
IMPORTANT
2. When connecting gas supply, factors such as length
of run, number of ttings and furnace rating must be
considered to avoid excessive pressure drop. Table 9
list recommended pipe sizes for typical applications.
NOTE: Use two wrenches when connecting gas piping
to avoid transferring torque to the manifold.
3. Gas piping must not run in or through air ducts,
clothes chutes, chimneys or gas vents, dumb waiters
or elevator shafts. Center gas line through piping hole.
Gas line should not touch side of unit. See Figure 61
and Figure 62.
4. Piping should be sloped 1/4 “ per 15 feet (6 mm per 5.6
m) upward toward the gas meter from the furnace. The
piping must be supported at proper intervals, every 8
to 10 feet (2.44 to 3.05 m), using suitable hangers or
straps. Install a drip leg in vertical pipe runs to serve as
a trap for sediment or condensate.
5. A 1/8” N.P.T. plugged tap or pressure post is located
on the gas valve to facilitate test gauge connection.
See Figure 60.
6. In some localities, codes may require installation of a
manual main shut-o valve and union (furnished by
installer) external to the unit. Union must be of the
ground joint type.
Compounds used on threaded joints of gas piping must
be resistant to the actions of liquied petroleum gases.
IMPORTANT
Leak Check
After gas piping is completed, carefully check all eld-
installed piping connections for gas leaks. Use a
commercially available leak detecting solution specically
manufactured for leak detection. Never use an open ame
to test for gas leaks.
The furnace must be isolated from the gas supply
system by closing the individual manual shut-o valve
during any gas supply system at pressures greater than
or equal to 1/2 psig (3.48 kPa, 14 inches w.c.). This
furnace and its components are designed, manufactured
and independently certied to comply with all applicable
ANSI/CSA standards. A leak check of the furnace and its
components is not required.
Figure 60.
When testing pressure of gas lines, gas valve must be
disconnected and isolated. See Figure 60. Gas valves
can be damaged if subjected to pressures greater than
1/2 psig (3.48 kPa).
IMPORTANT
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could
result in serious injury, death, or property damage.
Never use an open ame to test for gas leaks. Check
all connections using a commercially available soap
solution made specically for leak detection. Some
soaps used for leak detection are corrosive to certain
metals. Carefully rinse piping thoroughly after leak test
has been completed.
WARNING
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Figure 61. Gas Piping
Upow Applications
Figure 62. Gas Piping
Horizontal Applications
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Gas Pipe Capacity - FT³/HR (kL/HR)
Table 9.
Nominal
Iron Pipe
Size -
inches
(mm)
Internal
Diameter
- inches
(mm)
Length of Pipe - feet (m)
10
(3.048)
20
(6.096)
30
(9.144)
40
(12.192)
50
(15.240)
60
(18.288)
70
(21.336)
80
(24.384)
90
(27.432)
100
(30.480)
1/2
(12.7)
.622
(17.799)
175
(4.96)
120
(3.40)
97
(2.75)
82
(2.32)
73
(2.07)
66
(1.87)
61
(1.73)
57
(1.61)
53
(1.50)
50
(1.42)
3/4
(19.05)
.824
(20.930)
360
(10.19)
250
(7.08)
200
(5.66)
170
(4.81)
151
(4.28)
138
(3.91)
125
(3.54)
118
(3.34)
110
(3.11)
103
(2.92)
1
(25.4)
1.049
(26.645)
680
(19.25)
465
(13.17)
375
(10.62)
320
(9.06)
285
(8.07)
260
(7.36)
240
(6.80)
220
(6.23)
205
(5.80)
195
(5.52)
1-1/4
(31.75)
1.380
(35.052)
1400
(39.64)
950
(26.90)
770
(21.80)
660
(18.69)
580
(16.42)
530
(15.01)
490
(13.87)
460
(13.03)
430
(12.18)
400
(11.33)
1-1/2
(38.1)
1.610
(40.894)
2100
(59.46)
460
(41.34)
1180
(33.41)
990
(28.03)
900
(25.48)
810
(22.94)
750
(21.24)
690
(19.54)
650
(18.41)
620
(17.56)
2
(50.8)
2.067
(52.502)
3950
(111.85)
2750
(77.87)
2200
(62.30)
1900
(53.80)
1680
(47.57)
1520
(43.04)
1400
(39.64)
1300
(36.81)
1220
(34.55)
1150
(32.56)
2-1/2
(63.5)
2.469
(67.713)
6300
(178.39)
4350
(123.17)
3520
(99.67)
3000
(84.95)
2650
(75.04)
2400
(67.96)
2250
(63.71)
2050
(58.05)
1950
(55.22)
1850
(52.38)
3
(76.2)
3.068
(77.927)
11000
(311.48)
7700
(218.03)
6250
(176.98)
5300
(150.07)
4750
(134.50)
4300
(121.76)
3900
(110.43)
3700
(104.77)
3450
(97.69)
3250
(92.03)
4
(101.6)
4.026
(102.260)
23000
(651.27)
15800
(447.39)
12800
(362.44)
10900
(308.64)
9700
(274.67)
9700
(274.67)
8100
(229.36)
7500
(212.37)
7200
(203.88)
6700
(189.72)
NOTE: Capacity given in cubic feet of gas per hour (kilo liters of gas per hour) and based on 0.60 specic gravity gas.
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Electrical
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
Electrostatic discharge can aect electronic components.
Take precautions during furnace installation and service
to protect the furnace’s electronic controls. Precautions
will help to avoid control exposure to electrostatic
discharge by putting the furnace, the control and the
technician at the same electrostatic potential. Neutralize
electrostatic charge by touching hand and all tools on
an unpainted unit surface, such as the gas valve or
blower deck, before performing any service procedure.
CAUTION
Figure 63.
Figure 64.
The unit is equipped with a eld makeup box. The makeup
box may be moved to the right side of the furnace to
facilitate installation. Seal unused openings on left side
with plugs removed from right side. Secure the excess wire
to the existing harness to protect it from damage.
Refer to Figure 66 for eld wiring and Figure 67 for
schematic wiring diagram and troubleshooting.
The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select circuit
protection and wire size according to unit nameplate.
NOTE: Unit nameplate states maximum current draw.
Maximum Over-Current Protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate
wiring.
Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned o for servicing.
Before connecting the thermostat check to make sure the
wires will be long enough for servicing at a later date. Make
sure that thermostat wire is long enough to facilitate future
removal of blower for service.
Complete the wiring connections to the equipment. Use the
provided unit wiring diagram and the eld wiring diagram
shown in Figure 66. Use 18 gauge wire or larger that is
suitable for Class II rating for thermostat connections.
Electrically ground the unit according to local codes or,
in the absence of local codes, according to the current
National Electric Code (ANSI/HFPA No. 70) for the USA
and current Canadian Electric Code Part 1 (CSA standard
C22.1) for Canada. A green ground wire is provided in the
eld makeup box.
NOTE: The gas furnace contains electronic components
that are polarity sensitive. Make sure that the furnace is
wired correctly and is properly grounded.
Accessory Terminals
One line voltage “ACC” 1/4” spade terminal is provided
on the furnace control board. Any accessory rated up to
one amp can be connected to this terminal with the neutral
leg of the circuit being connected to one of the provided
neutral terminals. If an accessory rated at greater than one
amp is connected to this terminal, it is necessary to use an
external relay. See Figure 68 or Figure 69 for control board
conguration. This terminal is energized when the indoor
blower is operating.
One line voltage “HUM” 1/4” spade terminal is provided
on the furnace control board. Any humidier rated up to
one amp can be connected to this terminal with the neutral
leg of the circuit being connected to one of the provided
neutral terminals. If a humidier rated at greater than one
amp is connected to this terminal, it is necessary to use an
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external relay. See Figure 68 or Figure 69 for control board
conguration. This terminal is energized in the heating
mode when the combustion air inducer is operating.
Figure 65.
One 24V “H” 1/4” spade terminal is provided on the furnace
control board. Any humidier rated up to 0.5 amp can be
connected to this terminal with the ground leg of the circuit
connected to ground or the “C” terminal. See Figure 68 or
Figure 69 for control board conguration. This terminal is
energized in the heating mode when the combustion air
inducer is operating.
Install the room thermostat according to the instructions
provided with the thermostat. See Figure 65 for thermostat
designations. If the furnace is being matched with a
heat pump, refer to the FM21 installation instruction or
appropriate dual fuel thermostat instructions.
Indoor Blower Speeds
1. When the thermostat is set to “FAN ON”, the indoor
blower will run continuously on the fan speed when
there is no cooling or heating demand. See Table 20
for allowable continuous circulation speeds.
2. When the furnace is running in the heating mode, the
indoor blower will run on the heating speed.
3. When there is a cooling demand, the indoor blower will
run on the cooling speed.
Generator Use - Voltage Requirements
• The furnace requires 120 volts ± 10% (Range: 108
volts to 132 volts)
• The furnace operates at 60 Hz ± 5% (Range: 57 Hz
to 63 Hz)
• The furnace integrated control requires both proper
polarity and proper ground. Both polarity and proper
grounding should be checked before attempting to
operate the furnace on either permanent or temporary
power.
• Generator should have a wave form distortion of less
than 5% THD (total harmonic distortion).
Figure 66. Typical Field Wiring Diagram
NOTE-
IF ANY WIRE IN THIS APPLIANCE IS REPLACED,
IT MUST BE REPLACED WITH WIRE OF LIKE
SIZE, RATING, INSULATION THICKNESS AND
TERMINATION.
WARNING-
ELECTRIC SHOCK HAZARD. CAN CAUSE
INJURY OR DEATH. UNIT MUST BE GROUNDED
IN ACCORDANCE WITH NATIONAL AND LOCAL
CODES.
‘R’ IS REQUIRED ON SOME OUTDOOR UNITS
L13 POWER CHOKE USED ON 3/4 AND 1 HP
ONLY
S145 IS USED WITH GAS VALVE WHEN APPLIED
IN LP GAS UNTIS
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045*B3
070*B3
090*C4
110*C5
135*D5
Figure 67. Typical Wiring Diagram
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Red LED Flash Code
2
Diagnostic Codes / Status of Furnace
O No power to control or control hardware fault detected
Heartbeat
1
Normal operation - idle, continuous fan, cool
Continuous Rapid Flash Call for heat / burner operation
1 Flash Reverse line voltage polarity
2 Flashes Improper earth ground
3 Flashes Burner failed to light, or lost ame during heat demand
4 Flashes Low ame signal - check ame sensor
5 Flashes Watchguard - burner failed to light, exceeded maximum number of retries or recycles
6 Flashes Not used
7 Flashes Primary or Secondary limit open or watchguard mode - limit switch open longer than 3 minutes
8 Flashes Rollout switch open
9 Flashes Pressure switch failed to close or opened during heat demand
10 Flashes Watchguard - Pressure switch opened 5 times during one heat demand
11 Flashes Pressure switch stuck closed prior to activation of combustion air inducer
12 Flashes Flame sensed without gas valve energized
13 Flashes Low line voltage
1
A “heartbeat” is indicated by a “slow ash” - 1 sec on 1 sec o, repeating
2
Error codes are indicated by a “rapid ash” - the LED ashes X times at 1/2 sec on, 1/2 sec o, remains o for 3 sec, then repeats
NOTE: Last 10 error codes are stored in memory, including when power is shut o to the unit. To recall, press and release button.
Most recent will be displayed rst, LED o for 3 sec, then next error code is displayed, etc. To clear error codes, depress and hold
button longer than 5 sec.
Table 10. Diagnostic Codes for 103217-03 Control
Red LED Flash Code
2
Diagnostic Codes / Status of Furnace
O No power to control or control hardware fault detected
On Board Fault Detected
Fast Heartbeat
3
Call for Heat / Burner Operation
Slow Heartbeat
1
Normal Operation – Idle, Continuous Fan, or Cool
1 Flash
2
Reverse Line Voltage Polarity or Phasing of 120V power
2 Flashes
2
Improper earth ground
3 Flashes
2
Burner failed to light, or lost ame during heat demand
4 Flashes
2
Low ame signal - check ame sensor
5 Flashes
2
Watchguard – burner failed to light, exceeded maximum number of retries/recycles, 1 hour lockout
6 Flashes
2
Not used
7 Flashes
2
Primary or Secondary limit switch open or Watchguard mode – Limit Switch open longer than 3 minutes
8 Flashes
2
Rollout switch open
9 Flashes
2
Pressure switch failed to close or opened during heat demand
10 Flashes
2
Watchguard - Pressure switch opened 5 times during one heat demand
11 Flashes
2
Pressure switch stuck closed prior to activation of combustion air inducer
12 Flashes
2
Flame sensed without gas valve energized
13 Flashes
2
Low line voltage
1
A slow heartbeat is indicated by 1 sec on / 1 sec o. It is used for idle, continuous fan and cool modes.
2
Error codes are indicated by a “rapid ash” - the LED ashes X times at 1/2 sec on / 1/2 sec o, remains o for 2 sec, then repeats.
3
A fast heartbeat is indicated by 1/2 sec on / 1/2 sec o. It is only used during a heat call.
NOTE: Last 10 error codes are stored in memory, including when power is shut o to the unit. To recall, press and release button.
Most recent will be displayed rst, LED o for 3 sec, then next error code is displayed, etc. To clear error codes, depress and hold
button longer than 5 sec.
Table 11. Diagnostic Codes for 107163-01 Control
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Figure 68. 103217-03 Integrated Control
(Automatic Hot Surface Ignition System)
RED LED
RECALL BUTTON
BLOWER OFF DELAY
Figure 69. 107163-01 Integrated Control
Heating Blower Off
Delay Selector Switch
Diagnostic LED
Push Button
Error Recall
PARK
HUM24
FS
24VCOM COOL
HEAT FAN
WCRGY
1/4” Quick Connect Terminal Designations
120V HUM Power for Humidier (120VAC)
LINE Incoming Power Line (120VAC)
XFMR Transformer Primary (120VAC)
CIRC Indoor Blower Motor (120VAC)
EAC Electronic Air Cleaner (120VAC)
HUM24 Power For Humidier (24VAC)
NEUTRALS (5) Neutral
3/16” Quick Connect Terminal Designations
COOL
Cool Speed From Indoor Blower Motor
(24VAC)
HEAT
Heat Speed From Indoor Blower Motor
(24VAC)
FAN
Continuous Fan Speed From Indoor
Blower Motor (24VAC)
PARK (3)
Terminals For Unused Motor Speed
Taps
FS Flame Sensor Electrode (120VAC)
24V COM Common (24VAC)
Table 12. Terminal Designations
(Applicable to 103217-03 and 107163-01 Controls)
Unit Start-Up
FOR YOUR SAFETY READ BEFORE OPERATING
Do not use this furnace if any part has been underwater.
A ood-damaged furnace is extremely dangerous.
Attempts to use the furnace can result in re or explosion.
Immediately call a qualied service technician to inspect
the furnace and to replace all gas controls, control
system parts, and electrical parts that have been wet or
to replace the furnace, if deemed necessary.
WARNING
Danger of explosion. Can cause injury or
product or property damage. Should the gas
supply fail to shut o or if overheating
occurs, shut o the gas valve to the furnace
before shutting o the electrical blower
deck, before performing any service
procedure.
WARNING
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Before attempting to perform any service or
maintenance, turn the electrical power to unit OFF at
disconnect switch.
CAUTION
BEFORE LIGHTING the unit, smell all around the furnace
area for gas. Be sure to smell next to the oor because
some gas is heavier than air and will settle on the oor.
The gas valve on the unit is equipped with a gas control
switch (lever). Use only your hand to move switch. Never
use tools. If the switch will not move by hand, do not try to
repair it. Force or attempted repair may result in a re or
explosion.
Placing the Furnace into Operation
This furnace is equipped with an automatic hot surface
ignition system. Do not attempt to manually light burners
on this furnace. Each time the thermostat calls for heat, the
burners will automatically light. The ignitor does not get hot
when there is no call for heat on these units.
Priming Condensate Trap
The condensate trap should be primed with water prior
to start-up to ensure proper condensate drainage. Either
pour 10 . oz. (300 ml) of water into the trap, or follow
these steps to prime the trap:
1. Follow the lighting instructions to place the unit into
operation.
2. Set the thermostat to initiate a heating demand.
3. Allow the burners to re for approximately 3 minutes.
4. Adjust the thermostat to deactivate the heating
demand.
5. Wait for the combustion air inducer to stop. Set the
thermostat to initiate a heating demand and again
allow the burners to re for approximately 3 minutes.
6. Adjust the thermostat to deactivate the heating demand
and wait for the combustion air inducer to stop. At this
point, the trap should be primed with sucient water to
ensure proper condensate drain operation.
If you do not follow these instructions exactly, a re
or explosion may result causing property damage,
personal injury or death.
WARNING
Gas Valve Operation
See Figure 70
1. STOP! Read the safety information at the beginning
of this section.
2. Set the thermostat to the lowest setting.
3. Turn OFF all electrical power to the unit.
4. This furnace is equipped with an ignition device which
automatically lights the burners. Do not try to light the
burners by hand.
5. Remove the upper access panel.
6. Move gas valve switch to OFF. See Figure 70.
7. Wait ve minutes to clear out any gas. If you then
smell gas, STOP! Immediately call your gas supplier
from a neighbor’s phone. Follow the gas supplier’s
instructions. If you do not smell gas go to next step.
8. Move gas valve switch to ON. See Figure 70.
9. Replace the upper access panel.
10. Turn on all electrical power to the unit.
11. Set the thermostat to desired setting.
NOTE: When unit is initially started, steps 1 through
11 may need to be repeated to purge air from gas line.
12. If the appliance will not operate, follow the instructions
“Turning O Gas to Unit” and call your service
technician or gas supplier.
Figure 70.
Turning O Gas to Unit
1. Set the thermostat to the lowest setting.
2. Turn o all electrical power to the unit if service is to
be performed.
3. Remove the upper access panel.
4. Move gas valve switch to OFF.
5. Replace the upper access panel.
Failure to Operate
If the unit fails to operate, check the following:
1. Is the thermostat calling for heat?
2. Are access panels securely in place?
3. Is the main disconnect switch closed?
4. Is there a blown fuse or tripped breaker?
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5. Is the lter dirty or plugged? Dirty or plugged lters will
cause the limit control to shut the unit o.
6. Is gas turned on at the meter?
7. Is the manual main shut–o valve open?
8. Is the internal manual shut–o valve open?
9. Is the unit ignition system in lockout? If the unit locks
out again, inspect the unit for blockages.
Heating Sequence of Operation
1. When thermostat calls for heat, combustion air inducer
starts.
2. Combustion air pressure switch proves blower
operation. Switch is factory set and requires no
adjustment.
3. After a 15 second pre-purge, the hot surface ignitor
energizes.
4. After a 20 second ignitor warm-up period, the gas
valve solenoid opens. A 4-second “Trial for Ignition”
period begins.
5. Gas is ignited, ame sensor proves the ame, and the
combustion process continues.
6. If ame is not detected after rst ignition trial, the
ignition control will repeat steps 3 and 4 four more
times before locking out the gas valve. The ignition
control will then automatically repeat steps 1 through
6 after 60 minutes. To interrupt the 60 minute period,
move thermostat from “Heat” to “OFF” then back to
“Heat”. Heating sequence then restarts at step 1.
Gas Pressure Adjustment
Gas Flow (Approximate)
Gas Meter Clocking Chart
Capacity
Seconds for One Revolution
Natural LP
1 cu ft
Dial
2 cu ft
Dial
1 cu ft
Dial
2 cu ft
Dial
-45 80 160 200 400
-70 55 110 136 272
-110 33 66 82 164
-135 27 54 68 136
Natural-1000 btu/cu ft LP-2500 btu/cu ft
Table 13.
Supply Pressure Measurement
When testing supply gas pressure, use the 1/8” N.P.T.
plugged tap or pressure post located on the gas valve to
facilitate test gauge connection. See Figure 70. Check
gas line pressure with unit ring at maximum rate. Low
pressure may result in erratic operation or underre. High
pressure can result in permanent damage to gas valve or
overre.
On multiple unit installations, each unit should be checked
separately, with and without other units operating. Supply
pressure must fall within range listed in Table 15.
Manifold Pressure Measurement
1. Remove the threaded plug from the outlet side of
the gas valve and install a eld provided barbed
tting. Connect to a manometer to measure manifold
pressure.
2. Start unit and allow 5 minutes for unit to reach steady
state.
3. While waiting for the unit to stabilize, observe the
ame. Flame should be stable and should not lift from
burner. Natural gas should burn blue.
4. After allowing unit to stabilize for 5 minutes, record
manifold pressure and compare to value given in
Table 15.
NOTE: Shut unit o and remove manometer as soon as an
accurate reading has been obtained. Take care to remove
barbed tting and replace threaded plug.
Proper Combustion
Furnace should operate minimum 15 minutes with correct
manifold pressure and gas ow rate before checking
combustion. Take combustion sample beyond the ue
outlet and compare to the tables below.
Table 14.
Capacity CO
2
% for Nat CO
2
% for L.P.
All 7.5 - 8.5 8.2 - 9.5
The maximum carbon monoxide reading should not exceed
100 ppm.
High Altitude Information
NOTE: In Canada, certication for installations at
elevations over 4500 feet (1371 m) is the jurisdiction of
local authorities.
Units may be installed at altitudes up to 10,000 ft. above
sea level. See Table 15 for de-rate manifold values. Units
installed at altitude of 7501 - 10,000 feet require an orice
change. Units installed at altitudes of 4,501 - 10,000 feet
(1371 -3048 m) may require a pressure switch change
which can be ordered separately.
Furnace should operate at least 5 minutes before checking
gas ow. Determine time in seconds for two revolutions of
gas through the meter. (Two revolutions assures a more
accurate time.) Divide by two and compare to time in
Figure 68 or Figure 69. If manifold pressure matches Table
15 and rate is incorrect, check gas orices for proper size
and restriction. Remove temporary gas meter if installed.
NOTE: To obtain accurate reading, shut o all other gas
appliances connected to meter.
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Table 16 or Table 17 list required pressure switch changes and orice conversion kits at varying altitudes.
The combustion air pressure switches are factory set and require no adjustment.
Table 15.
Manifold and Supply Line Pressure 0-10,000 ft.
Capacity Gas
Manifold Pressure in. w.g.
Supply Line Pressure
in. w.g.
0-10,000 ft.
0-4500 ft. 4501-5500 ft. 5501-6500 ft. 6501-7500 ft. 7501-10000 ft.
All Sizes
Natural 3.5 3.3 3.2 3.1 3.5 4.5 13.0
LP /
Propane
10.0 9.4 9.1 8.9 10.0 11.0 13.0
NOTE: A natural to LP propane gas changeover kit is necessary to convert this unit. Refer to the changeover kit installation
instruction for the conversion procedure.
Capacity
0-7,500 ft
(0-2,286m)
7,501 - 10,000 ft
(2,286 - 3,048 m)
Natural to LP/Propane
High Altitude Natural Burner
Orice Kit
High Altitude LP/Propane
Burner Orice Kit
045
11K49 73W37 11K44
070
090
110
135
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-
1370 m).
Table 16. Burner Orice Conversion Kits at Varying Altitudes
Capacity
0 - 4500 ft
(0 - 1,371m)
4501 - 7500 ft
(1371 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
045 No Change 11U66 11U69
070 No Change 11U70 11U68
090 No Change 11U70
11U64
110 No Change 11U70
135 No Change 11U70 11U68
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-
1371 m).
Table 17. Pressure Switch Requirements at Varying Altitudes
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Testing for Proper Venting and Sucient Combustion Air for Non-Direct Vent Applications
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation.
WARNING
After the gas furnace has been started, the following
test should be conducted to ensure proper venting and
sucient combustion air has been provided to the unit as
well as to other gas red appliances which are separately
vented.
If this furnace replaces a Category I furnace which was
commonly vented with another gas appliance, the size
of the existing vent pipe for that gas appliance must be
checked. Without the heat of the original furnace ue
products, the existing vent pipe is probably oversized for
the single water heater or other appliance. The vent should
be checked for proper draw with the remaining appliance.
The test should be conducted while all appliances (both
in operation and those not in operation) are connected to
the venting system being tested. If the venting system has
been installed improperly, or if provisions have not been
made for sucient amounts of combustion air, corrections
must be made as outlined in the previous section.
1. Seal any unused openings in the venting system.
2. Visually inspect the venting system for proper size
and horizontal pitch. Determine there is no blockage
or restriction, leakage, corrosion, or other deciencies
which could cause an unsafe condition.
3. To the extent that it is practical, close all building doors
and windows and all doors between the space in
which the appliances connected to the venting system
are located and other spaces of the building.
4. Close replace dampers.
5. Turn on clothes dryers and any appliances not
connected to the venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhausts, so
they will operate at maximum speed. Do not operate
a summer exhaust fan.
6. Follow the lighting instruction to place the appliance
being inspected into operation. Adjust thermostat so
appliance will operate continuously.
7. Use the ame of a match or candle to test for spillage
of ue gases at the draft hood relief opening after 5
minutes of main burner operation.
8. If improper venting is observed during any of the
above tests, the venting system must be corrected or
sucient combustion/makeup air must be provided.
The venting system should be resized to approach the
minimum size as determined by using the appropriate
tables in appendix G in the current standards of the
National Fuel Gas Code ANSI-Z223.1/NPFA 54 in the
U.S.A., and the appropriate Natural Gas and Propane
appliances venting sizing tables in the current standard
of the CSA-B149 Natural Gas and Propane Installation
Codes in Canada.
9. After determining that each appliance remaining
connected to the common venting system properly
vents when tested as indicated in step 3, return doors,
windows, exhaust fans, replace dampers and any
other gas burning appliance to their previous condition
of use.
Other Unit Adjustments
Primary Limit
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no
adjustment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of
the burner box. These limits are factory set and require no
adjustment.
Pressure Switch
The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory set and must not be adjusted.
Temperature Rise
After the furnace has been started and supply and return
air temperatures have been allowed to stabilize, check
the temperature rise. If necessary, adjust the blower
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speed to maintain the temperature rise within the range
shown on the unit nameplate. See Table 19 for allowable
heating speeds. Increase the blower speed to decrease
the temperature. Decrease the blower speed to increase
the temperature rise. Failure to adjust the temperature rise
may cause erratic limit operation.
Fan Control
Ignition Control 103217-03
The fan on time of 45 seconds is not adjustable. The heat
fan o delay (amount of time that the blower operates after
the heat demand has been satised) may be adjusted by
changing the jumper position across the ve pins on the
integrated control. The unit is shipped with a factory fan
o delay setting of 90 seconds. The fan o delay aects
comfort and is adjustable to satisfy individual applications.
Adjust the fan o delay to achieve a supply air temperature
between 90° and 110° F at the moment that the blower
is de-energized. Longer o delay settings provide lower
return air temperatures; shorter settings provide higher
return air temperatures. See Figure 71.
Ignition Control 107163-01
The heat fan-on time of 30 seconds is not adjustable The
heat fan-o delay (amount of time that the blower operates
after the heat demand has been satised) may be adjusted
by changing the two position dip switch on the integerated
control, to one of four slections. Blower o delay is factory
set at 90 seconds. For other blower o delay settings,
please refer to Table 18.
SW2-1 SW2-2
60 OFF ON
90* OFF OFF
120 ON OFF
180 ON ON
* Factory setting
Table 18. Blower Delay Select
Figure 71. Heat Fan O Time in Seconds
To adjust fan-off timing, reposition jumper across pins to
achieve desired setting.
NO JUMPER
60
90
120
180
60
90
120
180
60
90
120
180
60
90
120
180
60 Second
off Time
90 Second
off Time
120 Second
off Time
180 Second
off Time
Constant Torque Motor
These units are equipped with a constant torque ECM
motor. It has a DC motor coupled to an electronic control
module both contained in the same motor housing. The
motor is programmed to provide constant torque at each of
the ve selectable speeds. The motor has ve speed taps.
Each tap requires 24 volts to energize.
Thermostat Heat Anticipation
Set the heat anticipator setting (if adjustable) according to
the amp draw listed on the wiring diagram that is attached
to the unit.
Electrical
1. Check all wiring for loose connections.
2. Check for the correct voltage at the furnace (with
furnace operating). Correct voltage is 120 VAC ± 10%
3. Check amp–draw on the blower motor with the blower
access panel in place.
Motor Nameplate____________Actual____________
Blower Speeds
Follow the steps below to change the blower speeds.
1. Turn o electrical power to furnace.
2. Remove blower access panel.
3. Disconnect existing speed tap at control board speed
terminal.
NOTE: Termination of any unused motor leads must
be insulated.
4. Place unused blower speed tap on integrated control
“PARK” terminal or insulate.
5. Refer to blower speed selection chart on unit wiring
diagram for desired heating or cooling speed. See
Blower performance data beginning on the next page.
See Table 19 for allowable heating speeds.
6. Connect selected speed tap at control board speed
terminal.
7. Re-secure blower access panel.
8. Turn on electrical power to furnace.
9. Recheck temperature rise.
Electronic Ignition
The integrated control has an added feature of an internal
Watchguard control. The feature serves as an automatic
reset device for integrated control lockout caused by
ignition failure. This type of lockout is usually due to low
gas line pressure. After one hour of continuous thermostat
demand for heat, the Watchguard will break and remake
thermostat demand to the furnace and automatically reset
the integrated control to begin the ignition sequence.
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Blower Performance
MGM96SE045B3X Performance (Less Filter)
External
Static
Pressure
in. w.c.
Air Volume / Watts at Various Blower Speeds
High Medium - High Medium Medium - Low Low
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1460 335 1285 235 1190 170 910 85 870 75
0.10 1430 350 1260 245 1155 185 885 95 830 85
0.20 1405 365 1235 255 1125 200 860 105 800 90
0.30 1375 370 1205 265 1090 210 825 115 755 95
0.40 1350 380 1175 275 1055 215 780 125 710 105
0.50 1315 385 1145 285 1020 230 735 130 665 115
0.60 1245 375 1110 295 980 240 685 140 620 125
0.70 N/A N/A 1070 305 940 250 640 145 575 135
0.80 N/A N/A 1020 310 905 260 600 155 530 140
MGM96SE070B3X Performance (Less Filter)
External
Static
Pressure
in. w.c.
Air Volume / Watts at Various Blower Speeds
High Medium - High Medium Medium - Low Low
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1445 315 1315 215 1215 165 930 85 925 75
0.10 1445 335 1275 230 1170 180 905 94 860 80
0.20 1415 345 1240 240 1125 190 870 101 800 85
0.30 1380 355 1205 250 1090 200 830 109 760 95
0.40 1345 370 1175 265 1055 210 790 117 710 105
0.50 1315 385 1150 280 1020 220 735 129 665 115
0.60 1275 390 1110 290 985 230 685 137 625 125
0.70 1210 395 1075 300 950 240 640 146 565 130
0.80 N/A N/A 1030 305 915 250 595 148 535 135
MGM96SE090C4X Performance (Less Filter)
External
Static
Pressure
in. w.c.
Air Volume / Watts at Various Blower Speeds
High Medium - High Medium Medium - Low Low
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 1765 375 1535 250 1410 180 1315 155 1155 115
0.10 1735 390 1500 260 1365 200 1270 165 1130 125
0.20 1700 405 1465 275 1330 215 1230 175 1095 135
0.30 1660 425 1435 290 1295 225 1195 190 1055 145
0.40 1640 435 1400 300 1265 235 1165 200 1010 155
0.50 1615 450 1370 315 1230 250 1125 215 965 165
0.60 1575 465 1340 325 1190 265 1080 230 925 180
0.70 1530 470 1305 340 1150 280 1045 235 885 190
0.80 N/A N/A 1260 345 1115 285 1000 245 845 195
NOTE: All air is measured external to unit without lter (lter not furnished - eld provided)
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MGM96SE110C5X Performance (Less Filter)
External
Static
Pressure
in. w.c.
Air Volume / Watts at Various Blower Speeds
Bottom Return Air, Side Return Air with Optional Return Air Base, Return Air from
Both Sides or Return Air from Bottom and One Side.
Single Side Return Air - Air volumes in bold require eld fabricated transition to
accommodate 20 x 25 x 1 in. air lter in order to maintain proper air velocity.
High Medium - High Medium Medium - Low Low High Medium - High Medium Medium - Low Low
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00 2220 655 1975 440 1800 325 1665 390 1050 180 2180 685 1910 460 1750 345 1660 285 1430 195
0.10 2185 680 1925 460 1750 345 1625 285 1440 200 2155 705 1885 480 1720 360 1610 295 1415 205
0.20 2150 705 1880 480 1710 365 1590 300 1390 220 2130 725 1855 495 1685 380 1565 305 1380 220
0.30 2110 720 1850 495 1680 380 1560 320 1350 230 2085 745 1825 510 1655 390 1535 325 1335 230
0.40 2080 735 1810 520 1650 405 1515 330 1310 245 2060 760 1795 530 1625 405 1495 340 1295 245
0.50 2045 755 1785 530 1610 415 1470 350 1265 255 2030 775 1765 545 1585 425 1450 355 1255 265
0.60 2010 775 1740 545 1575 430 1440 370 1220 270 1995 785 1725 565 1550 435 1420 370 1205 275
0.70 1980 790 1705 565 1525 450 1400 375 1170 280 1960 795 1690 575 1505 455 1385 385 1165 290
0.80 1950 795 1670 580 1485 460 1360 390 1140 293 1895 790 1650 590 1465 470 1335 395 1120 295
96G1UHE 135*D20 MGM96SE135D5X Performance (Less Filter)
External
Static
Pressure
in. w.c.
Air Volume / Watts at Various Blower Speeds
Bottom Return Air, Side Return Air with Optional Return Air Base, Return Air from
Both Sides or Return Air from Bottom and One Side.
Single Side Return Air - Air volumes in bold require eld fabricated transition to
accommodate 20 x 25 x 1 in. air lter in order to maintain proper air velocity.
High Medium - High Medium Medium - Low Low High Medium - High Medium Medium - Low Low
cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts cfm Watts
0.00
2400 920 2205 709 2035 513 1800 363 1625 268 2280 929 2100 703 1935 531 1720 368 1550 269
0.10
2370 930 2170 718 1985 524 1760 375 1585 279 2245 941 2075 720 1910 543 1700 380 1530 280
0.20
2345 937 2150 723 1960 552 1725 385 1535 291 2210 957 2050 745 1895 558 1695 396 1500 295
0.30
2305 958 2120 744 1920 565 1690 404 1505 305 2200 978 2030 757 1850 569 1675 408 1475 308
0.40
2275 974 2070 763 1885 576 1665 419 1475 323 2175 990 2015 774 1845 584 1640 427 1450 326
0.50
2230 986 2055 779 1845 593 1620 433 1435 330 2145 989 2010 783 1820 603 1605 446 1410 332
0.60
2195 988 2030 796 1810 614 1590 451 1385 348 2125 980 1990 809 1785 618 1580 455 1375 351
0.70
2125 961 1985 806 1780 626 1545 468 1355 359 2060 937 1960 819 1765 635 1545 474 1340 366
0.80
2065 931 1965 822 1760 642 1500 479 1310 377 1980 912 1925 825 1730 646 1510 491 1295 379
NOTE: All air is measured external to unit without lter (lter not furnished - eld provided)
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Service
ELECTRICAL SHOCK, FIRE, OR EXPLOSION
HAZARD.
Failure to follow safety warnings exactly could result in
dangerous operation, serious injury, death or property
damage.
Improper servicing could result in dangerous operation,
serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to
disconnecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
WARNING
At the beginning of each heating season, system should
be checked as follows by a qualied service technician:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are pre-lubricated for extended bearing
life. No further lubrication is needed.
The blower access panel must be securely in place
when the blower and burners are operating. Gas fumes,
which could contain carbon monoxide, can be drawn
into living space resulting in personal injury or death.
WARNING
Filters
All air lters are installed external to the unit. Filters should
be inspected monthly. Clean or replace the lters when
necessary to ensure proper furnace operation. Table 1 lists
recommended lter sizes.
Exhaust and Air Intake Pipes
Check the exhaust and air intake pipes and all connections
for tightness and to make sure there is no blockage.
NOTE: After any heavy snow, ice or frozen fog event the
furnace vent pipes may become restricted. Always check
the vent system and remove any snow or ice that may be
obstructing the plastic intake or exhaust pipes.
Electrical
1. Check all wiring for loose connections.
2. Check for the correct voltage at the furnace (with
furnace operating). Correct voltage is 120 VAC ± 10%
3. Check amp-draw on the blower motor with the blower
access panel in place.
Motor Nameplate____________Actual____________
Winterizing and Condensate Trap Care
1. Turn o power to the furnace.
2. Have a shallow pan ready to empty condensate water.
3. Remove the clean out cap from the condensate trap
and empty water. Inspect the trap then reinstall the
clean out cap.
Cleaning Heat Exchanger
If cleaning the heat exchanger becomes necessary,
follow the below procedures and refer to Figure 1 when
disassembling unit. Use papers or protective covering in
front of furnace while removing heat exchanger assembly.
1. Turn o electrical and gas supplies to the furnace.
2. Remove the burner access panel.
3. Mark all gas valve wires and disconnect them from
valve.
Allowable Heating Speeds
Model Red Yellow Blue Brown Black
045 Allowed Factory Setting Allowed Allowed Not Allowed
070 Not Allowed Not Allowed Factory Setting Allowed Not Allowed
090 Allowed Factory Setting Allowed Allowed Not Allowed
110 Not Allowed Allowed Factory Setting Allowed Not Allowed
135 Not Allowed Allowed Factory Setting Not Allowed Not Allowed
Table 19.
Allowable Circulation Speeds
Model Number Red Yellow Blue Brown Black
All Models Factory Setting Not Allowed Not Allowed Not Allowed Not Allowed
Table 20.
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4. Remove gas supply line connected to gas valve.
5. Remove sensor wire from ame sensor. Disconnect
2–pin plug from the ignitor.
6. Disconnect wires from ame rollout switches.
7. Remove four burner assembly screws at the vestibule
panel and remove gas valve /manifold and burner box
as a single unit.
8. If necessary, clean burners at this time. Follow
procedures outlined in Burner Cleaning section.
9. Remove the clean-out cap on trap and drain. Replace
cap.
10. Disconnect condensate drain line from the condensate
trap. Remove condensate trap (it may be necessary to
cut drain pipe). Remove the 1/2” NPT tting from the
cold end header box. Disconnect drain tubes from cold
end header collector box.
11. Disconnect condensate drain tubes from ue collar.
Remove screws that secures ue collar in place.
Remove ue collar. It may be necessary to cut the
exiting exhaust pipe for removal of the tting.
12. Loosen two clamps from exible no-hub exhaust collar.
13. Disconnect the 2–pin plug from the combustion air
inducer. Remove screws which secure combustion
air inducer to collector box. Remove combustion air
inducer assembly. Remove ground wire.
14. Mark and disconnect all combustion air pressure
tubing from cold end header collector box.
15. Mark and remove wires from pressure switch. Remove
pressure switch. Keep tubing attached to pressure
switch.
16. Remove electrical junction box from the side of the
furnace.
17. Remove blower access panel.
18. Mark and disconnect any remaining wiring to heating
compartment components. Disengage strain relief
bushing and pull wiring and bushing through the hole
in the blower deck.
19. Remove the primary limit from the vestibule panel.
20. Remove top cap screws to allow top cap to be
tilted upward to allow clearance for removing heat
exchanger.
21. Remove two screws from the front cabinet ange at
the blower deck. Spread cabinet sides slightly to allow
clearance for removal of heat exchanger.
22. Remove screws along vestibule sides and bottom
which secure vestibule panel and heat exchanger
assembly to cabinet. Remove two screws from blower
rails which secure bottom heat exchanger ange.
Remove heat exchanger from furnace cabinet.
23. Back wash heat exchanger with soapy water solution
or steam. If steam is used it must be below 275°F
(135°C).
24. Thoroughly rinse and drain the heat exchanger. Soap
solutions can be corrosive. Take care to rinse entire
assembly.
25. Reinstall heat exchanger into cabinet making sure
that the rear bae of the heat exchanger assembly
is nested under the support located at the rear of the
cabinet. Remove the indoor blower to view this area
through the blower opening.
26. Re–secure the supporting screws along the vestibule
sides.
27. Reinstall blower assembly and reinstall two screws
through rails.
28. Reinstall cabinet screws on front ange at blower
deck.
29. Reinstall screws securing top cap.
30. Reinstall the primary limit on the vestibule panel.
31. Route heating component wiring through hole in
blower deck and reinsert strain relief bushing.
32. Reinstall pressure switch and reconnect pressure
switch wiring.
33. Carefully connect combustion air pressure switch
hosing from pressure switch to proper stubs on cold
end header collector box.
34. Reinstall 1/2” NPT (if removed) in the cold end header
box. Reconnect drain tubing to collector box.
35. Reinstall condensate trap pipe. Reconnect condensate
drain line to the condensate trap.
36. Reinstall electrical junction box.
37. Reinstall the combustion air inducer and exible no
hub connector. Reconnect the 2 pin plug to the wire
harness.
38. Reconnect drain tubes between ue collar and cold
end header box.
39. Secure burner assembly to vestibule panel using four
existing screws. Burners are self aligning to center of
clam shells.
40. Reconnect gas supply line to gas valve.
41. Reconnect ame rollout switch wires.
42. Reconnect sensor wire and reconnect 2 pin plug from
ignitor.
43. Reconnect wires to gas valve.
44. Replace the blower compartment access panel.
45. Refer to instruction on verifying gas and electrical
connections when reestablishing supplies.
46. Follow lighting instructions to light and operate furnace
for 5 minutes to ensure that heat exchanger is clean
and dry and that furnace is operating properly.
47. Replace heating compartment access panel.
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Cleaning the Burner Assembly
1. Turn o gas and electrical power to the furnace.
Remove heating compartment access panel.
2. Disconnect the gas supply line from the gas valve.
3. Disconnect and label wires from gas valve.
4. Disconnect ignitor wiring at 2 circuit plug.
5. Disconnect and label wires from rollout switch.
6. Disconnect and label ame sensor wire.
7. Disconnect and label ground wire from burner/manifold
assembly.
8. Remove four screws that secures burner/manifold
assembly to vestibule. Remove the assembly and
make note not to allow ignitor plate to dislodge from
the assembly.
9. Gently clean the face of the burners using the soft
brush attachment on a vacuum cleaner. Visually
inspect the inside of the burners and crossovers for
any blockage caused by foreign matter. Remove any
blockage
10. Reinstall the burner/manifold assembly using the
existing four screws. Burners are self aligning to
center of clam shells.
11. Reconnect ground wire.
12. Reconnect ame sensor wire.
13. Reconnect rollout switch wires.
14. Reconnect ignitor wires.
15. Reconnect gas valve wires.
16. Reconnect gas supply line to gas valve.
17. Refer to instructions on verifying gas and electrical
connections when re-establishing supplies.
18. Follow instructions to place furnace in operation. Run
furnace 5 minutes to ensure burners are clean and
operating correctly.
19. Replace heating compartment access panel.
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Planned Service
A service technician should check the following items
during an annual inspection. Power to the unit must be
shut o for safety.
Fresh air grilles and louvers (on the unit and in the
room where the furnace is installed) - Must be open and
unobstructed to provide combustion air.
Burners - Must be inspected for rust, dirt, or signs of water.
Vent pipe - Must be inspected for signs of water, cracked,
damaged or sagging pipe, or disconnected joints.
Unit appearance - Must be inspected for rust, dirt, signs of
water, burnt or damaged wires, or components.
Blower access door - Must be properly in place and
provide a seal between the return air and the room where
the furnace is installed.
Return air duct - Must be properly attached and provide
an air seal to the unit.
Operating performance - Unit must be observed during
operation to monitor proper performance of the unit and
the vent system.
Combustion gases - Flue products must be analyzed and
compared to the unit specications.
Problems detected during the inspection may make it
necessary to temporarily shut down the furnace until the
items can be repaired or replaced.
Instruct the homeowners to pay attention to their
furnace. Situations can arise between annual furnace
inspections that may result in unsafe operation. For
instance, items innocently stored next to the furnace may
obstruct the combustion air supply. This could cause
incomplete combustion and the production of carbon
monoxide gas.
Repair Parts List
The following repair parts are available through MRCOOL dealers. When ordering parts, include the complete furnace model
number listed on the CSA nameplate. All service must be performed by a licensed professional installer (or equivalent),
service agency, or gas supplier.
Cabinet Parts
• Upper Access Panel
• Blower Access Panel
• Top Cap
Control Panel Parts
• Transformer
• Integrated Control Board
• Door Interlock Switch
Blower Parts
• Blower Wheel
• Motor
• Motor Mounting Frame
• Motor Capacitor
• Blower Housing Cuto Plate
Heating Parts
• Flame Sensor
• Heat Exchanger Assembly
• Gas Manifold
• Combustion Air Inducer
• Gas Valve
• Main Burner Cluster
• Main Burner Orices
• Pressure Switch
• Ignitor
• Primary Limit Control
• Flame Rollout Switches
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Requirements for Commonwealth of Massachusetts
Modications to NFPA-54, Chapter 10
Revise NFPA-54 section 10.8.3 to add the following
requirements:
For all side wall, horizontally vented, gas-fueled equipment
installed in every dwelling, building or structure used in
whole or in part for residential purposes, including those
owned or operated by the Commonwealth and where the
side wall exhaust vent termination is less than seven (7)
feet above the nished grade in the area of the venting,
including but not limited to decks and porches, the following
requirements shall be satised:
1. INSTALLATION OF CARBON MONOXIDE
DETECTORS. At the time of installation of the side
wall, horizontally vented, gas-fueled equipment, the
installing plumber or gas tter shall observe that a
hard-wired carbon monoxide detector with an alarm
and battery backup is installed on the oor level where
the gas equipment is to be installed. In addition, the
installing plumber or gas tter shall observe that a
battery-operated or hard-wired carbon monoxide
detector with an alarm is installed on each additional
level of the dwelling, building or structure served by the
side wall, horizontally vented, gas-fueled equipment.
It shall be the responsibility of the property owner to
secure the services of qualied licensed 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 backup
may be installed on the next adjacent oor level.
b. In the event that the requirements of this subdivision
cannot be met at the time of completion of
installation, the owner shall have a period of thirty
(30) days to comply with the above requirements;
provided, however, that during said thirty (30)
day period, a battery-operated carbon monoxide
detector with an alarm shall be installed.
2. APPROVED CARBON MONOXIDE DETECTORS.
Each carbon monoxide detector as required in
accordance with the above provisions shall comply
with NFPA 720 and be ANSI/UL 2034 listed and IAS
certied.
3. SIGNAGE. A metal or plastic identication 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 or local gas inspector of the
side wall, horizontally vented, gas-fueled equipment
shall not approve the installation unless, upon
inspection, the inspector observes carbon monoxide
detectors and signage installed in accordance with the
provisions of 248 CMR 5.08(2)(a) 1 through 4.
EXEMPTIONS: The following equipment is exempt
from 24 CMR 5.08(2)(a) 1 through 4:
1. The equipment listed in Chapter 10 entitled “Equipment
Not Required to Be Vented” in the most current edition
of NFPA 54 as adopted by the Board; and
2. Product Approved side wall, horizontally vented, 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.
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT
VENTING SYSTEM PROVIDED.
When the manufacturer of Product Approved side wall,
horizontally vented, gas-fueled equipment provides a
venting system design or venting system components
with the equipment, the instructions provided by the
manufacturer for installation of the equipment and the
venting system shall include:
1. Detailed instructions for the installation of the venting
system design or the venting system components: and
2. A complete parts list for the venting system design or
venting system.
MANUFACTURER REQUIREMENTS - GAS EQUIPMENT
VENTING SYSTEM NOT PROVIDED.
When the manufacturer of Product Approved sidewall,
horizontally vented, gas-fueled equipment does not
provide the parts for venting the ue gases, but identies
“special venting systems,” the following requirements shall
be satised by the manufacturer:
1. The referenced “special venting system” instructions
shall be included with the appliance or equipment
installation instructions; and
2. The “special venting systems” shall be Product
Approved by the Board, and the instructions for that
system shall include a parts list and detailed installation
instructions.
A copy of all installation instructions for all Product
Approved side wall, horizontally vented, gas-fueled
equipment, all venting instructions, all parts lists
for venting instructions, and/or all venting design
instructions shall remain with the appliance or
equipment at the completion of the installation.
The design and specifications of this product and/or manual are subject to change without prior notice.
Consult with the sales agency or manufacturer for details.
Signature Series
MGM*96SE*XA Gas Furnace
ELECTRICIAN and/or HVAC TECHNICIAN:
LICENSE #:
INSTALLATION DAT
E:
INSTALLATION LOCATION:
SERIAL NUMBER:
