Allied A96US2V User manual

507404-02 Page 1 of 80Issue 1448
(P) 507404-02
*P507404-02*
Manufactured By
Allied Air Enterprises LLC
A Lennox International, Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
Unit Dimensions .............................................................2
Parts Arrangement..........................................................3
Gas Furnace...................................................................4
Shipping and Packing List..............................................4
Safety Information .......................................................4
Use of Furnace as a Construction Heater......................5
General 6
Shipping Bolt Removal...................................................9
Setting Equipment..........................................................9
Removing Bottom Panel...............................................11
Upow Application ONLY..............................................11
Horizontal Application ONLY ........................................11
Filters .......................................................................13
Duct System.................................................................13
Pipe and Fittings Specications....................................13
Canadian Applications ONLY .......................................14
TABLE OF CONTENTS
Joint Cementing Procedure..........................................15
Venting Practices..........................................................16
Vent Piping Guidelines .................................................17
Gas Piping....................................................................39
Electrical.......................................................................42
Integrated Control.........................................................47
Thermostat ...................................................................48
Blower Motor Performance...........................................52
Heating Sequence of Operation ...................................51
Gas Pressure Adjustment.............................................64
Other Unit Adjustments.................................................65
High Altitude Information ..............................................65
Diagnostic.....................................................................68
Planned Service ...........................................................76
Repair Parts List...........................................................77
Start Up Checklist.........................................................78
.....................................................................................................
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.
This manual must be left with the homeowner for future reference.
INSTALLATION INSTRUCTIONS
A96US2V
Warm Air Gas Furnace
Upow/Horizontal Left Air Discharge
Direct Vent & Non-Direct Vent
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION 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

507404-02Page 2 of 80 Issue 1448
A96UH2V Unit Dimensions - inches (mm)
1NOTE - 20 C/D (5 Ton) size units installed in upflow
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) air lter.
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.
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.
FRONT VIEW SIDE VIEW
Model Number A B C D
A96UH2V in. mm in. mm in. mm in. mm
045-12
070-12 17-1/2 448 16-3/8 416 16 406 7-5/8 194
090-12
090-16
21 533 19-7/8 505 19-1/2 495 9-3/8 238
090-20
110-16
110-20
135-20 24-1/2 622 23-3/8 594 23 584 11-1/8 283

507404-02 Page 3 of 80Issue 1448
EXPANDED VIEW
Figure 1

507404-02Page 4 of 80 Issue 1448
A96US2V Gas Furnace
TheA96UH2VCategory IVgas furnace isshipped readyfor
installation in the upow 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 upow applications with bottom return air.
This furnace 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 ue gases are discharged outdoors.
Non-Direct Vent installations, combustion air is taken from
indoors or a ventilated attic or crawl space and ue gases
are discharged outdoors. See Figures 2A and 2B for
applications involving roof termination.
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
Check equipment for shipping damage. If you nd any
damage, immediately contact the last carrier.
Please refer to specication sheets for available accessories.
Safety Information
DANGER OF EXPLOSION!
DANGER
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
difcult to smell. An LP/Propane leak detector should
be installed in all LP applications.
Use only the type of gas approved for use with this furnace.
Refer to unit nameplate.
These units are CSA International certied 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.
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
Figure 2A
Figure 2B

507404-02 Page 5 of 80Issue 1448
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 upow or
horizontal position.
This furnace design has not been CSA certied for installation
in mobile homes, recreational vehicles, or outdoors.
Use of Furnace as a Construction Heater
Theseunits arenot recommendedfor use as a construction
heater during any phase of construction. Very low return air
temperature, harmful vapors and operation of the unit with
clogged or misplaced lters will damage the unit.
These units may be used for heating of buildings or
structures under construction, if the following conditions
are met:
•The vent system must be permanently installed per
these installation instructions.
•A room thermostat must control the furnace. The use
of xed jumpers that will provide continuous heating is
not allowed.
•The return air duct must be provided and sealed to the
furnace.
• Return air temperature range between 60°F (16°C) and
80°F (27°C) must be maintained.
• Air lters must be installed in the system and must be
maintained during construction.
• Air lters must be replaced upon construction completion.
Figure 3
Heating Unit Installed Parallel to Air Handler Unit
Heating Unit Installed Upstream of Cooling Unit
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 (CSAStandard C22.1)
and/or local codes.
In Canada, installation must conform with current National
Standard of Canada CSA-B149 Natural Gas and Propane
Installation Codes, local plumbing or waste water codes and
other applicable local codes.
In order to ensure proper unit operation in non-direct vent
applications, combustion and ventilation air supply must be
provided according to the current National Fuel Gas Code
or CSA-B149 standard.
Installed Locations
This furnace is CSA International certied for installation
clearances to combustible material as listed on the
unit nameplate and in the table in Figures 12 and 17.
Accessibilityand serviceclearances 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
damageby vehicles. Whena 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 specied 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 3),
it shall be installed in parallel with, or on the upstream
side of, cooling units to avoid condensation in the heating
compartment. With a parallel ow arrangement, a damper
(or other means to control the ow of air) must adequately
preventchilledairfrom entering thefurnace. Ifthedamper is
manuallyoperated,it must beequippedto 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

507404-02Page 6 of 80 Issue 1448
•The input rate and temperature rise must be set per the
furnace rating plate.
• One hundred percent (100%) outdoor air must be provided
for combustion air requirements during construction.
Temporary ductingmaysupply outdoorairto thefurnace.
Do not connect duct directly to the furnace. Size the
temporary duct following the instructions in section for
Combustion, Dilution and Ventilation Air in a conned
space with air from outside.
•Thefurnaceheat exchanger, components,ductsystem,
air lters and evaporator coils must be thoroughly
cleaned following nal construction cleanup.
•All furnaceoperating conditions (includingignition, input
rate, temperature rise and venting) must be veried
according to these installation instructions.
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
alsobe locatedclose to thechimney orvent termination
point.
•When the furnace is installed in an attic or other
insulated space, keep insulation away from the furnace.
•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.
•Whenthefurnaceisinstalled in anunconditionedspace,
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
toand service area surrounding theequipment shallbe
oored.
These units should not be installed in areas normally
subject to freezing temperatures.
CAUTION
WARNING
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.
Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result
in safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base swimming pool chemicals
Water softening chemicals
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
WARNING
In the past, there was no problem in bringing in sufcient
outdoor air for combustion. Inltration 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 intoaccount thatexhaust fans, appliance
vents, chimneys, and replaces force additional air that
could be used for combustion out of the house. Unless
outside
TheState ofCalifornia hasdetermined thatthis product
may contain or produce a chemical or chemicals, in
very low doses, which may cause serious illness or
death. It may also cause cancer, birth defects or other
repoductive harm.

507404-02 Page 7 of 80Issue 1448
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
gasesentertheliving space creatingapotentiallydangerous
situation.
Inthe absenceof localcodes concerningair forcombustion
and ventilation, use the guidelines and procedures in this
section to install these furnaces to ensure efcient and safe
operation. You must consider combustion air needs and
requirements for exhaust vents and gas piping. A portion
of this information has been reprinted with permission from
the National Fuel Gas Code (ANSI-Z223.1/NFPA 54). This
reprinted material is not the complete and ofcial position
of ANSI on the referenced subject, which is represented
only by the standard in its entirely.
In Canada, refer to the CSA B149 Installation codes.
Donot install thefurnace in acorrosive orcontaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.
CAUTION
All gas-red appliances require air for the combustion
process. If sufcient combustion air is not available, the
furnace or other appliance will operate inefciently and
unsafely. Enoughair must beprovided tomeet the needsof
allfuel-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. Insufcient 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
mayinclude 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 unconned or a conned space.
Unconned Space
An unconned 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 unconned,
it might be necessary to bring in outdoor air for combustion
if the structure does not provide enough air by
inltration. 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.
Conned Space
A conned 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 denition 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 conned 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
causea potentiallydangerous negative pressure condition.
Air for combustion and ventilation can be brought into the
conned space either from inside the building or from
outside.
Air from Inside
If the conned space that houses the furnace adjoins a
space categorized as unconned, 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 conned space.
Each opening must be at least 100 square inches (64516
mm²). One opening shall be within 12 inches (305 mm) of
the top of the enclosure and one opening within 12 inches
(305 mm) of the bottom. See Figure 4.
Figure 4
Equipment in Conned Space - All Air From Inside

507404-02Page 8 of 80 Issue 1448
Air from Outside
If air from outside is brought in for combustion and
ventilation, the conned 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
throughvertical ducts. Eachopening shallhave 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 Figures 5 and 6). It is also permissible to
bring air for combustion from a ventilated attic (Figure 8) or
ventilated crawl space (Figure 9).
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 7.
Figure 5
Equipment in Conned Space - All Air from Outside
(Inlet Air from Crawl Space and Outlet Air to Ventilated Attic)
Figure 6
Equipment in Conned Space - All Air from Outside
(All Air through Ventilated Attic)
Figure 7
Equipment in Conned Space - All Air from Outside
Figure 8
Equipment in Conned Space
(Inlet Air from Ventilated Attic and Outlet Air to Outside)
Equipment in Conned Space
(Inlet Air from Ventilated Crawlspace and Outlet Air to Outside)
Figure 9

507404-02 Page 9 of 80Issue 1448
INSTALLATION
Setting Equipment
Shipping Bolt Removal
Units with 1/2 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 10. The bolt and washer must
be removed before the furnace is placed into operation.
After the bolt and washer have been removed, the rigid leg
will not touch the blower housing.
Upow Applications
The gas furnaces can be installed as shipped in the upow
position. RefertoFigure12 for clearances. Selectalocation
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 11.
Allow for clearances to combustible materials as indicated
on the unit nameplate.
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
Do not connect the return air ducts to the back of the
furnace. Doing so will adversely affect the operation of
the safety control devices, which could result in personal
injury or death.
When ducts are used, they shall be of the same cross-
sectional area as the free area of the openings to which they
connect. The minimum dimension of rectangular air ducts
shall be no less than 3 inches (75 mm). In calculating free
area, the blocking effect of louvers, grilles, or screens must
be considered. If the design and free area of protective
covering is not known for calculating the size opening
required, it may be assumed that wood louvers will have 20
to 25 percent free area and metal louvers and grilles will
have60to 75 percentfreearea. Louvers and grillesmustbe
xed in the open position or interlocked with the equipment
so that they are opened automatically during equipment
operation.
Figure 11
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.
Figure 10
Units with 1/2 HP
Blower Motor

507404-02Page 10 of 80 Issue 1448
WARNING
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.
Fornoreasonshould return andsupplyair duct systems
everbeconnectedto or fromotherheatingdevices such
as a replace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
Return Air Guidlines
Return air can be brought in through the bottom or either
side of the furnace installed in an upow 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 13.
Figure 12
Installation Clearances
*Front clearanceinalcove installationmust be24in. (610mm). Main-
tain a minimum of 24 in. (610 mm) for front service access.
† Allow proper clearances to accommodate condensate trap and vent
pipe installation.
‡ For installations on a combustible oor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood ooring.
Figure 13
Side Return Air
(with transition and lter)

507404-02 Page 11 of 80Issue 1448
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 15.
Horizontal Applications
WARNING
Do not install the furnace on its front or its back. See
Figure 12.
This furnace can be installed in horizontal applications with
either right or left hand air discharge.
Refer to Figure 17 for clearances in horizontal applications.
Figure 15
Removing the Bottom Panel
Figure 14
Optional Return Air Base
(Upow Applications Only)
NOTE: Optional side return air lter kits are not for use with return air base.
1 Both the unit return air opening and the base return air opening must be covered by a single plenum or IAQ cabinet.
Minimum unit side return air opening dimensions for units requiring 1800 cfm or more of air (W x H): 23 x 11 in. (584 x 279 mm).
The opening can be cut as needed to accommodate plenum or IAQ cabinet while maintaining dimensions shown.
Side return air openings must be cut in the eld. There are cutting guides stenciled on the cabinet for the side return air opening.
The size of the opening must not extend beyond the markings on the furnace cabinet.
2 To minimize pressure drop, the largest opening height possible (up to 14 inches) is preferred.
FRONT VIEW SIDE VIEW
Figure 16

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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 18, or install the furnace on a
platform, as shown in Figure 19. A horizontal suspension
kit (51W10) may be ordered from your distributor or use
equivalent.
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. Selectlocation for unitkeepinginmindservice and other
necessary clearances. See Figure 17.
2. Construct a raised wooden frame and cover frame with a
plywood sheet. If unit is installed above nished space,
fabricateanauxiliarydrain pan tobeinstalledunder unit.
Set unit in drain pan as shown in Figure 19. 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. Ifnecessary, runthe condensate line into a condensate
pumpto meetdrain lineslope requirements. Thepump
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 17
Horizontal Application
Installation Clearances
Right-Hand Discharge
* Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
** An 8” service clearance must be maintained below the unit to
providefor servicingofthe condensatetrap unlessthetrap ismounted
remotely.
‡ For installations on a combustible oor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood ooring.
Typical Horizontal Application
Figure 18
Top 0
*Front 0
Back 0
Ends 0
Vent 0
Floor 0‡

507404-02 Page 13 of 80Issue 1448
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 13.
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 list
recommended lter sizes.
A lter must be in place whenever the unit is operating.
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 certied for operation in heating
mode (indoor blower operating at selected heating speed)
with an external static pressure which exceeds 0.8 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
accesspanel should beinstalled in thesupply air duct. The
access panel should be large enough to permit inspection
(by reected 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
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 Specications
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
affects the joint strength or chemical resistance of the
cement. The cement shall show no gelation, stratication,
or separation that cannot be removed by stirring. Refer to
Table 2 for approved piping and tting materials.
Figure 19
Table 1

507404-02Page 14 of 80 Issue 1448
A95UH2V/95G2UHV exhaust and intake connections
aremade ofPVC. Use PVCprimer and solvent cement
when using PVC vent pipe. When using ABS vent pipe,
use transitional solvent cement to make connections to
the PVC tting in the unit.
IMPORTANT
UsePVC primer andsolvent cement orABSsolvent cement
meeting ASTM specications, 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 certied 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.
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
makingjoints. Goodventilation shouldbemaintained to
reduce re hazard and to minimize breathing of solvent
vapors. Avoid contact of cement with skin and eyes.
CAUTION
PIPING AND FITTINGS SPECIFICATIONS
Table 2

507404-02 Page 15 of 80Issue 1448
Joint Cementing Procedure
All cementing of joints should be done according to the
specications outlined in ASTM D 2855.
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.
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
Outdoor Termination Kits Usage
A96DF2V

507404-02Page 16 of 80 Issue 1448
6. Promptlyapply solventcementto end ofpipe 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 insufcient solvent.
9. Handle joints carefully until completely set.
Exhaust Piping
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
vacationhome,makeprovisionsfordrainingcondensate
collection from trap and lines.
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.
Venting Practices
Piping Suspension Guidelines
NOTE: Isolate piping at the point where it exits the outside wall or
roof in order to prevent transmission of vibration to the structure.
Wall Thickness Guidelines
Figure 20
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation could result in carbon monoxide
poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
1. Seal any unused openings in the common venting
system.
2. Inspectthe venting systemforpropersizeand horizontal
pitch. Determine that there is no blockage, restriction,
leakage, corrosion, or other deciencies which could
cause an unsafe condition.

507404-02 Page 17 of 80Issue 1448
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
andotherspaces ofthebuilding. Turnonclothesdryers
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, widows, exhaust fans, replace
dampers,and anyother gasburning appliancesto their
previous mode of operation.
7. Ifa ventingproblemis foundduringany ofthepreceding
tests, the common venting system must be modied to
correct the problem.
Resizethecommonventing system totheminimumvent
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.)
Figure 21
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
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.
Theexhaustvent pipeoperatesunder positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
Exhaust Piping
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
stackthat alsoserves anothergas appliance. Ifvertical
dischargethrough anexisting unusedstack is required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.
CAUTION
Vent Piping Guidelines
This gas furnace can be installed as either 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.
Intake and exhaust pipe sizing - Size pipe according to
Tables 4 and 5. Table 4 lists the minimum vent pipe
lengths permitted. Table 5 lists the maximum pipe lengths
permitted.
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminations should be used. Exhaust vent termination
pipe is sized to optimize the velocity of the exhaust gas as
it exits the termination. Refer to Table 7.
In some applications which permit the use of several different
sizes of vent pipe, a combination vent pipe may be used.
ContactAlliedAir Technical Service for assistance in sizing
vent pipe in these applications.
NOTE: The exhaust collar on all models is sized to
accommodate 2” Schedule 40 vent pipe. When vent pipe
which is larger than 2” must be used in an upow application,
a transition must be applied at the exhaust collar in order
to properly step to the larger diameter vent pipe. Contact
Allied Air Technical Service for more information concerning
sizing of vent systems which include multiple pipe sizes.

507404-02Page 18 of 80 Issue 1448
Do not use screens or perforated metal in exhaust or
intake terminations. Doing so will cause freeze-ups and
may block the terminations.
IMPORTANT
NOTE: All horizontal runs of exhaust pipe must slope back toward unit.
A minimum of 1/4” (6 mm) drop for each 12” (305 mm) of horizontal
run is mandatory for drainage.
NOTE: Exhaust pipe MUST be glued to furnace exhaust ttings.
NOTE: Exhaust piping should be checked carefully to make sure
there are no sages or low spots.
EXHAUST PIPE
Horizontal Application
Figure 22
Use the following steps to correctly size vent pipe diameter.
Table 4
MINIMUM VENT PIPE LENGTHS
A96DF2V MIN. VENT LENGTH*
045, 070, 090, 110 15 ft. or 5 ft plus 2 elbows
or 10 ft plus 1 elbow
* Any approved termination may be added to the minimum lengh listed.

507404-02 Page 19 of 80Issue 1448
Maximum Allowable Intake or Exhaust Vent Length in Feet
Table 5A
*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.
Standard Termination at Elevation 0 - 4500 
Number of
90° Elbows
Used
2" Pipe 2-1/2" Pipe 3" Pipe
Model Model Model
45 70 90 110 135 45 70 90 110 135 45 70 90 110 135
1 76 61 39 19 n/a 110 110 88 53 n/a 133 132 113 113 109
2 71 56 34 14 105 105 83 48 128 127 108 108 104
3 66 51 29 9 100 100 78 43 123 122 103 103 99
4 61 46 24 n/a 95 95 73 38 118 117 98 98 94
5 56 41 19 90 90 68 33 113 112 93 93 89
6 5 36 14 85 85 63 28 108 107 88 88 84
7 46 31 9 80 80 58 23 103 102 83 83 79
8 41 26 n/a 75 75 53 18 98 97 78 78 74
9 36 21 70 70 48 13 93 92 73 73 69
10 31 16 65 65 43 8 88 87 68 68 64
Standard Termination Elevation 4500 - 10,000 
Number of
90° Elbows
Used
2" Pipe 2-1/2" Pipe 3" Pipe
Model Model Model
45 70 90 110 135 45 70 90 110 135 45 70 90 110 135
1 76 61 39 n/a n/a 110 110 88 53 n/a 133 132 113 113 109
2 71 56 34 105 105 83 48 128 127 108 108 104
3 66 51 29 100 100 78 43 123 122 103 103 99
4 61 46 24 95 95 73 38 118 117 98 98 94
5 56 41 19 90 90 68 33 113 112 93 93 89
6 5 36 14 85 85 63 28 108 107 88 88 84
7 46 31 9 80 80 58 23 103 102 83 83 79
8 41 26 n/a 75 75 53 18 98 97 78 78 74
9 36 21 70 70 48 13 93 92 73 73 69
10 31 16 65 65 43 8 88 87 68 68 64

507404-02Page 20 of 80 Issue 1448
*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.
Maximum Allowable Intake or Exhaust Vent Length in Feet
Table 5B
Concentric Termination at Elevation 0 - 4500 
Number of
90° Elbows
Used
2" Pipe 2-1/2" Pipe 3" Pipe
Model Model Model
45 70 90 110 135 45 70 90 110 135 45 70 90 110 135
1 68 53 37 17 n/a 100 100 84 49 n/a 116 116 109 109 100
2 63 48 32 12 95 95 79 44 111 111 104 104 95
3 58 43 27 7 90 90 74 39 106 106 99 99 90
4 53 38 22 n/a 85 85 69 34 101 101 94 94 85
5 48 33 17 80 80 64 29 96 96 89 89 80
6 43 28 12 75 75 59 24 91 91 84 84 75
7 38 23 7 70 70 54 19 86 86 79 79 70
8 33 18 n/a 65 65 49 14 81 81 74 74 65
9 28 13 60 60 44 9 76 76 69 69 60
10 23 8 55 55 39 n/a 71 71 64 64 55
Concentric Termination Elevation 4501 - 10,000 
Number of
90° Elbows
Used
2" Pipe 2-1/2" Pipe 3" Pipe
Model Model Model
45 70 90 110 135 45 70 90 110 135 45 70 90 110 135
1 68 53 37 n/a n/a 100 100 84 49 n/a 116 116 109 109 100
2 63 48 32 95 95 79 44 111 111 104 104 95
3 58 43 27 90 90 74 39 106 106 99 99 90
4 53 38 22 85 85 69 34 101 101 94 94 85
5 48 33 17 80 80 64 29 96 96 89 89 80
6 43 28 12 75 75 59 24 91 91 84 84 75
7 38 23 7 70 70 54 19 86 86 79 79 70
8 33 18 n/a 65 65 49 14 81 81 74 74 65
9 28 13 60 60 44 9 76 76 69 69 60
10 23 8 55 55 39 n/a 71 71 64 64 55