Allied A97USMV User manual

506887-01 Page 1 of 78Issue 1213
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
maintenancecancausepropertydamage,personalinjury
or loss of life. Installation and service must be performed
byalicensedprofessionalinstaller(orequivalent),service
agency or the gas supplier.
WARNING
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
A97USMV
Warm Air Gas Furnace
Upflow/Horizontal Left and RightAir Discharge
*P506887-01*
(P) 506887-01
ManufacturedBy
Allied Air Enterprises, Inc.
A Lennox International, Inc. Company
215MetropolitanDrive
West Columbia, SC 29170
Unit Dimensions ..................................................................................... 2
PartsArrangement ................................................................................. 3
GasFurnace .......................................................................................... 4
Shipping and Packing List ...................................................................... 4
SafetyInformation .................................................................................. 4
Use of Furnace as a Construction Heater .............................................. 5
General .................................................................................................. 6
Setting Equipment .................................................................................. 6
Filters ....................................................................................................11
Duct System .......................................................................................... 11
Pipe and Fittings Specifications............................................................ 12
Joint Cementing Procedure .................................................................. 13
Venting Practices ................................................................................. 14
VentPiping Guidelines ..........................................................................15
GasPiping.............................................................................................29
TABLE OF CONTENTS
Electrical ...............................................................................................32
Integrated Control .................................................................................41
Blower Motor Performance ....................................................................46
Unit Start Up .........................................................................................57
Gas Pressure Measurement .................................................................58
High Altitude Information ......................................................................59
Proper Combustion ...............................................................................59
Other Unit Adjustments ........................................................................61
Heating Sequence of Operation............................................................62
Service..................................................................................................64
Planned Service ....................................................................................66
Integrated Control Diagnostic Codes....................................................67
Configuring Unit Size Codes.................................................................70
Troubleshooting .....................................................................................71
Repair Parts List ...................................................................................77
A thermostat is not included and must be ordered
separately.
•A Comfort SyncTM thermostat must be used in
communicatingapplications.
•Innon-communicatingapplications, atraditionalnon-
communication thermostat may be used.
In all cases, setup is critical to ensure proper system
operation.
Field wiring for both communicating and non-
communicating applications is illustrated in these
instructions.
NOTICE

506887-01Page 2 of 78 Issue 1213
Unit Dimensions - inches (mm)
*NOTE -C/D20sizeunitsthatrequiresecondstageairvolumes
over 1800 cfm (850 L/S) 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 filter.
2. Single side return air with optional RAB ReturnAir 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.
* Optional External Side Return Air Filter Kit is not for use with
the optional RAB Return Air Base.
FRONT VIEW SIDE VIEW
Model Number
A
446
17-1/2
A97USMV070B12S
BC
in. mm in. mm in. mm
416
16-3/8 406
16
A97USMV090C12S
A97USMV090C16S
A97USMV090C20S
A97USMV110C20S
A97USMV135D20S
533
21 505
19-7/8 495
19-1/2
622
24-1/2 594
23-3/8 584
23
D
in. mm
283
11-1/8
238
9-3/8
194
7-5/8

506887-01 Page 3 of 78Issue 1213
A97USMV Exploded View
Figure 1

506887-01Page 4 of 78 Issue 1213
A97USMV Gas Furnace
TheA97USMV Category IV gas furnace is equipped with a
variable capacity, variable speed integrated control. Each
A97USMV is shipped ready for installation in the upflow,
horizontal left air discharge or horizontal right air discharge
position.
The furnace is equipped for installation in natural gas
applicationsonly. Achange overkitmust beorderedfor LP/
propaneapplications.
The A97USMV must be installed only as a Direct Vent
gas central furnace
NOTE: In Direct Vent installations, combustion air is taken
fromoutdoorsand fluegasesaredischarged outdoors. See
Figure 2 for applications including roof termination.
Shipping and Packing List
1 - AssembledA97USMV unit.
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 cap clamp
1 - 1/2” Threaded PVC street elbow
Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.
Pleaserefertospecificationsheetsforavailableaccessories.
Safety Information
As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION
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/
Propanegaswillsettleclosetothefloorandmaybedifficult
tosmell. AnLP/Propaneleakdetectorshouldbeinstalled
in all LP applications.
Use only the type of gas approved for use with this furnace.
Refer to unit nameplate.
Building Codes
In the USA, installation of gas furnaces must conform with
local building codes. In the absence of local codes, units
mustbe installed accordingtothecurrent NationalFuelGas
Code(ANSIZ223.1/NFPA54). TheNationalFuel GasCode
is available from the American National Standards
Institute, Inc., 11 West 42nd Street, New York, NY 10036.
Installed Locations
In Canada, installation must conform with current National
Standard of Canada CSA-B149 Natural Gas and Propane
InstallationCodes,localplumbing orwastewatercodes and
other applicable local codes.
The furnace is designed for installation clearances to
combustible material as listed on the unit nameplate and in
the tables in Figures 10 and 11. Accessibility and service
clearances must take precedence over fire protection
clearances.
NOTE: For installation on combustible floors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood flooring.
Improper installation, adjustment, alteration, service or
maintenancecancausepropertydamage,personalinjury
orloss oflife. Installationand servicemustbe performed
byalicensedprofessionalinstaller(orequivalent),service
agency or the gas supplier.
WARNING
Figure 2

506887-01 Page 5 of 78Issue 1213
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 floor.
The furnace must be located or protected to avoid physical
damageby vehicles. Whenafurnace isinstalledin apublic
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 CSAB149 standards.
Note: Furnace must be adjusted to obtain a temperature
rise (100% percent capacity) within the range (s) specified
on the unit nameplate. Failure to do so may cause erratic
limit operation and may also result in 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, it shall be
installed in parallel with, or on the upstream side of, cooling
units to avoid condensation in the heating compartment.
Witha parallel flowarrangement,a damper(orother means
tocontrol theflowof air)mustadequately preventchilled air
from entering the furnace. If the damper is manually
operated,it mustbeequipped toprevent operation ofeither
theheating orthecooling unit,unlessit isinthe full HEAT or
COOL setting. See Figure 3.
TheA97USMV furnacemaybe installed inalcoves,closets,
attics, basements, garages, crawl spaces and utility rooms.
This furnace design has not been CSA Certified for
installation in mobile homes, recreational vehicles, or
outdoors.
Use of Furnace as Construction Heater
Theseunits are notrecommendedfor useasa construction
heaterduring anyphaseof construction. Very low returnair
temperature, harmful vapors and operation of the unit with
clogged or misplaced filters will damage the unit.
Theseunitsmaybeusedforheatingofbuildingsorstructures
under construction, if the following conditions are met:
•Theventsystemmustbepermanentlyinstalledperthese
installationinstructions.
•Aroom thermostat must control the furnace. The use of
fixedjumpers thatwillprovide continuousheatingis not
allowed.
•The return air duct must be provided and sealed to the
furnace.
•Returnair temperaturerangebetween 60°F(16°C)and
80°F (27°C) must be maintained.
•Air filters must be installed in the system and must be
maintained during construction.
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/NFPANo.70. TheNationalElectricCode(ANSI/
NFPA No. 70) is available from the following address:
National Fire ProtectionAssociation
1 Battery March Park
Quincy, MA 02269
NOTE: This furnace is designed for a minimum continuous
return air temperature of 60°F (16°C) or an intermitent
operation down to 55°F (13°C) dry blub for cases where a
night setback thermostat is used. Return air temperature
must not exceed 85°F (29°C)dry bulb.
In Canada, all electrical wiring and grounding for the unit
must be installed according to the current regulations of the
CanadianElectrical CodePartI (CSAStandard C22.1)and/
or local codes.
Do Not set thermostat below 60° F (16° C) in heating
mode. Setting thermostat below 60° F (16° C) reduces
the number of heating cycles. Damage to the unit may
occur that is not covered by the warranty.
CAUTION
Figure 3
Heating Unit Installed Parallel toAir Handler Unit
Heating Unit Installed Upstream of Cooling Unit

506887-01Page 6 of 78 Issue 1213
•Air filters must be replaced upon construction completion.
•Theinput rateand temperaturerise must beset perthe
furnace rating plate.
•Onehundredpercent(100%)outdoorairmustbeprovided
for combustion air requirements during construction.
•Thefurnace heat exchanger, components, ductsystem,
air filters and evaporator coils must be thoroughly
cleaned following final construction cleanup.
•Allfurnaceoperatingconditions(including ignition,input
rate, temperature rise and venting) must be verified
according to these installation instructions.
General
Product Contains Fiberglass Wool.
Disturbing the insulation in this product during
installation, maintenance, or repair will expose you to
fiberglass wool. Breathing this may cause lung cancer.
(Fiberglass wool is known to the State of California to
cause cancer.)
Fiberglass wool may also cause respiratory, skin, and
eyeirritation.
To reduce exposure to this substance or for further
information,consultmaterialsafetydatasheetsavailable
from address shown below, or contact your supervisor.
Allied Air Enterprises, Inc.
215 Metropolitan Drive
West Columbia, SC 29170
WARNING
These units should not be installed in areas normally
subject to freezing temperatures.
CAUTION
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 should be considered
when installing one of these furnaces:
•Place the furnace as close to the center of the air
distributionsystemaspossible. The furnaceshouldalso
be located close to the vent termination point.
•Whenthefurnaceisinstalledinanatticorotherinsulated
space, keep insulation away from the furnace.
•Whenthefurnace is installed inanunconditionedspace,
consider provisions required to prevent freezing of
condensate drain system.
Installation – Setting Equipment
UpflowApplications
This gas furnace can be installed as shipped in the upflow
position. Refer to Figure 10 for clearances.
Selecta locationthatallows fortherequiredclearances 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[610mm]at unitfront). Theunit must
be level from side to side, for proper operation. It is
recommendedtotilttheunitslightly toward thedraintoinsure
proper drainage. See Figure 5.
Figure 4
Do not install the furnace on its front or its back. See
Figure 4.
Do not connect the return air ducts to the back of the
furnace. Doing so will adversely affect the operation of
thesafetycontroldevices, whichcouldresultinpersonal
injury or death.
WARNING
WARNING

506887-01 Page 7 of 78Issue 1213
SETTING EQUIPMENT
Figure 5
UNIT MUST BE LEVEL SIDE TO SIDE IN ALLAPPLICATIONS FOR PROPER OPERATION.
A SLIGHT TILT TOWARD THE DRAIN IS RECOMMENDED FOR PROPER DRAINAGE.
TILT THE UNIT SLIGHTLY (MAX. 1/2”) FROM BACK TO FRONT TO AID IN THE DRAINING OF THE HEAT EXCHANGER.

506887-01Page 8 of 78 Issue 1213
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 7.
Figure 7
Removing the Bottom Panel
Figure 6
Side Return Air
(with transition and filter)
A97USMV applications which include side return air and a
condensate trap installed on the same side of the cabinet
(trapcan beinstalledremotely within5 feet)requireeither a
returnair baseorfield fabricated transitiontoaccommodate
an optional IAQ accessory taller than 14.5”. See Figure 6.
Optional Return Air Base
(Upflow Applications Only)
NOTE: Optional side return air filter kits are not for use with return air base.
1Both 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 field. 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 8

506887-01 Page 9 of 78Issue 1213
NOTE: Units with 1/2 hp blower motor are equipped with
threeflexiblelegsand onerigidleg. Therigidlegisequipped
with a shipping bolt and a flat white plastic washer (rather
than the rubber mounting grommet used with a flexible
mounting leg). See Figure 9. 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 9
Units with 1/2 HP
Blower Motor
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or
alcove installations are shown in Figure 10.
WARNING
Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
couldcontaincarbonmonoxide,can bedrawnintoliving
space resulting in personal injury or death.
WARNING
Improperinstallationofthefurnacecanresultinpersonal
injury or death. Combustion and flue products must
never be allowed to enter the return air system or air in
theliving space. Usesheet metal screwsand joint tape
to seal return air system to furnace.
Inplatforminstallationswith furnacereturn,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.
Fornoreason should returnandsupplyairduct systems
everbeconnected to orfromotherheatingdevices such
as a fireplace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
Return Air – Upflow Units
Return air can be brought in through the bottom or either
side of the furnace installed in an upflow 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.
Installation Clearances
Figure 10
* Front 0
Back 0
Sides 0†
Vent
Floor
0
0‡
Top/Plenum 1 in. (25 mm)
* 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
installation.
‡ For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood flooring.

506887-01Page 10 of 78 Issue 1213
Setting and Upflow Unit
When the side return air inlets are used in an upflow
application, it may be necessary to install shims on the
bottom of the furnace.
HorizontalApplications
The A97USMV furnace can be installed in horizontal
applications with either right or left hand air discharge.
Refer to Figure 11 for clearances in horizontal applications.
Suspended Installation of Horizontal Unit
This furnace may be installed in either an attic or a
crawlspace. Eithersuspend the furnacefrom roofraftersor
floor joists, as shown in Figure 12 or install the furnace on a
platform,asshown inFigure13. Ahorizontal suspensionkit
(51W10) may be ordered or use equivalent.
NOTE: Heavy gauge sheet metal straps may be used to
suspend the unit from roof rafters or ceiling joists. When
strapsareusedto suspendtheunitin thisway,supportmust
beprovided forboththe ends. The strapsmustnot interfere
withtheplenumor exhaust pipinginstallation. Cooling coils
and supply and return air plenums must be supported
separately.
NOTE: When the furnace is installed on a platform in a
crawlspace, it must be elevated enough to avoid water
damage and to allow the evaporator coil to drain.
Platform Installation of Horizontal Unit
1. Selectlocationfor unit keepinginmindserviceandother
necessary clearances. See Figure 11.
2. Construct a raised wooden frame and cover frame with
aplywoodsheet. Ifunitisinstalledabovefinishedspace,
fabricateanauxiliary drain pantobe installedunderunit.
Set unit in drain pan as shown in Figure 13. Leave 8
inches for service clearance below unit for condensate
trap, unless trap is installed remotely.
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,run thecondensateline intoacondensate
pumpto meetdrainline sloperequirements. Thepump
mustberated for usewithcondensingfurnaces. 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.
Typical HorizontalApplication
Figure 12
Figure 11
HorizontalApplication
Installation Clearances
Right-Hand Discharge
* Front 0
Back 0
Ends 0
Vent
Floor
0
0‡
Top 0
* 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
provide for servicing of the condensate trap. Unless the trap is
mounted remotely.
‡ For installations on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood flooring.

506887-01 Page 11 of 78Issue 1213
Return Air - Horizontal Applications
Return air must be brought in 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 7.
Filters
Thisunit isnotequippedwith afilteror rack. Afieldprovided
filteris requiredfor theunitto operateproperly. Table 1lists
recommended filter sizes.
A filter must be in place when the unit is operating!
NOTE: In upflow applications where side return air filter is
installed on same side as the condensate trap, make sure
that clearance is maintained to ensure future access to the
filter access panel.
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: Operation of this furnace in heating mode (indoor
bloweroperatingat selectedheatingspeed)withan external
static pressure which exceeds 0.8 inches w.c. may result in
erratic limit operation.
Supply Air Plenum
Ifthe furnaceis installed without acooling coil,a removable
access panel should be installed in the supply air duct. The
access panel should be large enough to permit inspection
(by reflected light) of the heat exchanger for leaks after the
furnaceisinstalled. Ifpresent,thisaccesspanelmustalways
be in place when the furnace is operating and it must not
allow leaks into or from the supply air duct system.
Return Air Plenum
Returnairmustnotbedrawnfrom a roomwherethisfurnace,
or any other gas fueled appliance (i.e., water heater), or
carbon monoxide producing device (i.e., wood fireplace) is
installed. When return air is drawn from a room, a negative
pressure is created in the room. If a gas appliance is
operatingina roomwithnegativepressure,theflue products
can be pulled back down the vent pipe and into the room.
This reverse flow of the flue gas may result in incomplete
combustionandthe formationofcarbonmonoxidegas. This
toxic gas 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 fiberglass sealing
strips, caulking, or equivalent sealing method between the
plenum and the furnace cabinet to ensure a tight seal. If a
filter is installed, size the return air duct to fit the filter frame.
Figure 13
* GasConnector maybeused forCanadian installationifacceptable
by local authority having jurisdiction.
Table 1

506887-01Page 12 of 78 Issue 1213
Pipe and Fittings Specifications
All pipe, fittings, primer and solvent cement must conform
withAmericanNational StandardInstitute andthe American
Society for Testing and Materials (ANSI/ASTM) standards.
The solvent shall be free flowing 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, stratification,
or separation that cannot be removed by stirring. Refer to
Table 2 for approved piping and fitting materials.
PIPING AND FITTINGS SPECIFICATIONS
Table 2
IMPORTANT
The 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
solventcement tomakeconnections tothePVC fittings
in the unit.
CAUTION
Solvent cements for plastic pipe are flammable liquids
and should be kept away from all sources of ignition.
Donot useexcessiveamounts ofsolventcement when
making joints. Good ventilation should be maintained
to reduce fire hazard and to minimize breathing of
solvent vapors. Avoid contact of cement with skin and
eyes.
UsePVC primerandsolventcement orABSsolvent cement
meeting ASTM specifications, refer to Table 2. As an
alternate, use all purpose cement, to bond ABS, PVC, or
CPVC pipe when using fittings and pipe made of the same
materials. Usetransitionsolvent cementwhenbondingABS
to either PVC or CPVC.
Low temperature solvent cement is recommended. Metal
or plastic strapping may be used for vent pipe hangers.
Uniformly apply a liberal coat of PVC primer for PVC.
Canadian Applications Only – Pipe, fittings, primer and
solventcement usedtovent (exhaust)this applicance must
be certified to ULCS636 and supplied by a single
manufactureras part ofanapprovedvent (exhaust)system.
In addition, the first three feet of vent pipe from the furnace
flue collar must be accessible for inspection.
Table 3 lists the available exhaust termination kits, as well
asvent pipeequivalencieswhich mustbeused whensizing
vent pipe.

506887-01 Page 13 of 78Issue 1213
Joint Cementing Procedure
All cementing of joints should be done according to the
specifications outlined inASTM D2855.
1. Measure and cut vent pipe to desired length.
2. Deburand chamferendof pipe,removingany ridgesor
rough edges. If end is not chamfered, edge of pipe
may remove cement from fitting socket and result in a
leaking joint.
3. Clean and dry surfaces to be joined.
4. Test fit joint and mark depth of fitting 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 fitting and male end of pipe to depth of fitting
socket.
DANGER
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.
6. Promptlyapply solvent cementtoend of pipeandinside
socket surface of fitting. 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.
NOTE: Time is critical at this stage. Do not allow primer to
dry before applying cement.
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
socketuntilitbottomsout. TurnPVCpipe1/4turnduring
assembly(butnot after pipeisfullyinserted)to distribute
cementevenly. DO NOT turnABSorcellular corepipe.
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 fitting socket. Aproperly made joint will show a bead
around its entire preimeter. Any gaps may indicate a
defective asembly due to insufficient solvent.
9. Handle joints carefully until completely set.
OUTDOOR TERMINATION KITS USAGE
Table 3

506887-01Page 14 of 78 Issue 1213
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a
ventingsystemcommonly runwithseparate gasappliances,
the venting system is likely to be too large to properly vent
the remaining attached appliances.
Conductthe followingtestwhileeach applianceisoperating
and the other appliances (which are not operating) remain
connected to the common venting system. If the venting
systemhas beeninstalledimproperly, youmust correct the
system as indicated in the general venting requirements
section.
1. Sealanyunusedopeningsinthecommonventingsystem.
The following steps shall be followed for each appliance
connectedtotheventing system beingplacedintooperation,
while all other appliances connected to the venting system
are not in operation:
Venting Practices 1. In areas where piping penetrates joist or interior walls,
holemustbelargeenoughto allow clearanceonallsides
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,makeprovisionsfor drainingcondensate
collection from trap and lines.
Theexhaust vent pipeoperatesunderpositive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
Donot dischargeexhaustinto anexistingstackorstack
that also serves another gas appliance. If vertical
dischargethrough anexistingunused stackis required,
insert PVC pipe inside the stack until the end is even
with the top or outlet end of the metal stack.
CAUTION
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 14
CARBONMONOXIDEPOISONINGHAZARD
Failure to follow the steps outlined below for each
applianceconnectedto the ventingsystembeingplaced
intooperationcouldresult in carbonmonoxidepoisoning
or death.
WARNING
FIGURE15

506887-01 Page 15 of 78Issue 1213
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 Allied Air
Technical Service formore informationconcerning sizingof
vent systems which include multiple pipe sizes.
EXHAUSTPIPE
Figure 16
Horizontal Application
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 fittings.
NOTE: Exhaust piping should be checked carefully to make sure
there are no sages or low spots.
*Anyapproved terminationmay beadded tothe minimumequivalent
length listed.
MINIMUM VENT PIPE LENGTHS
Table 4
Do not use screens or perforated metal in exhaust or
intaketerminations. Doingsowill causefreeze-upsand
may block the terminations.
IMPORTANT
2. Inspecttheventing system forpropersizeandhorizontal
pitch. Determine that there is no blockage, restriction,
leakage, corrosion, or other deficiencies 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
andotherspacesofthebuilding. 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 fireplace 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 flue gases at the draft hood relief opening.
Use the flame 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, fireplace
dampers,and anyothergas burningappliancesto their
previous mode of operation.
7. Ifaventing problemisfoundduring any ofthepreceding
tests, the common venting system must be modified to
correct the problems.
Resizethecommonventingsystem totheminimumvent
pipe size determined by using the appropriate tables in
the current standards of the National Fuel Gas Code
ANSI Z223.1.
Vent Piping Guidelines
This unit is installed only as a Direct Vent gas central
furnace.
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and flue 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. Table5 liststhe maximum pipelengthspermitted.
Regardless of the diameter of pipe used, the standard roof
and wall terminations described in section Exhaust Piping
Terminationsshould be used. Exhaustventterminationpipe
issized tooptimizethe velocityofthe exhaustgasas itexits
the termination. Refer to Table 6.
Insomeapplicationswhichpermit theuseofseveraldifferent
sizes of vent pipe, a combination vent pipe may be used.
Contact Allied Air Technical Service for more information
concerning sizing of vent systems which include multiple
pipe sizes.
Use the steps in Figure 17 to correctly size vent pipe
diameter.

506887-01Page 16 of 78 Issue 1213
Figure 17

506887-01 Page 17 of 78Issue 1213
Table 5
Maximum Allowable Intake or Exhaust Vent Length (feet)
Standard Termination at Elevation 0 - 7500 f t
Number Of 2" Pipe 3" Pipe
90°Elbows Model Model Model
Used 110 135 070 090
110
135 070 090 110
135
1 86 64 135 88
38
157 138 113 109
2 81 59 130 83
33
152 133 108 104
3 76 54 125 78
28
147 128 103 99
4 71 49 120 73
23
142 123 98 94
5 66 44 115 68
18
137 118 93 89
n
/
a
6 61 39
110 63
13
132 113 88 84
7 56
n
/
a105 58
8
127 108 83 79
8 51 100 53
122 103 78 74
9 46 95 48
117
98 73 69
10 41 90 43
n/a
112 93 68 64
Standard Termination Elevation 4501 - 10,000 ft
Number Of 2” Pipe 3" Pipe
90° Elbows Model Model Model
Used 070 090 110 135 070 090
110
135 070 090 110
135
1 61 39 110 63
132 113 88 84
2 56 34 105 58
127 108 83 79
3 51 29 100 53
122 103 78 74
4 46 24 95 48
117 98 73 69
5 41 19 90 43 112 93 68 64
n
/
an
/
a
6 36 14 85 38 107 88 63 59
7 31 80 33
102 83 58 54
8 26 75 28
97 78 53 49
9 21 n/a 70 23
92
73 48 44
10
16 65 18
nla
87 68 43 39
2 -1/2" P ip e
n/a
n/a
2 -1/2" P ip e
070
090
34
29
24
19
9
Concentric Te rm in atio n at E leva tion 0 - 7,500 ft-
Number Of 2" Pipe 3" P ip
e
90°Elbows Model Model Model
Used 110 135 070 090
110
135 070 090 110
135
1 78 62 125 84
34
141 134 109 100
2 73 57 120 79
29
136 129 104 95
3 68 52 115 74
24
131 124 99 90
4 63 47 110 69
19
126 119 94 85
5 58 42 105 64
14
131 114 89 80
n
/
a
6 53 37
100
9
116 109 84 75
7 48
n
/
a95 54 111 104 79 70
8 43 90 49
106 99 74 65
9 38 85 44
101
94 69 60
10 33 80 39
n/a
96 89 64 55
Concentric Te rm in atio n E levatio n 4,50 1 - 10,000 ft-
Number Of 2” Pipe 3" Pipe
90° Elbows Model Model Model
Used 070 090 110 135 070 090
110
135 070 090 110
135
1 53 37 100 59
116 109 84 75
2 48 32 95 54
111 104 79 70
3 43 27 90 49
106 99 74 65
4 38 22 85 44
101 94 69 60
5 33 17 80 39 96 89 64 55
n
/
an
/
a
6 28 12 75 34 91 84 59 50
7 23 70 29
86 79 54 45
8 18 65 24
81 74 49 40
9 13 n/a 60 19
76 69 44 35
10
8 55 14
nla
71 64 39 30
2 -1/2" P ip e
n/a
n/a
2 -1/2" P ip e
070
090
32
27
22
17
7
59
*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.

506887-01Page 18 of 78 Issue 1213
TYPICALEXHAUSTANDINTAKE PIPE CONNECTIONS
IN UPFLOW APPLICATIONS
Figure 18
Figure 19
TYPICALEXHAUSTANDINTAKE PIPE CONNECTIONS
IN HORIZONTAL APPLICATIONS
(RIGHTHAND DISCHARGE SHOWN)
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.
* When transitioning up in pipe size, use the shortest length of 2” PVC pipe possible.

506887-01 Page 19 of 78Issue 1213
VENT TERMINATION CLEARANCES
FOR DIRECT VENT INSTALLATiONS IN THE USAAND CANADA
Figure 20

506887-01Page 20 of 78 Issue 1213
Table 6
Maximum Allowable Vent pipe Length without Insulation in Unconditioned Space for Winter Design
Temperatures Modulating High Efficiency Furnace
¹Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.
NOTE: Maximum unisulated vent lengths listed cannot exceedd the maximum allowable intake or exhaust vent length listed in Table 5.
General Guidelines for Vent Terminations
In Direct Vent applications, combustion air is taken from
outdoorsand the fluegasesare dischargedtothe outdoors.
This gas furnace is classified as a direct vent, Category IV
gas furnace.
In Direct Vent applications, the vent termination is limited
bylocal buildingcodes. Inthe absenceoflocal codes,refer
to the current National Fuel Gas CodeANSI 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
20. In addition, position termination so it is free from any
obstructionsand12" above theaveragesnowaccumulation.
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
belocated within 6feet(1.8m) of acondensingunit because
the condensate can damage the painted coating.
NOTE: See Table 6 for maximum allowed exhaust pipe
length without insulation in unconditioned space during
winter design temperatures below 32°F 0°C). If equired
exhaustpipeshouldbeinsulated with1/2"(13mm)Armaflex
or equivalent. In extreme cold climate areas, 3/4" (19mm)
Armaflex 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 specific
applications.
Do not use screens or perforated metal in exhaust
terminations. Doing so will cause freeze-ups and may
block the terminations.
IMPORTANT
FORCANADIANINSTALLATIONS ONLY:
In accorddance to CSA International B149 installation
codes, the minimum allowed distance between the
combustionairintakeinletandtheexhaustoutletofother
appliances shall not be less than 12 inches (305 mm).
IMPORTANT