Armstrong Air Conditioning A97DSMV User manual

507029-03 Page 1 of 68Issue 1622
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
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
A97DSMV
Warm Air Gas Furnace
Downow Air Discharge
(P) 507029-03
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
Setting Equipment ................................................................................... 6
Filters......................................................................................................11
Duct System ............................................................................................ 9
Pipe and Fittings Specications............................................................. 10
Joint Cementing Procedure................................................................... 13
Venting Practices................................................................................... 14
Vent Piping Guidelines .......................................................................... 16
Condensate Piping ............................................................................... 25
Gas Piping............................................................................................. 28
TABLE OF CONTENTS
Electrical ............................................................................................ 29
Integrated Control.................................................................................. 35
Blower Motor Performance.................................................................... 43
Unit Start Up.......................................................................................... 47
Gas Pressure Measurement.................................................................. 48
High Altitude Information ....................................................................... 49
Proper Combustion................................................................................ 49
Other Unit Adjustments.......................................................................... 51
Heating Sequence of Operation ............................................................ 52
Service ............................................................................................ 54
Planned Service .................................................................................... 56
Integrated Control Diagnostic Codes..................................................... 57
Conguring Unit Size Codes ................................................................. 60
Troubleshooting..................................................................................... 61
Repair Parts List.................................................................................... 67
A thermostat is not included and must be ordered
separately.
•A Comfort Sync™ thermostat must be used in
communicating applications.
•In non-communicating applications, a traditional
non-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
*P507029-03*

507029-03Page 2 of 68 Issue 1622
Unit Dimensions - inches (mm)
*NOTE - C/D20 size units that require second stage air volumes
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 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.
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

507029-03 Page 3 of 68Issue 1622
A97DSMV Exploded View
Figure 1

507029-03Page 4 of 68 Issue 1622
A97DSMV Gas Furnace
The A97DSMV Category IV gas furnace is equipped with a
variable capacity, varable speed integrated control. Each
A97DSMV is shipped ready for installation in the downow
air discharge position.
The furnace is equipped for installation in natural gas
applications only. A change over kit must be ordered for
LP/propane applications.
The A97DSMV must be installed only as a Direct Vent
gas central furnace
NOTE: In Direct Vent installations, combustion air is taken
from outdoors and ue gases are discharged outdoors. See
Figure 2 for applications including roof termination.
Shipping and Packing List
1 - Assembled A97DSMV unit.
1 - Bag assembly containing the following:
1 - Snap bushing
1 - Snap Plug
1 - Wire tie
1 - Condensate trap
1 - 3/4” Threaded PVC street elbow
2 - 2” Street elbows
2 - Side vent sealing plates
2 - Side vent sealing gaskets
6 - Sheetmetal screws
Check equipment for shipping damage. If you nd any
damage, immediately contact the last carrier.
The following items may also be ordered separately:
1 - Thermostat
1 - Natural to LP gas conversion kit
1 - High altitude kit
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/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.
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.
Installed Locations
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.
The furnace is designed for installation clearances to
combustible material as listed on the unit nameplate and in
Figure 7. 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.
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
Figure 2

507029-03 Page 5 of 68Issue 1622
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 (100% percent capacity) within the range (s) specied
on the unit nameplate. Failure to do so may cause erratic
limit operation and may also result in premature heat
exchanger failure.
This A97DSMV 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.
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. See Figure 3.
The A97DSMV furnace may be installed in alcoves, 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
These units are not recommended for 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.
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
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 Canadian Electrical Code Part I (CSA Standard 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 to Air Handler Unit

507029-03Page 6 of 68 Issue 1622
• Air lters must be replaced upon construction completion.
•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.
•The furnace heat exchanger, components, duct system,
air lters and evaporator coils must be thoroughly
cleaned following nal construction cleanup.
•All furnace operating conditions (including ignition, input
rate, temperature rise and venting) must be veried
according to these installation instructions.
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
distribution system as possible. The furnace should
also be located close to the vent 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 an unconditioned space,
consider provisions required to prevent freezing of
condensate drain system.
Installation – Setting Equipment
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, for proper operation. It
is recommended to tilt the unit slightly toward the drain to
insure proper drainage. See Figure 4.
The State of California has determined that this 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
reproductive harm.
WARNING
General
Figure 4
Setting Equipment
Do not install the furnace on its front or its back. See
Figure 5. 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.
WARNING
Figure 5

507029-03 Page 7 of 68Issue 1622
SETTING EQUIPMENT
Figure 5
UNIT MUST BE LEVEL SIDE TO SIDE IN ALL APPLICATIONS 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.

507029-03Page 8 of 68 Issue 1622
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 lter)
A97DSMV 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 feet) require either a
return air base or eld fabricated transition to accommodate
an optional IAQ accessory taller than 14.5”. See Figure 6.
Optional Return Air Base
(Upow Applications Only)
NOTE: Optional side return air lter 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 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 8

507029-03 Page 9 of 68Issue 1622
NOTE: 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 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.
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
could contain carbon monoxide, can be drawn into living
space resulting in personal injury or death.
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.
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.
Return Air – Downow Units
Return air can be brought in through either side of the
furnace installed in a downow application.
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 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 oor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood ooring.
Figure 9
Units with 1/2 HP
Blower Motor

507029-03Page 10 of 68 Issue 1622
Setting and Upow 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.
Horizontal Applications
The A97DSMV 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. Either suspend the furnace from roof rafters or
oor joists, as shown in Figure 12 or install the furnace on
a platform, as shown in Figure 13. A horizontal suspension
kit (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
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 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. Select location for unit keeping in mind service and other
necessary clearances. See Figure 11.
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 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. 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 11
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
provide for servicing of the condensate trap. Unless the trap is
mounted 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 12

507029-03 Page 11 of 68Issue 1622
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
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 when the unit is operating!
NOTE: In upow applications where side return air lter is
installed on same side as the condensate trap, make sure
that clearance is maintained to ensure future access to the
lter 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
blower operating at selected heating speed) with an external
static pressure which exceeds 0.8 inches w.c. may result in
erratic 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 reected light) of the heat exchanger for leaks after
the furnace is installed. If present, this access panel must
always 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
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 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 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.
Figure 13
* Gas Connector may be used for Canadian installation if acceptable
by local authority having jurisdiction.
Table 1

507029-03Page 12 of 68 Issue 1622
Pipe and 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.
Use PVC primer and solvent cement or ABS solvent 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. 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, ttings, primer and
solvent cement used to vent (exhaust) this applicance
must be certied to ULCS636 and supplied by a single
manufacturer as part of an approved vent (exhaust) system.
In addition, the rst three feet of vent pipe from the furnace
ue collar must be accessible for inspection.
Table 5 list the available exhaust termination kits.
Venting Options
This unit is shipped with vent exhaust / air intake connection
at the top cap. See Figure 13. Using parts provided, the
furnace may be eld modied to have these connections
on the right side of the furnace cabinet. See Figure 15 and
follow the steps below. For left side venting order kit 87W73.
1. Remove access panels.
2. Loosen hose clamps which attache rubber ttings to the
white PVC pipes inside the vestibule area, See Figure
13.
3. Loosen the clamp which secures the pipes at the blower
deck. See Figure 13.
4. Remove white PVC pipes, slide up and out thru the top
cap.
5. Remove the black plastic fitting in top cap which
previously aligned the PVC pipes.
6. Remove the sheet metal patch plate on the side of the
cabinet which covers the openings for side venting
option. Save screws for reuse.
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
solvent cement to make connections to the PVC ttings
in the unit.
CAUTION
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.
PIPING AND FITTINGS SPECIFICATIONS
Table 2
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

507029-03 Page 13 of 68Issue 1622
OUTDOOR TERMINATION KITS USAGE
Table 3

507029-03Page 14 of 68 Issue 1622
Venting Practices
Figure 15
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.
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
Joint Cementing Procedure
All cementing of joints should be done according to the
specications outlined in ASTM D2855.
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.
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. 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.
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
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 preimeter. Any gaps may indicate a
defective asembly due to insufcient solvent.
9. Handle joints carefully until completely set.

507029-03 Page 15 of 68Issue 1622
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.
Exhaust Piping (Figures 18 and 19)
3. Route piping to outside of structure. Continue with
installation following instructions given in piping
termination section.
The exhaust vent pipe operates under positive pressure
and must be completely sealed to prevent leakage of
combustion products into the living space.
CAUTION
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
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 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 6.
In some applications which permit the use of several different
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.
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a vent-
ing system commonly run with separate gas appliances,
the venting system is likely 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.
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.
WARNING
CARBON MONOXIDE POISONING HAZARD
* Any approved termination may be added to the minimum equivalent
length listed.
MINIMUM VENT PIPE LENGTHS
Table 4
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 for more information concerning sizing
of vent systems which include multiple pipe sizes.
NOTE: If right side venting option is used, you must include
the elbow at the furnace in the elbow count. If transitioning
to 3” diameter pipe, this elbow equates to 20’ of equivalent
vent length for all models.

507029-03Page 16 of 68 Issue 1622
Use the following steps to correctly size vent pipe diameter.
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. Inspect the venting system for proper size and horizontal
pitch. Determine that there is no blockage, restiction,
leakage, corrosion, or other deciencies which could
cause and unsafe condition.
3. Close all building doors and windows and all doors
beween 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 furning 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 modied to
correct the problem.
Resize the common venting system to the minimum vent
pipe size determined by using the appropriated tables
in Appendix G. (These are in the current standards of
the National Fuel Gas Code ANSI Z223.1.)
Figure 17
EXHAUST PIPE
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 ttings.
NOTE: Exhaust piping should be checked carefully to make sure
there are no sages or low spots.

507029-03 Page 17 of 68Issue 1622
Table 5
Maximum Allowable Intake or Exhaust Vent Length (feet)

507029-03Page 18 of 68 Issue 1622
TYPICAL EXHAUST PIPE CONNECTIONS AND CONDENSATE TRAP INSTALLATION
IN UPFLOW APPLICATIONS
Figure 18
Figure 19
TYPICAL EXHAUST PIPE CONNECTIONS AND CONDENSATE TRAP INSTALLATION
IN HORIZONTAL AIR APPLICATIONS
(RIGHT HAND DISCHARGE SHOWN)

507029-03 Page 19 of 68Issue 1622
VENT TERMINATION CLEARANCES
FOR DIRECT VENT INSTALLATiONS IN THE USA AND CANADA
Figure 20

507029-03Page 20 of 68 Issue 1622
General Guidelines for Vent Terminations
In Direct Vent applications, combustion air is taken from
outdoors and the ue gases are discharged to the outdoors.
This gas furnace is classied as a direct vent, Category IV
gas furnace.
In 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
20. 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 (1.8m) of a condensing unit 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 (O°C). If equired
exhaust pipe should be insulated with 1/2” (13mm)
Armaex or equivalent. In extreme cold climate areas,
3/4” (19mm) Armaex 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 specic
applications.
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 accorddance 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
Table 6
Maximum Allowable Vent pipe Length without Insulation in Unconditioned Space for Winter Design
Temperatures Modulating High Efciency Furnace
Winter Design Temperatures1
ºF (ºC)
Vent Pipe
Diameter 070 090 110 135
32 to 21
(0 to -6)
PVC 2PP PVC 2PP PVC 2PP PVC 2PP
2 in. 11 9 14 12 18 15 N/A N/A
2-1/2 in. 7 N/A 10 N/A 12 N/A N/A N/A
3 in. N/A N/A 6 6 8 8 13 13
20 to 1
(-7 to -17)
2 in. N/A N/A 6 4 8 6 N/A N/A
2-1/2 in. N/A N/A N/A N/A N/A N/A N/A N/A
3 in. N/A N/A N/A N/A N/A N/A N/A N/A
0 to -20
(-18 to -29)
2 in. N/A N/A N/A N/A N/A N/A N/A N/A
2-1/2 in. N/A N/A N/A N/A N/A N/A N/A N/A
3 in. N/A N/A N/A N/A N/A N/A N/A N/A
1Refer 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
NOTE - Concentric terminations are the equivalent of 5’ and should be considered when measuring pipe 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 5 or 6.
NOTE - If insulation is required an unconditioned space, it must be located on the pipe closed to the furnace.