International comfort products H8UH5050B12C2 User manual

CARBON MONOXIDE POISONING AND FIRE
HAZARD.
Failure to follow this warning could result in
injury, death, and/or property damage.
This furnace is not designed for use in mobile
homes, trailers or recreational vehicles.
!
ELECTRIC SHOCK HAZARD
Failure to follow this warning
could result in injury or death.
Turn Off All Power Before
Servicing.
!
International Comfort Products, LLC
Lewisburg, TN 37091 U.S.A.
See section 5 for Category I definition.
INSTALLER: Affix these instructions
on or adjacent to the furnace.
CONSUMER: Retain these
instructions for future reference.
Portions of the text and tables are reprinted from NFPA 54 / ANSI Z223.1--2006©, with permission of National Fire Protection Association, Quincy, MA 02269 and American Gas Association,
Washington, DC 20001. This reprinted material is not the complete and official position of the NFPA or ANSI, on the referenced subject, which is represented only by the standard in its entirety.
WARNING WARNING
Printed in U.S.A. 441 01 5003 01 July 2007
80+ SINGLE STAGE GAS FURNACE
Category I Furnace
H8UH5, MUF, HL
220V- 1 ph- 50Hz
SAFETY REQUIREMENTS
Recognize safety information. This is the safety--alert symbol !. When you see this symbol on the furnace and in instruction manuals be alert
to the potential for personal injury.
Understand the signal words DANGER, WARNING, or CAUTION. These words are used with the safety--alert symbol. DANGER identifies the
most serious hazards, those that will result in severe personal injury or death. WARNING signifies a hazard that could result in personal injury or
death. CAUTION is used to identify unsafe practices that may result in minor personal injury or product and property damage. Note is used to
highlight suggestions that will result in enhanced installation, reliability, or operation.
Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained and qualified personnel should
install, repair, or service heating equipment.
Untrained service personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be
performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels at-
tached to or shipped with the furnace and other safety precautions that may apply.
Follow all safety codes. In the United States, follow all safety codes including the National Fuel Gas Code (NFGC) ANSI Z223.1--2006/NFPA
54--2006. Wear safety glasses and work gloves. Have fire extinguisher available during start--up and adjustment procedures and service calls.
These instructions cover minimum requirements and conform to existing national standards and safety codes. In some instances, these instruc-
tions exceed certain local codes and ordinances, especially those that may not have kept up with changing residential construction practices. We
require these instructions as a minimum for a safe installation.
Table of Contents
1. Safe Installation Requirements 3...............
2. Installation 4..............................
3. Side Venting 6.............................
4. Combustion & Ventilation Air 7.................
5. Gas Vent Installation 10.......................
6. Horizontal Venting 11.........................
7. Masonry Chimney Venting 13...................
8. Gas Supply and Piping 15.....................
9. Electrical Wiring 18.........................
10. Ductwork and Filter 19.......................
11. Checks and Adjustments 22...................
12. Furnace Maintenance 27......................
13. Sequence of Operation & Diagnostics 28.........
Technical Support/Parts 31......................

2441 01 5003 01
Specifications are subject to change without notice
START--UP CHECK SHEET
For 80+ Furnace
(This sheet is optional. Keep this page for future reference.)
Date of Start--Up:
Dealer Name:
Address:
City, State(Province), Zip or Postal Code:
Phone:
Owner Name:
Address:
City, State(Province), Zip or Postal Code:
Model Number:
Serial Number:
Setup Checks
Check the box when task is complete
Thermostat: Heat Cooling Fan
Subbase level:
Anticipator Set: Setting of Anticipator ____
All Electrical Connections Tight:
Supply voltage: ____
Blower Motor H.P.: ____
Fan “Time ON” setting: ____ Fan “Time OFF” Setting ___
Manual Gas Shut--Off Upstream of Furnace/Drip--Leg?
Gas Valve turned ON?
Type of Gas: Natural: Propane:
Filter Type and Size:
Calculated Firing Rate:(See Checks and Adjustments
Section).
Heating Check
Measured Line Pressure when Firing Unit:
Measured Manifold Gas Pressure:
Temperature of Supply Air: (°)
Temperature of Return Air: (°)
Temperature Rise (supply--return temperature): (°)
In Rise (see furnace rating plate)? (°)
Static Pressure (Ducts): Supply Air Return
Blower speed tap used for heating
Limit Opens: (°)________ Limit Closes: (°)
Optional Check: CO ? CO2 ?
Cooling Check
Temperature of Supply Air: (°)
Temperature of Return Air: (°)
Temperature Difference: (°)
Static Pressure (Ducts) cooling: Supply Air Return
Blower Speed Tap used for cooling: _______
Dealer Comments:

3
441 01 5003 01
Specifications are subject to change without notice
1. Safe Installation Requirements
FIRE, EXPLOSION, AND ASPHYXIATION HAZARD.
Improper adjustment, alteration, service,
maintenance or installation could cause personal
injury, death and/or property damage.
Installation or repairs made by unqualified persons
could result in hazards to you and others.
Installation MUST conform with local codes or, in the
absence of local codes, with codes of all
governmental authorities having jurisdiction.
The information contained in this manual is
intended for use by a qualified service agency that is
experienced in such work, is familiar with all
precautions and safety procedures required in such
work, and is equipped with the proper tools and test
instruments.
!
NOTE: This furnace is design--certified by the CSA International
(formerly AGA and CGA) for installation in the United States and
Canada. Refer to the appropriate codes, along with this manual, for
proper installation.
•Use only the Type of gas approved for this furnace (see
Rating Plate on furnace). Overfiring will result in failure of
heat exchanger and cause dangerous operation. (Furnaces
can be converted to Propane gas with approved kit as noted
on rating plate.)
•Install this furnace only in a location and position as specified
in “Installation” of these instructions.
•Provide adequate combustion and ventilation air to the
furnace as specified in “Combustion and Ventilation Air” of
these instructions.
WARNING
!
CARBON MONOXIDE POISONING HAZARD.
Failure to follow this warning could result in personal
injury and or death.
Do NOT install this furnace in DOWNFLOW applica-
tions.
AVERTISSEMENT
!
RISQUE D‘EMPOISONNEMENT PAR MONOXYDE DE
CARBONE.
Si les conseils de cette avertissement ne sont pas sui-
vi, cela peut entraîner des blessures et/ou la mort.
Ne pas installer cette fournaise avec un débit DE-
SCENDANT.
•Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only, as
specified in “Gas Vent Installation, Horizontal Venting and
Masonry Chimney Venting” of these instructions.
•Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifically for
the detection of leaks to check all connections, as specified
in “Gas Supply and Piping, Final Check” of these
instructions.
•Always install furnace to operate within the furnace’s
intended temperature--rise range with a duct system which
has an external static pressure within the allowable range,
as specified in “Technical Support Manual” of these
instructions.
•When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space
containing the furnace, the return air shall also be handled by
a duct(s) sealed to the furnace casing and terminating
outside the space containing the furnace.
•A gas--fired furnace for installation in a residential garage
must be installed as specified in “Installation” of these
instructions.
•This furnace is not to be used for temporary heating of
buildings or structures under construction. See “Installation ”
•This furnace is NOT approved for installation in mobile
homes, trailers or recreation vehicles.
•Seal around supply and return air ducts.
•Install correct filter type and size.
•Furnace MUST be installed so electrical components are
protected from direct contact with water.
Safety Rules
Your furnace is built to provide many years of safe and dependable
service providing it is properly installed and maintained. However,
abuse and/or improper use can shorten the life of the furnace and
create hazards for you, the owner.
A. The U.S. Consumer Product Safety Commission encourages
installation of carbon monoxide alarms. There can be various
sources of carbon monoxide in a building or dwelling. The
sources could be gas--fired clothes dryers, gas cooking stoves,
water heaters, furnaces, gas--fired fireplaces, wood fireplaces.
Carbon monoxide can cause serious bodily injury and/or death.
Carbon monoxide or “CO” is a colorless and odorless gas
produced when fuel is not burned completely or when the flame
does not receive sufficient oxygen.
Therefore, to help alert people of potentially dangerous carbon
monoxide levels, you should have a commercially available
carbon monoxide alarm that is listed by a nationally recognized
testing agency in accordance with Underwriters Laboratories
Inc. Standard for Single and Multiple Station Carbon Monoxide
Alarms, ANSI/UL 2034 or the CSA 6.19--01 Residential Carbon
Alarming Devices installed and maintained in the building or
dwelling concurrently with the gas--fired furnace installation
(see Note below). The alarm should be installed as
recommended by the alarm manufacturer’s installation
instructions.
B. There can be numerous sources of fire or smoke in a building or
dwelling. Fire or smoke can cause serious bodily injury, death,
and/or property damage. Therefore, in order to alert people of
potentially dangerous fire or smoke, you should have fire
extinguisher and smoke alarms listed by Underwriters
Laboratories installed and maintained in the building or dwelling
(see Note below).
Note: The manufacturer of your furnace does not test any alarms
and makes no representations regarding any brand or type of
alarms.
C. To ensure safe and efficient operation of your furnace, you
should do the following:
1. Thoroughly read this manual and labels on the furnace.
This will help you understand how your furnace operates and
the hazards involved with gas and electricity.
2. Do not use this furnace if any part has been under water.
Immediately call a qualified service agency to inspect the

4441 01 5003 01
Specifications are subject to change without notice
furnace and to replace any part of the control system and any
gas control which has been under water.
3. Never obstruct the vent grilles, or any ducts that provide
air to the furnace. Air must be provided for proper combustion
and ventilation of flue gases.
Frozen Water Pipe Hazard
WATER DAMAGE TO PROPERTY HAZARD.
FaiIure to follow this warning could result in
property damage.
Do not leave your home unattended for long periods
during freezing weather without turning off water
supply and draining water pipes or otherwise
protecting against the risk of frozen pipes and
resultant damage.
!WARNING
Your furnace is designed solely to provide a safe and comfortable
living environment. The furnace is NOT designed to ensure that
water pipes will not freeze. It is equipped with several safety devices
that are designed to turn the furnace off and prevent it from
restarting in the event of various potentially unsafe conditions.
If your furnace remains off for an extended time, the pipes in your
home could freeze and burst, resulting in serious water damage.
If the structure will be unattended during cold weather you should
take these precautions.
1. Turn off the water supply to the structure and drain the water
lines if possible and add an antifreeze for potable water to drain
traps and toilet tanks. Open faucets in appropriate areas.
-- o r --
2. Have someone check the structure frequently during cold
weather to make sure it is warm enough to prevent pipes from
freezing. Instruct them on a service agency to call to provide
service, if required.
-- o r --
3. Install a reliable remote sensing device that will notify
somebody of freezing conditions within the home.
2. Installation
CARBON MONOXIDE POISONING HAZARD.
Failure to follow this warning could result in
personal injury or death.
If this furnace is replacing a previously
common-vented furnace, it may be necessary
to resize the existing vent system to prevent
oversizing problems for the other remaining
appliances(s). See Venting and Combustion Air
Check in the Gas Vent Installation section of
this instruction.
!
Location and Clearances
If furnace is a replacement, it is usually best to install the furnace
where the old one was. Choose the location or evaluate the existing
location based upon the minimum clearance and furnace
dimensions (Figure 1).
CARBON MONOXIDE POISONING HAZARD.
FaiIure to follow this warning could result in
personal injury or death.
Do NOT operate furnace in a corrosive atmosphere
containing chlorine, fluorine or any other damaging
chemicals, which could harm the furnace and vent
system and permit spillage of combustion products
into an occupied space.
Refer to Combustion & Ventilation Air section,
Contaminated Combustion Air for combustion air
evaluation and remedy.
!
Installation Requirements
1. Install furnace level.
2. This furnace is NOT to be used for temporary heat of buildings
or structures under construction.
3. Install furnace as centralized as practical with respect to the
heat distribution system.
4. Install the vent pipes as short as practical. (See Gas Vent
Installation section).
5. Do NOT install furnace directly on carpeting, tile or other
combustible material other than wood flooring.
6. Maintain clearance for fire safety and servicing. A front
clearance of 24″(610mm) is minimum for access to the burner,
controls and filter. See clearance requirements in Figure 1.
7. Use a raised base if the floor is damp or wet at times.
8. Residential garage installations require:
•Burners and ignition sources installed at least 18″(457 mm)
above the floor.
•Furnace must be located or physically protected from
possible damage by a vehicle.
9. If the furnace is to be suspended from the floor joists in a
basement or a crawl space or the rafters in an attic, it is
necessary to use steel pipe straps or an angle iron frame to
attach the furnace. These straps should be attached to the
furnace bottom side with sheet metal screws and to the rafters
or joists with bolts. The preferred method is to use an angle iron
frame bolted to the rafters or joists.
10. This furnace may be used for construction heat provided that:
•The furnace is permanently installed with all electrical wiring,
piping, venting, air filters and ducting installed according to
these installation instructions. A return air duct is provided,
sealed to the furnace casing, and terminated outside the
space containing the furnace. This prevents a negative
pressure condition as created by the circulating air blower,
causing a flame rollout and/or drawing combustion products
into the structure.
•The furnace is controlled by a thermostat. It may not be “hot
wired” to provide heat continuously to the structure without
thermostatic control.
•Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and
other construction materials. It also prevents the entrainment
of drywall dust into combustion air, which can cause fouling
and plugging of furnace components.
•The temperature of the return air to the furnace is maintained
between 55°F(13°C) and 80°F(27°C) , with no evening
setback or shutdown. The use of the furnace while the
structure is under construction is deemed to be intermittent
operation per our installation instructions.

5
441 01 5003 01
Specifications are subject to change without notice
•The air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
rating plate value.
•The filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
•The furnace, ductwork and filters are cleaned as necessary to
remove drywall dust and construction debris from all HVAC
system components after construction is completed.
•Verify proper furnace operating conditions including ignition,
gas input rate, air temperature rise, and venting according to
these installation instructions.
MINIMUM CLEARANCES TO COMBUSTIBLE
MATERIALS FOR ALL MODELS
REAR 0
FRONT (combustion air openings
in furnace and structure)
3″(76mm)
Required For Service *24″(610mm)
ALL SIDES Of SUPPLY PLENUM 1″(25.4mm)
SIDES 0
VENT
Single--Wall Vent 6″(152mm)
Type B--1 Double Wall Vent 1″(25.4mm)
TOP OF FURNACE 1″(25.4mm)
*30″(762 mm) clearance recommended for casing removal.
Horizontal position: Line contact is permissible only between lines
formed by intersections of top and two sides of furnace jacket, and
building joists, studs or framing.
DIMENSIONAL INFORMATION
Furnace
Capacity
Cabinet Top Bottom Return Air
Opening
A B F C D
H8UH5050/075B12
MUF050/075W3C
HL12/18H3TRC
151/2
(394)
14
(356)
6
(152)
13/8
(35)
125/8
(321) H
H8UH5100F14
MUF100W3C
HL25H3TRC
191/8
(486)
175/8
(447)
73/4
(197)
21/8
(54)
143/4
(375) J
H8UH5125/140J20
MUF125/140W5C
HL31H4TRC
HL34H5TRC
223/4
(578)
211/4
(540)
91/2
(241)
115/16
(49)
183/4
(476) J
Installation Positions
This furnace can be installed in an upflow, horizontal (either left or
right) airflow position. DO NOT install this furnace on its back. For
the upflow position, the return air ductwork can be attached to either
the left or right side panel and/or the bottom. For horizontal position,
the return air ductwork must be attached to the bottom. The return
air ductwork must never be attached to the back of the furnace.
Furnace Installation
Inspect the rating plate to be certain the model number begins with
“H8UH5”, “MUF”,or“HL”. This identifies the furnace as a
multi--position furnace and can be Installed in an Upflow, Horizontal
Right or Horizontal Left position. This furnace is NOT approved to
be installed in the downflow position.
51/3
(135mm)
41/16
(103mm)
38
(965mm)
321/2
(826mm)
277/8
(708mm)
175/16
(440mm)
33/4(95mm)
11/2(38mm)
21/4(57mm)
47/8
(124mm)
331/2
(851mm)
303/4
(781mm)
175/16
(440mm)
291/2
(749mm)
2 (51mm)
33/4(92mm)
47/8
(124mm)
21/4(57mm)
17/8
(48mm)
RIGHT SIDE
281/2(724mm)
181/2(470mm)
40
(1016mm)
TOP
F
LEFT SIDE
FRONT
A
B
BOTTOM
D
C
H
*24″MIN.
(610mm MIN.)
KO starting
hole to cut side
duct opening
131/4
(337mm)
213/4(552mm)
265/8(676mm)
37
(940mm)
131/4
(337mm)
213/4(552mm)
265/8(676mm)
17/8
(48mm)
7
(178 mm)
1(25.4 mm)
5
(127mm)
271/2
(698mm)
231/8(587mm)
J
Dimensions and Clearances (H8UH5, MUF, HL Models)
Figure 1
Drawing is representative.
Some models may vary
DIMENSIONS IN INCHES (mm)
KNOCK--OUT = KO
NOTE: Evaporator “A” coil drain pan dimensions may
vary from furnace duct opening size. Always consult
evaporator specifications for duct size requirements.
Furnace is designed for bottom return or side return.
Return air through back of furnace is NOT allowed.
KO starting
hole to cut side
duct opening
11/2(38mm)
1(25.4mm)
7
(178 mmm)
3/4
(19 mm)

6441 01 5003 01
Specifications are subject to change without notice
Upflow
No modifications are required for upflow installation. (See Figure 2)
Typical Upflow Installation
Figure 2
25--23--17
VENT
SUPPLY
AIR
GAS SUPPLY
RETURN
AIR
Pressure Switch Relocation
If the furnace is installed in the upflow position, the pressure switch
will remain in the same position as installed by the factory unless the
inducer is rotated. If the furnace is installed in an orientation that
places the pressure switch below the pressure tap on the inducer
housing, then the switch MUST be relocated. In order to relocate
the switch, locate 2 mounting holes or drill above the inducer
pressure tap. When drilling the 2 holes make sure to keep the switch
and tubing far enough away from the burners or hot surfaces as to
not melt the hose, switch, or wires. To prevent possible kinking of
the pressure switch hose, trim the hose to remove excess length.
Note: When drilling new holes make sure metal shavings do not fall
on or in components, as this can shorten the life of the furnace.
Horizontal
If you purchased a multi--position furnace, it can be installed
horizontally in an attic, basement, crawl space, alcove, or
suspended from a ceiling in a basement or utility room in either a
right or left airflow position. (see Figure 3)
Horizontally installed furnaces may be vented out the top of the
furnace or out the side facing up. See “Side venting” for
instructions to rotate the vent to the side.
The minimum clearances to combustibles MUST be maintained
between the furnace and adjacent construction, as shown in
Figure 1.ONLY the corner of the cabinet is allowed to contact the
rafters as shown in Figure 3. All other clearances MUST be
observed as shown in Figure 1.
Typical Horizontal Installation
Figure 3
VENT
VENT
GAS SUPPLY
SUPPLY
AIR
RETURN
AIR
25- 23- 18a
OPTIONAL
VENT LOCATION
If the furnace is to be suspended from the floor joists in a basement
or crawl space or the rafters in an attic, it is necessary to use steel
pipe straps or an angle iron frame to attach the furnace. These
straps should be attached to the furnace bottom side with sheet
metal screws and to the rafters or joists with bolts. The preferred
method is to use an angle iron frame bolted to the rafters or joists.
If the furnace is to be installed at ground level in a crawl space,
consult local codes. A concrete pad 1″(25.4 mm) to 2″(51 mm)
thick is recommended.
Twenty--four inches (24″or 610 mm) is required between the front of
the furnace and adjacent construction or other appliances. This
should be maintained for service clearance.
Keep all insulating materials clear from louvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
wood flooring or supports, however, it is recommended for further
fire protection cement board or sheet metal is placed between the
furnace and the combustible wood floor and extend 12″(305 mm)
beyond the front of the furnace louver door. (This is a
recommendation only, not a requirement).
This furnace MUST NOT be installed directly on carpeting, tile or
other combustible material other than wood flooring or supports.
3. Side Venting
This furnace is shipped from the factory in the upflow configuration
(top vent). It can easily be converted to a side vent configurations for
horizontal installations by rotating the venter assembly.
When using a side vent configuration (side outlet instead of top
outlet), it may be necessary to relocate the pressure switch to the
alternate position on the opposite side of the top panel. Two screw
holes are provided at the alternate position. Route the pressure
switch tubing so the tubing is not kinked and not touching the hot
collector box, venter housing, or motor. It may be necessary to
shorten the length of the tubing to properly route the tubing and
eliminate kinks.
Rotating the Venter Assembly
1. If gas and electrical power have already been connected to
furnace, shut off gas and remove power from furnace. Unscrew
screws on burner compartment door and remove burner
compartment door. (see Figure 4.)
2. Disconnect power leads to the venter motor and hose to
pressure switch. Remove four (4) screws which secure the
venter to the collector box, (see Figure 5).
3. Cut webbing with a pair of snips holding the vent plate to the
cabinet on either the left or right side of furnace depending on
right or left venting as desired. Discard vent plate, (see
Figure 4).

7
441 01 5003 01
Specifications are subject to change without notice
Figure 4
25--23--45
Screws (2)
Furnace with Screws
Vent Plate
4. Replace venter gasket (part # 1013540, if needed) to venter
assembly with adhesive in the same location as the old one.
5. Clip the wire tie for the venter wires, if needed.
6. Rotate venter assembly 90°right or left from original location
depending on venting configurations.
Figure 5 Venter Gasket
25--23--52c
7. Tighten the four (4) screws that secure the venter assembly to
the collector box. Do tighten screws enough to compress
venter gasket.
8. Replace power leads to venter motor and reconnect hose to
pressure switch.
NOTE: Unused open vent hole must be covered. A 5 5/16″(135 mm)
diameter Vent Cover is available separately from your distributor, or
one can be fabricated with sheet metal for side vent installations.
4. Combustion & Ventilation Air
CARBON MONOXIDE POISONING HAZARD.
Failure to follow this warning could result in
personal injury or death.
Use methods described here to provide
combustion and ventilation air.
!WARNING
Furnaces require ventilation openings to provide sufficient air for
proper combustion and ventilation of flue gases. All duct or
openings for supplying combustion and ventilation air must comply
with the gas codes, or in the absence of local codes, the applicable
national codes.
Combustion and ventilation air must be supplied in accordance with
one of the following:
Note: The Combustion & Ventilation Air Section in this document,
uses tables and information from the ANSI Z223.1/NFPA 54.
For use in Canada, use CSA B149.1 for this information.
1. Section 9.3, Air for Combustion and Ventilation, of the National
Fuel Gas Code, (NFGC), ANSI Z223.1--2006/NFPA 54--2006.
2. Sections 8.2, 8.3, 8.5, 8.6, 8.7, and 8.8 of National Standard of
Canada, Natural Gas and Propane Installation Code
(NSCNGPIC), CSA B149.1--05 in Canada,
3. Applicable provisions of the local building code.
When the installation is complete, check that all appliances have
adequate combustion air and are venting properly. See Venting And
Combustion Air Check in “Gas Vent Installation” Section in this
manual.
Contaminated Combustion Air
Installations in certain areas or types of structures could cause
excessive exposure to contaminated air having chemicals or
halogens that will result in safety and performance related problems
and may harm the furnace. These instances must use only outdoor
air for combustion.
The following areas or types of structures may contain or have
exposure to the substances listed below. The installation must be
evaluated carefully as it may be necessary to provide outdoor air for
combustion.
•Commercial buildings.
•Buildings with indoor pools.
•Furnaces installed in laundry rooms.
•Furnaces installed in hobby or craft rooms.
•Furnaces installed near chemical storage areas.
•Permanent wave solutions for hair.
•Chlorinated waxes and cleaners.
•Chlorine based swimming pool chemicals.
•Water softening chemicals.
•De--icing salts or chemicals.
•Carbon tetrachloride.
•Halogen type refrigerants.
•Cleaning solvents (such as perchloroethylene).
•Printing inks, paint removers, varnishes, etc.
•Hydrochloric acid.
•Sulfuric Acid.
•Solvent cements and glues.
•Antistatic fabric softeners for clothes dryers.
•Masonry acid washing materials.
Outdoor Combustion Air Method
A space having less than 50 cubic feet per 1,000 BTUH input rating
for all gas appliances installed in the space requires outdoor air for
combustion and ventilation.
Air Openings and Connecting Ducts
1. Total input rating for all gas appliances in the space MUST be
considered when determining free area of openings.
2. Connect ducts or openings directly to the outdoors.
3. When screens are used to cover openings, the openings MUST
be no smaller than 1/4″(6.4 mm) mesh.
4. The minimum dimension of air ducts MUST NOT be less than
3″(76 mm).
5. When sizing a grille, louver or screen use the free area of
opening. If free area is NOT stamped or marked on grill or
louver, assume a 20% free area for wood and 60% for metal.
Screens shall have a mesh size not smaller than 1/4″(6 mm).

8441 01 5003 01
Specifications are subject to change without notice
Requirements
1. Provide the space with sufficient air for proper combustion and
ventilation of flue gases using horizontal or vertical ducts or
openings.
2. Figure 6 illustrates how to provide combustion and ventilation
air when two permanent openings, one inlet and one outlet, are
used.
a. One opening MUST commence within 12″(305 mm) of the
floor and the second opening MUST commence within 12″
(305 mm) of the ceiling.
b. Size openings and ducts per Table 1.
c. Horizontal duct openings require 1 square inch of free area
per 2,000 BTUH (1,100 mm2/kW) of combined input for all
gas appliances in the space (see Table 1).
d. Vertical duct openings or openings directly communicating
with the outdoors require 1 square inch of free area per 4,000
BTUH (550 mm2/kW) for combined input of all gas appliances
in the space (see Table 1).
3. When one permanent outdoor opening is used, the opening
requires:
a. 1 sq. in of free area per 3,000 BTUH (700 mm2/kW) for
combined input of all gas appliances in the space (see
Table 1) and
b. not less than the sum of the areas of all vent connectors in the
space.
The opening shall commence within 12″(305 mm) of the top of the
enclosure. Appliances shall have clearances of at least 1″(25.4
mm) from the sides and back and 6″(152 mm) from the front. The
opening shall directly communicate with the outdoors or shall
communicate through a vertical or horizontal duct to the outdoors or
spaces (crawl or attic) that freely communicate with the outdoors.
4. Combination of Indoor and Outdoor Air shall have:
a. Indoor openings that comply with the Indoor Combustion
Air Method below and
b. Outdoor openings located as required in the Outdoor
Combustion Air Method above and
c. Outdoor openings sized as follows.
1) Calculate the Ratio of all Indoor Space volume divided by
required volume for Indoor Combustion Air Method.
Outdoor openings sized as follows.
2) Outdoor opening size reduction Factor is 1minus the
Ratio in 1) above.
3) Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor.
Furnace
Furnace
Minimum One Inlet and One Outlet Air Supply is Required
May be in and Combination Shown
Inlet Air Opening Must be Within12″(305mm) of floor
Outlet Air Opening Must be Within12″(305mm) of ceiling
(1) 1 Square Inch (6cm2) per 4000 BTUH
(2) 1 Square Inch (6cm2) per 2000 BTUH
Outside Air (This is ONLY a guide. Subject to codes of country having jurisdiction.)
Figure 6
Gas Vent
Gas Vent
Gas Vent
Gable Vent Gable Vent
Outlet
Air (1)
Outlet Air (1)
Outlet Air (1)
Furnace
Outlet
Air (2)
Optional Inlet Air (1)
Ventilated Attic Ventilated Attic
Ventilated Crawl Space
Inlet
Air (1)
Inlet
Air (1)
Inlet
Air (1)
Inlet
Air (2)
Inlet
Air (2)
Top Above Insulation
Top Above Insulation
Soffit Vent
Soffit Vent
This installation NOT approved in Canada
Table 1 Free Area
BTUH
Input
Rating
Minimum Free Area Required for Each Opening or Duct to Outdoors
Two Horizontal Ducts
(sq. in./2,000 BTUH)
Single Opening
(sq. in./3,000 BTUH)
Two Vertical Ducts or
Openings
(sq. in./4,000 BTUH)
Rd Duct
(sq. in. /4,000 BTUH)
50,000 25 sq. in. 16.7 sq. in. 12.5 sq. in. 4″
75,000 37.5 sq. in. 25 sq. in. 18.75 sq. in. 5″
100,000 50 sq. in. 33.3 sq. in. 25 sq. in. 6″
125,000 62.5 sq. in. 41.7 sq. in. 31.25 sq. in. 7″
140,000 70 sq. in. 46.7 sq. in. 35 sq. in. 7″
EXAMPLE: Determining Free Area
Furnace
100,000
Furnace
100,000
+
+
Water Heater
30,000
Water Heater
30,000
=
=
Total Input
(130,000 ÷4,000)
Total Input
(130,000 ÷2,000)
=
=
32.5 Sq. In. Vertical
65 Sq. In. Horizontal

9
441 01 5003 01
Specifications are subject to change without notice
Indoor Combustion Air
Standard and Known- Air- Infiltration Rate Methods
©NFPA&AGA
Indoor air is permitted for combustion and ventilation, if the
Standard or Known--Air--Infiltration Rate Method is used.
!
CARBON MONOXIDE POISONING HAZARD.
Failure to supply adequate combustion air could
result in personal injury or death.
Most homes will require additional air from
outdoors for combustion and ventilation. A space
with at least 50 cubic feet per 1,000 BTUH input
rating or homes with tight construction may need
outdoor air, supplied through ducts, to supplement
air infiltration for proper combustion and
ventilation of flue gases.
The Standard Method may be used, if the space has no less
volume than 50 cubic feet per 1,000 BTUH of the maximum input
ratings for all gas appliances installed in the space. The standard
method permits indoor air to be used for combustion and ventilation
air.
The Known Air Infiltration Rate Method shall be used if the
infiltration rate is known to be less than 0.40 air changes per hour
(ACH) and equal to or greater than 0.10 ACH. Infiltration rates
greater than 0.60 ACH shall not be used. The minimum required
volume of the space varies with the number of ACH and shall be
determined per Table 2 or Equations 1 and 2. Determine the
minimum required volume for each appliance in the space, and add
the volumes together to get the total minimum required volume for
the space.
Table 2
MINIMUM SPACE VOLUME FOR 100% COMBUSTION AND VENTILATION AIR FROM INDOORS (ft3)
Other Than Fan- Assisted Total
(1,000’s Btuh)
Fan- assisted Total
(1,000’s Btuh)
ACH 30 40 50 50 75 100 125 150
0.60 1,050 1,400 1,750 1,250 1,875 2,500 3,125 3,750
0.50 1,260 1,680 2,100 1,500 2,250 3,000 3,750 4,500
0.40 1,575 2,100 2,625 1,875 2,813 3,750 4,688 5,625
0.30 2,100 2,800 3,500 2,500 3,750 5,000 6,250 7,500
0.20 3,150 4,200 5,250 3,750 5,625 7,500 9,375 11,250
0.10 6,300 8,400 10,500 7,500 11,250 15,000 18,750 22,500
0.00 NP NP NP NP NP NP NP NP
NP = Not Permitted
Table 2 Minimum Space Volumes were determined by using the
following equations from the National Fuel Gas Code ANSI
Z223.1/NFPA 54--2006, 9.3.2.2:
1. For other than fan--assisted appliances such as a draft
hood--equipped water heater,
1000 Btu / hr
21 ft3(Iother )
Volume other =ACH
2. For fan--assisted appliances such as this furnace,
1000 Btu / hr
15 ft3(Ifan )
Volume fan =ACH
If:
Iother = combined input of all other than fan--assisted
appliances in Btu/hr
Ifan = combined input of all fan--assisted appliances in Btu/hr
ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the Standard Method and to
the Known Air Infiltration Rate Method.
•Adjoining rooms can be considered part of a space, if there are
no closable doors between rooms.
•An attic or crawl space may be considered a space that freely
communicates with the outdoors provided there are adequate
ventilation openings directly to outdoors. Openings MUST
remain open and NOT have any means of being closed off.
Ventilation openings to outdoors MUST be at least 1 square
inch of free area per 4,000 BTUH of total input rating for all gas
appliances in the space.
•In spaces that use the Indoor Combustion Air Method,
infiltration should be adequate to provide air for combustion,
ventilation and dilution of flue gases. However, in buildings with
unusually tight construction, additional air MUST be provided
using the methods described in section titled Outdoor
Combustion Air Method:
•Unusually tight construction is defined as
Construction with:
1. Walls and ceilings exposed to the outdoors have a
continuous, sealed vapor barrier. Openings are gasketed or
sealed and
2. Doors and openable windows are weather stripped and
3. Other openings are caulked or sealed. These include joints
around window and door frames, between sole plates and
floors, between wall--ceiling joints, between wall panels, at
penetrations for plumbing, electrical and gas lines, etc.
Ventilation Air
Some provincial codes and local municipalities require ventilation
or make--up air be brought into the conditioned space as
replacement air. Whichever method is used, the mixed return air
temperature across the heat exchanger MUST not fall below 60°F
so that flue gases will not condense excessively in the heat
exchanger. Excessive condensation will shorten the life of the heat
exchanger and possibly void your warranty.

10 441 01 5003 01
Specifications are subject to change without notice
5. Gas Vent Installation
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Failure to properly vent this furnace could result in
personal injury, death and/or property damage.
Read and follow all instructions in this section.
!
Install the vent in compliance with codes of the country having
jurisdiction, local codes or ordinances and these instructions.
This Category Ifurnace is fan--assisted.
A fan assisted appliance is an appliance equipped with an integral
mechanical means to either draw or force products of combustion
through the heat exchanger.
Category Ifurnace definition: A central furnace which operates with
a non--positive vent static pressure and with a flue loss not less than
17 percent. These furnaces are approved for common--venting and
multi--story venting with other fan--assisted or draft hood--equipped
appliances in accordance with the NFGC.
Category ISafe Venting Requirements
Category Ifurnace vent installations shall be in accordance with
Parts 10 and 13 of the National Fuel Gas Code (NFGC), ANSI
Z223.1--2006/NFPA 54--2006; and/or Section 7 and Appendix C of
the CSA B149.1--05, National Standard of Canada, Natural Gas
and Propane Installation Code; the local building codes; furnace
and vent manufacturer’s instructions.
NOTE: The following instructions comply with the ANSI
Z223.1/NFPA 54 National Fuel Gas Code, based on the input rate
on the furnace rating plate.
1. If a Category Ivent passes through an attic, any concealed
space or floor, use ONLY Type B or Type L double wall vent
pipe. If vent pipe passes through interior wall, use Type B vent
pipe with ventilated thimble ONLY.
2. Do NOT vent furnace into any chimney serving an open
fireplace or solid fuel burning appliance.
3. Use the same diameter Category Iconnector or pipe as
permitted by the National Fuel Gas Code Code (NFGC) ANSI
Z223.1--2006 / NFPA 54--2006 Sections 12 and 13 venting
requirements.
4. Push the vent connector onto the furnace flue collar of the
venter assembly until it touches the bead [at least 5/8″(16 mm)
overlap] and fasten with at least two field--supplied,
corrosion--resistant, sheet metal screws located at least 140°
apart.
5. Keep vertical Category Ivent pipe or vent connector runs as
short and direct as possible.
6. Vertical outdoor runs of Type--B or ANY single wall vent pipe
below the roof line are NOT permitted.
7. Slope all horizontal runs up from furnace to the vent terminal a
minimum of 1/4″per foot (6 mm/305 mm).
8. Rigidly support all horizontal portions of the venting system
every 6′(1.8 m) or less using proper clamps and metal straps to
prevent sagging and ensure there is no movement after
installation.
9. Check existing gas vent or chimney to ensure they meet
clearances and local codes. See Figure 1
10. The furnace MUST be connected to a factory built chimney or
vent complying with a recognized standard, or a masonry or
concrete chimney lined with a lining material acceptable to the
authority having jurisdiction. Venting into an unlined
masonry chimney or concrete chimney is prohibited. See
the 6. Masonry Chimney Venting section in these
instructions.
11. Fan--assisted combustion system Category Ifurnaces shall
not be vented into single--wall metal vents.
12. Category Ifurnaces must be vented vertically or nearly
vertically, unless equipped with a listed mechanical venter.
13. Vent connectors serving Category I furnaces shall not be
connected into any portion of mechanical draft systems
operating under positive pressure.
Venting and Combustion Air Check
NOTE: When an existing Category I furnace is removed or
replaced, the original venting system may no longer be sized to
properly vent the attached appliances, and to make sure there is
adequate combustion air for all appliances, MAKE THE
FOLLOWING CHECK.
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 venting system.
2.Inspect the venting system for proper size and horizontal pitch,
as required in the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 or the CSA B149.1, Natural Gas and Pro-
pane Installation Code and these instructions. Determine that
there is no blockage or restriction, leakage, corrosion and oth-
er deficiencies which could cause an unsafe condition.
3.As far as practical, close all building doors and windows and all
doors between the space in which the appliance(s)
connected to the venting system are located and other spaces
of the building.
4.Close fireplace dampers.
5.Turn on clothes dryers and any appliance not connected to the
venting system. Turn on any exhaust fans, such as range
hoods and bathroom exhausts, so they are operating at
maximum speed. Do not operate a summer exhaust fan.
6.Follow the lighting instructions. Place the appliance being in-
spected into operation. Adjust the thermostat so appliance is
operating continuously.
7.Test for spillage from draft hood equipped appliances at the
draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle. (Figure 7)
8.If improper venting is observed during any of the above tests,
the venting system must be corrected in accordance with the
National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or CSA
B149.1, Natural Gas and Propane Installation Code.
9.After it has been determined that each appliance connected to
the venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, fireplace
dampers and any other gas--fired burning appliance to their
previous conditions of use.
!

11
441 01 5003 01
Specifications are subject to change without notice
Vent Check
Draft HoodVent Pipe
Match
Typical Gas
Water Heater
Figure 7
NOTE: If flame pulls towards draft hood, this indicates sufficient
infiltration air.
Venting to Existing Masonry Chimney
Dedicated venting of one fan assisted furnace into any
masonry chimney is restricted. A chimney must first be lined with
either Type B vent sized in accordance with NFGC tables 13.1 or
13.2 or a listed, metal lining system. (See Section Masonry
Chimney Venting of these instructions)
Listed, corrugated metallic chimney liner systems in masonry
chimneys shall be sized by using NFGC tables per 13.1.7 for
dedicated venting and per 13.2.20 for common venting with the
maximum capacity reduced by 20% (0.80 X maximum capacity)
and the minimum capacity as shown in the applicable table. In
Canada, use the NSCNGPIC, appendix C, Section 10. Corrugated
metal vent systems installed with bends or offsets require additional
reduction of 5% of the vent capacity for each bend up to 45°and
10% of the vent capacity for each bend from 45°up to 90°.
NOTE:Two(2)45°elbows are equivalent to one (1) 90°elbow.
Combined Venting into an Interior Masonry Chimney
Venting into an interior masonry or concrete chimney is only
permitted as outlined in the NFGC venting tables. Follow all
safe venting requirements.
Note: See section “Masonry Chimney Venting”.
6. Horizontal Venting
Category IFurnaces With External Power
Venters
In order to maintain a Category Iclassification of fan--assisted
furnaces when vented horizontally with sidewall termination, a
power venter is REQUIRED to maintain a negative pressure in the
venting system.
In the U.S.: Per the NFGC, a listed power venter may be used,
when approved by the authority having jurisdiction.
In Canada: Only power venters approved by the appliance
manufacturer and where allowed by the authority having jurisdiction
may be used.
Please consult the Fields Controls Co. or Tjernlund Products, Inc.
for power venters certified for use with our furnaces.
Vent Termination
Venting Through a Non- Combustible and Combustible
Wall
Consult External Power Venter manufacturer instructions.
Select the power venter to match the Btuh input of the furnace being
vented. Follow all of the power venter manufacturer’s installation
requirements included with the power venter for:
•venting installation,
•vent terminal location,
•preventing blockage by snow,
•protecting building materials from degradation by flue gases,
•see Figure 8 for required vent termination.
NOTE: It is the responsibility of the installer to properly
terminate the vent and provide adequate shielding. This is
essential in order to avoid water/ice damage to building,
shrubs and walkways.

12 441 01 5003 01
Specifications are subject to change without notice
Item Clearance Descriptions Canadian Installation (1) U.S. Installation (2)
AClearance above grade, veranda, porch, deck, balcony, or
anticipated snow level
12″(30cm) # 12″(30 cm)
BClearance to a window or door that may be opened 6″(15 cm) for appliances ≤10,000 BTUH (3kW), 12″(30
cm) for appliances > 10,000 Btuh (3 kW) and ≤100,000 Btuh
(30 kW), 36″(91 cm) for appliances > 100,000 Btuh (30 kW)
4′(1.2 m) below or to the side of the opening. 1′(30 cm)
above the opening.
CClearance to a permanently closed window * *
DVertical clearance to a ventilated soffit located above the
terminal within a horizontal distance of 2′(61cm) from the
centerline of the terminal
* *
EClearance to an unventilated soffit * *
FClearance to an outside corner * *
GClearance to an inside corner * *
HClearance to each side of the centerline extended above
electrical meter or gas service regulator assembly
3′(91 cm) within 15′(4.5 m) above the meter/regulator
assembly *
IClearance to service regulator vent outlet 3′(91 cm) *
JClearance to non--mechanical air supply inlet to building or
the combustion air inlet to any other appliance
6″(15 cm) for appliances ≤10,000 BTUH (3kW), 12″(30
cm) for appliances > 10,000 Btuh (3 kW) and ≤100,000 Btuh
(30 kW), 36″(91 cm) for appliances > 100,000 Btuh (30 kW)
4′(1.2 m) below or to the side of opening: 1′(30 cm) above
opening.
KClearance to a mechanical air supply inlet 6′(1.83 m) 3′(91 cm) above if within 10′(3m) horizontally
LClearance under a veranda, porch, deck, or balcony 12″(30 cm) ‡ *
MClearance to each side of the centerline extended above or
below vent terminal of the furnace to a dryer or water heater
vent, or other appliance’s direct vent intake or exhaust.
* *
NClearance from a plumbing vent stack 3′(91 cm) 3′(91 cm)
OClearance above a paved sidewalk or paved driveway located
on public property.
7′(2.13 m) + 7′(2.13 m)
(1.) In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code
(2.) In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code
#18″(46 cm) above roof surface
+ A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
*For clearances not specified in ANSI Z223.1/NFPA 54 or CSA B149.1, clearances shall be in accordance with local installation codes and the requirements of the gas supplier and the manufacture’s
installation instructions.
Notes:
1. The vent for this appliance shall not terminate
a. Near soffit vents or crawl space vents or other areas where condensate or vapor could create a nuisance or hazard or property damage; or
b. Where condensate vapor could cause damage or could be detrimental to the operation of regulators, relief valves, or other equipment.
2. When locating vent terminations, consideration must be given to prevailing winds, location, and other conditions which may cause recirculation of the combustion products of adjacent vents.
Recirculation can cause poor combustion, inlet condensate problems, and accelerated corrosion of the heat exchangers.
A
X
B
V
V
V
V
X
X
AIR SUPPLY INLET
VVENT TERMINAL AREA WHERE TERMINAL IS NOT PERMITED
A
B
B
B
B
B
C
D
E
F
J
I
L
HM
K
G
25--24--65--2
N
V
O
Other than Direct Vent Termination Clearance
Figure 8
VV

13
441 01 5003 01
Specifications are subject to change without notice
7. Masonry Chimney Venting
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Failure to properly vent this furnace could result in
personal injury, death and/or property damage.
Follow these installation instructions.
!
Chimney Inspection
All masonry chimney construction must conform to the Standard for
Chimneys, Fireplaces, Vents, and Solid Fuel--Burning Appliances
ANSI/NFPA 211--2006 and to any state or local codes applicable.
The chimney must be in good condition and a complete chimney
inspection must be conducted prior to furnace installation. If the
inspection reveals damage or abnormal conditions, make
necessary repairs or seek expert help. See “The Chimney
Inspection Chart” Figure 9. Measure inside area of tile--liner and
exact height of chimney from the top of the chimney to the highest
appliance flue collar or drafthood outlet.
Connector Type
To reduce flue gas heat loss and the chance of condensate
problems, the vent connector must be double--wall Type B vent.
Venting Restrictions for Chimney Types
Interior Chimney -- has no sides exposed to the outdoors below
the roofline. Venting is permitted into an interior masonry chimney
in accordance with Table 13.8 and section 13.2 of the National Fuel
Gas Code ANSI Z223.1/NFPA 54--2006, if the furnace is
common--vented with at least one draft hood--equipped water
heater or furnace.
These furnaces are NOT permitted to be vented into interior
masonry chimneys singly (not common--vented with a draft
hood--equipped water heater or furnace).
Exterior Chimney -- has one or more sides exposed to the
outdoors below the roof line. All installations with a 99% Winter
Design Temperature* below 17°F(--8°C) must be common vented
only with a draft hood equipped Category I appliance.
*The 99.6% Winter Design Dry--Bulb (db) temperatures are
found in the 1997 or 2001 ASHRAE Climatic Design
Information chapter, Table 1A (United States) and 2B
(Canada), or the 2005 ASHRAE Fundamentals Handbook,
Climatic Design Information chapter, and the CD--ROM
included with the 2005 ASHRAE Fundamentals Handbook.
Chimneys shall conform to the Standard for Chimneys, Fireplaces,
Vents, and Solid Fuel Burning Appliances ANSI/NFPA 211--2006
and must be in good condition.
Refer to Sections 13.1.9 or 13.2.20 of the NFGC or the authority
having jurisdiction to determine whether relining is required.
If relining is required, use a properly sized listed metal liner or
Type--B vent to reline the chimney.
Inspections before the sale and at the time of installation will
determine the acceptability of the chimney or the need for repair
and/or (re)lining. Refer to the Chimney Inspection Chart to perform
a chimney inspection.
If the inspection of a previously used tile--lined chimney:
a. Shows signs of vent gas condensation, the chimney should
be relined in accordance with local codes and the authority
having jurisdiction. The chimney should be relined with a
listed metal liner or Type--B vent to reduce condensation. If a
condensate drain is required by local code, refer to the
NFGC, Section 12.1 for additional information on
condensate drains.
b. Indicates the chimney exceeds the maximum permissible
size in the tables, the chimney should be rebuilt or relined to
conform to the requirements of the appliances being installed
and the authority having jurisdiction.
A chimney without a clay tile liner, which is otherwise in good
condition, shall be rebuilt to conform to ANSI/NFPA 211 or be lined
with a UL listed metal liner or UL listed Type--B vent. Relining with a
listed metal liner or Type--B vent is considered to be a
vent--in--a--chase.
If a metal liner or Type--B vent is used to line a chimney, no other
appliance shall be vented into the annular space between the
chimney and the metal liner.
APPLIANCE APPLICATION REQUIREMENTS
Appliance operation has a significant impact on the performance of
the venting system. If the appliances are sized, installed, adjusted,
and operated properly, the venting system and/or the appliances
should not suffer from condensation and corrosion. The venting
system and all appliances shall be installed in accordance with
applicable listings, standards, and codes.
The furnace should be sized to provide 100 percent of the design
heating load requirement plus any margin that occurs because of
furnace model size capacity increments. Heating load estimates
can be made using approved methods available from Air
Conditioning Contractors of America (Manual J); American Society
of Heating, Refrigerating, and Air--Conditioning Engineers; or other
approved engineering methods. Excessive oversizing of the
furnace could cause the furnace and/or vent to fail prematurely.
When a metal vent or metal liner is used, the vent or liner must be in
good condition and be installed in accordance with the vent or liner
manufacturer’s instructions.
To prevent condensation in the furnace and vent system, the
following precautions must be observed:
1. This furnace is designed for minimum continuous return--air
temperature of 60°F (155°C) db or intermittent operation down
to 55°F(13°C) db such as when used with a night setback
thermostat.
2. Adjust the gas input rate per the installation instructions. Low
gas input rate causes low vent gas temperatures, causing
condensation and corrosion in the furnace and/or venting
system. Derating is permitted only for altitudes above 2000′
(610 m).
3. Adjust the air temperature rise to the midpoint of the rise range
or slightly above. Low air temperature rise can cause low vent
gas temperature and potential for condensation problems.
4. Set the thermostat heat anticipator or cycle rate to reduce short
cycling.
Air for combustion must not be contaminated by halogen
compounds, which include chlorides, fluorides, bromides, and
iodides.
These compounds are found in many common home products such
as detergent, paint, glue, aerosol spray, bleach, cleaning solvent,
salt, and air freshener, and can cause corrosion of furnaces and
vents. Avoid using such products in the combustion--air supply.
Furnace use during construction of the building could cause the
furnace to be exposed to halogen compounds, causing premature
failure of the furnace or venting system due to corrosion.
Vent dampers on any appliance connected to the common vent can
cause condensation and corrosion in the venting system. Do not
use vent dampers on appliances common vented with this furnace.

14 441 01 5003 01
Specifications are subject to change without notice
Chimney is
acceptable for use
Crown
condition:
Missing mortar
or brick?
Rebuild
crown
Is
Chimney properly
lined with clay tile
liner?
Yes
Yes
No
No
Yes
Is
liner and top
seal in good
condition
No
Debris in
cleanout? Mortar, tile,
metal vent, fuel oil
residue?
Repair
liner or top seal
or reline chimney as
necessary.
Reline
Yes Repair
Yes
No
Yes
Clay
tile misalignment,
missing sections,
gaps?
No
Is Chimney
lined with properly
sized, listed liner or
Type--B vent? Line chimney with properly
sized, listed flexible metal
liner or Type--B vent per NFGC or
NSCNGPIC Vent Sizing Tables
and liner or vent manufacturer’s
installation instructions.
CHIMNEY INSPECTION CHART
For additional requirements refer to the National Fuel Gas Code NFPA 54/ANSI Z223.1--2006 and ANSI/NFPA 211--2006 Chimneys, Fire-
places, Vents, and Solid Fuel Burning Appliances in the U.S.A. or to the Canadian Installation Code CSA B149.1--05 in Canada.
Yes
No
No
Mortar or
tile debris?
Yes Remove mortar
and tile debris?
No
Remove metal vent or liner.
Consult
Part B of chimney
adapter venting
instructions for
application
suitability.
Chimney
exposed to outdoors
below roof line?
Is Chimney to
be dedicated to a
single furnace?
Yes Install chimney
adapter per
instructions.
Not Suitable
Not Suitable
Suitable
No
Consult
Part C of chimney
adapter venting
instructions for
application
suitability.
Suitable
Install chimney
adapter per
instructions.
No
Condensate
drainage at bottom
of chimney?
Yes
Figure 9

15
441 01 5003 01
Specifications are subject to change without notice
8. Gas Supply and Piping
CARBON MONOXIDE POISONING, FIRE AND
EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death, and/or property damage.
Models designated for Natural Gas are to be used
with Natural Gas ONLY, unless properly converted to
use with Propane gas.
!
Gas Supply Requirements
•Use only the Type of gas approved for this furnace. See rating
plate for approved gas type.
•Gas input must not exceed the rated input shown on the rating
plate. Overfiring will result in failure of heat exchanger and
cause dangerous operation.
•Do NOT allow minimum supply pressure to vary downward.
Doing so will decrease input to furnace. Refer to Table 3 for
gas supply. Refer to Table 7 or Table 8 for manifold pressures.
Table 3 Gas Pressures
Gas Type Supply Pressure in wc
Recommended Max. Min.
Natural 7″14″4.5″
Propane 11″14″11″
Natural to Propane Gas Conversion
Note: An accessory kit shall be used to convert to propane gas use,
see the furnace rating plate for the Propane conversion accessory
kit part number.
1. After disconnecting power and gas supply to the furnace,
remove the access door, exposing gas valve and burner
compartment.
2. Disconnect gas line from gas valve so manifold assembly
can be removed.
3. Disconnect wiring at gas valve. Be sure to note the proper
location of any and all electrical wiring disconnected.
4. Remove the four (4) screws holding the manifold and gas
valve to the manifold supports. Do Not discard any screws.
5. Carefully remove the manifold assembly.
6. Remove the Natural gas (brass) burner orifices from the
manifold assembly and replace them with the appropriate
Propane (silver) orifices furnished in the conversion kit
unless converting high altitude unit, then see Table 6 or
Table 8 for appropriate orifices. (Figure 10)
Figure 10 Remove Orifices
25--21--00
7. Tighten the orifices so they are seated and gas tight about 1
1/8″from the face of the orifice to the back of the manifold
pipe (Figure 11). Make sure orifice is installed straight so that
it forms a right angle (90°) to the manifold.
Figure 11 Changing Orifices
Measure from face of orifice to
the back side of the manifold.
1.11″(28.2mm)
1.21″(30.8mm)
8. Remove the cap screw and pressure regulator adjusting
screw from valve. (see Figure 12)
9. Remove the existing regulator spring from the regulator
housing.
10. Insert the replacement spring (red color) contained in this kit
into regulator housing.
11. Install the pressure regulator adjusting screw and give it
eleven (11) full clockwise turns. This will set the manifold
pressure close to required setting for normal operation.
12. Replace the regulator cap screw.
13. Attach the Yellow Attention Label contained in the kit to the
Gas Valve where it can be readily seen.
Color Code For
Propane
Gas Natural Gas
Pressure
Regulator
Adjusting Screw
Black Black
Spring Red Stainless
Steel
Note: A low gas pressure switch is required for conversion.
Figure 12 Typical Regulator Assembly

16 441 01 5003 01
Specifications are subject to change without notice
14. Using pipe joint compound that is resistant to Propane gas,
tighten the fitting assembly into the inlet side of the gas valve.
(Figure 13). Position fitting assembly as shown.
15. Screw the Propane pressure switch into the bushing. Use
pipe dope on connection. Tighten securely.
Note: Do not block inlet port of pressure switch with pipe dope.
Switch will not operate if inlet port is blocked.
16. Remove one yellow wire from the air pressure switch.
Connect this wire to the male insulated yellow wire in the wire
harness provided.
17. Connect the other yellow wire in the harness to the open
termination on the air pressure switch.
18. Connect the other end of the wire harness to the two
terminals on the Propane switch.
19. Reassemble all parts in reverse order as removed. Attach
Propane Conversion Label next to the furnace rating plate or
to the front exterior of the furnace.
20. Be sure to engage the main burner orifices in the proper
openings in the burners.
21. After reassembly, turn the gas on and check all joints for gas
leaks using a soapy solution. All leaks must be repaired
immediately.
22. Affix Propane Gas Conversion Rating plate next to furnace
rating plate.
23. Fill and attach Conversion Label to front exterior of furnace.
24. Check operation in Section Checks and Adjustments.
O
N
O
F
F
Right Hand gas
pipe entry detail
Use elbows and 3″pipe nipple to
connect valve to piping when using
right side gas pipe entry.
# Union should be outside cabinet except when
clearances disallow, then it may be installed inside
the cabinet .
Manual shut- off valve MUST be upstream of dripleg, union, and furnace.
Propane Low
pressure switch. Manual shut- off
valve
Typical Gas Piping and Adding Propane Low Pressure Switch
Propane
Low
Pressure
Switch
Detail
Alterative
installation
Figure 13
Right pipe entry
O
N
O
F
F
25--25--51
Left Hand gas pipe
entry detail
25--25--53
Drip Leg &
Union #
O
N
O
F
F
Left pipe entry
O
N
O
F
F
Gas Piping Requirements
NOTE: The gas supply line must be installed by a qualified service
technician in accordance with all building codes.
1. Install gas piping in accordance with local codes, or in the
absence of local codes, the applicable national codes.
2. It is recommended that a manual equipment shutoff valve be
installed in the gas supply line outside the furnace. Locate
valve as close to the furnace as possible where it is readily
accessible. Refer to Figure 13.
3. Use black iron or steel pipe and fittings or other pipe approved
by local code.
4. Use pipe thread compound which is resistant to natural and
Propane gases.
5. Use ground joint unions and install a drip leg no less than 3″
(76mm) long to trap dirt and moisture before it can enter gas
valve inside furnace.
6. Provide a 1/8″(3mm) NPT plugged tapping for test gauge
connection immediately up stream of gas supply connection to
furnace.
FIRE HAZARD.
Failure to follow this warning could result in
personal injury or death.
Use wrench to hold furnace gas valve when turning
elbows and gas line to prevent damage to the gas
valve and furnace.
!
7. Use two pipe wrenches when making connections to prevent
furnace gas valve from turning.
NOTE: If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not use a
connector which has previously served another gas appliance.
8. Flexible corrugated metal gas connector may NOT be used
inside the furnace or be secured or supported by the furnace or
ductwork.
9. Properly size gas pipe to handle combined appliance load or
run gas pipe directly from gas meter or Propane gas regulator.
10. Install correct pipe size for run length and furnace rating.

17
441 01 5003 01
Specifications are subject to change without notice
11. Measure pipe length from gas meter or Propane second stage
regulator to determine gas pipe size.
Left Side Gas Supply Piping
Gas line can be installed directly to the gas valve through the hole
provided in the left side of the cabinet. See Figure 13
Right Side Gas Supply Piping
Two(2) 90°street elbows or two(2) 90°standard elbows and two(2)
close nipples are required for right side gas supply. See Figure 13.
Piping with Street Elbows
1. Assemble the elbows so that the outlet of one(1) elbow is 90°
from the inlet of the other. The elbows should be tight enough to
be leak proof. An additional 1/4turn will be required at the end of
step 2, see Figure 14.
Figure 14
2 5 -- 2 3 -- 2 3 c
Elbows
2. Screw elbow assembly into gas valve far enough to be leak
proof. Position elbow assembly so that the inlet of the elbow is
at the bottom of the gas valve. An additional 1/2turn will be
required in step 3. Turn open end of inlet elbow to face the right
side of the furnace (1/4turn), see Figure 15.
Figure 15 Gas Valve with Elbows
25--25--03
Representative drawing only, some models may vary in appearance.
3. Turn assembly an additional 3/8turn to position inlet near the
top of the gas valve in line with gas opening on right side of
furnace, see Figure 16.
Figure 16 Gas Valve with Elbows
Representative drawing only, some models may vary in appearance.
4. Gas supply line then can be run directly into opening of elbow.
Piping with Close Nipples and Standard Elbows
1. Assemble elbows and nipples similar to street elbows shown in
Figure 14.
2. Follow steps 2 through 4 of Piping with Street Elbows.
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in personal
injury, death and/or property damage.
A flexible corrugated metal gas connector must be
properly installed, shall not extend through the side
of the furnace, and shall not be used inside the
furnace.
Black iron pipe shall be installed at the furnace gas
valve and extend a minimum of 2″(50.8mm) outside
furnace.
!
Additional Propane Piping Requirements
•Have a licensed Propane gas dealer make all connections at
storage tank and check all connections from tank to furnace.
•If copper tubing is used, it MUST comply with limitation set in
local codes, or in the absence of local codes, the gas codes of
the country having jurisdiction.
•Two--stage regulation of Propane gas is recommended.
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
A natural gas or Propane gas leak ignited by an open
flame or spark could result in personal injury, death
and/or property damage.
Natural gas is lighter than air and will rise. Propane
gas is heavier than air and will settle and remain in
low areas and open depressions.
Thoroughly ventilate area and dissipate gas. Do
NOT use a match or open flame to test for leaks, or
attempt to start up furnace before thoroughly
ventilating area.
!W
A
RNING

18 441 01 5003 01
Specifications are subject to change without notice
Final Check
FIRE OR EXPLOSION HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
Never test for gas leaks with an open flame. Use a
commercially available soap solution made
specifically for the detection of leaks to check all
connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
!W
A
RNING
•Test all pipe for leaks.
•If orifices were changed, make sure they are checked for leaks.
•During pressure testing of gas supply piping system:
a. If test pressure does not exceed 1/2″psi, isolate the
furnace from the gas supply piping system by closing the
equipment shutoff valve.
b. If test pressure exceeds 1/2″psi, the furnace and its
manual equipment shutoff valve must be disconnected from
the gas supply piping system.
•To check for leaks apply soap suds or a liquid detergent to each
joint. Bubbles forming indicate a leak.
•Correct even the smallest leak at once.
9. Electrical Wiring
ELECTRICAL SHOCK HAZARD.
Failure to follow this warning could result in
personal injury or death.
Turn OFF electrical power at fuse box or service
panel before making any electrical connections and
ensure a proper ground connection is made before
connecting line voltage.
!
Power Supply Wiring
The furnace MUST be electrically wired and grounded in
accordance with local codes, or in the absence of local codes, with
the National Electrical Code (NEC), ANSI/NFPA 70--2005.
The power supply to the furnace connections must be between 198
VAC and 242 VAC during furnace operation for acceptable
performance.
Field wiring connections must be made inside the furnace
connection box. A suitable strain relief should be used at the point
the wires exit the furnace casing.
Copper conductors shall be used. Line voltage wires should
conform to temperature limitation of 63°F(35°C) rise. Wire and
circuit breaker sizing shall be based on the ampacity of the furnace
electrical components plus the amps for all installed accessories
(1.0 amps total for EAC and HUM). Ampacity can be determined by
using the NEC or CEC.
Furnace must be installed so the electrical components are
protected from water and connected to its own separate circuit.
Junction Box (J- Box) Relocation
The J--Box is installed in the burner compartment on left side of
casing. An alternate J--Box location on right side can be used.
1. Remove and save two screws holding J--Box to casing.
2. Move large hole plug from right to left J--Box location.
3. Clip wire tie holding the J--Box wires.
4. Move J--Box to alternate location and attach using two screws
removed from left side location.
5. Position all wires away from sharp edges, hot surfaces, and
moving parts. Do not pinch J--Box wires or other wires when
reinstalling burner compartment door.
Thermostat
Thermostat location has an important effect on the operation of the
furnace. Follow instructions included with thermostat for correct
mounting and wiring.
Low voltage connections to furnace must be made on terminal
board to fan control. (See Figure 17)
If cooling is used, the Yfrom the thermostat must be connected to
the control board Yto energize cooling blower speed.
Heat anticipator setting will need to be measured if 24VAC
humidifier is installed. Measure current in series from R to W at the
thermostat. Be sure 24VAC humidifier is wired up to control. Allow
furnace to operate for 2 minutes before recording the AC amperage
reading. Set anticipator on thermostat to recorded value.
Optional Equipment
All wiring from furnace to optional equipment MUST conform to
local codes or, in the absence of local codes, the applicable national
codes. Install wiring in accordance with manufacturer’s
instructions.
Humidifier/Electronic Air Cleaner
The furnace is wired for 220 VAC humidifier and/or electronic air
cleaner connection.
!
REDUCED FURNACE LIFE HAZARD.
Failure to follow this caution may result in reduced
furnace life.
Do NOT exceed 220V/0.8 amp. maximum current
load for both the EAC terminal and the HUM
terminal combined.
C
A
UTION
HUMIDIFIER -- The 24VAC HUM is energized when the
pressure switch closes on a call for heat. The HUM (220VAC) is
energized when the inducer is energized.
ELECTRONIC AIR CLEANER -- EAC is energized when there
is a blower speed call, except is NOT energized when blower
operates in the hard--wired continuous fan mode.

19
441 01 5003 01
Specifications are subject to change without notice
220V. 50Hz.
W
BK
G
Connection
Box
Ground
HOT
NEUT.
Thermostat
Low Voltage
Terminal Board
R
G
G
YR
Y
W
W
C
Figure 17 Electrical Connections
NOTE: 220 VAC/50Hz/single--phase
Operating voltage range*: 242 max, 198 min.
* Permissible limits of voltage at which furnace will operate
satisfactorily
Furnace Control
The furnace control is preset at the factory with ON delay of 36
seconds in the heating mode. The blower OFF timing is preset at
168 seconds. If desired, the fan OFF delay can be reset to obtain
the longest delay times while still maintaining comfort levels. See
“Furnace Wiring Diagram”.
Furnace Control Fuse
The 24V circuit contains a 5--amp, automotive--type fuse located on
furnace control. (See Figure 18) Any electrical shorts of 24V wiring
during installation, service, or maintenance may cause fuse to blow.
If fuse replacement is required, use only a fuse of identical size (5
amp.).
Control Connections
Figure 18
FUSE
25--24--98
Diagnostic Light
Jumper
24 VAC
HUM
HUM
10. Ductwork and Filter
CARBON MONOXIDE POISONING HAZARD.
Failure to follow this warning could result in
personal injury or death.
Do NOT draw return air from inside a closet or utility
room where furnace is located. Return air duct
MUST be sealed to furnace casing.
!
FIRE HAZARD.
Failure to follow this warning could result in
personal injury, death and/or property damage.
Place furnace on noncombustible subbase on
downflow applications, unless installing on
non--combustible flooring.
!WARNING
Duct Connections
This furnace may be installed in only a bottom or side return
application. Return air duct connection through the back of the
furnace is NOT allowed.
Upflow ONLY: Side return--air duct connections can be made by
cutting out the embossed area shown in Figure 19. A plugged hole
is provided at each furnace side duct location to help start cutting
the opening. Side duct connections are NOT permitted in horizontal
flow applications.
Cut out Side Return Air Opening
Cut out
Starting
Hole
Figure 19
Upflow and Horizontal Flow: Bottom return--air duct connections
can be made by removing the knockout panel in the furnace base.
Do NOT remove knock-out except for a bottom return--air duct
connection.
Duct Design
Design and install air distribution system to comply with Air
Conditioning Contractors of America manuals or other approved
methods that conform to local codes and good trade practices.

20 441 01 5003 01
Specifications are subject to change without notice
When the furnace is located in an area near or adjacent to the living
area, the system should be carefully designed with returns to
minimize noise transmission through the return air grille. Any
blower moving a high volume of air will produce audible noise which
could be objectionable when the furnace is located very close to a
living area. It is often advisable to route the return air ducts under the
floor or through the attic.
•Refer to furnace Technical Support Manual (Blower Data) for
air flow information.
•Size ductwork to handle air flow for heating (and air
conditioning if so equipped).
Duct Installation Requirements
•When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside of the space
containing the furnace, the return air shall also be handled by
duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace.
CARBON MONOXIDE POISONING HAZARD.
Failure to follow warning could result in personal
injury or death.
Install cooling coil on furnace discharge. Cool air
passing over heat exchanger could cause
condensate to form resulting in heat exchanger
failure.
!
•When the furnace is used with a cooling unit, the furnace shall
be installed parallel with or on the upstream side of the cooling
unit to avoid condensation in the heating element.
•With a parallel flow arrangement, the dampers or other means
used to control flow of air shall be adequate to prevent chilled
air from entering the furnace. Chilled air going through the
furnace could cause condensation and shorten furnace life.
Dampers (purchased locally) can be either automatic or
manual. Manually or automatically operated dampers MUST
be equipped with a means to prevent furnace and air
conditioning operation, unless damper is in the full heat or cool
position.
•Installation of locking-type dampers are recommended in all
branches, or in individual ducts to balance system’s air flow.
•Non--combustible, flexible duct connections are
recommended for return and supply connections to furnace.
•If air return grille is located close to the fan inlet, install at least
one 90°air turn between fan and inlet grille to reduce noise.
•Ductwork installed in attic, or exposed to outside temperatures
requires a minimum of 2″of insulation with outdoor type vapor
barrier.
•Ductwork installed in an indoor unconditioned space requires a
minimum of 1″of insulation with indoor type vapor barrier.
Inspection Panel on some models
For a furnace not equipped with a cooling coil, the outlet duct shall
be provided with a removable access panel. This opening shall be
accessible when the furnace is installed and shall be of such a size
that the heat exchanger can be viewed for possible openings using
light assistance or a probe can be inserted for sampling the air
stream. This access cover shall be attached in such a manner as
to prevent air leaks.
Filters
A filter MUST be used.
A high--velocity filter(s) and rack(s) is supplied with these furnaces.
See Table 4 for required high--velocity filter sizes.
Table 4 High--Velocity Air Filter Sizes (max. 600 FPM)
Cabinet
Width
Internal Filter External Filter Rack
Bottom Bottom Side+
151/2″
(39 cm)
14″X25″
(36 cm X 64 cm)
14″X25″14″X25″or 16″X25″
191/2″
(50 cm)
16″X25″*
(41 cm X 64 cm)
16″X25″*16″X25″*
223/4″
(59 cm)
20″X25″*
(51 cm X 64 cm)
20″X25″*16″X25″*
* Greater than 1600 CFM requires both (left and right) side return filter
racks in upflow position.
+ Side return air duct(s) is not permitted with horizontal furnace installation.
Use either filter type:
•Washable, high--velocity filters are based on a maximum air
flow rating of 600 FPM.
•Disposable, low velocity filters are based on a maximum air
flow of 300 FPM when used with external filter grille.
!
RISK OF REDUCED FURNACE LIFE.
Failure to follow this caution may result in
premature furnace component failure.
Use of excessively dirty and/or restrictive air filters
may increase furnace operating temperatures and
shorten the life of the furnace.
Filters specified for the furnace are rated at a maximum
of 600 FPM air velocity and sized for the furnace’s
airflow rate. Replacement filters must be of equivalent
type, size, and rating except as described below.
Disposable, low--velocity filters may be used to replace
washable, high--velocity filters, providing they are sized
for 300 FPM or less.
CAUTION
•The furnaces with 1600 or less CFM rating use a 16” x 25”
high--velocity filter. On these models the filter may be
mounted internally for bottom return or a filter and rack may
be mounted externally for bottom return.
•The furnaces with greater than 1600 CFM may require that
both (left and right) side returns are used. Two side return
filters and racks are required. Filter racks must be mounted
externally. See Figure 22.
•If return air must be on one side only, an optional 20″x25″
filter standoff rack kit can be used. (See Figure 20.) For
bottom return, an internal filter can be used or a filter rack kit
can be mounted externally (NAHA001TK).
•See Circulator Air Blower Data for additional data.
NOTE: The 20″x25″(51 cm X 64 cm) standoff side filter rack gives
more filter area but does not provide more air. See Figure 20. To
achieve 2000 CFM 2 side returns are still needed. See Figure 22.
NOTE: Disposable low--velocity filters may be replaced with
washable, high--velocity filters. Washable, high--velocity filters can
be replaced ONLY with same type and size filter unless
low--velocity filters meet the minimum size areas for 300 FPM or
less.