AHRI F80CSU User manual

441 01 4200 01 11/15/2019
INSTALL
A
TION INSTRUCTIONS
4--Way Multipoise, Ultra Low NOx
Communicating, 80% AFUE Gas Furnace
F80CSU, G80CSU
SAFETY CONSIDERATIONS 2........................
INTRODUCTION 2..................................
CODES AND STANDARDS 4.......................
SAFETY 4......................................
GENERAL INSTALLATION 4......................
COMBUSTION AND VENTILATION AIR 4...........
DUCT SYSTEMS 4...............................
ACOUSTICAL LINING AND FIBROUS GLASS DUCT 4
GAS PIPING AND GAS PIPE PRESSURE TESTING 4...
ELECTRICAL CONNECTIONS 4...................
VENTING 4........................................
ELECTROSTATIC DISCHARGE
PRECAUTIONS PROCEDURE 4.......................
LOCATION 5.......................................
SAFETY CONSIDERATIONS 7........................
AIR FOR COMBUSTION AND VENTILATION 7..........
INSTALLATION 9...................................
UPFLOW INSTALLATION 9.......................
DOWNFLOW INSTALLATION 9....................
HORIZONTAL INSTALLATION 10..................
AIR DUCTS 11...................................
GAS PIPING 14..................................
ELECTRICAL CONNECTIONS 15..................
115--V WIRING 16................................
J--BOX RELOCATION 16..........................
24--V WIRING 17.................................
ACCESSORIES 17................................
VENTING 20.......................................
MASONRY CHIMNEY REQUIREMENTS 20..........
APPLIANCE APPLICATION REQUIREMENTS 21.....
ADDITIONAL VENTING REQUIREMENTS 23........
SIDEWALL VENTING 23..........................
START--UP, ADJUSTMENT, AND SAFETY CHECK 25.....
GENERAL 25....................................
START--UP PROCEDURES 25......................
ADJUSTMENTS 25...............................
FURNACE SETUP SWITCHES 26...................
AIR DELIVERY -- CFM 30.........................
COOLING OR CONTINUOUS AIRFLOW 32..........
CHECK SAFETY CONTROLS 32...................
CHECKLIST 33..................................
SERVICE AND MAINTENANCE PROCEDURES 35.......
ELECTRICAL CONTROLS AND WIRING 35.........
CARE AND MAINTENANCE 36....................
COMPONENT TEST 36...........................
CLEANING AND/OR REPLACING AIR FILTER 37.
BLOWER MOTOR AND WHEEL 37..............
FLAME SENSOR CLEANING AND SERVICING 38.
CLEANING HEAT EXCHANGER 39..............
SEQUENCE OF OPERATION 40....................
WIRING DIAGRAMS 43...........................
PARTS REPLACEMENT INFORMATION GUIDE 44
....
Approved for installations up to 5,400 feet (1646 meters)
NOTE: Read the entire instruction manual before starting the
installation.
Portions of the text and tables are reprinted from current edition
of NFPA 54/ANSI Z223.1E, 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.

Specifications are subject to change without notice.
2441 01 4200 01
SAFETY CONSIDERATIONS
FIRE, EXPLOSION, ELECTRICAL SHOCK, AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in dangerous
operation, serious injury, death, or property damage.
Improper installation, adjustment, alteration, service,
maintenance, or use could cause carbon monoxide
poisoning, explosion, fire, electrical shock, or other
conditions which may cause personal injury or property
damage. Consult a qualified service agency, local gas
supplier, or your distributor or branch for information or
assistance. The qualified service agency must use only
factory--authorized and listed kits or accessories when
modifying this product.
!WARNING
FURNACE RELIABILITY HAZARD
Improper installation or misapplication of furnace may
require excessive servicing or cause premature component
failure.
Application of this furnace should be indoors with special
attention given to vent sizing and material, gas input rate,
air temperature rise, unit leveling, and unit sizing.
CAUTION
!
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock, or
other conditions which may cause death, personal injury, or
property damage. Consult a qualified installer, service agency, or
your distributor or branch for information or assistance. The
qualified installer or agency must use factory--authorized kits or
accessories when modifying this product. Refer to the individual
instructions packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Have a fire extinguisher available. Read these
instructions thoroughly and follow all warnings or cautions
include in literature and attached to the unit. Consult local
building codes, the current editions of the current edition of
National Fuel Gas Code (NFGC) NFPA 54/ANSI Z223.1 and the
current edition of National Electrical Code (NEC) NFPA 70.
Recognize safety information. This is the safety--alert symbol .
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER,WARNING,and
CAUTION. These words are used with the safety--alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies hazards
which could result in personal injury or death. CAUTION is
used to identify unsafe practices which may result in minor
personal injury or product and property damage. NOTE is used
to highlight suggestions which will result in enhanced
installation, reliability, or operation.
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing, safety glasses and
gloves when handling parts and servicing furnaces.
CAUTION
!
1. Use only with type of gas approved for this furnace. Refer
to the furnace rating plate.
2. Install this furnace only in a location and position as
specified in the “Location” section of these instructions.
3. Provide adequate combustion and ventilation air to the
furnace space as specified in “Air for Combustion and
Ventilation” section.
4. Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only, as
specified in the “Venting” section of these instructions.
5. 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 the “Gas Piping” section.
6. 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 the “Start--Up, Adjustments, and Safety
Check” section. See furnace rating plate.
7. 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 duct(s) sealed to the furnace casing and terminating
outside the space containing the furnace. See “Air Ducts”
section.
8. A gas--fired furnace for installation in a residential garage
must be installed as specified in the warning box in the
“Location” section (see Fig. 5).
9. The furnace is not permitted to be used for heating of
buildings under construction.
10. These Multipoise Gas--Fired Furnaces are CSA (formerly
A.G.A. and C.G.A). design--certified for use with natural
gas (see furnace rating plate) and for installation in
alcoves, attics, basements, closets, utility rooms,
crawlspaces, and garages. The furnace is factory--shipped
for use with natural gas and cannot be converted for use
with propane.
11. See Fig. 2 for required clearances to combustible
construction.
12. Maintain a 1--in. (25 mm) clearance from combustible
materials to supply air ductwork for a distance of 36
inches (914 mm) horizontally from the furnace. See
current edition of NFPA 90B or local code for further
requirements.
13. These furnaces SHALL NOT be installed directly on car-
peting, tile, or any other combustible material other than
wood flooring. In downflow installations, factory access-
ory floor base MUST be used when installed on combust-
ible materials and wood flooring. Special base is not re-
quired when this furnace is installed on manufacturer’s
approved coil assembly or a manufacturer’s coil casing
box is used. See Fig. 2 for clearance to combustible con-
struction.
INTRODUCTION
This 4--way multipoise Category I fan--assisted furnace is CSA
design--certified. A Category I fan--assisted furnace is an
appliance equipped with an integral mechanical means to either
draw or force products of combustion through the combustion
chamber and/or heat exchanger. The furnace is factory--shipped
for use with natural gas.
This furnace is not approved for installation in mobile homes,
recreational vehicles, or outdoors. The furnace is not permitted to
be used for heating of buildings under construction. This furnace
is designed for minimum continuous return--air temperature of
60_F(16_C)db or intermittent operation down to 55_F(13_C)
db such as when used with a night setback thermostat. Return--air
temperature must not exceed 80_F(27_C) db. Failure to follow
these return--air temperature limits may affect reliability of heat
exchangers, motors, and controls. (See Fig. 3).
For accessory installation details, refer to the applicable
instruction literature.
NOTE: Remove all shipping brackets and materials before
operating the furnace.

Specifications are subject to change without notice. 3441 01 4200 01
A180207
Fig. 1 -- Dimensional Drawing
Table1–Dimensions
FURNACE SIZE
A B C D
V
ENT
CABINET
WIDTH
IN. (MM)
OUTLET WIDTH
IN. (MM)
TOP FLUE
COLLAR ONLY
IN. (MM)
BOTTOM WIDTH
IN. (MM)
VENT
CONNECTION
SIZE*
IN. (MM)
SHIP WT
(LB / KG)
0401712 17--1/2 (445) 15--7/8 (403) 11--9/16 (294) 16 (406) 4 (102) 119 (54)
0601716 17--1/2 (445) 15--7/8 (403) 11--9/16 (294) 16 (406) 4 (102) 124 (56)
0802120 21 (533) 19--3/8 (492) 13--5/16 (338) 19--1/2 (495) 4 (102) 144 (65)
1002120 21 (533) 19--3/8 (492) 13--5/16 (338) 19--1/2 (495) 4 (102) 154 (70)

Specifications are subject to change without notice.
4441 01 4200 01
A190402
Fig. 2 -- Clearances to Combustibles
A02055
Fig. 3 -- Return Air Temperature
CODES AND STANDARDS
Follow all national and local codes and standards in addition to
these instructions. The installation must comply with regulations
of the serving gas supplier, local building, heating, plumbing, and
other codes. In absence of local codes, the installation must
comply with the national codes listed below and all authorities
having jurisdiction.
In the United States, follow all codes and standards for the
following:
Safety
SUSA: Current edition of National Fuel Gas Code
(NFGC) NFPA 54/ANSI Z223.1 and the Installation
Standards, Warm Air Heating and Air Conditioning
Systems ANSI/NFPA 90B
General Installation
SCurrent edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association
Inc., Batterymarch Park, Quincy, MA 02269;
(www.NFPA.org) or for only the NFGC, contact the
American Gas Association, 400 N. Capitol Street,
N.W., Washington, DC 20001 (www.AGA.org).
Combustion and Ventilation Air
SCurrent edition of NFGC NFPA54/ANSI Z223.1 Sec-
tion 9.3, Air for Combustion and Ventilation.
Duct Systems
SAir Conditioning Contractors Association (ACCA)
Manual D, Sheet Metal and Air Conditioning Contract-
ors National Association (SMACNA), or American
Society of Heating, Refrigeration, and Air Condition-
ing Engineers (ASHRAE) 2005 Fundamentals Hand-
book Chapter 35 or 2004 HVAC Systems and Equip-
ment Handbook Chapters 9 and 16.
Acoustical Lining and Fibrous Glass Duct
SCurrent edition of SMACNA and NFPA 90B as tested
by UL Standard 181 for Class I Rigid Air Ducts
Gas Piping and Gas Pipe Pressure T
esting
SCurrent edition of NFGC NFPA54/ANSI Z223.1;
chapters 5, 6, 7, and 8 and National Plumbing Codes.
Electrical Connections
SCurrent edition of National Electrical Code (NEC) NF-
PA 70.
Venting
SCurrent edition of NFGC NFPA 54 / ANSI Z223.1;
Chapters 12 and 13.
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS PROCEDURE
FURNACE RELIABILITY HAZARD
Improper installation or service of furnace may cause
premature furnace component failure.
Electrostatic discharge can affect electronic components.
Follow the Electrostatic Discharge Precautions Procedure
listed below during furnace installation and servicing to
protect the furnace electronic control. Precautions will
prevent electrostatic discharges from personnel and hand
tools which are held during the procedure. These
precautions will help to avoid exposing the control to
electrostatic discharge by putting the furnace, the control,
and the person at the same electrostatic potential.
CAUTION
!
1. Disconnect all power to the furnace. Multiple disconnects
maybe required. DO NOT TOUCH THE CONTROL OR
ANY WIRE CONNECTED TO THE CONTROL PRIOR
TO DISCHARGING YOUR BODY’S ELECTROSTAT-
IC CHARGE TO GROUND.
2. Firmly touch the clean, unpainted, metal surface of the
furnace chassis which is close to the control. Tools held in
a person’s hand during grounding will be satisfactorily
discharged.
3. After touching the chassis, you may proceed to service the
control or connecting wires as long as you do nothing to
recharge your body with static electricity (for example;
DO NOT move or shuffle your feet, do not touch
ungrounded objects, etc).
4. If you touch ungrounded objects (and recharge your body
with static electricity), firmly touch a clean, unpainted
metal surface of the furnace again before touching control
or wires.
5. Use this procedure for installed and uninstalled
(ungrounded) furnaces.
6. Before removing a new control from its container,
discharge your body’s electrostatic charge to ground to
protect the control from damage. If the control is to be
installed in a furnace, follow items 1 through 4 before
bringing the control or yourself in contact with the
furnace. Put all used and new controls into containers
before touching ungrounded objects.
7. An ESD service kit (available from commercial sources)
mayalsobeusedtopreventESDdamage.

Specifications are subject to change without notice. 5441 01 4200 01
THE BLOWER IS LOCATED
TO THE RIGHT OF THE
BURNER SECTION, AND
AIR CONDITIONED AIR IS
DISCHARGED TO THE LEFT.
THE BLOWER IS
LOCATED BELOW THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED UPWARD.
THE BLOWER IS
LOCATED ABOVE THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED DOWNWARD
THE BLOWER IS
LOCATED TO THE LEFT
OF THE BURNER SECTION,
AND CONDITIONED AIR IS
DISCHARGED TO THE RIGHT.
A02097
Fig. 4 -- Multipoise Orientations
LOCATION
GENERAL
This multipoise furnace is shipped in packaged configuration.
Some assembly and modifications are required when used in any
of the four applications shown in Fig. 4.
This furnace must:
Sbe installed so the electrical components are protected
from water.
Snot be installed directly on any combustible material
other than wood flooring for upflow applications.
Downflow installations require use of a factory--ap-
proved floor base or coil assembly when installed on
combustible materials or wood flooring (refer to SAFE-
TY CONSIDERATIONS).
Sbe located close to the chimney or vent and attached to
an air distribution system. Refer to Air Ducts section.
Sbe provided ample space for servicing and cleaning.
Always comply with minimum fire protection clear-
ances shown on the furnace clearance to combustible
label.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death, and unit component damage.
Corrosive or contaminated air may cause failure of parts
containing flue gas, which could leak into the living space.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements can corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products. Do not install
furnace in a corrosive or contaminated atmosphere. Make
sure all combustion and circulating air requirements are met,
in addition to all local codes and ordinances.
!WARNING
The following types of furnace installations may require
OUTDOOR AIR for combustion due to chemical exposures:
SCommercial buildings
SBuildings with indoor pools
SLaundry rooms
SHobby or craft rooms, and
SChemical storage areas
If air is exposed to the following substances, it should not be used
for combustion air, and outdoor air may be required for
combustion:
SPermanent wave solutions
SChlorinated waxes and cleaners
SChlorine based swimming pool chemicals
SWater softening chemicals
SDe--icing salts or chemicals
SCarbon tetrachloride
SHalogen type refrigerants
SCleaning solvents (such as perchloroethylene)
SPrinting inks, paint removers, varnishes, etc.
SHydrochloric acid
SCements and glues
SAntistatic fabric softeners for clothes dryers
SMasonry acid washing materials
All fuel--burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal must be
made between the furnace cabinet and the return--air duct to
prevent pulling air from the burner area and from draft safeguard
opening.
PERSONAL INJURY AND/OR PROPERTY
DAMAGE
Improper use or installation of this furnace may cause
premature furnace component failure.
This furnace is not permitted to be used for heating of
buildings under construction.
CAUTION
!

Specifications are subject to change without notice.
6441 01 4200 01
18-IN. (457.2 mm)
MINIMUM TO BURNERS
A93044
Fig. 5 -- Installation in a Garage
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least 18
inches above the floor. (See Fig. 5) The furnace must be
located or protected to avoid damage by vehicles. When the
furnace is installed in a public garage, airplane hangar, or
other building having a hazardous atmosphere, the furnace
must be installed in accordance with the NFGC.
!WARNING
Table 2 – Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
FURNACE
INPUT
(BTUH)
TWO HORIZONT
A
LDUCTS
(1 SQ. IN./2,000 BTUH)
(1,100 SQ. MM/KW)
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH)
(734 SQ. MM/KW)
TWO OPENINGS OR
VERTICAL DUCTS
(1 SQ. IN./4,000 BTUH)
(550 SQ. MM/KW)
Free
A
rea of Open-
ing and Duct
Sq. In (Sq. mm)
Round Duct
In. (mm)
Dia
Free
A
rea of Open-
ing and Duct
Sq. In (Sq. mm)
Round
Duct
In. (mm)
Dia
Free
A
rea of Opening
and Duct
Sq. In (mm)
Round Duct
In. (mm) Dia.
40,000 20 (12904) 5 (127) 14 (8696) 5 (127) 10 (6452) 4 (102)
60,000 30 (19355) 6 (152) 20 (13043) 5 (127) 15 (9678) 5 (127)
80,000 40 (25807) 7 (178) 27 (17391) 6 (152) 20 (12904) 5 (127)
100,000 50 (32258) 8 (203) 34 (21739) 7 (178) 25 (16130) 6 (152)
EXAMPLE:Determining Free Area
FURNACE WATER HEATER TOT
A
L INPUT
100,000 + 30,000 = (130,000 divided by 4,000) = 32.5 Sq. In.
f
or each two Vertical Ducts or
Openings
60,000 + 40,000 = (100,000 divided by 3,000) = 33.3 Sq. In.
f
or each Single Duct or Opening
80,000 + 30,000 = (110,000 divided by 2,000) = 55.0 Sq. In.
f
or each two Horizontal Ducts
Table 3 – Minimum Space volumes for 100% combustion, Ventilation, and Dilution from Indoors
ACH*
OTHER THAN FAN---ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE
FAN---ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
30 40 50 40 60 80 100
SpaceVolume(ft.
3
)
0.60 1,050 1,400 1,750 1,000 1,500 2,000 3,300
0.50 1,260 1,680 2,100 1,200 1,800 2,400 3,960
0.40 1,575 2,100 2,625 1,500 2,250 3,000 4,950
0.30 2,100 2,800 3,500 2,000 3,000 4,000 6,600
0.20 3,150 4,200 5,250 3,000 4,500 6,000 9,900
0.10 6,300 8,400 10,500 6,000 9,000 12,000 19,800
0.00 NP NP NP NP NP NP NP
*Air Changes/Hour
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect
return--air ducts to the back of the furnace. (See Fig. 6)
!WARNING
A02054
Fig. 6 -- Prohibit Installation on Back

Specifications are subject to change without notice. 7441 01 4200 01
FURNACE CORROSION HAZARD
Failure to follow this caution may result in furnace damage.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements can corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
CAUTION
!
LOCATION RELATIVE TO COOLING EQUIPMENT
The cooling coil must be installed parallel with, or on the
downstream side of the unit to avoid condensation in the heat
exchangers. When installed parallel with the furnace, dampers or
other flow control must prevent chilled air from entering the
furnace. If the dampers are manually operated, they must be
equipped with means to prevent operation of either unit unless
the damper is in the full--heat or full--cool position.
AIR FOR COMBUSTION AND
VENTILATION
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
SU.S. installations: Section 9.3 of the current edition of
NFGC NFPA54/ANSI Z223.1, Air for Combustion
and Ventilation, and applicable provisions of the local
building codes.
!WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make--up air MUST be provided for the ventilation devices,
in addition to that required by the furnace. Refer to Carbon
Monoxide Poisoning Hazard warning in venting section of
these instructions to determine if an adequate amount of
make--up air is available.
The requirements for combustion and ventilation air depend upon
whether or not the furnace is located in a space having a volume
of at least 50 cubic feet per 1,000 Btuh input rating for all gas
appliances installed in the space.
SSpaces having less than 50 cubic feet per 1,000 Btuh
require the OUTDOOR COMBUSTION AIR
METHOD.
SSpaces having at least 50 cubic feet per 1,000 Btuh
may use the INDOOR COMBUSTION AIR, STAN-
DARD or KNOWN AIR INFILTRATION
METHOD.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper
combustion, ventilation, and dilution of flue gases using
permanent horizontal or vertical duct(s) or opening(s)
directly communicating with the outdoors or spaces that
freely communicate with the outdoors.
2. Fig. 7 illustrates how to provide TWO OUTDOOR
OPENINGS, one inlet and one outlet combustion and
ventilation air opening, to the outdoors.
a. One opening MUST commence within 12--in. (300 mm)
of the ceiling and the second opening MUST commence
within 12--in. (300 mm) of the floor.
b. Size openings and ducts per Fig. 7 and Table 2.
1 SQ IN.
PER
4000
BTUH*
DUCTS
TO
OUTDOORS
1 SQ IN.
PER 4000
BTUH*
CIRCULATING
AIR DUCTS
VENT
THROUGH
ROOF
D
B
A
C
E
1 SQ IN.
PER 4000
BTUH*
DUCT
TO
OUTDOORS
CIRCULATING AIR DUCTS
1 SQ IN.
PER 2000
BTUH*
1 SQ IN.
PER 2000
BTUH*
DUCTS
TO
OUTDOORS
12″MAX
12″MAX
12″MAX
12″
MAX
12″
MAX
OUTDOORS
1 SQ IN.
PER
4000
BTUH*
F
G
CLEARANCE IN FRONT
OF COMBUSTION AIR
OPENINGS SHALL BE
AT LEAST 3 IN.
(305mm)
(305mm)
(305mm)
(305mm)
(305mm)
(76mm)
*Minimum dimensions of 3 in. (76 mm).
NOTE: Use any of the following combinations of openings:
A&B, C&D, D&E, F&G
A03174
Fig. 7 -- Air for Combustion, Ventilation, and Dilution from
Outdoors
c. TWO HORIZONTAL DUCTS 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 per Fig. 7 and Ta-
ble 2.
d. TWO OPENINGS OR VERTICAL DUCTS require 1
square inch of free area per 4,000 Btuh (550 mm2/kW)
for combined input of all gas appliances in the space per
Fig. 7 and Table 2.
3. ONE OUTDOOR OPENING requires:
a. 1 square inch of free area per 3,000 Btuh (734 mm2/kW)
for combined input of all gas appliances in the space per
Table 2 and
b. Not less than the sum of the areas of all vent connectors
in the space.
The opening shall commence within 12” (300 mm) of the ceiling.
Appliances in the space shall have clearances of at least 1” (25
mm) from the sides and back and 6” (150 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.
Indoor Combustion Air -- NFPA & AGA
Standard and Known--Air--Infiltration Rate Methods
Indoor air is permitted for combustion, ventilation, and dilution,
if the Standard or Known--Air--Infiltration Method is used.

Specifications are subject to change without notice.
8441 01 4200 01
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in death and/or
personal injury.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
!WARNING
CIRCULATING AIR
DUCTS
6" MIN
(FRONT)Ü
CIRCULATING AIR DUCTS
VENT THROUGH ROOF
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MAX
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MAX
UNCONFINED
SPACE
INTERIOR
HEATED
SPACE
CLEARANCE IN FRONT OF COMBUSTION AIR
OPENINGS SHALL BE AT LEAST 3 IN.
(305mm)
(152mm)
(305mm)
*Minimum opening size is 100 in.2with minimum dimensions of 3 in. (76 mm).
*Minimum of 3 in. (76 mm), when type ---B1 vent is used.
A03175
Fig. 8 -- Air for Combustion, Ventilation, and Dilution from
Indoors
The Standard Method:
1. 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 and
2. The air infiltration rate is not known to be less than 0.40
air changes per hour (ACH).
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
1. Less than 0.40 ACH and
2. 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 3 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 3 -- Minimum Space Volumes were determined by using
the following equations from the current edition of National Fuel
Gas Code ANSI Z223.1/NFPA 54, 9.3.2.2:
1. For other than fan--assisted appliances, such as a draft
hood--equipped water heater:
Volume
Other
=21ft
3
ACH
I
other
1000 Btu/hr
A04002
2. For fan--assisted appliances such as this furnace:
Volume
Fan
=15ft
3
ACH
I
fan
1000 Btu/hr
A004003
If:
Iother = combined input of all other than fan--assisted appliances
in Btuh/hr
Ifan = combined input of all fan--assisted appliances in Btuh/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.
1. Adjoining rooms can be considered part of a space if:
a. There are no closeable doors between rooms.
b. Combining spaces on same floor level. Each opening
shall have free area of at least 1 in.2/1,000 Btuh (2,000
mm2/kW) of the total input rating of all gas appliances
in the space, but not less than 100 in.2(0.06 m2). One
opening shall commence within 12”(300 mm) of the ceil-
ing and the second opening shall commence within 12”
(300 mm) of the floor. The minimum dimension of air
openings shall be at least 3 in. (80 mm). (See Fig. 8)
c. Combining space on different floor levels. The volumes
of spaces on different floor levels shall be considered as
communicating spaces if connected by one or more per-
manent openings in doors or floors having free area of
at least 2 in.2/1,000 Btuh (4,400 mm2/kW) of total input
rating of all gas appliances.
2. An attic or crawlspace may be considered a space that
freely communicates with the outdoors provided there are
adequate permanent ventilation openings directly to out-
doors having free area of at least 1--in.2/4,000 Btuh of total
input rating for all gas appliances in the space.
3. In spaces that use the Indoor Combustion Air Method,
infiltration should be adequate to provide air for combus-
tion, permanent ventilation and dilution of flue gases.
However, in buildings with unusually tight construction,
additional air MUST be provided using the methods de-
scribedintheOutdoor Combustion Air Method section.
Unusually tight construction is defined as construction with:
a. Walls and ceilings exposed to the outdoors have a contin-
uous, sealed vapor barrier. Openings are gasketed or
sealed and
b. Doors and openable windows are weatherstripped and
c. 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.
Combination of Indoor and Outdoor Air
1. Indoor openings shall comply with the Indoor
Combustion Air Method below and,
2. Outdoor openings shall be located as required in the
Outdoor Combustion Air Method mentioned previously
and,
3. Outdoor openings shall be sized as follows:
a. Calculate the Ratio of all Indoor Space volume divided
by required volume for Indoor Combustion Air
Method below.

Specifications are subject to change without notice. 9441 01 4200 01
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. Theminimum
dimension of air openings shall be not less than 3 in. (80
mm).
INSTALLATION
UPFLOW INSTALLATION
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove two screws holding bot-
tom filler panel. (See Fig. 9)
Bottom
Closure Panel
Bottom Filler Panel
A10273
Fig. 9 -- Removing Bottom Closure Panel
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. This panel MUST be in place when
only side return air is used.
NOTE: Side return--air openings can be used in UPFLOW and
most HORIZONTAL configurations. Do not use side return--air
openings in DOWNFLOW configuration.
Leveling Legs (If Desired)
In upflow position with side return inlet(s), leveling legs may be
used. (See Fig. 10) Install field--supplied, 5/16 x 1--1/2 in. (8 x 38
mm) (max) corrosion--resistant machine bolts, washers and nuts.
NOTE: Bottom closure must be used when leveling legs are
used. It may be necessary to remove and reinstall bottom closure
panel to install leveling legs. To remove bottom closure panel, see
Item 1. in Bottom Return Air Inlet section.
To install leveling legs:
1. Position furnace on its back. Locate and drill a hole in
each bottom corner of furnace. (See Fig. 10)
2. For each leg, install nut on bolt and then install bolt and
nut in hole. (Install flat washer if desired.)
3. Install another nut on other side of furnace base. (Install
flat washer if desired.)
4. Adjust outside nut to provide desired height, and tighten
inside nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
1
3
/ 4 
1
3
/ 4 
1
3/
4 
1
3/
4 
5/
16 
5
/ 16 
5/
16 
5/
16 
(44mm)
(8mm)
(44mm)
(8mm)
(8mm)
(8mm)
(44mm)
(44mm)
A89014
Fig. 10 -- Leveling Legs
DOWNFLOW INSTALLATION
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following 3
accessories are used:
SDownflow combustible floor subbase
SManufacturer’s approved Cased Coil or Coil Casing
1. Determine application being installed from Table 4.
2. Construct hole in floor per Table 4 and Fig. 11.
3. Construct plenum to dimensions specified in Table 4 and
Fig. 11.
4. If downflow subbase is used, install as shown in Fig. 12. If
Coil or Coil Casing, install as shown in Fig. 13.
NOTE: It is required that the perforated supply--air duct flanges
be completely folded over or removed from furnace when
installing the furnace on a factory--supplied cased coil or coil box.
To remove the supply--air duct flange, use wide duct pliers or
hand seamers to bend flange back and forth until it breaks off. Be
careful of sharp edges. (See Fig. 14)
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove two screws holding bot-
tom filler panel. (See Fig. 9)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.

Specifications are subject to change without notice.
10 441 01 4200 01
4. Reinstall bottom filler panel and screws
PLENUM
OPENING
C
A
BD
FLOOR
OPENING
A96283
Fig. 11 -- Floor and Plenum Opening Dimensions
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
A96285
Fig. 12 -- Furnace, Plenum, and Subbase Installed
on a Combustible Floor
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
A08556
Fig. 13 -- Furnace, Plenum, and Coil Assembly or
Coil Box Installed on a Combustible Floor
HORIZONTAL INSTALLATION
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control
operation will be adversely affected. Never connect
return--air ducts to the back of the furnace.
!WARNING
The furnace can be installed horizontally in an attic or crawl space
on either the left--hand (LH) or right--hand (RH) side. The furnace
can be hung from floor joists, rafters or trusses or installed on a
non--combustible platform, blocks, bricks or pad.
Table 4 – Opening Dimensions -- In. (mm)
FURNACE
CASING
WIDTH APPLICATION PLENUM OPENING FLOOR OPENING
A
B C D
17–1/2
(445)
Upflow
A
pplications on Combustible or Noncombustible
Flooring (subbase not required)
16
(406)
2 1 --- 5
/
8
(549)
1 6 --- 5
/
8
(422)
2 2 --- 1
/
4
(565)
Downflow
A
pplications on Noncombustible Flooring (subbase
not required)
1 5 --- 7
/
8
(403)
19
(483)
1 6 --- 1
/
2
(419)
1 9 --- 5
/
8
(498)
Downflow applications on combustible
f
looring (subbase
required)
1 5 --- 1
/
8
(384)
19
(483)
1 6 --- 3
/
4
(425)
2 0 --- 5
/
8
(600)
Downflow
A
pplications on Combustible Flooring with Coil
Assembly or coil box (subbase not required)
1 5 --- 1
/
2
(394)
19
(483)
1 6 --- 1
/
2
(419)
20
(508)
21
(533)
Upflow
A
pplications on Combustible or Noncombustible
Flooring (subbase not required)
1 9 --- 1
/
2
(495)
2 1 --- 5
/
8
(549)
2 0 --- 1
/
8
(511)
2 2 --- 1
/
4
(565)
Downflow
A
pplications on Noncombustible Flooring (subbase
not required)
1 9 --- 3
/
8
(492)
19
(483)
20
(508)
1 9 --- 5
/
8
(498)
Downflow applications on combustible
f
looring subbase
required)
1 8 --- 5
/
8
(473)
19
(483)
2 0 --- 1
/
4
(514)
2 0 --- 5
/
8
(600)
Downflow
A
pplications on Combustible Flooring with Coil
Assembly or coil box (subbase not required)
19
(483)
19
(483)
20
(508)
20
(508)

Specifications are subject to change without notice. 11441 01 4200 01
Suspended Furnace Support
The furnace may be supported under each end with threaded rod,
angle iron or metal plumber’s strap as shown. (See Fig. 15 and
16) Secure angle iron to bottom of furnace as shown.
Heavy--gauge sheet metal straps (plumber’s straps) may be used
to suspend the furnace from each bottom corner. To prevent
screws from pulling out, use 2 #8 x 3/4--in. (19 mm) screws into
the side and 2 #8 x 3/4--in. (19 mm) screws in the bottom of the
furnace casing for each strap. (See Fig. 15 and 16) If the screws
are attached to ONLY the furnace sides and not the bottom, the
straps must be vertical against the furnace sides and not pull away
from the furnace sides, so that the strap attachment screws are not
in tension (are loaded in shear) for reliable support.
Platform Furnace Support
Construct working platform at location where all required furnace
clearances are met. (See Fig. 2 and 17) For furnaces with 1--in.
(25 mm) clearance requirement on side, set furnace on
noncombustible blocks, bricks or angle iron. For crawl space
installations, if the furnace is not suspended from the floor joists,
the ground underneath furnace must be level and the furnace set
on blocks or bricks.
Roll--Out Protection
Provide a minimum 17--3/4 in. x 22 in. (451 mm x 559 mm)
piece of sheet metal for flame roll--out protection in front of
burner area for furnaces closer than 12 inches (305 mm) above
the combustible deck or suspended furnaces closer than 12 inches
(305 mm) to joists. The sheet metal MUST extend underneath the
furnace casing by 1 in. (25 mm) with the door removed.
The bottom closure panel on furnaces of widths 17--1/2 in. (445
mm) and larger may be used for flame roll--out protection when
bottom of furnace is used for return air connection. See Fig. 17
for proper orientation of roll--out shield.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove two screws holding bot-
tom filler panel. (See Fig. 9)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws. Side Return Air
Inlet
Side Return Air Inlet
These furnaces are shipped with bottom closure panel installed in
bottom return--air opening. This panel MUST be in place when
side return air inlet(s) is used without a bottom return air inlet.
FILTER ARRANGEMENT
CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in personal
injury, or death.
Never operate a furnace without a filter or with filter access
door removed.
!WARNING
There are no provisions for an internal filter rack in these
furnaces.
A field--supplied accessory external filter is required.
Refer to the instructions supplied with the external filter rack for
assembly and installation options.
AIR DUCTS
General Requirements
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA)
or American Society of Heating, Refrigerating and Air
Conditioning Engineers (ASHRAE) or consult The Air Systems
Design Guidelines reference tables available from your local
distributor. The duct system should be sized to handle the
required system design CFM at the design external static pressure.
The furnace airflow rates are provided in Table 11 -- AIR
DELIVERY--CFM (with filter).
When a furnace is installed so that the supply ducts carry air
circulated by the furnace to areas outside 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.
Secure ductwork with proper fasteners for type of ductwork used.
Seal supply-- and return--duct connections to furnace with code
approved tape or duct sealer.
NOTE: Flexible connections should be used between ductwork
and furnace to prevent transmission of vibration. Ductwork
passing through unconditioned space should be insulated and
sealed to enhance system performance. When air conditioning is
used, a vapor barrier is recommended.
Maintain a 1--in. (25 mm) clearance from combustible materials
to supply air ductwork for a distance of 36 in. (914 mm)
horizontally from the furnace. See NFPA 90B or local code for
further requirements.
Ductwork Acoustical Treatment
NOTE: Metal duct systems that do not have a 90 degree elbow
and 10 ft. (3 M) of main duct to the first branch take--off may
require internal acoustical lining. As an alternative, fibrous
ductwork may be used if constructed and installed in accordance
with the latest edition of SMACNA construction standard on
fibrous glass ducts. Both acoustical lining and fibrous ductwork
shall comply with NFPA 90B as tested by UL Standard 181 for
Class 1 Rigid air ducts.
Supply Air Connections
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 airstream. The cover attachment shall prevent leaks.
Upflow and Horizontal Furnaces
Connect supply--air duct to flanges on furnace supply--air outlet.
Bend flange upward to 90_with wide duct pliers. (See Fig. 14)
The supply--air duct must be connected to ONLY the furnace
supply--outlet--air duct flanges or air conditioning coil casing
(when used). DO NOT cut main furnace casing side to attach
supply air duct, humidifier, or other accessories. All accessories
MUST be connected to duct external to furnace main casing.
NOTE: For horizontal applications, the top--most flange may be
bent past 90 degrees to allow the evaporator coil to hang on the

Specifications are subject to change without notice.
12 441 01 4200 01
flange temporarily while the remaining attachment and sealing of
the coil are performed.
Downflow Furnaces
Connect supply--air duct to supply--air outlet on furnace. Bend
flange inward past 90_with wide duct pliers. (See Fig. 14) The
supply--air duct must be connected to ONLY the furnace supply
outlet or air conditioning coil casing (when used). When installed
on combustible material, supply--air duct must be connected to
ONLY the factory--approved accessory subbase or a factory--
approved air conditioning coil casing. DO NOT cut main furnace
casing to attach supply side air duct, humidifier, or other
accessories. All accessories MUST be connected to duct external
to furnace casing.
A190346
Fig. 14 -- Duct Flanges
1
/4 " (6mm) THREADED ROD
4 REQ.
SECURE ANGLE
IRON TO BOTTOM
OF FURNACE WITH
3 #8 x
3/4" (19mm) SCREWS
TYPICAL FOR 2 SUPPORTS
1” (25mm) SQUARE, 1-1/4”x1-1/4”x1/8” (32x32x3mm)
ANGLE IRON OR UNI-STRUT MAY BE USED
(2) HEX NUTS, (2) WASHERS & (2) LOCK WASHERS
REQ. PER ROD
8" (203mm)
MIN
FOR DOOR REMOVAL
OUTER DOOR
ASSEMBLY
A10130
Fig. 15 -- Horizontal Unit Suspension
METHOD 2
USE (4) #8 x 3/4 (19 mm) SHEET
METAL SCREWS FOR EACH
STRAP. THE STRAPS
SHOULD BE VERTICAL
AGAINST THE FURNACE
SIDES AND NOT PULL AWAY
FROM THE FURNACE
SIDES.
METHOD 1
FOLD ALL STRAPS UNDER
FURNACE AND SECURE WTH
(4) #8 x 3/4 (19 mm) SHEET METAL SCREWS
(2 SCREWS IN SIDE AND 2 SCREWS
IN BOTTOM).
A10131
Fig. 16 -- Horizontal Suspension with Straps

Specifications are subject to change without notice. 13441 01 4200 01
A180240
Fig. 17 -- Typical Attic Installation
Return Air Connections
FIRE HAZARD
Failure to follow this warning could cause personal injury,
death and/or property damage.
Never connect return--air ducts to the back of the furnace.
Follow instructions below
!WARNING
Downflow Furnaces
The return--air duct must be connected to return--air opening
(bottom inlet) as shown in Fig. 19. DO NOT cut into casing sides
(left or right). Side opening is permitted for only upflow and most
horizontal furnaces. (See Fig. 19) Bypass humidifier connections
should be made at ductwork or coil casing sides exterior to
furnace.
Upflow and Horizontal Furnaces
The return--air duct must be connected to bottom, sides (left or
right), or a combination of bottom and side(s) of main furnace
casing as shown in Fig. 18 and 20. Bypass humidifier may be
attached into unused return air side of the furnace casing. (See
Fig. 18 and 20)
A190364
Fig. 18 -- Upflow Return Air Configurations and Restrictions

Specifications are subject to change without notice.
14 441 01 4200 01
A190365
Fig. 19 -- Downflow Return Air Configurations and
Restrictions
A190366
Fig. 20 -- Horizontal Return Air Configurations and
Restrictions
GAS PIPING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber. 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.
!WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury,death, and/or property damage.
Use proper length of pipe to avoid stress on gas control
assembly and a gas leak.
!WARNING
FURNACE OVERHEAT HAZARD
Failure to follow this caution may result in property
damage.
Connect gas pipe to gas valve using a backup wrench to
avoid damaging gas controls and burner misalignment.
CAUTION
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
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. Black iron pipe shall be installed at the furnace
gas control valve and extend a minimum of 2 in.(51 mm)
outside the furnace.
!WARNING
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
NOTE: In the state of Massachusetts:
1. Gas supply connections MUST be performed by a
licensed plumber or gas fitter.
2. When flexible connectors are used, the maximum length
shall not exceed 36 inches (915 mm).
3. When lever handle type manual equipment shutoff valves
are used, they shall be T--handle valves.
4. The use of copper tubing for gas piping is NOT approved
by the state of Massachusetts.
Refer to Table 5 for recommended gas pipe sizing. Risers must be
used to connect to furnace and to meter. Support all gas piping
with appropriate straps, hangers, etc. Use a minimum of 1 hanger
every 6 ft. (2 M). Joint compound (pipe dope) should be applied
sparingly and only to male threads of joints. Pipe dope must be
resistant to the action of propane gas.
An accessible manual equipment shutoff valve MUST be
installed external to furnace casing and within 6 ft. (2 M) of
furnace. A 1/8--in. (3 mm) NPT plugged tapping, accessible for
test gauge connection, MUST be installed immediately upstream
of gas supply connection to furnace and downstream of manual
equipment shutoff valve.
NOTE: The furnace gas control valve inlet pressure tap
connection is suitable to use as test gauge connection providing
test pressure DOES NOT exceed maximum 0.5 psig (14--In.
W.C.) stated on gas control valve. (See Fig. 37)
Install a sediment trap in riser leading to furnace as shown in Fig.
21. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of furnace gas controls. Place a ground
joint union between furnace gas control valve and exterior
manual equipment gas shutoff valve. A 1/8--in. (3 mm) NPT
plugged tapping, accessible for test gauge connection, MUST be
installed immediately upstream of gas supply connection to
furnace and downstream of manual equipment shutoff valve.
Piping should be pressure and leak tested in accordance with
NFGC in the United States, local, and national plumbing and gas
codes before the furnace has been connected. After all
connections have been made, purge lines and check for leakage at
furnace prior to operating furnace.

Specifications are subject to change without notice. 15441 01 4200 01
If pressure exceeds 0.5 psig (14--In. W.C.), gas supply pipe must
be disconnected from furnace and capped before and during
supply pipe pressure test. If test pressure is equal to or less than
0.5 psig (14--In. W.C.), turn off electric shutoff switch located on
furnace gas control valve and accessible manual equipment
shutoff valve before and during supply pipe pressure test. After
all connections have been made, purge lines and check for
leakage at furnace prior to operating furnace.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON and OFF.
UNION
SEDIMENT
TRAP
MANUAL
SHUTOFF
VALVE
(REQUIRED)
GAS
SUPPLY
A02035
Fig. 21 -- Typical Gas Pipe Arrangement
Table 5 – Maximum Capacity of Pipe*
NOMINAL IRON PIPE INTERNAL DIAMETER LENGTH OF PIPE --- FT. (M)
SIZE IN. (mm) In. (mm) 10 20 30 40 50
1/2 (13) 0.622 (16) 175 (53) 120 (37) 97 (30) 82 (25) 73 (22)
3/4 (19) 0.824 (21) 360 (110) 250 (76) 200 (61) 170 (52) 151 (46)
1 (25) 1.049 (27) 680 (207) 465 (142) 375 (114) 320 (98) 285 (87)
1---1/4 (32) 1.380 (35) 1400 (427) 950 (290) 770 (235) 660 (201) 580 (177)
1---1/2 (38) 1.610 (41) 2100 (640) 1460 (445) 1180 (360) 990 (301) 900 (274)
* Cubic ft. of natural gas per hr for gas pressures of 0.5 psig (14 ---In. W.C.) or less and a pressure drop of 0.5 ---In. W.C. (based on a 0.60 specific gravity
gas). Ref: Chapter 6 current edition of ANSI Z223/NFPA 54.
Table 6 – Electrical Data
Unit Size
Volts-
Hertz-
Phase
Operating Voltage*
Range Maximum
Unit Amps
Unit
Ampacity#
Minimum
Wire Size
AWG
Maximum
Wire
Length‡ ft
Maximum
Fuse or
CKT BKR†
Amps
Maximum Minimum
0401712 115-60-1 127 104 11.4 12.6 14 29 15
0601716 115-60-1 127 104 11.4 12.6 14 29 15
0802120 115-60-1 127 104 17.8 18.9 12 30 20
1002120 115-60-1 127 104 17.8 18.9 12 30 20
* Permissible limits of the voltage range at which the unit operates satisfactorily.
# Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier,
etc.) full load amps.
{Time---delay type is recommended.
}Length shown is as measured one way along wire path between unit and service panel for maximum 2 percent voltage drop.
ELECTRICAL CONNECTIONS
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow safety warnings could result in dangerous
operation, serious injury, death or property damage.
Improper servicing could result in dangerous operation,
serious injury, death or property damage.
-- Before servicing, disconnect all electrical power to
furnace.
-- When servicing controls, label all wires prior to
disconnecting. Reconnect wires correctly.
-- Verify proper operation after servicing.
!WARNING ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Blower access panel door switch opens 115--v power to
control. No component operation can occur. Do not bypass
or close switch with panel removed.
!WARNING
See Fig. 24 for field wiring diagram showing typical field 115--v
wiring. Check all factory and field electrical connections for
tightness.
Field--supplied wiring shall conform with the limitations of 63_F
(35_C) rise.

Specifications are subject to change without notice.
16 441 01 4200 01
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
The cabinet MUST have an uninterrupted or unbroken
ground according to current edition of NEC NFPA 70 or
local codes to minimize personal injury if an electrical fault
should occur. This may consist of electrical wire, conduit
approved for electrical ground or a listed, grounded power
cord (where permitted by local code) when installed in
accordance with existing electrical codes. Refer to the
power cord manufacturer’s ratings for proper wire gauge.
Do not use gas piping as an electrical ground.
!WARNING
FURNACE MAY NOT OPERATE
Failure to follow this caution may result in intermittent
furnace operation.
Furnace control must be grounded for proper operation or
else control will lock out. Control must remain grounded
through green/yellow wire routed to gas valve and gas
valve mounting bracket screw.
CAUTION
!
115--V WIRING
Verify that the voltage, frequency, and phase correspond to that
specified on unit rating plate. Also, check to be sure that service
provided by utility is sufficient to handle load imposed by this
equipment. Refer to rating plate or Table 6 for equipment
electrical specifications.
Make all electrical connections in accordance with current edition
of National Electrical Code (NEC) NFPA 70 and any local codes
or ordinances that might apply.
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
!WARNING
Use a separate, fused branch electrical circuit with a properly
sized fuse or circuit breaker for this furnace. See Table 6 for wire
size and fuse specifications. A readily accessible means of
electrical disconnect must be located within sight of the furnace.
NOTE: Proper polarity must be maintained for 115--v wiring. If
polarity is incorrect, control LED status indicator light will
rapidly flash RED and furnace will NOT operate.
J--BOX RELOCATION
NOTE: If factory location of J--Box is acceptable, go to next
section (ELECTRICAL CONNECTION TO J--BOX).
1. Remove and save two screws holding J--Box.
NOTE: The J--Box cover need not be removed from the J--Box
in order to move the J--Box. Do NOT remove green ground
screw inside J--Box.
2. Cut wire tie on loop in furnace wires attached to J--box.
3. Move J--Box to desired location.
4. Fasten J--Box to casing with two screws removed in Step 1.
5. Route J--Box wires within furnace away from sharp edges,
rotating parts and hot surfaces.
ELECTRICAL CONNECTION TO J--BOX
Electrical Box on Furnace Casing Side
FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
If field--supplied manual disconnect switch is to be mounted
on furnace casing side, select a location where a drill or
fastener cannot damage electrical or gas components.
!WARNING
1. Select and remove a hole knockout in the casing where the
electrical box is to be installed.
NOTE: Check that duct on side of furnace will not interfere with
installed electrical box.
2. Remove the desired electrical box hole knockout and posi-
tion the hole in the electrical box over the hole in the fur-
nace casing.
3. Fasten the electrical box to casing by driving two field
supplied screws from inside electrical box into casing
steel.
4. Remove and save two screws holding J--Box.
5. Pull furnace power wires out of 1/2--in. (12 mm) diameter
hole in J--Box. Do not loosen wires from strain--relief
wire--tie on outside of J--Box.
6. Route furnace power wires through holes in casing and
electrical box and into electrical box (see Fig. 22)
7. Pull field power wires into electrical box.
8. Remove cover from furnace J--Box.
9. Route field ground wire through holes in electrical box
and casing, and into furnace J--Box.
10. Reattach furnace J--Box to furnace casing with screws re-
movedinStep4.
11. Secure field ground wire to J--Box green ground screw.
12. Complete electrical box wiring and installation. Connect
line voltage leads as shown in Fig. 24. Use best practices
(NEC in U.S. for wire bushings, strain relief, etc.)
13. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
POWER CORD INSTALLATION IN FURNACE J--BOX
NOTE: Power cords must be able to handle the electrical
requirements listed in Table 6. Refer to power cord
manufacturer’s listings.
1. Remove cover from J--Box.
2. Route listed power cord through 7/8--in. (22 mm) diameter
hole in J--Box.
3. Secure power cord to J--Box bracket with a strain relief
bushing or a connector approved for the type of cord used.
4. Secure field ground wire to green ground screw on J--Box
bracket.
5. Connect line voltage leads as shown in Fig. 24.
6. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.
BX CABLE INSTALLATION IN FURNACE J--BOX
1. Remove cover from J--Box.
2. Route BX cable into 7/8--inch diameter hole in J--Box.
3. Secure BX cable to J--Box bracket with connectors ap-
proved for the type of cable used.
4. Secure field ground wire to green ground screw on J--Box
bracket.
5. Connect line voltage leads as shown in Fig. 24.
6. Reinstall cover to J--Box. Do not pinch wires between
cover and bracket.

Specifications are subject to change without notice. 17441 01 4200 01
A10141
Fig. 22 -- Field--Supplied Electrical Box on Furnace Casing
24--V WIRING
Make field 24--v connections at the 24--v terminal strip. (See Fig. 24)
Connect terminal Y as shown in Fig. 43 for proper cooling
operation. Use only AWG No. 18, color--coded, copper thermostat
wire.
The 24--v circuit contains an automotive--type, 3--amp. fuse located
on the control. Any direct shorts during installation, service, or
maintenance could cause this fuse to blow. If fuse replacement is
required, use ONLY a 3--amp. fuse of identical size.
ACCESSORIES
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used) us-
ing 1/4--in female quick connect terminals to the two male
1/4--in quick--connect terminals on the control board
marked EAC--1 and EAC--2. The terminals are rated for
115VAC, 1.0 amps maximum and are energized during
blower motor operation. (See Fig. 23)
2. Humidifier (HUM)
The HUM terminal is a 24 VAC output, energized when
the blower is operating during a call for heat.
Connect an accessory 24 VAC, 0.5 amp. maximum hu-
midifier (if used) to the 1/4--in male quick--connect HUM
terminal and COM--24V screw terminal on the control
board thermostat strip. (See Fig. 23)
A190350
Fig. 23 -- Furnace Control

Specifications are subject to change without notice.
18 441 01 4200 01
115-VOLT FIELD-
SUPPLIED
FUSED
DISCONNECT
JUNCTION
BOX
CONTROL
BOX
24-VOLT
TERMINAL
BLOCK
THREE-WIRE
HEATING-
ONLY
FIVE
WIRE
NOTE 2
NOTE 1
1-STAGE
THERMOSTAT
TERMINALS
FIELD-SUPPLIED
FUSED DISCONNECT
CONDENSING
UNIT
FURNACE
COM
R
WCY RG
GND
GND
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
Connect Y/Y2-terminal as shown for proper operation.
Some thermostats require a "C" terminal connection as shown.
If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
208/230- OR
460-VOLT
THREE
PHASE
208/230-
VOLT
SINGLE
PHASE
WHT
BLK
WHT
BLK
W/W1
W2
Y/Y2
G
NOTES: 1.
2.
3.
A95236
Fig. 24 -- Heating and Cooling Application Wiring Diagram
A190372
Fig. 25 -- 1--Speed Variable Furnace with Single--Speed
Air Conditioner
A190373
Fig. 26 -- 1--Speed Variable Furnace with Two--Speed Air
Conditioner

Specifications are subject to change without notice. 19441 01 4200 01
A190374
Fig. 27 -- 1--Speed Variable Furnace with Single--Speed Heat
Pump (Dual Fuel)
A190375
Fig. 28 -- 1--Speed Variable Furnace with Two--Speed Heat
Pump (Dual Fuel)
NOTES FOR FIGURES 25 -- 28
1. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
2. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
3. Refer to ICP thermostat Installation Instructions for additional information and setup procedure.
4. When using a Humidity Sensing Thermostat, set DEHUMIDIFY OPTIONS to H DE--ENRGZD FOR DEHUM.
5. HUM connection is 24 VAC and is energized when the blower turns on during a call for heat.
6. When connecting 115 VAC to humidifier use a separate 115 VAC supply.
7. When using a humidifier on a HP installation connect humidifier to hot water.

Specifications are subject to change without notice.
20 441 01 4200 01
VENTING
The furnace shall be connected to a listed factory built chimney
or vent, or a clay--tile lined masonry or concrete chimney. Venting
into an unlined masonry chimney or concrete chimney is
prohibited.
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. An improperly sized Category I venting
system could cause the formation of condensate in the furnace
and vent, leakage of condensate and combustion products, and
spillage of combustion products into the living space.
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 venting system.
2. Inspect the venting system for proper size and
horizontal pitch, as required in the current edition of
National Fuel Gas Code, ANSI Z223.1/NFPA 54
and these instructions. Determine that there is no
blockage or restriction, leakage, corrosion and other
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 inspected 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.
8. If improper venting is observed during any of the
above tests, the venting system must be corrected in
accordance with the current edition of National Fuel
Gas Code, ANSI Z223.1/NFPA 54.
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.
!WARNING
Vent system or vent connectors may need to be resized. Vent
systems or vent connectors, must be sized to approach minimum
size as determined using appropriate table found in the NFGC.
GENERAL VENTING REQUIREMENTS
Follow all safety codes for proper vent sizing and installation
requirements, including local building codes, the current edition
of National Fuel Gas Code ANSI Z223.1/NFPA 54 (NFGC),
Parts 12 and 13, the local building codes, and furnace and vent
manufacturers’ instructions.
These furnaces are design--certified as Category I furnaces in
accordance with current edition of ANSI Z21.47/CSA 2.3 and
operate with a non--positive vent static pressure to minimize the
potential for vent gas leakage. Category I furnaces operate with a
flue loss not less than 17 percent to minimize the potential for
condensation in the venting system. These furnaces are approved
for common venting and multistory venting with other fan
assisted or draft hood equipped appliances in accordance with the
NFGC, the local building codes, and furnace and vent
manufacturers’ instructions. The following information and
warning must be considered in addition to the requirements
defined in the NFGC.
1. If a vent (common or dedicated) becomes blocked, the
furnace will be shut off by the draft safeguard switch
located on the vent elbow.
2. Do not vent this Category I furnace into a single--wall
dedicated or common vent. The dedicated or common
vent is considered to be the vertical portion of the vent
system that terminates outdoors.
3. Vent connectors serving Category I furnaces shall not be
connected into any portion of a mechanical draft system
operating under positive pressure.
4. Do not vent this appliance with any solid fuel burning
appliance.
5. Category I furnaces must be vented vertically or nearly
vertically unless equipped with a listed power venter.
6. Do not vent this appliance into an unlined masonry
chimney. Refer to Chimney Inspection Chart, Fig. 29.
MASONRY CHIMNEY REQUIREMENTS
If a clay tile--lined masonry chimney is being used and it is
exposed to the outdoors below the roof line, relining might be
required. Chimneys shall conform to the Standard for Chimneys,
Fireplaces, Vents, and Solid Fuel Burning Appliances current
edition of ANSI/NFPA 211 and must be in good condition.
USA -- Refer to Sections 13.1.8 and 13.2.20 of the current edition
of NFGC NFPA54/ANSI Z223.1 or the authority having
jurisdiction to determine whether relining is required. If relining
is required, use a properly sized listed metal liner, Type--B vent,
or a listed alternative venting design.
NOTE: See the current edition of NFPA54/ANSI Z223.1, 13.1.8
and 13.2.20 regarding alternative venting design and the
Exception.
This furnace is permitted to be vented into a clay tile--lined
masonry chimney that is exposed to the outdoors below the roof
line, provided:
1. Vent connector is Type--B double--wall, and
2. This furnace is common vented with at least 1 draft hood
equipped appliance, and
3. The combined appliance input rating is less than the maxi-
mum capacity given in Table 8, and
4. The input rating of each space heating appliance is greater
than the minimum input rating given in Table 7 for the lo-
cal 99% Winter Design Temperature. Chimneys having in-
ternal areas greater than 38 square inches require furnace
input ratings greater than the input ratings of these fur-
naces. See footnote at bottom of Table 7, and
5. The authority having jurisdiction approves.
If all of these conditions cannot be met, an alternative venting
design shall be used, a listed chimney--lining system, or a Type--B
common vent.