Comfortmaker F80CTL Guide

Installation, Start–Up, Operating and
Service and Maintenance Instructions
NOTE: Read the entire instruction manual before starting the
installation.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Table 1 – Minimum Free Area Required for Each Combustion Air
opening of Duct to Outdoors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Table 2 – Minimum Space Volumes for 100% Combustion, Ventila-
tion, and Dilution from Indoors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Table 3 – Opening Dimensions - In. (mm). . . . . . . . . . . . . . . . . . . . 10
AIR DUCTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
GAS PIPING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Table 4 – Maximum Capacity of Pipe . . . . . . . . . . . . . . . . . . . . . . . 14
ELECTRICAL CONNECTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 5 – Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
VENTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Table 6 – Minimum Allowable Input Rating of
Space-Heating Appliance in Thousands of Btuh per Hour. . . . . . . . 21
Table 7 – Combined Appliance Maximum Input Rating
in Thousands of Btuh per Hour. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 8 – Recommended Minimum Vent Height Per Furnace and Vent
Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
START-UP, ADJUSTMENT, AND SAFETY CHECK . . . . . . . . . . . 25
Table 9 – Altitude Derate Multiplier for U.S.A.. . . . . . . . . . . . . . . . 26
Table 10 – Gas Rate (CU ft./hr) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Table 11 – Blower Off Delay Setup Switch . . . . . . . . . . . . . . . . . . . 28
Table 12 – Cooling Airflow Adjustments from 1.5 to 6 Tons . . . . . 29
Table 13 – Air Delivery - CFM (With Filter). . . . . . . . . . . . . . . . . . 30
Table 14 – Furnace Setup Switch Description . . . . . . . . . . . . . . . . . 34
Table 15 – Orifice Size and Manifold Pressure (In. W.C.) for Gas Input
Rate (Tabulated Data Based on 22,000 Btuh High-Heat/14,500 Btuh
for Low-Heat per Burner, Derated 4 Percent for Each 1000 Ft. (305 M)
Above Sea Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Table 16 – Orifice Size and Manifold Pressure (In. W.C.) for Gas Input
Rate (Tabulated Data Based on 21,000 Btuh High-Heat/14,500 Btuh
for Low-Heat Per Burner, Derated 4 Percent for Each 1000 Ft. (305 M)
Above Sea level). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
SERVICE AND MAINTENANCE PROCEDURES. . . . . . . . . . . . . . 37
Table 17 – Filter Size Information - In. (mm) . . . . . . . . . . . . . . . . . 39
SEQUENCE OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
TROUBLESHOOTING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
PARTS REPLACEMENT INFORMATION GUIDE . . . . . . . . . . . . . 48
EXAMPLE OF MODEL NUMBER . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Most states in the USA an jurisdictions in Canada have laws that require
the use of Carbon Monoxide (CO) alarms with fuel burning products.
Examples of fuel burning products are furnaces, boilers, space heaters,
generators, water heaters, stoves/ranges, clothes dryers, fireplaces,
incinerators, automobiles, and other internal combustion engines. Even
if there are no laws in your jurisdiction requiring a CO Alarm, it’s highly
recommended that whenever any fuel burning product is used in or
around the home or business that the dwelling be equipped with a CO
Alarm(s). The Consumer Product Safety Commission recommends the
use of CO Alarm(s). The CO Alarm(s) must be installed, operated, and
maintained according to the CO Alarm manufacturer’s instructions. For
more information about Carbon Monoxide, local laws, or to purchase a
CO Alarm online, please visit the following website.
https://www.kidde.com.
A200115
Portions of the text and tables are reprinted from 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.
F80CTL & G80CTL
80% AFUE, Two-Stage, Variable–Speed
4–Way Multipoise Gas Furnace
(Series A)
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury and/or
death.
Carbon Monoxide (CO) is a colorless, odorless, and tasteless poisonous
gas that can be fatal when inhaled. Follow all installation, maintenance,
and service instructions. See additional information below regarding
the installation of a CO Alarm.
Use of the AHRI Certified TM Mark indicates
a manufacturer’s participation in the program.
For verification of certification for individual
products, go to www.ahridirectory.org .

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
2
A190045
Fig. 1 – Dimensional Drawing
FURNACE SIZE
A
CABINET WIDTH
B
OUTLET WIDTH
C
TOP AND
BOTTOM FLUE
COLLAR
D
BOTTOM
INLET WIDTH
VENT
CONNECTION
SIZE
SHIP WT.
LB (KG)
0451712 17-1/2 (445) 15-7/8 (403) 11-9/16 (294) 16 (406) 4 (102) 118 (53.5)
0701412 14-3/16 (360) 12-9/16 (319) 9-5/16 (237) 12-11/16 (322) 4 (102) 118 (53.5)
0701716 17-1/2 (445) 15-7/8 (403) 11-9/16 (294) 16 (406) 4 (102) 126 (57.1)
0702120 21 (533) 19-3/8 (492) 13-5/16 (338) 19-1/2 (495) 4 (102) 147 (66.7)
0901716 17-1/2 (445) 15-7/8 (403) 11-9/16 (294) 16 (406) 4 (102) 134 (60.8)
0902120 21 (533) 19-3/8 (492) 13-5/16 (338) 19-1/2 (495) 4 (102) 153 (69.4)
1102120 21 (533) 19-3/8 (492) 13-5/16 (338) 19-1/2 (495) 4 (102) 156 (70.7)
1352422 24-1/2 (622) 22-7/8 (581) 15-1/16 (383) 23 (584) 4 (102)*
*. 135 size furnace require a 5 or 6-in. (127 or 152 mm) vent. Use a vent adapter between furnace and vent stack. See Installation Instructions for complete installation
requirements.
169 (76.6)
U.S. ECCN: Not Subject to Regulation (N.S.R.)
SD5523-4 REV. B
NOTE: ALL DIMENSIONS IN INCH (MM)

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
3
SAFETY CONSIDERATIONS
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 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
literature, on tags, and on labels attached to or shipped with furnace and
other safety precautions that may apply.
These instructions cover minimum requirements and conform to existing
national standards and safety codes. In some instances, these instructions
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.
Wear safety glasses, protective clothing and work gloves. Have fire
extinguisher available during start-up and adjustment procedures and
service calls.
This is the safety-alert symbol . When you see this symbol on the
furnace 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 a hazard which could result in personal
injury or death. CAUTION is used to identify hazards 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.
The following additional safety considerations should be followed for
gas furnaces:
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.
9. The furnace may be used for construction heat provided that the
furnace installation and operation complies with the first
CAUTION in the LOCATION section of these instructions.
10. These Multipoise Gas-Fired Furnaces are CSA (formerly A.G.A.
and C.G.A.) design-certified for use with natural and propane gases
(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. A CSA (A.G.A.
and C.G.A.) listed accessory gas conversion kit is required to
convert furnace for use with propane gas.
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 in. (914 mm) horizontally
from the furnace. See NFPA 90B or local code for further
requirements.
13. These furnaces SHALL NOT be installed directly on carpeting, tile,
or any other combustible material other than wood flooring. In
downflow installations, factory accessory floor base MUST be used
when installed on combustible materials and wood flooring. Special
base is not required when this furnace is installed on manufacturer’s
Coil Assembly Part No. END4X, ENW4X or coil casing model
number NAEA. See Fig. 2 for clearance to combustible
construction information.
WARNING
!
FIRE, EXPLOSION, ELECTRICAL SHOCK, AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in dangerous operation,
personal injury, death, or property damage.
Improper installation, adjustment, alteration, service, maintenance, or
use can 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.
CAUTION
!
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in unit component damage.
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
!
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.

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
4
INTRODUCTION
A10269
Fig. 2 – Clearances to Combustibles
The 4-way multipoise Category I fan-assisted furnace is CSA (formerly
A.G.A. and C.G.A.) 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.
This furnace is designed for minimum continuous return-air temperature
of 60°F (15°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.
A06745
Fig. 3 – Return Air Temperature
A02054
Fig. 4 – Prohibit Installation on Back
A93044
Fig. 5 – Installation in a Garage
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
NFPA 54/ANSI Z223.1 and the Installation Standards, Warm Air
Heating and Air Conditioning Systems ANSI/NFPA 90B.
General Installation
Current 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
Section 9.3 NFPA 54/ANSI Z223.1, Air for Combustion and Ventilation.
WARNING
!
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. 4.
60
80 / 27 C
/ 16 C
WARNING
!
FIRE, INJURY OR DEATH 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 in. (457 mm) above the
floor. 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 NFPA 54/ANSI Z223.1, see
Fig. 5.
18-IN. (457.2 mm)
MINIMUM TO BURNERS

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
5
Duct Systems
Air Conditioning Contractors Association (ACCA) Manual D, Sheet
Metal and Air Conditioning Contractors National Association
(SMACNA), or American Society of Heating, Refrigeration, and Air
Conditioning Engineers (ASHRAE) 2001 Fundamentals Handbook
Chapter 34 or 2000 HVAC Systems and Equipment Handbook Chapters
9 and 16.
Acoustical Lining and Fibrous Glass Duct
Current edition of SMACNA and NFPA 90B as tested by UL Standard
181 for Class I Rigid Air Ducts.
Gas Piping and Gas Pipe Pressure Testing
NFPA 54/ANSI Z223.1; Chapters 5, 6, and 7 and National Plumbing
Codes.
Electrical Connections
National Electrical Code (NEC) ANSI/NFPA70.
Venting
NFPA 54/ANSI Z223.1; Chapters 12 and 13.
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS PROCEDURE
1. Disconnect all power to the furnace. Multiple disconnects may be
required. DO NOT TOUCH THE CONTROL OR ANY WIRE
CONNECTED TO THE CONTROL PRIOR TO DISCHARGING
YOUR BODY’S ELECTROSTATIC 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) may also
be used to prevent ESD damage. LOCATION
GENERAL
This multipoise furnace is shipped in packaged configuration. Some
assembly and modifications are required when used in any of four
applications, see in Fig. 6.
CAUTION
!
FURNACE RELIABILITY HAZARD
Failure to follow this caution may result in unit component damage.
Electrostatic discharge can affect electronic components. Take
precautions 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
!
PERSONAL INJURY AND/OR PROPERTY
DAMAGE HAZARD
Improper use or installation of this furnace may result in premature
furnace component failure. This gas furnace may be used for heating
buildings under construction provided that:
– The furnace is permanently installed with all electrical wiring, piping,
venting 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.
– The air temperature rise is within the rated rise range on the furnace
rating plate, and the gas input rate has been set to the nameplate 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.
WARNING
!
CARBON MONOXIDE POISONING / COMPONENT
DAMAGE 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.

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
6
A02097
Fig. 6 – Multipoise Orientations
NOTE: For high-altitude installations, the high-altitude conversion kit
MUST be installed at or above 5500 ft. (1676 M) above sea level. Obtain
high-altitude conversion kit from your area authorized distributor.
This furnace must:
• be installed so the electrical components are protected from water.
• not be installed directly on any combustible material other than
wood flooring (refer to SAFETY CONSIDERATIONS).
• be located close to the chimney or vent and attached to an air
distribution system. Refer to Air Ducts section.
• be provided ample space for servicing and cleaning. Always
comply with minimum fire protection clearances shown on the
furnace clearance to combustible construction label.
The following types of furnace installations may require OUTDOOR
AIR for combustion due to chemical exposures:
• Commercial buildings
• Buildings with indoor pools
• Laundry rooms
• Hobby or craft rooms, and
• Chemical 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:
• Permanent wave solutions
• 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
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry 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.
AIR FOR COMBUSTION AND VENTILATION
Provisions for adequate combustion, ventilation, and dilution air must be
provided in accordance with:
• U.S. Installations: Section 9.3 of the NFPA 54/ANSI Z223.1, Air
for Combustion and Ventilation and applicable provisions of the
local building codes.
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.
• Spaces having less than 50 cubic feet per 1,000 Btuh require the
OUTDOOR COMBUSTION AIR METHOD.
• Spaces having at least 50 cubic feet per 1,000 Btuh may use the
INDOOR COMBUSTION AIR, STANDARD or KNOWN AIR
INFILTRATION METHOD.
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 for Outdoors
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.
CAUTION
!
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.
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. 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
the Carbon Monoxide Poisoning Hazard warning in the venting section
of these instructions to determine if an adequate amount of make-up air
is available.
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)

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
7
b. Size openings and ducts per Fig. 7 and Table 1.
c. TWO HORIZONTAL DUCTS require 1 sq. in. (645 sq. mm) 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 Table 1.
d. TWO OPENINGS OR VERTICAL DUCTS require 1 sq. in.
(645 sq. mm) 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 1.
3. ONE OUTDOOR OPENING requires:
a. 1 sq. in. (645 sq. mm) of free area per 3,000 Btuh (734 mm2/kW)
for combined input of all gas appliances in the space per Table 1
and
b. Not less than the sum of the areas of all vent connectors in the
space.
.
NP = Not Permitted
The opening shall commence within 12 in. (300 mm) of the ceiling.
Appliances in the space shall have clearances of at least 1 in. (25 mm)
from the sides and back and 6 in. (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. The Standard Method:
Use the Standard Method if:
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).
Table 1 – Minimum Free Area Required for Each Combustion Air opening of Duct to Outdoors
FURNACE
INPUT
(BTUH)
TWO HORIZONTAL DUCTS SINGLE DUCT OR OPENING TWO OPENINGS OR VERTICAL DUCTS
(1 SQ. IN./2,000 BTUH) (1,100 SQ. MM/KW) (1 SQ. IN./3,000 BTUH) (734 SQ. MM/KW) (1 SQ. IN./4,000 BTUH) (550 SQ. MM/KW)
Free Area of Opening and
Duct
Sq. In. (Sq. mm)
Round Duct Dia.
In. (mm)
Free Area of Opening and
Duct
Sq. In. (Sq. mm)
Round Duct Dia.
In. (mm)
Free Area of Opening and
Duct
Sq. In. (Sq. mm)
Round Duct Dia.
In. (mm)
44,000 22 (14194) 6 (152) 14.7 (9484) 5 (127) 11 (7096) 4 (102)
66,000 33 (21290) 7 (178) 22 (14193) 6 (152) 16.5 (10645) 5 (127)
88,000 44 (28387) 8 (203) 29.3 (18903) 7 (178) 22 (14193) 6 (152)
110,000 55 (35484) 9 (229) 36.7 (23677) 7 (178) 27.5 (17742) 6 (152)
132,000 66 (42580) 10 (254) 44 (28387) 8 (203) 33 (21290) 7 (178)
EXAMPLES: DETERMINING FREE AREA
FURNACE WATER HEATER TOTAL INPUT
110,000 + 30,000 = (140,000 divided by 4,000) = 35.0 Sq. In. for each two Vertical Ducts or Openings
66,000 + 40,000 = (106,000 divided by 3,000) = 35.3 Sq. In. for a Single Duct or Opening
88,000 + 30,000 = (118,000 divided by 2,000) = 59.0 Sq. In. for each of two Horizontal Ducts
Table 2 – Minimum Space Volumes for 100% Combustion, Ventilation, and Dilution from Indoors
OTHER THAN FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
ACH
30 40 50 44 66 88 110 132 154
Space Volume Ft3 (M3)
0.60 1,050
(29.7)
1,400
(39.6)
1,750
(49.5)
1,100
(31.1)
1,650
(46.7)
2,200
(62.2)
2,750
(77.8)
3,300
(93.4)
3,850
(109.0)
0.50 1,260
(35.6)
1,680
(47.5)
2,100
(59.4)
1,320
(37.3)
1,980
(56.0)
2,640
(74.7)
3,300
(93.4)
3,960
(112.1)
4,620
(130.8)
0.40 1,575
(44.5)
2,100
(59.4)
2,625
(74.3)
1,650
(46.7)
2,475
(70.0)
3,300
(93.4)
4,125
(116.8)
4,950
(140.1)
5,775
(163.5)
0.30 2,100
(59.4)
2,800
(79.2)
3,500
(99.1)
2,200
(62.2)
3,300
(93.4)
4,400
(124.5)
5,500
(155.7)
6,600
(186.8)
7,700
(218.0)
0.20 3,150
(89.1)
4,200
(118.9)
5,250
(148.6)
3,300
(93.4)
4,950
(140.1)
6,600
(186.8)
8,250
(233.6)
9,900
(280.3)
11,550
(327.0)
0.10 6,300
(178.3)
8,400
(237.8)
10,500
(297.3)
6,600
(186.8)
9,900
(280.3)
13,200
(373.7)
16,500
(467.2)
19,800
(560.6)
23,100
(654.1)
0.00 NP NP NP NP NP NP NP NP NP
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury or death.
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.

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
8
Use the Known Air Infiltration Rate Method 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 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 Volumes were determined by using the
following equations from the 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, use the following equation:
A04002
2. For fan-assisted appliances such as this furnace, use the following
equation:
A04003
If the following is applied to either equation:
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.)
* Minimum opening size is 100 sq in. (64516 sq. mm) with 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
Then the following requirements apply to both 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
in. (300 mm) of the ceiling and the second opening shall
commence within 12 in. (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 permanent
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 outdoors 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 combustion, permanent
ventilation and dilution of flue gases. However, in buildings with
unusually tight construction, additional air MUST be provided
using the methods described in the Outdoor Combustion Air
Method section.
4. Unusually tight construction is defined as Construction with:
a. Walls and ceilings exposed to the outdoors have a continuous,
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.
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. The minimum 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 2 screws holding bottom 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.
A10273
Fig. 9 – Removing Bottom Closure Panel
Volume Other =21ft3
ACH
I other
1000 Btu/hr
Volume Fan =15ft3
ACH
I fan
1000 Btu/hr
CIRCULATING AIR
DUCTS
6" MIN
(FRONT)Ü
CIRCULATING AIR DUCTS
VENT THROUGH ROOF
1 SQ IN.
PER 1000
BTUH* IN DOOR
ORWALL
12" MAX
1 SQ IN.
PER 1000
BTUH* IN DOOR
ORWALL
12" MAX
UNCONFINED
SPACE
INTERIOR
HEATED
SPACE
CLEARANCE IN FRONT OF COMBUSTION AIR
OPENINGS SHALL BE AT LEAST3 IN.
(305mm)
(152mm)
(305mm)
Bottom
Closure Panel
Bottom Filler Panel

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
9
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.
DOWNFLOW INSTALLATION
NOTE: For downflow applications, this furnace is approved for use on
combustible flooring when any one of the following accessories are
used:
•Downflow combustible factory-approved floor subbase
•Coil model numbers EAM4X, EDM4X, EMA4X, END4X or ENW4X
•Coil casing model number NAEA
1. Determine application being installed from Table 3.
2. Construct hole in floor, see Table 3 and Fig. 10.
3. Construct plenum to dimensions specified, see Table 3 and Fig. 10.
4. If downflow subbase is used, install as, see Fig. 11. If coil model
numbers END4X, ENW4X or coil casing model number NAEA are
used, install as, see Fig. 12.
NOTE: It is recommended 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. Refer
to Duct Flanges (Fig. 17) in the “Air Ducts” section.
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 2 screws holding bottom filler
panel, Fig. 9.
2. Rotate bottom filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
A96283
Fig. 10 – Floor and Plenum Opening Dimensions
A96285
Fig. 11 – Furnace, Plenum, and Subbase Installed on a Combustible
Floor
A08556
Fig. 12 – Furnace, Plenum, and Coil Assembly or Coil Box Installed
on a Combustible Floor
HORIZONTAL INSTALLATION
The furnace can be installed horizontally in an attic or crawlspace 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.
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. 14 and Fig. 15. 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 in. screws
into the side and 2 #8 x in. screws in the bottom of the furnace casing for
each strap, see Fig. 14 and Fig. 15.
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 Fig. 13. For furnaces with 1-in. (25
mm) clearance requirement on side, set furnace on non-combustible
blocks, bricks or angle iron. For crawlspace installations, if the furnace
is not suspended from the floor joists, the ground underneath furnace
must be level and the furnace set in blocks or bricks.
PLENUM
OPENING
C
A
BD
FLOOR
OPENING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
APPROVED
COIL ASSEMBLY
OR
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING

F80CTL & G80CTL: Installation, Start–Up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
10
Roll-Out Protection
Provide a minimum 17-3/4-in. X 22-in. (451 X 559 mm) piece of sheet
metal for flame roll-out protection in front of burner area for furnaces
closer than 12-in. (305 mm) above the combustible deck or suspended
furnaces closer than 12-in. (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. 13 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 bottom 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.
A10164
Fig. 13 – Typical Attic Installation
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) are used without a bottom return air inlet.
Not all horizontal furnaces are approved for side return air connections,
see Fig. 20.
Table 3 – Opening Dimensions - In. (mm)
FURNACE
CASING
WIDTH
IN. (mm)
APPLICATION
PLENUM OPENING FLOOR OPENING
A B C D
14–3/16
(360)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
12-11/16
(322)
21-5/8
(549)
13-5/16
(338)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
12-9/16
(319)
19
(483)
13-3/16
(335)
19-5/8
(498)
Downflow applications on Combustible Flooring
(subbase required)
11-13/16
(284)
19
(483)
13-7/16
(341)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly or coil
box (subbase not required)
12-5/16
(319)
19
(483)
13-5/16
(338)
20
(508)
17–1/2
(445)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
16
(406)
21-5/8
(549)
16-5/8
(422)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
15-7/8
(403)
19
(483)
16-1/2
(419)
19-5/8
(498)
Downflow Applications on Combustible Flooring
(subbase required)
15-1/8
(384)
19
(483)
16-3/4
(425)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly or coil
box (subbase not required)
15-1/2
(394)
19
(483)
16-1/2
(419)
20
(508)
21
(533)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
19-1/2
(495)
21-5/8
(549)
20-1/8
(511)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
19-3/8
(492)
19
(483)
20
(508)
19-5/8
(498)
Downflow Applications on Combustible Flooring
(subbase required)
18-5/8
(473)
19
(483)
20-1/4
(514)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly or coil
box (subbase not required)
19
(483)
19
(483)
20
(508)
20
(508)
24-1/2
(622)
Upflow Applications on Combustible or Noncombustible
Flooring (subbase not required)
23
(584)
21-1/8
(537)
23-5/8
(600)
22-1/4
(565)
Downflow Applications on Noncombustible Flooring
(subbase not required)
22-7/8
(581)
19
(483)
23-1/2
(597)
19-5/8
(498)
Downflow Applications on Combustible Flooring
(subbase required)
22-1/8
(562)
19
(483)
23-3/4
(603)
20-5/8
(600)
Downflow Applications on Combustible Flooring with coil assembly or coil
box (subbase not required)
22-1/2
(572)
19
(483)
23-1/2
(597)
20
(508)
30-IN. (762mm)
MIN WORK AREA
6″ MIN*
TYPE-B
VENT
17 3/4 ″
22 ″
SHEET
METAL
SEDIMENT
TRAP
EQUIPMENT MANUAL
SHUT-OFF GAS VALVE
LINE CONTACT ONLY PERMISSIBLE BETWEEN
LINES FORMED BY INTERSECTIONS OF
THE TOP AND TWO SIDES OF THE FURNACE
JACKET AND BUILDING JOISTS,
STUDS, OR FRAMING.
GAS
ENTRY
17 3/4
″ (451mm) OVERALL
4 3/4 ″ (121mm) UNDER DOOR
1″
(25mm) UNDER FURNACE
EXTEND OUT 12″
(305mm)
FROM FACE OF DOOR
* WHEN USED WITH
SINGLE WALL VENT
CONNECTIONS
UNION
(152mm)
(451mm)
(559mm)