Nordyne Upfl ow/Horizontal, G7XA, G7XA046-A, G7XA061-B, G7XA076-B Installation Instructions Manual

GAS FURNACE

Installation Instructions

G7XA Series - Single Stage High Effi ciency Furnace

80+ AFUE

Upfl ow/Horizontal Model

WARNING:

• PROPOSITION 65 WARNING: This product
contains chemicals known to the state of
California to cause cancer, birth defects or
other reproductive harm.

• This furnace is not approved for installation
in mobile homes. Installing this furnace in
a mobile home could cause fi re, property
damage, and/or personal injury.

ATTENTION INSTALLERS:

It is your responsibility to know this product better than your
customer. This includes being able to install the product according
to strict safety guidelines and instructing the customer on how to
operate and maintain the equipment for the life of the product.
Safety should always be the deciding factor when installing this
product and using common sense plays an important role as well.
Pay attention to all safety warnings and any other special notes
highlighted in the manual. Improper installation of the furnace
or failure to follow safety warnings could result in serious injury,
death, or property damage.

These instructions are primarily intended to assist qualifi ed
individuals experienced in the proper installation of this appliance.
Some local codes require licensed installation/service personnel
for this type of equipment. Please read all instructions carefully
before starting the installation. Return these instructions to the
customer’s package for future reference.

WARNING:

FIRE OR EXPLOSION HAZARD

• Failure to follow safety warnings exactly
could result in serious injury or property
damage.

• Installation and service must be performed
by a qualifi ed installer, service agency or
the gas supplier.

• Do not store or use gasoline or other
fl ammable vapors and liquids in the
vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not

use any phone in your building.

• Leave the building immediately.

• Immediately call your gas supplier from a

neighbors phone. Follow the gas suppliers
instructions.

• If you cannot reach your gas supplier, call

the fi re department.

DO NOT DESTROY THIS MANUAL

KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

2

TABLE OF CONTENTS

SAFETY INFORMATION .............................................4

REQUIREMENTS AND CODES .................................. 4

GENERAL INSTRUCTIONS ........................................ 4

Combustion Air Quality ...........................................4

Clearances to Combustible Materials .....................4

Installation in a Garage ...........................................6

Heating Load ...........................................................6

COMBUSTION AIR REQUIREMENTS .......................6

General Information ................................................6

Installation in a Confi ned Space ..............................6

Air From Inside ...................................................6

Outdoor Air Using a Crawl Space or

Vented Attic ........................................................ 6

Outdoor Air Using Vertical Ducts ........................7

Outdoor Air Using Horizontal Ducts ...................7

Air Directly Through an Exterior Wall .................7

Installation in an Unconfi ned Space ........................ 8

VENTING REQUIREMENTS ........................................8

Category I Venting ...................................................8

CIRCULATING AIR REQUIREMENTS ........................9

Plenums and Air Ducts ............................................ 9

Supply Air Connections ...........................................9

Return Air Connections ...........................................9

Side Return Installations .....................................9

Bottom Return Installations ................................. 9

FURNACE INSTALLATION ....................................... 10

General Requirements .......................................... 10

Upfl ow Installation ................................................. 10

Side Return Air Inlet ......................................... 10

Bottom Return Air Inlet .....................................10

Horizontal Installation ............................................ 10

Bottom Panel Removal ..................................... 10

Alternate Bottom Panel Removal ..................... 11

GAS SUPPLY AND PIPING ....................................... 11

Leak Check ........................................................... 11

High Altitude Application........................................ 12

Conversion to LP/Propane ....................................13

ELECTRICAL WIRING ............................................... 13

Low Voltage Wiring ................................................ 13

Line Voltage Wiring ................................................13

Twinning ................................................................. 14

Grounding .............................................................. 15

START-UP & ADJUSTMENTS ...................................15

Pre-Start Checklist ................................................15

Start-Up Procedures ..............................................15

Verifying and Adjusting Input Rate ........................15

Verifying and Adjusting Temperature Rise .............16

Verifying Burner Operation ....................................16

Verify Operation of the Supply Air Limit Switch .....16

OPERATING SEQUENCE .........................................17

Heating Cycle ........................................................17

Cooling Cycle ........................................................17

Fan Mode ..............................................................17

MAINTENANCE .........................................................17

Air Filters ...............................................................17

Blower Compartment ............................................17

Cleaning of Burners ..............................................18

Cleaning of Flue Passages ...................................18

Heat Exchanger and Burner Maintenance ............18

Lubrication ............................................................18

Vent System ..........................................................19

DESCRIPTION OF COMPONENTS ..........................19

TROUBLESHOOTING ...............................................20

FIGURES AND TABLES ............................................21

Figure 16 - Furnace Dimensions ......................21

Airfl ow Data ...........................................................22

Table 5 - Maximum Airfl ow and Temp Rises .....22

Electrical Information.............................................24

Figure 17 - Wiring Diagram ..............................24

Gas Information .....................................................25

Table 6 - Gas Flow Rates.................................25

Table 7 - Gas Pipe Capacities .........................25

Table 8 - High Altitude Deration Chart for

Natural Gas .......................................26

Table 9 - High Altitude Deration Chart for

Propane Gas .....................................26

Location of Furnace Components .........................27

Figure 18 - Upfl ow/Horizontal Gas Furnace

Components ..................................27

INSTALLATION/PERFORMANCE CHECKLIST .......28

3

SAFETY INFORMATION

Safety markings are used frequently throughout this

manual to designate a degree or level of seriousness and
should not be ignored. WARNING indicates a potentially
hazardous situation that if not avoided, could result in
personal injury or death. CAUTION indicates a potentially
hazardous situation that if not avoided, may result in minor
or moderate injury or property damage.

WARNING:

The safety information listed below must be
followed during the installation, service, and
operation of this furnace. Failure to follow safety
recommendations could result in possible
damage to the equipment, serious per

injury or death

• Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.

• Install this furnace only in a location and position as
specifi ed in Table 1 (page 5).

• Provide adequate combustion and ventilation air to the
furnace space as specifi ed on pages 6 - 8.

• Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only,
as specifi ed on page 8.

• Never test for gas leaks with an open fl ame. Use a
commercially available soap solution to check all
connections (page 11).

• This furnace is designed to operate with a maximum
external pressure rise of 0.5 inches of water column.
Consult Table 5 (pages 22 - 23), and the rating plate
for the proper circulating air fl ow and temperature rise.
NOTE: It is important that the duct system be designed
to handle the desired fl ow rate and temperature rise. An
improperly designed duct system can result in nuisance
shutdowns, and comfort or noise issues.

• When 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 page 9.

• A gas-fi red furnace for installation in a residential garage
must be installed as specifi ed on page 6.

.

sonal

GENERAL INSTRUCTIONS

Combustion Air Quality

CAUTION:

Combustion air must not be drawn from a
corrosive atmosphere.

To maximize heat exchanger life, the combustion air
must be free of chemicals that can form corrosive acidic
compounds in the combustion gases. The recommended
source of combustion air is to use outdoor air. However,
the use of indoor air in most applications is acceptable
except as listed:

• If the furnace is installed in a confi ned space it is
required that the necessary combustion air come from
the outdoors by way of attic, crawl space, air duct, or
direct opening. For installations in confi ned spaces, see
pages 6 - 7 for combustion air requirements.

• Installation in these locations may require outdoor air
for combustion, due to chemical exposures:

Commercial buildings
Buildings with indoor pools
Furnaces installed in laundry rooms
Furnaces installed in hobby or craft rooms
Furnaces installed near chemical storage areas

• Exposure to the following substances in the combustion
air supply may require outdoor air 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 (Perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric Acid
Cements and glues
Antistatic fabric softeners
Masonry acid washing materials

REQUIREMENTS AND CODES

This furnace must be installed in accordance with
these instructions, all applicable local building codes
or the current revision of the International Fuel Gas
Code.

Any additional codes shown are for reference purposes
only and do not necessarily have jurisdiction over local or
state codes. Always consult with local authorities before
installing any gas appliance.

4

Clearances to Combustible Materials

Access for positioning and servicing the unit must be
considered when locating unit. The need to provide
clearance for access to panels or doors may require
clearance distances over and above the requirements.

Allow 24 inches minimum clearance from the front of
the unit. However, 36 inches is strongly recommended.

Specifi c clearance information can be found on the furnace
rating plate.

UPFLOW/HORIZONTAL INSTALLATION CLEARANCES*

Left Side .................0 Inches Back ...........................0 Inches

Right Side ............. 0 Inches Top .............................0 Inches

Vent ...........................1 Inch

*

Allow 24 in. minimum clearance for servicing.

Recommended clearance is 36 in.

†

The IFGC requires that single wall metal vent connectors

must maintain a minimum 5” clearance to combustibles,
including the outer casing of the furnace.

NOTE: This furnace is listed for installation on combustible
or non-combustible fl ooring. However, wood is the only
combustible fl ooring allowed for installation.

Front......................... 4 Inches

Table 1. Minimum Clearances to Combustible Materials

WARNING:

†

TOP

LEFT SIDE

BOTTOM

HORIZONTAL APPLICATION

UPFLOW APPLICATION

RIGHT SIDE

SIDE

TOP

BOTTOM

SIDE

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 with each individual appliance connected to the venting system being
placed in operation, while all other appliances connected to the venting system are not in
operation:

1. Seal any unused openings in the venting system.

2. Inspect the venting system for proper size and horizontal pitch, as required in the National

Fuel Gas Code, ANSI Z223. 1/NFPA 54 or the CSA B149.1, Natural Gas and Propane Installation
Codes and these instructions. Determine that there is no blockage or restriction, leakage,

corrosion and other defi ciencies 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 fi replace 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 fl ame 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 National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/or
CSA B149.1, Natural Gas and Propane Installation Codes.

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, fi replace
dampers and any other gas-fi red burning appliance to their previous conditions of use.

5

Installation in a Garage

WARNING:

Do not place combustible material on or
against the furnace cabinet or within 6 inches
of the vent pipe. Do not place combustible
materials, including gasoline and any other
fl ammable vapors and liquids, in the vicinity
of the furnace.

This Gas-fi red furnace may be installed in a residential
garage with the provision that the burners and igniter
are located no less than 18 inches (457mm) above the
fl oor. The furnace must be located or protected to prevent
physical damage by vehicles.

Heating Load

The ductwork should be appropriately sized to the
capacity of the furnace to ensure its proper airfl ow rating.
For installations above 2,000 ft., the furnace should have
a sea level input rating large enough that it will meet
the heating load after deration for altitude. Excessive

oversizing of the furnace could cause the furnace
and/or vent to fail prematurely.

COMBUSTION AIR REQUIREMENTS

Provisions must be made during the installation of
this furnace that provide an adequate supply of air for
combustion.

Installation In A Confi ned Space

A confi ned space is an area with volume less than 50
cubic feet per 1,000 Btuh of the combined input rates of
all appliances drawing combustion air from that space.
Furnace closets, small equipment rooms and garages are
confi ned spaces. Furnaces installed in a confi ned space
which supply heated air to areas outside the space must
draw return air from outside the space and must have the
return air ducts tightly sealed to the furnace.

NOTE: The required sizing of these openings is determined
by whether inside or outside air is used to support
combustion, the method by which the air is brought to
the space, and by the total input rate of all appliances in
the space. In all cases, the minimum dimension of any
combustion air opening is 3 inches.

Air From Inside
If combustion air is taken from the heated space, the
two openings must each have a free area of at least one
square inch per 1,000 Btuh of total input of all appliances
in the confi ned space, but not less than 100 square
inches of free area (Figure 1). See example.

Example:

If the combined input rate of all appliances is less than or
equal to 100,000 Btuh, each opening must have a free
area of at least 100 square inches. If the combined input
rate of all appliances is 120,000 Btuh, each opening
must have a free area of at least 120 square inches.

General Information

• Instructions for determining the adequacy of an
installation can be found in the current revision of the IFGC.

Consult local codes for special requirements.

CAUTION:

Exhaust fans, clothes dryers, fi replaces and
other appliances that force air from the house
to the outdoors can create a negative pressure
inside the house, resulting in improper furnace
operation or unsafe conditions such as fl ame
roll out. It is imperative that suffi cient air
exchange with the outdoors is provided to
prevent depressurization.

• Air openings on top of the furnace and in closet doors
or walls must never be restricted. If the furnace is
operated without adequate air for combustion, the fl ame
roll-out switch will open, turning off the gas supply to
the burners. This safety device is a manually reset

switch. DO NOT reset or install jumper wires across
this switch to defeat its function without identifying
and correcting the fault condition. If the switch must

be replaced, use only the correct sized part specifi ed
in the Replacement Parts List provided online.

6

Vent or

Chimney

NOTES:
Each opening must
be at least 100 sq. in.
or 1 sq. in. per 1,000
Btuh of total input rating,
whichever is greater.

Openings must start at
no more than 12 inches
from the top and bottom
of the enclosure.

Water
Heater

Total Input Rating

(Btuh)

40,000 100 sq. In 12 inches
60,000 100 sq. In 12 inches

80,000 100 sq. In 12 inches
100,000 100 sq. In 12 inches
120,000 120 sq. In 13 inches
140,000 140 sq. In 14 inches
160,000 160 sq. In 15 inches

Minimum Free Area

(Each Opening)

12" Max.

Furnace

See Notes

12” Max.

See

Notes

Round Duct

Diameter

Figure 1. Combustion Air Drawn from Inside

Outdoor Air from a Crawl Space or Vented Attic
When the openings can freely exchange air with the
outdoors, each opening shall have a minimum free area
of 1 square inch per 4,000 Btuh of total appliance input.

The openings shall exchange directly, or by ducts, with
the outdoor spaces (crawl or attic) that freely exchange
with the outdoors (Figure 2).

Ventilation louvers

Vent or

Chimney

Attic
Insulation

at each end of attic

Outlet air duct must be
at least 1 sq. in. per
4,000 Btuh of total
input rating. Must

Water
Heater

Furnace

extend above attic
insulation

Inlet air duct must be at
least 1 sq. in. per 4,000
Btuh of total input rating.

Crawl Space

Ventilated Louvers for
unheated crawl space

Figure 2. Combustion Air Drawn from a Crawl

Space or Vented Attic

Outdoor Air Using Vertical Ducts
If combustion air is taken from outdoors through vertical
ducts, the openings and ducts must have a minimum
free area of one square inch per 4,000 Btuh of total
appliance input. In installations drawing combustion air
from a ventilated attic, both air ducts must extend above
the attic insulation (Figure 3).

Ventilation Louvers at
each end of attic

Vent or
Chimney

Water
Heater

Total Input Rating

(Btuh)

Attic

Insulation

Furnace

12" Max

Minimum Free Area

(Each Opening)

Outlet Air Duct must
be at least 1 sq. in.
per 4,000 Btuh of
total input rating.

Inlet and Outlet
Ducts must
extend above
attic insulation.

Inlet Air Duct must
be at least 1 sq. in.
per 4,000 Btuh of
total input rating.

Round Duct

Diameter

40,000 100 sq. In 12 inches
60,000 100 sq. In 12 inches

80,000 100 sq. In 12 inches
100,000 100 sq. In 12 inches
120,000 120 sq. In 13 inches
140,000 140 sq. In 14 inches
160,000 160 sq. In 15 inches

Figure 3. Combustion Air Drawn from Outside

Through Vertical Ducts

Outdoor Air Using Horizontal Ducts
If combustion air is taken from outdoors through horizontal
ducts, the openings and ducts must have a minimum free
area of one square inch per 2,000 Btuh of total appliance
input (Figure 4).

Vent or

Chimney

12" Max

-

-

-

-

-

-

-

-

-

-

-

See

Note

-

-

-

-

-

-

-

-

-

12" Max

Total Input Rating

(Btuh)

Water Heater

-

-

-

-

-

-

Air Duct

-

Furnace

-

-

-

-

-

-

-

-

Air Duct

-

Minimum Free Area

(Each Opening)

-

-

-

-

NOTE: Each

-

-

-

-

-

opening to
outside must
be at least 1
sq. in. per 2,000
Btuh of total

-

-

-

-

-

-

input rating.

-

-

-

Round Duct

Diameter

40,000 10 sq. In 5 inches
60,000 15 sq. In 6 inches

80,000 20 sq. In 7 inches
100,000 25 sq. In 8 inches
120,000 30 sq. In 9 inches
140,000 35 sq. In 10 inches
160,000 40 sq. In 10 inches

Figure 4. Combustion Air Drawn from Outside

Through Horizontal Ducts

Air Directly Through An Exterior Wall
If combustion air is provided directly through an exterior
wall, the two openings must each have free area of at
least one square inch per 4,000 Btuh of total appliance
input (Figure 5).

Vent or

12" Max

-

-

-

-

-

-

-

-

-

See

Note

-

-

-

-

-

-

-

-

-

12" Max

Total Input Rating

(Btuh)

40,000 10 sq. In 4 inches

60,000 15 sq. In 5 inches

80,000 20 sq. In 5 inches

100,000 25 sq. In 6 inches
120,000 30 sq. In 6 inches
140,000 35 sq. In 7 inches
160,000 40 sq. In 8 inches

Chimney

Furnace

Water Heater

Minimum Free Area

(Each Opening)

NOTE: Each opening

to outside must be at
least 1 sq. in. per
4,000 Btuh of total
input rating.

Round Duct

Diameter

Figure 5. Combustion Air Drawn from Outside

Through an Exterior Wall

7

Installation In An Unconfi ned Space

An unconfi ned space is an area including all rooms not
separated by doors with a volume greater than 50 cubic
feet per 1,000 Btuh of the combined input rates of all
appliances which draw combustion air from that space.

In general, a furnace installed in an unconfi ned space will
not require outside air for combustion. However, in homes
built for energy effi ciency (low air change rates), it may
be necessary to provide outside air to ensure adequate
combustion and venting, even though the furnace is
located in an unconfi ned space. See example.

Example:
A space with a water heater rated at 45,000 Btuh
input and a furnace rated at 75,000 Btuh requires a
volume of 6,000 cubic feet [50 x (45 + 75) = 6,000] to
be considered unconfi ned. If the space has an 8 foot
ceiling, the fl oor area of the space must be 750 square
feet (6,000 / 8 = 750).

VENTING REQUIREMENTS

WARNING:

Upon completion of the furnace installation,
carefully inspect the entire fl ue system both
inside and outside the furnace to assure it is
properly sealed. Leaks in the fl ue system can
result in serious personal injury or death due
to exposure of fl ue products, including carbon
monoxide.

This furnace must be vented in compliance with the
current revision of the International Fuel Gas Code and
the instructions provided below. Consult local codes for

special requirements.

Category I Venting

This furnace is listed as a Category I vented appliance.
Category I furnaces generally operate with a slight negative
pressure (draft) and must be vented vertically or near
vertically. Additionally it is important to guard against
excessive condensation.

IMPORTANT NOTE: This furnace must never be vented
to a chimney or fl ue that services a fi replace or other
appliance designed to burn solid fuel. If the furnace
vent is to be connected to a chimney serving a fi replace,
the fi replace must be sealed off from the chimney.

WARNING:

Venting into an unlined masonry chimney or
concrete chimney is prohibited. This may result
in improper draft and excess condensation
forming in the chimney.

• This furnace may be vented with a dedicated venting
system or common vented with other Category I
appliances. The vent system dimensions and material
must conform to local Codes.

• The venting system should be designed to have the
minimum number of elbows or turns. All horizontal runs
shall slope upwards from the furnace at ¼ inch per
running foot of vent. Supports for the vent pipe must
be installed a minimum of every fi ve feet along the
vent run to ensure no displacement after installation.

IMPORTANT NOTE: Under no circumstances shall
any portion of the vent system extend into or pass
through any return air duct, supply air duct, or
plenum.

• Single wall vent connectors may be used under the
limited capacity ranges found in the vent sizing tables.

It is recommended that Type “B” double wall vent
be used for the connector whenever possible. An

existing masonry chimney should be inspected and
relined if necessary.

• Single wall metal vertical vents shall not be used for

Category I venting. The furnace vent, if metal, may be
insulated if local codes allow. Any part of the vent system,
metal vent only, not exposed to weather, but which are
exposed to temperatures below 35° F (1° C) must be
insulated to prevent condensation. All vent insulation
shall be foil backed fi berglass of one inch minimum
thickness.

• Sheet metal fasteners should be used to secure the vent

pipe to the furnace fl ue.

• When an existing furnace is removed from a vent system

serving other appliances, the existing vent system
may no longer be sized to properly vent the remaining
appliances. An improperly sized venting system can result
in the formation of condensate, leakage, or spillage. The
existing vent system should also be checked to make
sure it is in compliance with local codes. If it isn’t, the
vent system must be brought into compliance before
installing the furnace.

• Category I furnace installations must be connected
to a factory built vent complying with a recognized
standard, or a masonry or concrete chimney lined with
a lining material acceptable to the authority having
jurisdiction.

8

CIRCULATING AIR REQUIREMENTS

WARNING:

• Do not allow combustion products to enter the

circulating air supply. Failure to prevent the
circulation of combustion products into the
living space can create potentially hazardous
conditions including carbon monoxide
poisoning that could result in personal injury
or death.

• All return ductwork must be secured to

the furnace with sheet metal screws. For
installations in confi ned spaces, all return
ductwork must be adequately sealed. When
return air is provided through the bottom of
the furnace, the joint between the furnace and
the return air plenum must be air tight.

• The surface that the furnace is mounted on must

provide sound physical support of the furnace
with no gaps, cracks or sagging between the
furnace and the fl oor or platform.

• Return air and circulating air ductwork must

not be connected to any other heat producing
device such as a fi replace insert, stove, etc.
This may result in fi re, explosion, carbon
monoxide poisoning, personal injury, or
property damage.

Plenums and Air Ducts

• Supply and return air must be delivered to the furnace

by duct(s) secured to the furnace casing, running full
size and without interruption.

• Table 5 (pages 22 - 23) contains the maximum airfl ow

and temperature rise data for each furnace input rate.
NOTE: If the maximum airfl ow is 1,600 CFM or more, it
is recommended that two openings be used for return
air on upfl ow furnaces.

• It is recommended that the outlet duct contain a

removable access panel that is accessible when the
furnace is installed in service. The opening shall be of
a size that smoke or refl ected light may be observed
inside the casing to indicate the presence of leaks in
the heat exchanger. The cover for the opening shall be
attached in such a manner as to prevent leaks.

• If outside air is used as return air to the furnace for

ventilation or to improve indoor air quality, the system
must be designed so that the return air is not less than
60° F (15° C) during operation. If a combination of indoor
and outdoor air is used, the ducts and damper system
must be designed so that the return air supply to the
furnace is equal to the return air supply under normal,
indoor return air applications.

• If a cooling system is installed which uses the furnace

blower to provide airfl ow over the indoor coil, the coil

must be installed downstream (on the outlet side) of the
furnace or in parallel with the furnace.

• If a cooling system is installed in parallel with the
furnace, a damper must be installed to prevent chilled air
from entering the furnace and condensing on the heat
exchanger. If a manually operated damper is installed,
it must be designed so that the furnace will not operate
when the damper is in the cooling position or when in
heating position, the cooling system is inoperable.

• It is good practice to seal all connections and joints
with industrial grade sealing tape or liquid sealant.
Requirements for sealing ductwork vary from region
to region. Consult with local codes for specific
requirements.

Supply Air Connections

To attach the supply air duct to the furnace, bend the
furnace fl anges (Figure 16, page 21) upward 90° with
wide duct pliers. Position the duct on top of the furnace
and secure together with sheet metal screws. The screws
must penetrate the sheet metal casing and furnace fl ange.
Tape or seal all seams if required by local code.

Return Air Connections

For upfl ow installations, the return air ductwork may be
connected to the left side, right side, or bottom. The bottom
panel (Figure 16) must be installed for left or right return
air. Do not use the back of the furnace for return air.

Side Return Installations

WARNING:

The solid base of the furnace must be in
place when the furnace is installed with side
return air ducts. Removal of all or part of the
base could cause circulation of combustible
products into the living space and create
potentially hazardous conditions, including
carbon monoxide poisoning that could result
in personal injury or death.

To attach the return air duct to the left or right side of the
furnace, punch out the four knockouts (Figure 16) from the
preferred side of the furnace. Using sharp metal cutters,
cut an opening between all four knockouts to expose
the blower assembly. Position the return air duct over
the opening in the side and secure together with sheet
metal screws. The screws must penetrate the duct and
furnace cabinet.

Bottom Return Installations
The bottom panel (Figure 16) must be removed from the
bottom of the furnace for bottom return air. Refer to pages
10 - 11 for removal instructions. Position the furnace over
the return air duct and secure together with sheet metal
screws. The screws must penetrate the duct and furnace
cabinet.

9

FURNACE INSTALLATION

G7XA series gas furnaces are shipped ready for installation
in the upfl ow or horizontal right or left positions. Access
for positioning and servicing must be considered when
locating the unit. See Table 1 (page 5) for the required
clearances needed to move the furnace to its installation
point (hallways, doorways, etc).

WARNING:

The furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood fl ooring.

General Requirements

• The furnace must be leveled at installation and attached
to a properly installed duct system. Refer to pages
8 - 9 for venting and circulating air requirements

• The furnace must be installed so that all electrical
components are protected from water.

• The furnace must be installed upstream from a
refrigeration system.

Upfl ow Installation

The furnace is shipped with the bottom panel installed. If
furnace is installed horizontally, remove the bottom panel
from the furnace before attaching the duct system. See
Bottom Panel Removal section.

If the furnace will be suspended from the ceiling, assemble
a support frame (Figure 7) using slotted iron channel and
full threaded rod. Fasten the frame together with nuts,
washers, and lockwashers. Secure the support frame to the
rafters with lag bolts. The furnace can also be suspended
using steel straps around each end of the furnace. The
straps should be attached to the furnace with sheet metal
screws and to the rafters with bolts.

If the furnace is to be installed in an attic, it is required that
a drip pan be placed under the furnace. If the installation
is on a combustible platform (Figure 6), it is recommended
that the drip pan extend at least 12 inches past the top
and front of the furnace.

Note: It is recommended for further reduction of fi re hazard
that cement board or sheet metal be placed between the
furnace and the combustible fl oor and extend 12 inches
beyond the front of the door and top of the furnace.

Side Return Air Inlet
This gas furnace is shipped with the bottom panel installed
(Figure 16, page 21). If the upfl ow furnace is installed with
side return air, the bottom panel must not be removed.

Bottom Return Air Inlet
If the furnace is installed where the bottom is the return
air inlet, the bottom panel must be removed. See Bottom
Panel Removal section.

Horizontal Installation

This gas furnace can be installed horizontally in an attic,
basement, crawl space or alcove (Figure 6). It can also
be suspended from a ceiling in a basement or utility
room in either a right to left airfl ow or left to right airfl ow
as shown in Figure 7.

Electrical Supply

Connection

Type “B” Vent

Coil Plenum

Gas Inlet

Combustible
Platform

Figure 6. *XA Horizontal Installation on a Platform

10

Nuts (x2)

Lag

Threaded

Rod

Washer

and

Lockwasher

Nuts (x2)

Bolt

Figure 7. *XA Horizontally Suspended

in Attic or Crawl Space

Bottom Panel Removal

The steps listed below explain how to remove the bottom

panel from the furnace. See Figure 8 (page 11).

1. Remove the door (1) from the blower compartment.

2. Disconnect the blower motor wiring harness (2) from
the control board.

3. Remove two screws (3) securing the blower assembly
(4) to the furnace.

4. Carefully pull the blower assembly (4) out thru the
front of the furnace.

5. Remove all screws (5) securing bottom panel (6) to
bottom of furnace and front brace (7).

6. Lift up and slide bottom panel (6) out through front of
furnace.

7. Reinstall the blower assembly (4) in reverse order.

1

Alternate Bottom Panel Removal

If the bottom panel cannot be removed using the previous
instructions, the steps below are an alternate method for
removing the bottom panel. See Figure 9.

1. Remove the door (1) from the blower compartment .

2. Remove all screws securing the bottom panel (2) to

the front brace (3).

3. Remove two screws (4) securing the furnace cabinet

to the blower deck (5).

4. Remove all screws (6) securing the furnace cabinet

to the bottom panel (2).

5. Remove the screw (7) securing the bottom corner of the

furnace cabinet to the front brace (3).

6. Carefully spread the bottom corner of the furnace

cabinet outwards while sliding the bottom panel (2)
out through the front of the furnace.

7. Reassemble the furnace in reverse order.

3

4

6

Figure 8. Bottom Panel Removal

2

7

5

GAS SUPPLY AND PIPING

All gas piping must be installed in compliance with local
codes and utility regulations.

IMPORTANT NOTES:

• Some local regulations require the installation
of a manual main shut-off valve and ground joint
union external to the furnace as shown in Figure 10
(page 12). The shut-off valve should be readily
accessible for service and/or emergency use.
Consult the local utility or gas supplier for additional
requirements regarding placement of the manual
main gas shut-off.

• Gas piping must never run in or through air ducts,
chimneys, gas vents, or elevator shafts.

• Compounds used to seal joints on gas piping must
be resistant to the actions of LP propane gas.

• The main gas valve and main power disconnect to
the furnace must be properly labeled by the installer
in case emergency shutdown is required.

• A drip leg should be installed in the vertical pipe
run to the unit (Figure 10).

Table 7 (page 25) lists gas pipe capacities for standard
pipe sizes as a function of length in typical applications
based on nominal pressure drop in the line. Table 8
(page 26) contains the orifi ce sizes and manifold pressure
at various altitudes for natural gas installations.

The furnace may be installed for either left or right side
gas entry. A typical gas service hookup is shown in Figure

10. NOTE: When connecting the gas supply, provide

clearance between the gas supply line and the entry hole
in the furnace casing to avoid unwanted noise and/or
damage to the furnace.

4

1

5

7

2

3

Figure 9. Alternate Removal Method

Leak Check

WARNING:

FIRE OR EXPLOSION HAZARD
Never test for gas leaks with an open fl ame.
Check all connections using a commercially
available soap solution. A fi re or explosion

6

may result causing property damage, personal
injury or loss of life. Failure to follow the safety
warnings exactly could result in serious injury,
death or property damage.

After the gas piping to the furnace is complete, all
connections must be tested for gas leaks. This includes
pipe connections at the main gas valve, emergency
shutoff valve and fl exible gas connectors (if applicable).
Apply the soap and water solution on each joint or union
using a small paintbrush. If any bubbling is observed,
the connection is not sealed adequately and must be
retightened. Repeat the tightening and soap check process
until bubbling ceases.

11

IMPORTANT NOTE: When pressure testing gas supply
lines at pressures greater than 1/2 psig (14 inch W.C.),
the gas supply piping system must be disconnected
from the furnace to prevent damage to the gas control
valve. If the test pressure is less than or equal to 1/2
psig (14 inch W.C.), close the manual shut-off valve.

High Altitude Application

The installation of this furnace at altitudes above 2,000
feet must meet the requirements of the International
Fuel Gas Code or local codes. High altitude conversion
of this furnace depends on the installation altitude and
heating value of the gas (at sea level) from your local
gas utility. NOTE: At high altitudes, the heating value is
always lower than heating value at sea level.

The *XA furnace is shipped from the factory with orifi ces
and gas regulator settings for natural gas operation at sea
level. At 2,000 feet, this appliance needs to be derated 4%
per 1,000 feet of altitude. For example, the input needs to

UPFLOW FURNACE

be reduced 8% at 2,000 feet, 12% at 3,000 feet, etc. This
deration is in reference to the input rate and gas heating
value at sea level.

WARNING:

The reduction of input rating necessary for high
altitude installation may only be accomplished
with factory supplied orifi ces. Do not attempt
to drill out orifi ces in the fi eld. Improperly
drilled orifi ces may cause fi re, explosion,
carbon monoxide poisoning, personal injury
or death.

From 2,000 to 5,000 feet, deration may be performed by
adjusting the manifold pressure on the gas valve (see
page 15). Above 5,000 feet, it is necessary to change
both the orifi ce and manifold pressure. Table 8 (page 26)
contains the manifold pressure and orifi ce sizes to use at
various altitudes for natural gas installations.

1

RCYGW

STATUS

24V

See

Note

8

9
8
7

63
5
4

NEUTRALS

FAN

COOL

HEAT

FLAME

63

180

BLOWER

2

120

5

OFF

90

1

4

DELAY

60

L1A
2

1

XFMR

HIGH

LOW

HUM

EAC

MH

ML

L1

1

See

STATUS

FLAME

Note

180
120

OFF

90

DELAY

60

HIGH

LOW

EAC

MH

ML

8

9
8
7

63
5
4

NEUTRALS

RCYGW

24V

FAN

COOL

HEAT

63

BLOWER

2

5

1

4

L1A
2

1

XFMR

HUM

L1

4

3

7

5

2

6

Left Side Entry

ITEM # and COMPONENT

2

6

Right Side Entry

5

3

(1) Automatic Gas Valve

(w/ manual shut-off)

(2) Burner Assembly (3) Dripleg (4) Elbow

(5) Ground Joint Union (6) Manifold (7) Plug (8) Shut - Off Valve

NOTE: Some utilities require Shut- Off Valve to be 4 to 5 feet above fl oor.

12

Figure 10. Typical Gas Connection

When deration is completed, it is required that you measure
the gas input rate. This may be accomplished in the usual
way, by clocking the gas meter and using the local gas
heating value. NOTE: It will be necessary to check the
input rate using the actual heating value, (which will be
less) because the atmospheric pressure is also lower
than sea level. See Verifying and Adjusting the Input Rate
(page 15).

Conversion to LP/Propane

WARNING:

The furnace was shipped from the factory
equipped to operate on natural gas. Conversion
to LP/propane gas must be performed by
qualifi ed service personnel using a factory
supplied conversion kit. Failure to use the
proper conversion kit can cause fi re, explosion,
property damage, carbon monoxide poisoning,
personal injury, or death.

Conversion to LP/propane is detailed in the installation
instructions provided with the conversion kit. Generally,
this will require the replacement of the burner orifi ces and
the spring found under the cap screw on the pressure
regulator.

The LP/Propane Gas Sea Level and High Altitude
Conversion Kit (P/N 904923) is an approved conversion
kit for LP/propane conversion at altitudes between zero
and 10,000 ft. above sea level. If the installation is above
2,000 ft., refer to Table 9 (page 26) to determine the correct
orifi ce size and manifold pressure. When conversion is
complete, verify the manifold pressure and input rate are
correct as listed in Table 9. Please follow the instructions

provided with the kit.

A/C CONDENSING UNIT

CONDENSING UNIT
CONTROL BOX

EXPANSION PORT
(MOTOR CONNECTION)

COM

ROOM

THERMOSTAT

Connect

R & W

For Heating

Only

NOTE: The “Y” terminal
on the control board
must be connected to
the thermostat for
proper cooling mode
operation.

FIELD WIRING

LOW VOLTAGE

CONNECTION

R
C
Y
G

W

NEUTRAL LEADS

3 AMP
FUSE

9
8
7

6
5
4

NEUTRALS

Figure 11. Low Voltage Field, Four-wire

Heating/Cooling Applications

RCYGW

63
5
4

3

2

1

2

1

24V

SPEED

SELECT

FAN

HUM

STATUS

COOL

HEAT

FLAME

BLOWER

OFF

DELAY

XFMR

HIGH

EAC

MH

ML

L1

ELECTRONIC AIR CLEANER

HUMIDIFIER TAP

RED

GREEN
YELLOW

180
120

90
60

LOW

MOTOR SPEED TAPS
(NOT USED)

ELECTRICAL WIRING

Electrical connections must be in compliance with all
applicable local codes. For electrical requirements, refer
to Table 2 (page 14) or the furnace nameplate.

WARNING:

To avoid electric shock, personal injury, or death,
turn off the electric power at the disconnect
or the main service panel before making any
electrical connections.

CAUTION:

Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation. Verify
proper operation after servicing.

NOTE: If replacing any of the original wires supplied with

the furnace, the replacement wire must be copper wiring
and have a temperature rating of at least 105° F (40° C).

Low Voltage Wiring

The thermostat must be installed according to the
instructions supplied by the thermostat manufacturer. The
thermostat must not be installed on an outside wall or
any other location where its operation may be adversely
affected by radiant heat from fi replaces, sunlight, or lighting
fi xtures, and convective heat from warm air registers or
electrical appliances.

Low voltage connections (24 VAC) from the thermostat
are wired to the terminal strip on the integrated control
in the furnace. See Figure 11 for proper connections for
heating only (two-wire) and heating/cooling (four-wire)
applications. Recommended minimum wire gauge for
thermostat wiring is shown in Table 2.

NOTE: Set the heat anticipator according to the instructions

supplied by the thermostat manufacturer. To determine the
heat anticipator setting, perform the following steps:

1. Add the current draw of the system components; or

2. Measure the current fl ow on the thermostat R-W circuit
after the circulating blower motor has started.

Line Voltage Wiring

It is recommended that the line voltage (230 VAC) to
the furnace be supplied from a dedicated branch circuit
containing the correct fuse or circuit breaker for the
furnace (Table 2).

IMPORTANT NOTES:
An electrical disconnect must be installed readily
accessible from and located within sight of the
furnace. Any other wiring methods must be acceptable
to authority having jurisdiction.

13

Furnace

Model

Number

G7XA

046-23A 46,000

061-24B 61,000

076-24B 76,000

Furnace

Input

(Btu/hr)

Cabinet

Width

(in.)

¼

14
17 ½

17

½

Nominal

Electrical

Supply

Maximum
Operating

Voltage

Minimum

Operating

Voltage

Maximum

Furnace

Amperes

Minimum

Wire

Gauge

230-50-1 230 208 6.3 14 15

230-50-1 230 208 9.7 14 20

230-50-1 230 208 9.7 14 20

092-35C 92,000 21 230-50-1 230 208 11.7 14 20

107-45D 107,000

24

230-50-1 230 208 15.2 12 30

½

** Time-delay fuses or HACR-type circuit breakers are required.

Recommended Thermostat Wire Length

Thermostat Wire Gauge

2 - wire

(Heating only)

4 or 5 wire

(Heating/Cooling)

24 55 ft. 25 ft.
22 90 ft. 45 ft.
20 140 ft. 70 ft.
18 225 ft. 110 ft.

Table 2. Wire Length and Voltage Specifi cations

Maximum

Fuse or Circuit

Breaker Amps**

Field Supplied

Fused Service

Panel

Black (Hot)

White (Neutral)

Field Supplied
Disconnect w/in
Sight of Furnace

Black

White

Green or Bare

(Ground)

Ground

Field Line Voltage Wiring

Figure 12. Line Voltage Field Wiring

Proper line voltage polarity must be maintained in
order for the control system to operate correctly.
Verify the incoming neutral line is connected to the
white wire and the incoming “hot” line is connected
to the black wire. The furnace will not operate unless
the polarity and ground are properly connected as
shown in Figure 12 or the wiring diagram label inside
of the control door.

Junction Box (may be int. or ext.
to the furnace). These connections
can be made in the field supplied
disconnect at the furnace.

Black

White

Ground

Field Supplied

Panel Connector

Factory Line Voltage Wiring

THERMOSTAT

WGYR

R
C

G
W

FURNACE

Black

White

Y

BOARD

Ground

R
C
Y
G

W

FURNACE

BOARD

Twinning

The control boards on fi xed speed furnaces are capable
of being twinned to other furnaces of the same series,
only if the following criteria are met:

• The circuit boards are the same.

• The thermostat wires and the 1/4 inch thick quick-connect
terminals marked “TWIN” (Figure 13) on the furnace
controls must be connected together.

• The fuses must remain installed on each board.

• Twinned furnaces must be properly grounded according
to local codes.

14

MOTOR

BOARD

TWIN TERMINAL

A/C

UNIT

MOTOR
BOARD

TWIN TERMINAL

FURNACE 1 FURNACE 2

Figure 13. Twinning

IMPORTANT NOTE: G7 furnaces equipped with
variable speed iSEER™ motors may not be twinned
under any circumstances.

Grounding

WARNING:

To minimize personal injury, the furnace cabinet
must have an uninterrupted or unbroken electrical
ground. The controls used in this furnace
require an earth ground to operate properly.
Acceptable methods include electrical wire or

conduit approved for ground service. Do not
use gas piping as an electrical ground!

START-UP AND ADJUSTMENTS

Pre-Start Check List

√ Verify the polarity of the connections are correct, the

line voltage power leads are securely connected and
the furnace is properly grounded.

√ Verify the thermostat wires (R, W, Y, and G) are

securely connected to the correct leads on the
terminal strip of the circuit board.

√ Verify the gas line service pressure does not exceed

10.0 inches of W.C., and is not less than 4.5 inches
W.C. for natural gas. For LP gas the line service
pressure must not exceed 14 in. W.C., and must not
be less than 11.0 in. W.C.

√ Verify the roll-out and manual reset switch is closed.

If necessary, press the red button to reset a switch.
If a switch reopens on startup, DO NOT reset the
switch without identifying and correcting the fault
condition. DO NOT install a jumper wire across a

switch to defeat its function.

√ Verify the blower door is in place, closing the door

switch in the line voltage circuit.

√ Verify the gas line has been purged and all connections

are leak free.

Start-up Procedures

Do not perform these steps until all of the checks in the
previous steps have been completed:

1. Set the thermostat to the lowest setting.

2. Turn off all electrical power to the furnace.

3. Follow the Operating Instructions on the label attached

to the furnace.

4. Set the thermostat above room temperature and verify

the Operating Sequence (Page 17).

5. After 5 minutes of operation, set the thermostat

below room temperature and verify steps 9 - 10 of
the Operating Sequence.

1. Shut off all other gas fi red appliances.

2. Start the furnace and run it for at least 3 minutes.

3. Measure the time (in seconds) required for the gas
meter to complete one revolution.

4. Convert the time per revolution to cubic feet of gas
per hour using Table 6 (page 25).

5. Multiply the gas fl ow rate in cubic ft per hr by the
heating value of the gas in Btu per cubic ft to obtain
the input rate in Btuh. See example.

Example:

• Time for 1 revolution of a gas meter with a 1
cubic ft dial = 40 seconds.

• From Table 6 read 90 cubic ft gas per hr.

• Local heating value of the gas (obtained from
gas supplier) = 1,040 Btu per cubic ft.

• Input rate = 1,040 x 90 = 93,600 Btuh.

6. The manifold pressure must be set to the appropriate
value for each installation by a qualifi ed installer,
service agency or the gas supplier.

WARNING:

Do not attempt to drill the gas orifi ces. Use
only factory supplied orifices. Improperly
drilled orifi ces may cause fi re, explosion,
carbon monoxide poisoning, personal injury
or death.

a.) Obtain the manifold pressure setting required for

this installation by referring to Table 8 (page 26)
for Natural Gas or Table 9 for Propane gas

b.) Remove the regulator capscrew (Figure 14) from

the INLET side of the regulator.

c.) Slowly turn the adjustment screw inside the

regulator to obtain the appropriate manifold
pressure. NOTE: Turning the screw clockwise
increases the pressure and turning the screw
counter-clockwise decreases the pressure. To
prevent backing the screw all the way out from
the valve, turn the screw slowly.

d.) Replace and tighten the regulator capscrew over

the adjustment screw.

Capscrew

Verifying and Adjusting Input Rate

The input rate must be verifi ed at installation to prevent
over-fi ring of the furnace. The input rate must not exceed

the specifi cation listed on the furnace rating plate. At
altitudes above 2,000 feet, it must not exceed that on
the rating plate less 4% for each 1,000 feet. To determine

the exact input rate, perform these steps:

Figure 14. Regulator Capscrew

15

Verifying and Adjusting Temperature Rise

Confi rm the temperature rise through the furnace is
within the limits specifi ed on the furnace rating plate. Any
temperature rise outside the specifi ed limits could result
in premature failure of the heat exchanger.

1. Place thermometers in the retur n and supply air stream
as close to the furnace as possible. The thermometer
on the supply air side must be shielded from direct
radiation from the heat exchanger to avoid false
readings.

2. Adjust all registers and duct dampers to the desired
position and run the furnace for 10 to 15 minutes before
taking any temperature readings. The temperature
rise is the difference between the supply and return
air temperatures.

For typical duct systems, the temperature rise will fall
within the limits specifi ed on the rating plate with the blower
speed at the factory recommended setting. If the measured
temperature rise is outside the specifi ed limits, it may be
necessary to change the speed of the blower.

The *XA furnace is equipped with a multi-speed motor.
Heating, cooling, and fan speed selection is made by
moving the switch located on the motor control board
(Figure 15). NOTE: Lowering the blower speed will
increase the temperature rise and a higher blower speed
will decrease the temperature rise.

W1

PORT

RCY1

DHUM

TWIN

FAN SPEED

1 2 345 6 7

OFF ON

HEAT

THERMOSTAT

COOL

TERMINAL TO

CONNECTION

TWIN FURNACES

8

NOT USED

CONNECTION TO

FURNACE CONTROL

RED

STATUS

GREEN

BOARD

NOT USED

EXPANSION

MOTOR WIRE

HARNESS

Verifying Burner Operation

CAUTION:

The door over the burners may only be open
for inspection purposes only. The door must be
installed during unattended operation.

1. Remove the burner compartment door.

2. Set the thermostat above room temperature and observe
the ignition sequence. The burner fl ame should carry

over immediately between all burners without lifting
off, curling, or fl oating. The fl ames should be blue,
without yellow tips.

3. After validating the fl ame, change the thermostat setting
to below room temperature.

4. Verify the burner fl ame is completely extinguished.

5. Replace the burner compartment door.

Verify Operation of the Supply Air Limit Switch

A properly functioning limit switch should turn off the
gas valve when the return is blocked (time depends on
how well the return air is blocked). The circulating air and
combustion blowers should continue to run when the limit
switch opens.

1. Verify the blower door is securely mounted in place

and that there is power to the furnace.

2. Block the return airfl ow to the furnace by installing

a close-off plate in place of or upstream of the
fi lter(s).

3. Set the thermostat above room temperature and

observe the Operating Sequence (page 17).

4. Remove the close-off immediately after the limit

switch opens. If the furnace continues to operate
with no return air, set the thermostat below room
temperature, shut off the power to the furnace, and
replace the limit switch.

Figure 15. Motor Control Board

16

OPERATING SEQUENCE

The operating sequences for the heating, cooling,
and fan modes are described below. Refer to the fi eld
and furnace wiring diagrams: (Figure 11, page 13),
(Figure 12, page 14), and (Figure 17, page 24).

Heating Cycle

1. The thermostat calls for heat by energizing the W
terminal with 24VAC.

2. The control verifi es if the pressure switch is open.

3. If the pressure switch is open, the control energizes
the inducer and waits for the pressure switch to close.
The pressure switch must close within 10 seconds.

4. The control runs the inducer for a 30 second pre-purge.

5. The control energizes the igniter output for the
appropriate warm-up time limit.

6. The control energizes the gas valve for 3 seconds.

7. If the fl ame proved and ignites the gas, the control de­energizes the igniter. The gas valve and inducer remains
energized. The control goes to blower on delay.

8. If fl ame is present, the control energizes the blower
on the selected HEAT speed 30 seconds after the
gas valve opened. The gas valve and inducer remain
energized.

9. When the thermostat demand for heat is satisfi ed, the
control de-energizes the gas valve. The inducer output
remains on for a 30 second post-purge period.

10. Blower off timing begins when the thermostat is
satisfi ed. The control will operate at the selected HEAT
speed of 60, 90, 120, or 180 seconds. If the blower
off delay jumper is not present, the fan should still
operate for 120 seconds at the selected HEAT speed.
The Indoor blower motor is de-energized after a blower
off delay as selected by the movable jumper.

Cooling Cycle

1. The thermostat calls for cooling by energizing the Y
terminal with 24VAC.

2. The control energizes the blower (in cooling speed)
and sends 24VAC to the contactor in the condensing
unit.

3. When the thermostat removes the call for cooling,
the contactor in the outdoor condensing unit is de­energized and the control continues to run the fan for
a period of 60 seconds.

Fan Mode

• When the thermostat energizes the G terminal for

continuous fan (without calling for heat or cooling), the
indoor fan is energized on the selected FAN speed.

• If a call for cooling occurs during continuous fan, the

blower will switch over to the selected COOL speed.

• If the W terminal receives a call for heat during continuous

fan, the blower will de-energize.

• A call for fan is ignored while in lockout.

MAINTENANCE

WARNING:

These maintenance instructions are primarily
intended to assist qualified technicians
experienced in the proper maintenance and
operation of this appliance.

To prevent electric shock, personal injury, or
death, disconnect the electric power before
performing any maintenance.

Proper maintenance is most important to achieve the best
performance from a furnace. Follow these instructions for
years of safe, trouble free operation.

• Always replace the doors on the furnace after servicing
or cleaning/changing the fi lters. Do not operate the
furnace without all doors and covers in place.

• Verify the thermostat is properly installed and is not
being affected by drafts or heat from lamps or other
appliances.

• To achieve the best performance and minimize
equipment failure it is recommended that a yearly
maintenance checkup be performed. At a minimum,
this check should include the following items.

Air Filter(s)

WARNING:

Never operate the furnace without a fi lter in
place. Dust and lint in the return air can build
up on internal components, resulting in loss
of effi ciency, equipment damage, and possible
fi re.

Air fi lter(s) are not supplied with the furnace as shipped
from the factory. The installer must provide a high velocity
fi lter and rack for a fi lter in the return air duct adjacent to
the furnace, or in a return air grill to the furnace.

NOTE: It is recommended that fi lters be cleaned or
replaced monthly. New or newly renovated homes may
require more frequent changing until the construction dust
has minimized. Filters designed to remove smaller particles
such as pollen, may require additional maintenance.
Filters for side return and bottom return applications are
available from most local distributors.

Blower Compartment

Dirt and lint can create excessive loads on the motor
resulting in higher than normal operating temperatures
and shortened service life. It is recommended that the
blower compartment be cleaned of dirt or lint that may
have accumulated in the compartment or on the blower
and motor as part of the annual inspection.

17

Cleaning of Burners

If the burners must be cleaned, follow steps 1-12. Refer
to Figure 18 (page 27) for component locations.

1. Shut off gas supply to the furnace at the meter or at
a manual valve in the supply piping.

2. Turn off all power to the furnace and set the thermostat
to its lowest setting.

3. Remove the burner door from the furnace.

4. Turn the gas control switch to the OFF position.

CAUTION:

Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.

5. Disconnect the wires from the gas valve, igniter, fl ame
sensor, and fl ame rollout switch.

6. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.

7. Remove the piping between the gas valve and the
ground-joint union. (If applicable).

8. Remove all screws securing the burner assembly to
the furnace.

9. Carefully remove the burner assembly from the furnace.

DO NOT DAMAGE THE IGNITER WHILE REMOVING
THE BURNER ASSEMBLY.

10. Inspect the burners for accumulated dust or debris.
If necessary carefully clean them with a soft wire
brush and a vacuum cleaner. DO NOT DAMAGE THE

IGNITER WHILE CLEANING THE BURNER.

11. Replace all the parts in reverse order that they were
removed.

12. Follow the lighting instructions found on the furnace
door to return the furnace to operation. Verify proper
operation after servicing.

Cleaning Of Flue Passages

If the fl ue passages must be cleaned, follow the steps
below. Refer to Figure 18 for component locations.

1. Shut off the gas supply to the fur nace either at the meter
or at the manual valve in the gas supply piping.

2. Turn off all power to the furnace and set the thermostat
to the lowest temperature setting.

3. Remove the blower door from the furnace.

4. Turn the gas control switch to the OFF position.

5. Disconnect the wires from the gas valve, fl ame sensor,
inducer, fl ame roll-out switch, limit switch, pressure
switch and igniter.

6. Remove the silicone rubber tube from the inducer.

7. Using two wrenches, separate the ground-joint union
in the gas supply piping at the furnace.

8. Remove the piping between the gas valve and the
ground-joint union. (If applicable).

9. Remove all screws securing the burner assembly to
the furnace.

10. Carefully remove the burner assembly from the
furnace. DO NOT DAMAGE THE IGNITER WHILE

REMOVING THE BURNER ASSEMBLY.

11. Remove all screws securing the inducer assembly

to the vent pipe running out of the furnace.

12. Remove all screws securing the inducer assembly

to the collector pan.

13. Carefully remove the inducer assembly and

combustion tube assembly from the furnace.

14. Remove all screws securing the collector pan to the

furnace.

15. Remove the collector pan and gasket from the

furnace.

16. Attach a round wire brush to a length of high grade

stainless steel cable. Attach the other end of the
cable to a variable speed reversible drill. Slowly insert
the cable into the top portion of the heat exchanger.
Operate the drill alternating between forward and
reverse, working the cable in and out several times
to obtain suffi cient cleaning. Repeat this sequence
for each heat exchanger tube.

17. Remove all loosened debris from the heat exchanger

tubes using a vacuum cleaner.

18. Using a bright light, check the condition of the upper

and lower sections of the heat exchanger tubes.

19. Inspect the burners for accumulated dust or debris.

If burners must be cleaned, see Cleaning of Burners
section.

20. Replace all the parts in reverse order that they were

removed.

21. Check gaskets for damage and replace if needed.

22. Follow the lighting instructions found on the furnace

door to return the furnace to operation. Verify proper
operation after servicing.

Lubrication

The bearings in the blower motor and inducer blower used
in these furnaces are pre-lubricated and sealed by the
manufacturer. No further oiling of the bearings is required
for the life of the motor.

Heat Exchanger and Burner Maintenance

The furnace should operate for many years without
soot buildup in the fl ue passageways, however, the fl ue
passageways, the vent system, and the burners should be
inspected and cleaned (if required) by a qualifi ed service
technician annually to ensure continued safe operation.
Particular attention must be given to identify deterioration
from corrosion or other sources.

18

WARNING:

Holes in the vent pipe or heat exchanger can
cause combustion products to enter the home.
Replace the vent pipe or heat exchanger if leaks
are found. Failure to prevent the circulation
of combustion products into the living space
can create potentially hazardous conditions
including carbon monoxide poisoning that
could result in personal injury or death.

Vent System

Check the vent pipe and/or chimney to ensure that it is not
corroded or blocked by debris. Any corroded section of vent
pipe must be replaced, and any obstruction or blockage
must be removed prior to operating the furnace.

DESCRIPTION OF COMPONENTS

The descriptions below are various functional components
that affect the operation and shutting down of the furnace.
Some of these components and their locations are shown
in Figure 18 (page 27). Refer to the Operating Sequence
section (page 17) for additional component information.

If any component of the furnace must be replaced, use
only factory authorized replacement parts specifi ed in the
Replacement Parts List provided online.

Blower Limit Switch

Blower switches prevent operation when blower is not
operational.

Flame Sensor

The fl ame sensor verifi es when a fl ame has carried over
from the igniter to the opposite end burner. If no fl ame is
detected, the furnace will shut down within 4 seconds.

Flame Roll-Out Switch

The fl ame roll-out switch verifi es that the burner fl ames
are drawn into the heat exchanger tubes. If the burner
fl ames are not properly drawn into the heat exchanger, the
fl ame roll-out switch will close the gas valve and initiate
the shutdown cycle.

Gas Valve

The gas valve controls the fl ow of gas to the burners.
When the gas valve is energized it automatically opens
and regulates the gas pressure in the manifold.

Inducer Assembly

The inducer assembly vents products of combustion to
the outside.

Pressure Switch

The pressure switch verifi es that the inducer is drawing
the combustion gases through the heat exchanger. If
the fl ame is not properly drawn into the heat exchanger
tube, the rollout switch or the fl ame sensor will shut the
furnace down.

Supply Air Limit Switch

The supply air limit switch prevents the air temperature
leaving the furnace from exceeding the maximum
allowable outlet air temperature.

19

TROUBLESHOOTING

If the furnace fails to operate check the following:

• Is the thermostat operating properly?

• Are the blower compartment door(s) in place?

• Is the furnace disconnect closed?

• Has the circuit breaker tripped or the control board fuse burned
open?

• Is the gas turned on?

• Are any manual reset switches open?

• Is the fi lter dirty or plugged?

• Is the fl ame sensor coated? (Remove and clean with steel wool).

• Are all the LED’s on the furnace control board constantly ON? If
not, refer to Tables 3 - 4 or the wiring diagram (Figure 17, page

24) to determine fault condition

IMPORTANT NOTE: The furnace will lock out after 5 failed
attempts for ignition and will try again every hour if the call
for heat remains.

• If the Inducer Blower is operating, and items above have been
verifi ed, check the Blower Limit Switch (Figure 18, page 27) and
reset if necessary.

• If the furnace operates when the Blower Limit Switch is reset,
contact a qualifi ed service technician to identify and repair the
problem.

• If the furnace still doesn’t operate, check the Flame Roll-out
Switches (Figure 18, page 27) and reset if necessary.

• If the furnace operates when the Flame Rollout Switch is reset,
contact a qualifi ed service technician to identify and repair the
problem.

Diagnostic Description

Control Fault (No Power) Off Off

L1/Neutral Polarity Fault Flash Flash

1 Hour Lockout Alternating Flash

Normal Operation On On

Pressure Switch Closed Fault On Flash

Pressure Switch Open Fault Flash On

Open Limit Switch Fault Flash Off

Diagnostic Description Yellow LED

Low Flame Sensor Signal Continuous Flash

Flame Present On

Green

LED

Red
LED

Table 3. Furnace Control Board

Fault Conditions

Diagnostic Description

Control Fault (No Power) Off Off

Normal Operation On On

Motor Fault On Flash

Twin Fault (no motor fault) Flash On

Communications Fault Flash Flash

Red
LED

Green

LED

Table 4. Motor Control Board

Fault Conditions

20

FIGURES AND TABLES

*XA 80+ Upfl ow/Horizontal Furnace

34

D

FRONT BRACE

BOTTOM

23 ½

½

PA NE L

BOTTOM VIEW

25 ⅜

1 ⅝ X 3 ½

HOLE FOR GAS

Ø ⅞ HOLE FOR

ELECTRIC

23

ACCEPTS 4”

TYPE B

VENT PIPE

23

C

TOP VIEW

FLANGES

B

19

Ø ⅞ HOLE FOR

THERMOSTAT

Ø ⅞ HOLE FOR

ELECTRIC

29 ½

*XA

Model #’s

046E-23A
061E-24B
076E-24B
092E-35C
107E-45D

22 ½

Dim.

14

17

“A”

Dim.

“B”

¼

10

½

11

21 14

½

24

15

22 ¼

25
21 ⁄

1

⅝ X 3 ½ X 45°

HOLE FOR GAS

4 KNOCKOUTS

(BOTH SIDES)

¾

¾

¼

Dim.

12

15

19

“C”

Dim.

“D”

⅝

12

⅞

16

⅜

19

22 ⅞ 23

15

⅞

⅛

⅞
⅛

22 ¾

LEFT SIDE

28

A

Figure 16. Furnace Dimensions

1

RIGHT SIDE

23

1

¼

21

AIRFLOW DATA

*G7XA UPFLOW / HORIZONTAL GAS FURNACE

Model

Number

XA046-A 46,000

XA061-B 61,000

XA076-B 76,000

Heating

Input

(Btuh)

Motor Switch

Setting

1/5 2/6 3/7 4/8 CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise

0000

1000

0 1 0 0 600 57 555 61 510

1 1 0 0 705 48 670 51 635 54 600 57

0 0 1 0 775 44 740 46 705 48 665 51

1 0 1 0 900 38 870 39 835 41 800 43 765 45 730 47 695 49 660 52

0 1 1 0 950 36 920 37 890 38 855 40 825 41 795 43 765 45 730 47

1 1 1 0 1000 34 970 35 940 36 910 37 880 39 850 40 820 42 790 43

0 0 0 1 1075 32 1045 33 1015 34 985 35 960 35 925 37 900 38 870 39

1 0 0 1 1110 31 1080 32 1055 32 1025 33 1000 34 975 35 945 36 920 37

0 1 0 1 1170 29 1140 30 1115 31 1090 31 1060 32 1035 33 1010 34 985 35

1 1 0 1 1210 28 1185 29 1160 29 1130 30 1105 31 1080 32 1055 32 1025 33

0 0 1 1 1520 22 1225 28 1200 28 1175 29 1150 30 1120 30 1095 31 1070 32

1 0 1 1 1305 26 1280 27 1255 27 1230 28 1205 28 1180 29 1155 30 1130 30

0 1 1 1 1350 25 1230 28 1305 26 1285 27 1260 27 1240 27 1215 28 1195 29

1 1 1 1 1440 24 1400 24 1365 25 1230 28 1295 26 1255 27 1220 28 1185 29

0000

1000

0 1 0 0 600 74 555 80 510

1 1 0 0 705 63 670 66 635 70 600 74

0 0 1 0 775 57 740 60 705 63 665 67

1 0 1 0 900 49 870 51 835 53 800 56 765 58 730 61 695 64 660 67

0 1 1 0 950 47 920 48 890 50 855 52 825 54 795 56 765 58 730 61

1 1 1 0 1000 44 970 46 940 47 910 49 880 51 850 52 820 54 790 56

0 0 0 1 1075 41 1045 43 1015 44 985 45 960 46 925 48 900 49 870 51

1 0 0 1 1110 40 1080 41 1055 42 1025 43 1000 44 975 46 945 47 920 48

0 1 0 1 1170 38 1140 39 1115 40 1090 41 1060 42 1035 43 1010 44 985 45

1 1 0 1 1210 37 1185 38 1160 38 1130 39 1105 40 1080 41 1055 42 1025 43

0 0 1 1 1520 29 1225 36 1200 37 1175 38 1150 39 1120 40 1095 41 1070 42

1 0 1 1 1305 34 1280 35 1255 35 1230 36 1205 37 1180 38 1155 38 1130 39

0 1 1 1 1350 33 1230 36 1305 34 1285 35 1260 35 1240 36 1215 37 1195 37

1 1 1 1 1440 31 1400 32 1365 33 1230 36 1295 36 1255 35 1220 36 1185 38

0000

1000

0100

1100

0 0 1 0 775 73 740 76 705 80 665 85

1 0 1 0 900 63 870 65 835 67 800 70 765 74 730 77 695 81 660 85

0 1 1 0 950 59 920 61 890 63 855 66 825 68 795 71 765 74 730 77

1 1 1 0 1000 56 970 58 940 60 910 62 880 64 850 66 820 69 790 71

0 0 0 1 1075 52 1045 54 1015 55 985 57 960 59 925 61 900 63 870 65

1 0 0 1 1110 51 1080 52 1055 53 1025 55 1000 56 975 58 945 60 920 61

0 1 0 1 1170 48 1140 49 1115 50 1090 52 1060 53 1035 54 1010 56 985 57

1 1 0 1 1210 47 1185 48 1160 49 1130 50 1105 51 1080 52 1055 53 1025 55

0 0 1 1 1520 37 1225 46 1200 47 1175 48 1150 49 1120 50 1095 51 1070 53

1 0 1 1 1305 43 1280 44 1255 45 1230 46 1205 47 1180 48 1155 49 1130 50

0 1 1 1 1350 42 1230 46 1305 43 1285 44 1260 45 1240 45 1215 46 1195 47

1 1 1 1 1440 39 1400 40 1365 41 1230 46 1295 43 1255 45 1220 46 1185 48

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

External Static Pressure (in.w.c.)

Table 5. Maximum Airfl ow and Temperature Rises (°F) - Upfl ow/Horizontal Gas Furnaces

22

G7XA UPFLOW / HORIZONTAL GAS FURNACES

Model

Number

XA092-C 92,000

XA107-D 107,000

Heating

Input

(Btuh)

Notes:

Motor Switch

Setting

1/5 2/6 3/7 4/8 CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise

00001125611040
10001205 57 1120 61 1040 66
01001305 52 1225 56 1150 59 1070 64
11001430 48 1350 50 1270 54 1190 57 1110 61 1030 66
00101525 45 1450 47 1375 50 1300 52 1225 56 1150 59 1075 63 1000 68
10101620 42 1540 44 1465 47 1390 49 1315 52 1240 55 1165 58 1090 63
01101695 40 1620 42 1545 44 1465 47 1390 49 1315 52 1235 55 1160 59
11101770 39 1700 40 1630 42 1555 44 1485 46 1410 48 1340 51 1265 54
00011875 36 1805 38 1730 39 1655 41 1580 43 1510 45 1435 47 1340 51
10011905 36 1840 37 1775 38 1710 40 1640 42 1575 43 1510 45 1445 47
01011980 34 1910 36 1845 37 1780 38 1715 40 1650 41 1580 43 1515 45
11012025 34 1960 35 1895 36 1830 37 1765 39 1700 40 1635 42 1570 43
00112085 33 2025 34 1960 35 1900 36 1840 37 1775 38 1715 40 1655 41
10112135 32 2070 33 2010 34 1945 35 1880 36 1815 38 1750 39 1685 40
01112200 31 2145 32 2090 33 2035 33 1980 34 1925 35 1870 36 1820 37
11112280 30 2225 31 2170 31 2115 32 2065 33 2010 34 1955 35 1900 36

00001395 57 1350 59 1305 61 1260 63 1210 66 1165 68
10001465 54 1420 56 1375 58 1330 60 1290 61 1245 64 1200 66
01001555 51 1510 52 1470 54 1425 56 1380 57 1340 59 1295 61 1250 63
11001625 49 1585 50 1540 51 1500 53 1460 54 1415 56 1375 58 1335 59
00101690 47 1650 48 1610 49 1570 50 1530 52 1485 53 1445 55 1405 56
10101760 45 1715 46 1670 47 1625 49 1575 50 1530 52 1485 53 1440 55
01101835 43 1790 44 1745 45 1695 47 1650 48 1605 49 1555 51 1510 52
11101885 42 1840 43 1790 44 1745 45 1700 47 1655 48 1610 49 1565 51
00011945 41 1900 42 1850 43 1805 44 1760 45 1710 46 1665 48 1620 49
10011950 41 1905 42 1860 43 1820 44 1775 45 1735 46 1690 47 1650 48
01012075 38 2030 39 1990 40 1945 41 1900 42 1855 43 1810 44 1770 45
11012125 37 2085 38 2040 39 2000 40 1955 41 1910 41 1870 42 1825 43
00112170 37 2130 37 2090 38 2045 39 2005 40 1965 40 1925 41 1880 42
10112215 36 2180 36 2140 37 2105 38 2070 38 2035 39 2000 40 1965 40
0111 2225 36 2165 37 2100 38 2040 39
1111 2170 37 2120 37 2065 38

1. Motor Switch Settings are for heating speeds using HEAT switches 1, 2, 3, & 4 and cooling speeds using COOL
switches 5, 6, 7, & 8.

2. Two openings are recommended for airfl ows above 1,600 CFM if the fi lter(s) is (are) adjacent to the furnace.

3. Data is shown without fi lter.

4. Temperature rises in the table are approximate. Actual temperature rises may vary.

5. Temperature rises that are shaded in grey are for reference only. These conditions are not recommended.

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

External Static Pressure (in.w.c.)

Table 5. Continued

23

ELECTRICAL INFORMATION

112233445566778899

Green LED Red LED

Control Fault (No Power) Off Off

L1 / Neutral Polarity Fault Flash Flash

1 Hour Lockout

Normal Operation On On

Pressure Switch Closed Fault On Flash

Pressure Switch Open Fault Flash On

Open Limit Switch Fault Flash Off

Low Flame Sensor Signal

Flame Present

Diagnostic Description

FAULT CONDITIONS

Continuous Flash

On

Alternating Flash

Yellow LED
Diagnostic Description

BLUE

SPEED

W

W

TORQUE

NONE

HP(PWM)

COMMON

TX

RX

GND

C

R

LIMIT

SWITCH

GND

PWM

C

RX

NONE

MODE

R

TX

W

BLUE

MOTOR

LIMIT

BOARD

CONTROL

SWITCH

RED

BLACK

COOL

FAN SPEED

1185-200

BLUE

HEAT

R C Y1 TWINDEHUM

BLACKBLACK

3/4 AND 1 HP

MOTORS ONLY

YELLOW

GREEN

BROWN

TX

RX

TX

RX

R

R

RED

C

C

BLUE

ORANGE

W

COM

W

COM

WD#710807-C

BLACK

WHITE

BLACK

WHITE

208/240 V

24 V

GREY

RED

SWITCH

THERMOSTAT

SINGLE STAGE

ORANGE

PRESSURE

SWITCH

PRESSURE

If any of the original wire as supplied with the

furnace must be replaced, it must be replaced

with wiring material having a temperature

rating of at least 105° C.

Use copper conductors only.

MODELS)

(ON SELECT

CONDENSATE

For 80+ and 90+ Export Furnaces

Refer to the installation instructions

provided with the kit for the proper

heating and cooling speeds for your

application.

BLACK

WHITE

1234

1234

TO OUTDOOR UNIT

W
RX
TX
COM
C
R

HIGH

MHMLLOW

FAN

COM

24V

RCYGW

3 AMP FUSE

WHITE

BLACK

ORANGE

ORANGE

HEAT

COOL

RED

GREEN

YELLOW

RELAY

BLWR OFF

GREEN

FLAME SENSOR

123

456

789

RED

LOW

ML

MH

HIGH

EAC

L1

XFMR

HUM

L1A

123

NEUTRALS

456

BLACK

BLACK

YELLOW

YELLOW

1

2

1

2

IGNITOR

GAS

VALVE

BLACK

BLACK

1

2

1

2

C

INDUCER

R

BLACK

BLUE

BLUE BLUE BLUE

BLACK

WHITE

SUPPLY

AIR LIMIT

FLAME

ROLLOUT

LIMIT

VENT

BLACK

WHITE

(ON SELECT MODELS)

DOOR

SWITCH

GREEN

GROUND

BLACK 208/240V

WHITE (NEUTRAL)

LEGEND:

FIELD WIRING

LOW VOLTAGE

HIGH VOLTAGE

24

Figure 17. Wiring Diagram for G7XA Upfl ow Furnace

TIME FOR

ONE REVOLUTION

(SECONDS)

10 360 1,800 3,600 66 55 273 545
12 300 1,500 3,000 68 53 265 529
14 257 1,286 2,571 70 51 257 514
16 225 1,125 2,250 72 50 250 500
18 200 1,000 2,000 74 49 243 486
20 180 900 1,800 76 47 237 474
22 164 818 1,636 78 46 231 462
24 150 750 1,500 80 45 225 450
26 138 692 1,385 82 44 220 439
28 129 643 1,286 84 43 214 429
30 120 600 1,200 86 42 209 419
32 113 563 1,125 88 41 205 409
34 106 529 1,059 90 40 200 400
36 100 500 1,000 92 39 196 391
38 95 474 947 94 38 191 383
40 90 450 900 96 38 188 375
42 86 429 857 98 37 184 367
44 82 409 818 100 36 180 360
46 78 391 783 102 35 176 353
48 75 375 750 104 35 173 346
50 72 360 720 106 34 170 340
52 69 346 692 108 33 167 333
54 67 333 667 110 33 164 327
56 64 321 643 112 32 161 321
58 62 310 621 114 32 158 316
60 60 300 600 116 31 155 310
62 58 290 581 118 31 153 305
64 56 281 563 120 30 150 300

GAS INFORMATION

GAS FLOW RATES (CUBIC FEET PER HOUR)

CUBIC FEET PER REVOLUTION

OF GAS METER

1 5 10 1 5 10

TIME FOR

ONE REVOLUTION

(SECONDS)

CUBIC FEET PER REVOLUTION

OF GAS METER

Table 6. Gas Flow Rates

CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)

FOR NATURAL GAS (SPECIFIC GRAVITY - 0.60)

NOMINAL BLACK

IRON PIPE

DIAMETER (IN.)

1/2 130 90 75 65 55 50 45 40

3/4 280 190 150 130 115 105 95 90

1 520 350 285 245 215 195 180 170

1 1/4 1,050 730 590 500 440 400 370 350

1 1/2 1,600 1,100 890 760 670 610

The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas fl ow required by the
furnace. To determine the cubic feet per hour of gas fl ow required by the furnace, divide the input rate of the furnace by the
heating value (from gas supplier) of the gas.

10 20 30 40 50 60 70 80

Cubic Feet Per Hour Required =

LENGTH OF PIPE RUN (FT)

NOTES

Input To Furnace (Btu/hr)

Heating Value of Gas (Btu/Cu. Ft.)

Table 7. Black Iron Gas Pipe Capacities

25

ALTITUDE ABOVE

SEA LEVEL

0 to 1,999 FT

2,000 to 2,999 FT

3,000 to 4,999 FT

5,000 to 5,999 FT

6,000 to 7,999 FT

8,000 to 10,000 FT

NATURAL GAS

INPUT (BTU)

46,000 61,000 76,000 107,000

49 49 49 49 ORIFICE SIZE

10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

49 49 49 49 ORIFICE SIZE

9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

49 49 49 49 ORIFICE SIZE

8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

51 51 51 51 ORIFICE SIZE

10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

51 51 51 51 ORIFICE SIZE

9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

51 51 51 51 ORIFICE SIZE

8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

Table 8. High Altitude Deration - Natural Gas

ALTITUDE ABOVE

SEA LEVEL

0 to 1,999 FT

2,000 to 2,999 FT

3,000 to 4,999 FT

5,000 to 5,999 FT

6,000 to 7,999 FT

8,000 to 10,000 FT

PROPANE

INPUT (BTU)

46,000 61,000 76,000 107,000

57 57 57 57 ORIFICE SIZE

10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

57 57 57 57 ORIFICE SIZE

9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

57 57 57 57 ORIFICE SIZE

8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

59 59 59 59 ORIFICE SIZE

10.0 10.0 10.0 10.0 MANIFOLD PRESSURE

59 59 59 59 ORIFICE SIZE

9.0 9.0 9.0 9.0 MANIFOLD PRESSURE

59 59 59 59 ORIFICE SIZE

8.5 8.5 8.5 8.5 MANIFOLD PRESSURE

Table 9. High Altitude Deration - Propane Gas

26

LOCATION OF FURNACE COMPONENTS

ITEM COMPONENT NAME

Blower Assembly

1.

Blower Door Switch

2.

Burner Assembly

3.

Flame Roll-Out Switch

4.

Flame Sensor

5.

Furnace Control Board

6.

Gas Manifold

7.

Gas Valve

8.

14

9

2

10

11

8

9
8
7

63
5
4

NEUTRALS

6

RCYGW

STATUS

24V

FAN

COOL

HEAT

FLAME

63

180

BLOWER

2

120

5

OFF

90

1

4

DELAY

60

L1A
2

1

XFMR

HIGH

LOW

HUM

EAC

MH

ML

L1

13

5

7

Igniter

9.

Inducer Assembly

10.

Main Air Limit Switch

11.

Motor Control Board

12.

Pressure Switch

13.

Transformer

14.

Figure 18.

4

Upfl ow/Horizontal Gas Furnace

3

1

12

27

INSTALLATION/PERFORMANCE CHECK LIST

INSTALLER NAME:

CITY _______________ STATE _____________

INSTALLATION ADDRESS:

CITY _______________ STATE _____________

UNIT MODEL #

UNIT SERIAL # ____________________________

Minimum clearances per
Table 1 (page 5)?

Has the owner’s information
been reviewed with the
home-owner?

YES NO

YES NO

ELECTRICAL SYSTEM:

Electrical connections tight? YES NO

Line voltage polarity correct? YES NO

Supply Voltage: ______________________ VOLTS

Has the thermostat been
calibrated?

Is the thermostat level? YES NO

Is the heat anticipator setting
correct?

YES NO

YES NO

GAS SYSTEM:

Gas Type: (circle one)

Gas pipe connections leak
tested?

Gas Line Pressure: __________________ (in - W.C.)

Is there adequate fresh
air supply for combustion
and ventilation?

Natural

Gas

YES NO

YES NO

Propane

Has the literature package
been left near the
furnace?

YES NO

Installation Altitude: ____________________ (FT.)

Deration Percentage: ___________________ (%)

Furnace Input: _______________________ (Btuh)

Supply Air Temperature: ________________ (° F)

Return Air Temperature: ________________ (° F)

Temperature Rise: ____________________ (° F)

VENTING SYSTEM:

Vent free from restrictions? YES NO

Filter(s) secured in place? YES NO

Filter(s) clean? YES NO

Flue connections tight? YES NO

Is there proper draft? YES NO

O’Fallon, MO

¢708910«¤

708910B

708910B (Replaces 708910A)

Specifi cations and illustrations subject to change

without notice or incurring obligations.

Printed in U.S.A. (07/09)