Lennox 80G1DF, A80DF Installation Instructions Manual

INSTALLATION INSTRUCTIONS

A80DF & 80G1DF

Warm Air Gas Furnace

Downflow Air Discharge

This manual must be left with the homeowner for future reference.

This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in
manuals, be alert to the potential for personal injury or death.

CAUTION

As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.

WARNING

Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal injury
or loss of life. Installation and service must be performed
by a licensed professional installer (or equivalent), service
agency or the gas supplier.

TABLE OF CONTENTS

Unit Dimensions ............................................................ 2

A80DF & 80G1DF Parts Arrangement .......................... 3

A80DF & 80G1DF Gas Furnace ................................... 4

Shipping and Packing List ............................................ 4

Safety Information ......................................................... 4

Use of Furnace as a Construction Heater .................... 5

General ......................................................................... 6

Combustion, Dilution, Ventilation Air ............................. 6

Setting Equipment ........................................................ 9

Filters .......................................................................... 12

Duct System ................................................................ 12

Venting ........................................................................ 12

Gas Piping .................................................................. 21

*506528-01*

Electrical ..................................................................... 22

Unit Start-Up ............................................................... 27

Heating Sequence of Operation ................................. 28

Gas Pressure Adjustment ........................................... 28

Control Settings .......................................................... 28

High Altitude ................................................................ 29

Other Unit Adjustments ............................................... 29

Service ........................................................................ 31

Planned Service .......................................................... 34

Control Diagnostic Codes ........................................... 34

Troubleshooting .......................................................... 34

Repair Parts List ......................................................... 35

Manufactured By

Allied Air Enterprises, Inc.

A Lennox International, Inc. Company

215 Metropolitan Drive

West Columbia, SC 29170

506528-01 Page 1 of 37Issue 1035

A80DF & 80G1DF Unit Dimensions - inches (mm)

FRONT VIEW

Model

A801DF/80G1DF

045-08
045-12
070-08
070-12

090-12
090-16

110-12
110-16
110-20

135-20

in.

14-1/2

17-1/2

21

24-1/2

SIDE VIEW

A

mm

368

446

533

622

13-3/8

16-3/8

19-7/8

23-3/8

B

in.

mm

340

416

504

546

19-1/2

C

in.

13

16

23

mm

330

406

495

584

in.

4-3/4

6-1/4

9-3/4

D

mm

121

159

8

203

248

506528-01Page 2 of 37 Issue 1035

BLOWER ASSEMBLY

CONTROL BOX

FLUE CHASE

A80DF & 80G1DF

Expanded View

INTERNAL FLUE
PIPE ASSEMBLY

BURNER BOX ASSEMBLY

CABINET

HEAT EXCHANGER

COMBUSTION AIR INDUCER

GAS VALVE

ACCESS PANEL

506528-01 Page 3 of 37Issue 1035

Figure 1

A80DF & 80G1DF Gas Furnace

The A80DF & 80G1DF gas furnace is shipped ready for
installation in the downflow position.

The furnace is equipped for installation in natural gas
applications. A conversion kit (ordered separately) is required
for use in propane/LP gas applications.

This unit can be installed as either a Direct Vent or a
Non-Direct Vent gas central furnace

NOTE: In Direct Vent installations, combustion air is taken
from outdoors and flue gases are discharged outdoors. In
Non-Direct Vent installations, combustion air is taken from
indoors and flue gases are discharged outdoors.

Shipping and Packing List

1 - Assembled Gas Furnace
1 - Bag assembly containing the following:

2 - Screws
3 - Wire nuts
1 - Snap bushing
1 - Snap Plug
1 - Wire tie
1 - Vent warning label
1 - Owner’s manual and warranty card

Check equipment for shipping damage. If you find any
damage, immediately contact the last carrier.

Please refer to the technical specification sheets for available
accessories.

Safety Information

CAUTION

As with any mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.

Certifications

These units are CSA International certified to ANSI Z21.47.

In the USA, installation of gas furnaces must conform with
local building codes. In the absence of local codes, units
must be installed according to the current National Fuel Gas
Code (ANSI-Z223.1). The National Fuel Gas Code is
available from the following address: American National

Standards Institute, Inc., 11 West 42nd Street, New York,
NY 10036.

Clearances

Adequate clearance must be made around the air openings
into the vestibule area. In order to ensure proper unit
operation, combustion and ventilation air supply must be
provided according to the current National Fuel Gas Code.
Vent installations must be consistent with the venting tables
(in this instruction) and applicable provisions of local building
codes.

This furnace is CSA International certified for installation
clearances to combustible material as listed on the unit
nameplate and in the tables in figures 8 and 10. Accessibility
and service clearances must take precedence over fire
protection clearances.

DANGER

DANGER OF EXPLOSION!

There are circumstances in which odorant used with LP/
Propane gas can lose its scent. In case of a leak, LP/
Propane gas will settle close to the floor and may be difficult
to smell. An LP/Propane leak detector should be installed
in all LP applications.

WARNING

Improper installation, adjustment, alteration, service or
maintenance can cause property damage, personal injury
or loss of life. Installation and service must be performed
by a licensed professional installer (or equivalent), service
agency or the gas supplier.

NOTE: For installation on combustible floors, the furnace
shall not be installed directly on carpeting, tile, or other
combustible material other than wood flooring.

Installed Locations

For installation in a residential garage, the furnace must be
installed so that the burner(s) and the ignition source are
located no less than 18 inches (457 mm) above the floor.
The furnace must be located or protected to avoid physical
damage by vehicles. When a furnace is installed in a public
garage, hangar, or other building that has a hazardous
atmosphere, the furnace must be installed according to
recommended good practice requirements and current
National Fuel Gas Code.

506528-01Page 4 of 37 Issue 1035

Temperature Rise

NOTE: Furnace must be adjusted to obtain a temperature

rise within the range specified on the unit nameplate. Failure
to do so may cause erratic limit operation and may result in
premature heat exchanger failure.

This furnace may be installed in alcoves, closets, attics,
basements, garages, and utility rooms in the upflow or
horizontal position.

This furnace design has not been certified for installation in
mobile homes, recreational vehicles, or outdoors.

This furnace must be installed so that its electrical
components are protected from water.

Installed in Combination with a Cooling Coil

When this furnace is used with cooling units, it shall be
installed in parallel with, or on the upstream side of, cooling
units to avoid condensation in the heating compartment. See
Figure 2. With a parallel flow arrangement, a damper (or
other means to control the flow of air) must adequately
prevent chilled air from entering the furnace. If the damper
is manually operated, it must be equipped to prevent
operation of either the heating or the cooling unit, unless it
is in the full HEAT or COOL setting. See Figure 2.

Heating Unit Installed Parallel to Air Handler Unit

Use of Furnace as a Construction Heater

These units are not recommended for construction heating
during any phase of construction. Very low return air
temperature, harmful vapors and operation of the unit with
clogged or misplaced filters will damage the unit.

These units may be used for heating of buildings or structures
under construction, if the following conditions are met:

• The vent system must be permanently installed per these
installation instructions.

• A room thermostat must control the furnace. The use
of fixed jumpers that will provide continuous heating is
not allowed.

• The return air duct must be provided and sealed to the
furnace.

• Return air temperature range between 60°F (16°C) and
80°F (27°C) must be maintained.

• Air filters must be installed in the system and must be
maintained during construction.

• Air filters must be replaced upon construction
completion.

Figure 2

When installed, this furnace must be electrically grounded
according to local codes. In addition, in the United States,
installation must conform with the current National Electric
Code, ANSI/NFPA No. 70. The National Electric Code (ANSI/
NFPA No. 70) is available from the following address:

National Fire Protection Association
1 Battery March Park
Quincy, MA 02269

NOTE: This furnace is designed for a minimum continuous
return air temperature of 60° F (16°C) or an intermittent
operation down to 55° F (13°C) dry bulb for cases where a
night setback thermostat is used. Return air temperature
must not exceed 85° F (29°C) dry bulb.

• The input rate and temperature rise must be set per the
furnace rating plate.

• One hundred percent (100%) outdoor air must be
provided for combustion air requirements during
construction. Temporary ducting may supply outdoor
air to the furnace. Do not connect duct directly to the
furnace. Size the temporary duct following these
instructions in section for Combustion, Dilution and
Ventilation Air in a confined space with air from outside.

• The furnace heat exchanger, components, duct system,
air filters and evaporator coils must be thoroughly
cleaned following final construction clean-up.

• All furnace operating conditions (including ignition, input
rate, temperature rise and venting) must be verified
according to these installation instructions.

506528-01 Page 5 of 37Issue 1035

General

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

In addition to the requirements outlined previously, the
following general recommendations must be considered
when installing one of these furnaces:

• Place the furnace as close to the center of the air
distribution system as possible. The furnace should also
be located close to the chimney or vent termination point.

• Do not install the furnace where drafts might blow directly
into it. This could cause improper combustion.

• Do not block the furnace combustion air openings with
clothing, boxes, doors, etc. Air is needed for proper
combustion and safe unit operation.

• When the furnace is installed in an attic or other insulated
space, keep insulation away from the furnace.

Combustion, Dilution & Ventilation Air

In the past, there was no problem in bringing in sufficient
outdoor air for combustion. Infiltration provided all the air
that was needed. In today’s homes, tight construction
practices make it necessary to bring in air from outside for
combustion. Take into account that exhaust fans, appliance
vents, chimneys, and fireplaces force additional air that could
be used for combustion out of the house. Unless outside
air is brought into the house for combustion, negative
pressure (outside pressure is greater than inside pressure)
will build to the point that a downdraft can occur in the furnace
vent pipe or chimney. As a result, combustion gases enter
the living space creating a potentially dangerous situation.

In the absence of local codes concerning air for combustion
and ventilation, use the guidelines and procedures in this
section to install this furnaces to ensure efficient and safe
operation. You must consider combustion air needs and
requirements for exhaust vents and gas piping.

NOTE: The Commonwealth of Massachusetts stipulates
these additional requirements:

• Gas furnaces shall be installed by a licensed plumber
or fitter only.

• The gas cock must be “T handle” type.

• When a furnace is installed in an attic, the passageway

to and service area surrounding the equipment shall be
floored.

WARNING

Product Contains Fiberglass Wool.

Disturbing the insulation in this product during
installation, maintenance, or repair will expose you to
fiberglass wool. Breathing this may cause lung cancer.
(Fiberglass wool is known to the State of California to
cause cancer.)

Fiberglass wool may also cause respiratory, skin, and
eye irritation.

To reduce exposure to this substance or for further
information, consult material safety data sheets available
from address shown below, or contact your supervisor.

Allied Air Enterprises, Inc.
215 Metropolitan Drive
West Columbia, SC 29170

A portion of this information has been reprinted with
permission from the National Fuel Gas Code (ANSI-Z223.1).
This reprinted material is not the complete and official
position of the ANSI on the referenced subject, which is
represented only by the standard in its entirety.

WARNING

Insufficient combustion air can cause headaches,
nausea, dizziness or asphyxiation. It will also cause
excess water in the heat exchanger resulting in rusting
and premature heat exchanger failure. Excessive
exposure to contaminated combustion air will result in
safety and performance related problems. Avoid
exposure to the following substances in the combustion
air supply:

Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine base 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
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials

506528-01Page 6 of 37 Issue 1035

All gas fired appliances require air for the combustion
process. If sufficient combustion air is not available, the
furnace or other appliances will operate inefficiently and
unsafely. Enough air must be provided to meet the needs
of all fuelburning appliances and appliances such as exhaust
fans which force air out of the house. When fireplaces,
exhaust fans, or clothes dryers are used at the same time
as the furnace, much more air is necessary to ensure proper
combustion and to prevent a downdraft. Insufficient air
causes incomplete combustion which can result in carbon
monoxide.

In addition to providing combustion air, fresh outdoor air
dilutes contaminants in the indoor air. These contaminants
may include bleaches, adhesives, detergents, solvents and
other contaminants which can corrode furnace components.

Equipment in Confined Space - All Air From Inside

The requirements for providing air for combustion and
ventilation depend largely on whether the furnace is installed
in an unconfined or a confined space.

Unconfined Space

An unconfined space is an area such as a basement or
large equipment room with a volume greater than 50 cubic
feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the
combined input rating of all appliances installed in that space.
This space also includes adjacent rooms which are not
separated by a door. Though an area may appear to be
unconfined, it might be necessary to bring in outdoor air for
combustion if the structure does not provide enough air by
infiltration. If the furnace is located in a building of tight
construction with weather stripping and caulking around the
windows and doors, follow the procedures in the air from
outside section.

Confined Space

A confined space is an area with a volume less than 50
cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the
combined input rating of all appliances installed in that space.
This definition includes furnace closets or small equipment
rooms.

When the furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space
containing the furnace, the return air must be handled by
ducts which are sealed to the furnace casing and which
terminate outside the space containing the furnace. This is
especially important when the furnace is mounted on a
platform in a confined space such as a closet or small
equipment room. Even a small leak around the base of the
unit at the platform or at the return air duct connection can
cause a potentially dangerous negative pressure condition.
Air for combustion and ventilation can be brought into the
confined space either from inside the building or from outside.

NOTE: Each opening shall have a free area of at least one square
inch per 1,000 Btu (645 mm² per .29 kW) per hour of the total input
rating of all equipment in the enclosure, but not less than 100 square
inches (64546 mm²).

Figure 3

Air from Inside

If the confined space that houses the furnace adjoins a space
categorized as unconfined, air can be brought in by providing
two permanent openings between the two spaces. Each
opening must have a minimum free area of 1 square inch
(645 mm2) per 1,000 Btu (.29 kW) per hour of total input
rating of all gas fired equipment in the confined space. Each
opening must be at least 100 square inches (64516 mm2).
One opening shall be within 12 inches (305 mm) of the top
of the enclosure and one opening within 12 inches (305 mm)
of the bottom. See Figure 3.

Air from Outside

If air from outside is brought in for combustion and ventilation,
the confined space must have two permanent openings. One
opening shall be within 12 inches (305 mm) of the top of the
enclosure and one opening within 12 inches (305 mm) of
the bottom. These openings must communicate directly or
by ducts with the outdoors or spaces (crawl or attic) that
freely communicate with the outdoors or indirectly through
vertical ducts. Each opening shall have a minimum free
area of 1 square inch (645 mm2) per 4,000 Btu (1.17 kW)
per hour of total input rating of all equipment in the enclosure.
See Figures 4 and 5. When communicating with the
outdoors through horizontal ducts, each opening shall have
a minimum free area of 1 square inch (645 mm2) per 2,000
Btu (.56 kW) per total input rating of all equipment in the
enclosure. See Figure 6.

506528-01 Page 7 of 37Issue 1035

When ducts are used, they shall be of the same cross
sectional area as the free area of the openings to which
they connect. The minimum dimension of rectangular air
ducts shall be no less than 3 inches (75 mm). In calculating
free area, the blocking effect of louvers, grilles, or screens
must be considered. If the design and free area of protective
covering is not known for calculating the size opening
required, it may be assumed that wood louvers will have
20 to 25 percent free area and metal louvers and grilles will
have 60 to 75 percent free area. Louvers and grilles must
be fixed in the open position or interlocked with the
equipment so that they are opened automatically during
equipment operation.

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE

(Inlet Air from Crawlspace &

Outlet Air to Ventilated Attic)

EQUIPMENT IN CONFINED SPACE

(ALL AIR FROM OUTSIDE)

NOTE: Each air duct opening shall have a free area of at least one
square inch per 2,000 Btu (645 mm² per .59 kW) per hour of the
total input rating of all equipment in the enclosure. If the equipment
room is located against an outside wall and the air openings
communicate directly with the outdoors, each opening shall have a
free area of at least 1 square inch per 4,000 Btu (645 mm² per 1.17
kW) per hour of the total input rating of all other equipment in the
enclosure.

NOTE: The inlet and outlet air openings shall each have a free area
of at least one square inch per 4,000 Btu (645 mm² per 1.17 kW) per
hour of the total input rating of all equipment in the enclosure.

Figure 4

EQUIPMENT IN CONFINED SPACE - ALL AIR FROM OUTSIDE

(All Air through Ventilated Attic)

Figure 6

NOTE: The inlet and outlet air openings shall each have a free area

of at least one square inch per 4,000 Btu (645 mm² per 1.17 kW) per
hour of the total input rating of all equipment in the enclosure.

Figure 5

506528-01Page 8 of 37 Issue 1035

Setting Equipment

WARNING

Do not install the furnace on its front or its back. Do not
connect the return air ducts to the back of the furnace.
Doing so will adversely affect the operation of the safety
control devices, which could result in personal injury or
death.

The gas furnace can be installed as shipped in either the
upflow position or the horizontal position.

Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection, and
installation and service clearances [24 inches (610 mm) at
unit front]. The unit must be level.

NOTE: Units with 1/2 hp blower motors are equipped with
three flexible legs and one rigid leg. See Figure 7. The
rigid leg is equipped with a shipping bolt and a flat white
plastic washer (rather than the rubber mounting grommet
used with a flexible mounting leg). The bolt and washer

must be removed before the furnace is placed into
operation. After the bolt and washer have been removed,

the rigid leg will not touch the blower housing.

Downflow Applications

Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or
alcove installations are shown in Figure 8.

Downflow Application Installation Clearances

Figure 7

Units with 1/2 HP

Blower Motor.

* Front clearance In alcove Installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
‡ For installation on a combustible floor, do not install the furnace
directly on carpeting, tile or other combustible materials other than
wood flooring.
† Left side requires 3 inches if a single wall vent is used on 14-1/2
inch cabinets.

Figure 8

Return Air

Return air must be brought in through the top of the furnace
installed in an downflow application.

506528-01 Page 9 of 37Issue 1035

Figure 9

WARNING

Improper installation of the furnace can result in personal
injury or death. Combustion and flue products must
never be allowed to enter the return air system or air in
the living space. Use sheet metal screws and joint tape
to seal return air system to furnace.

In platform installations with furnace return, the furnace
should be sealed airtight to the return air plenum. A
door must never be used as a portion of the return air
duct system. The base must provide a stable support
and an airtight seal to the furnace. Allow absolutely no
sagging, cracks, gaps, etc.

For no reason should return and supply air duct systems
ever be connected to or from other heating devices such
as a fireplace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.

Installation on Non-Combustible Flooring (Figure 11)

1. Cut floor opening keeping in mind clearances listed on
unit rating plate. Also keep in mind gas supply
connections, electrical supply, flue and air intake
connections and sufficient installation and servicing
clearances. See Table 1 for correct floor opening size.

2. Flange warm air plenum and lower the plenum into the
opening.

3. Set the unit over the plenum and seal the plenum to the
unit.

4. Ensure that the seal is adequate.

NON-COMBUSTIBLE FLOOR OPENING SIZE

NOTE: Floor opening dimensions listed are 1/4 inch (6 mm) larger

than the unit opening. See dimension drawing on page 2.

Table 1

Installation Clearances

* Front

Back

Sides

Vent

Floor

* Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
† Allow proper clearances to accommodate condensate trap and vent
pipe installation.
‡ The furnace may be installed on a combustible wood floor if an
optional additive base is installed between the furnace and the
combustivle floor.

0

0

0†

0

NC‡

Figure 11

Installation on Combustible Flooring (Figure 12)

1. When unit is installed on a combustible floor, a downflow
combustible flooring base must be installed between the
furnace and the floor. The base must be ordered
separately. See Table 2 for opening size to cut in floor.

CAUTION

The furnace and combustible flooring base shall not be
installed directly on carpeting, tile, or other combustible
material other than wood flooring.

Figure 10

506528-01Page 10 of 37 Issue 1035

COMBUSTIBLE FLOORING BASE OPENING SIZE

Table 2

Figure 12

2. After opening is cut, set the combustible flooring base
into opening.

3. Check fiberglass strips on the combustible flooring base
to make sure they are properly glued and positioned.

4. Lower supply air plenum into the combustible flooring
base until plenum flanges seal against fiberglass strips.

er opening is

NOTE: Be careful not to damage fiberglass strips. Check
for a tight seal.

Figure 13

Return Air Opening - Downflow Units

Return air may be brought in only through the top opening
of a furnace installed in the downflow position. The following
steps should be taken when installing plenum:

1. Bottom edge of plenum should be flanged with a
hemmed edge (See Figure 14 or 15).

2. Sealing strips should be used to ensure an airtight seal
between the cabinet and the plenum.

3. In all cases, plenum should be secured to top of furnace
using sheet metal screws.

4. Make certain that an adequate seal is made.

5. Set the furnace over the plenum.

6. Ensure that the seal between the furnace and plenum
is adequate.

Installation on Cooling Coil Cabinet (Figure 13)

NOTE: Downflow combustible flooring kit is not used.

1. Refer to reverse flow coil installation instructions for
correctly sized opening in floor and installation of cabinet.

2. When cooling cabinet is in place, set and secure the
furnace according to the instructions that are provided
with the cooling coil. Secure the furnace to the cabinet.

3. Seal the cabinet and check for air leaks.

506528-01 Page 11 of 37Issue 1035

Figure 14

Figure 15

Filters

This unit is not equipped with a filter or rack. A field provided
high velocity filter is required for the unit to operate properly.

Venting

A 4 inch diameter flue transition is factory installed on the
combustion air inducer outlet of all models.

A filter must be in place any time the unit is operating.

Duct System

Use industry approved standards (such as those published
by Air Conditioning Contractors of America or American
Society of Heating, Refrigerating and Air Conditioning
Engineers) to size and install the supply and return air duct
system. This will result in a quiet and low static system that
has uniform air distribution.

NOTE: Do not operate the furnace in the heating mode
with an external static pressure that exceeds 0.8 inches w.c.
Higher external static pressures may cause erratic limit
operation.

Supply Air Plenum

If the furnace is installed without a cooling coil, a removable
access panel must be installed in the supply air duct. The
access panel should be large enough to permit inspection
(either by smoke or reflected light) of the heat exchanger
for leaks after the furnace is installed. The furnace access
panel must always be in place when the furnace is operating
and it must not allow leaks into the supply air duct system.

Return Air Plenum

IMPORTANT

The unit will not vent properly with the flue transition pointed
down in the 6 o’clock position.

The combustion air inducer may be rotated clockwise or
counterclockwise by 90° to allow for top or side vent
discharge in all applications. When the unit is installed,
the flue transition must be in the 9 o’clock, 12 o’clock or 6
o’clock position.

These series units are classified as fan assisted Category I
furnaces when vertically vented according to the latest edition
of National Fuel Gas Code (NFPA 54 / ANSI Z223.1) in the
USA. A fan assisted Category I furnace is an appliance
equipped with an integral mechanical means to either draw
or force combustion products through the combustion
chamber and/or heat exchanger. This unit is not approved
for use with horizontal venting.

NOTE: Use these instructions as a guide. They do not
supersede local codes. This furnace must be vented
according to all local codes these installation instructions,
and the provided venting tables in these instructions.

NOTE: Return air must not be drawn from a room where
this furnace, or any other gas fueled appliance (i.e., water
heater), or carbon monoxide producing device (i.e., wood
fireplace) is installed.

When return air is drawn from a room, a negative pressure
is created in the room. If a gas appliance is operating in a
room with negative pressure, the flue products can be pulled
back down the vent pipe and into the room. This reverse
flow of the flue gas may result in incomplete combustion
and the formation of carbon monoxide gas. This toxic gas
might then be distributed throughout the house by the furnace
duct system.

The venting tables in this manual were extracted from the
National Fuel Gas Code (NFPA 54 / ANSI Z223.1) and are
provided as a guide for proper vent installation. Proper
application, termination, construction and location of vents
must conform to local codes having jurisdiction. In the
absence of local codes, the NFGC serves as the defining
document.

Refer to the tables and the venting information contained in
these instructions to properly size and install the venting
system.

IMPORTANT

Once the venting system is installed, attach the
“Disconnected Vent” warning sticker to a visible area of
the plenum near the vent pipe. See Figure 15. The
warning sticker is provided in the bag assembly. Order
kit 66W04 for additional stickers.

506528-01Page 12 of 37 Issue 1035