Bryant 376CAV Installation Instruction

Installation, Start-Up, and

376CAV

Operating Instructions

DOWNFLOW/HORIZONTAL
GAS-FIRED
INDUCED-COMBUSTION FURNACES

NOTE: Read the entire instruction manual before starting the
installation.

This symbol → indicates a change since the last issue.

TABLE OF CONTENTS

SAFETY CONSIDERATIONS.....................................................1

INTRODUCTION..........................................................................1

CODES AND STANDARDS........................................................3

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS........3

LOCATION....................................................................................4

General......................................................................................4

Location Relative to Cooling Equipment ................................4

Hazardous Locations.................................................................4

Unconfined Space.....................................................................4

Confined Space.........................................................................5

AIR DUCTS...................................................................................5

General Requirements...............................................................5

Ductwork Acoustical Treatment...............................................5

Supply Air Connections............................................................5

Return Air Connections............................................................6

Downflow Installation ..............................................................6

Horizontal Attic Installation.....................................................6

Horizontal Crawlspace Installation ..........................................7

Filter Arrangement....................................................................8

Gas Piping.................................................................................9

Electrical Connections............................................................11

Venting....................................................................................11

START-UP PROCEDURES, ADJUSTEMENT, AND SAFETY

CHECK.........................................................................................11

General....................................................................................11

Sequence of Operation............................................................12

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

Adjustments.............................................................................15

Check Safety Controls............................................................19

Checklist..................................................................................20

SAFETY CONSIDERATIONS

Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified person­nel should install, repair, or service heating equipment.

Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations must
be performed by trained service personnel. When working on
heating equipment, observe precautions in literature, on tags, and
on labels attached to or shipped with unit and other safety
precautions that may apply.

In the United States, follow all safety codes including the National
Fuel Gas Code (NFGC) NFPA 54-1999/ANSI Z223.1-1999 and
the Installation Standards, Warm Air Heating and Air Condition­ing Systems (NFPA 90B) ANSI/NFPA 90B.

In Canada, refer to the current edition of the CAN/CGA-B149.1­and .2-M99 National Standard of Canada, Natural Gas and
Propane Installation Codes (NSCNGPIC).

Series H&J

Cancels: II 376C-50–3 II 376C–50–5

10–00

EFFICIENCY
RATING
CERTIFIED

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9

REGISTERED QUALITY SYSTEM

Wear safety glasses and work gloves. Have a fire extinguisher
available during start-up and adjustment procedures and service
calls.
Recognize safety information. This is the safety-alert symbol
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Understand these signal words; DANGER, WARNING, and
CAUTION and NOTE. These words are used with the safety-alert
symbol. DANGER identifies the most serious hazards which will
result in severe personal injury or death. WARNING signifies a
hazard which could result in personal injury or death. CAUTION
is used to identify unsafe practices which would result in minor
personal injury or product and property damage. NOTE is used to
highlight suggestions which will result in enhanced installation,
reliability, or operation
These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept pace with changing
residential construction practices. We require these instructions as
a minimum for a safe installation.

INTRODUCTION

The Model 376CAV, Series H and J Furnace is available in sizes
46,000 through 135,000 Btuh input capacities.
The design of the downflow/horizontal gas-fired furnace is
(A.G.A. & C.S.A.) certified for natural and propane gases and for
installation on noncombustible flooring. The furnace is factory­shipped for use with natural gas. A factory accessory gas conver­sion kit, as listed on the furnace rating plate is required to convert
furnace for use with propane gas.
These furnaces SHALL NOT be installed directly on carpeting,
tile, or any combustible material other than wood flooring. In
downflow installations, a factory accessory floor base, as listed on
the furnace rating plate, MUST be used when installed on
combustible materials and wood flooring. A factory base is not
required when this furnace is installed on manufacturer’s Coil
Assembly Part No. CD5 or CK5, or when Coil Box Part No.
KCAKC is used. This furnace is for installation in alcoves, attics,
crawlspaces, basements, closets, or utility rooms. The design of
this furnace line is not (A.G.A./C.S.A.) certified for installation in
mobile homes, recreation vehicles, or outdoors.

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.

—1—

1

28

⁄2†

20†

13

⁄16†

39

7

⁄8†

INLET

7

⁄8† DIA

ACCESSORY

3

⁄4† DIA HOLE

1

GAS ENTRY

11

⁄16†

OUTLET

19†

NOTE:

ADDITIONAL
LOCA TED IN THE TOP PLA TE

7

⁄8† DIA K.O.’s ARE

AND BOTTOM PLATE

VENT CONNECTION

13

⁄16†

1

9

⁄8†

1

10

⁄4†

1

1

⁄16†

1

2

⁄8†

1

8

⁄4†

11

⁄16†

AIRFLOW

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11

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13

⁄16†

4

2

⁄16†

3

5

⁄16†

15

⁄16†

10

⁄16†

1

⁄4†

DIMPLES TO DRILL HOLES
FOR HANGER BOLTS (4 PLACES)
IN HORIZONTAL POSITION

1

⁄2† DIA

2†

THERMOSTAT
WIRE ENTRY

7

⁄8† DIA

ACCESSORY

7

⁄8† DIA HOLE

POWER ENTRY

1

1

⁄2† DIA

R.H. GAS ENTRY

7

⁄8† DIA

ACCESSORY

1

1

⁄16†

1

2

⁄8†

† TYP

1

5

⁄8† TYP

NOTE:

Minimum return-air openings at furnace, based on metal duct. If flex duct is used,
see flex duct manufacturer's recommendations for equivalent diameters.
a. For 800 CFM–16-in. round or 14
b. For 1200 CFM–20-in. round or 14
c. For 1600 CFM–22-in. round or 14
d. For airflow requirements above 1800 CFM, must use entire return air opening.

1

⁄2 x 12-in. rectangle.

1

⁄2 x 191⁄2-in. rectangle.

1

⁄2 x 231⁄4-in. rectangle.

TABLE 1—DIMENSIONS (IN.)

UNIT SIZE A D E VENT CONN SHIP. WT (LB)

024050 14-3/16 12-9/16 12-11/16 4 123
036050 14-3/16 12-9/16 12-11/16 4 128
024070 14-3/16 12-9/16 12-11/16 4 130
036070 14-3/16 12-9/16 12-11/16 4 139
036096 17-1/2 15-7/8 16 4 151
048096 17-1/2 15-7/8 16 4 153
048115 17-1/2 15-7/8 16 4 161
060115 21 19-3/8 19-1/2 4 177
066115 21 19-3/8 19-1/2 4 176
060135 24-1/2 22-7/8 23 5 193

Fig. 1—Dimensional Drawing

These instructions cover minimum requirements for a safe instal­lation and conform to existing national standards and safety codes.
In some instances, these instructions exceed certain local codes
and ordinances, especially those that may not have kept pace with
changing residential construction practices. We require these
instructions as a minimum for a safe installation.

A99288

CAUTION: Application of this furnace should be in­doors with special attention given to vent sizing and
material, gas input rate, air temperature rise, and unit
sizing. Improper installation or misapplication of the
furnace can require excessive servicing or cause prema­ture component failure.

NOTE: These furnaces are designed for a minimum continuous
return-air temperature of 60°F or intermittent operation down to
55°F such as when used with a night setback thermostat. Return-air
temperature must not exceed a maximum of 85°F. Failure to
follow these return-air temperature limits may affect reliability of
heat exchangers, motors, and controls.

A93042

—2—

MINIMUM INCHES CLEARANCE TO COMBUSTIBLE CONSTRUCTION

This fo rced air furnace is equipped for use with natural

gas at altitudes 0-10,000 ft (0-3,050m).

An accessory kit, supplied by the manufacturer,shall be
used to convert to propane gas use or may be require d for
somenatura l gas applications.

This furnace is for indoor installatio n in a building
constructed on site.

This furnace may be installed on combustible flooring in
alcove or closet at minimum clearance from combustible
material.

This furnace may be used with a Type B-1 Vent and may
be vented in com m on with other gas-fired appliances.

For installation on non-combustible floors only.

†

For installation on combustible flooring onlywhen
installedon specia l base, Part No. KGA SB02 01ALL,
Coil Assembly, Part No.CD5 or CK5, or Coil Casing,
Part No. KCAKC.

For furnaces wider than 14.25 inches (362mm) may

#

be 0 inches.

18 inches fro nt clearance re quired for alcove.

Ø

Indicates supply or return sides whenfurnaceisin

*

the horizonta l position. Line contact only permissible
betweenlines formed by intersectionsof the Top and
two Sides of thefurnace jacke t, and building joists,
studs or fram ing.

For single wall vent typ e 6 inches.

##

ForTypeB-1venttype3inches.

††

Clearance to Back 0 inches in downflow and
horizontal (attic/alcove & craw lspace) positionsand
3 inches in horizontal closet positions.

Fig. 2—Clearances to Combustibles

ThisfurnaceisapprovedforDOWNFLOWandHORIZONTAL
installatio ns .

Clearance arrow s
do not change with
furnace orientatio n.

0"

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Clearance in inch es

1"

TOP / PLENUM

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30"

MIN

Vent Clearance to combustibles:

For Sin gle Wall vents 6 inches.
For Type B-1 vent type1 inch .

322286-101REV. F (LIT)

A99262

WARNING: Improper installation, adjustment, alter­ation, service, maintenance, or use can cause carbon
monoxide poisoning, explosion, fire, electrical shock, or
other conditions which may cause personal injury or
property damage. Consult a qualified installer, service
agency, local gas supplier, or your distributor or branch
for information or assistance. The qualified installer or
agency must use only factory-authorized and listed kits or
accessories when modifying this product. Failure to
follow this warning could result in electrical shock, fire,
personal injury, or death.

For accessory installation details, refer to the applicable installa­tion literature.

NOTE: Remove all shipping brackets and materials before oper­ating the furnace.

CODES AND STANDARDS

Before installing the furnace in the United States, refer to the
current edition of the NFGC and the NFPA 90B. For further
information the NFGC and NFPA 90B are available from National
Fire Protection Association Inc., Batterymarch Park, Quincy, MA
02269; or for only the NFGC contact the American Gas Associa­tion, 400 N. Capitol St., N.W., Washington DC 20001.

Before installing the furnace in Canada, refer to the current edition
of the NSCNGPIC. For a copy of the NSCNGPIC, contact
Standard Sales, CSA International, 178 Rexdale Boulevard, Eto­bicoke (Toronto), Ontario, M9W 1R3, Canada.

Installation must comply with regulations of serving gas supplier
and local building, heating, plumbing or other codes in effect in the
area in which installation is made. In absence of local building
codes, installation must comply with NFGC in the United States
and the NSCNGPIC and all authorities having jurisdiction in
Canada.

ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS

CAUTION: Electrostatic discharge can affect electronic

components. Take precautions during furnace installation
and servicing to protect the furnace electronic control.
Precautions will prevent electrostatic discharges from
personnel and hand tools which are held during the
procedure. These precautions will help to avoid exposing
the control to electrostatic discharge by putting the
furnace, the control, and the person at the same electro­static potential.

1. Disconnect all power to the furnace. DO NOT TOUCH

THE CONTROL OR ANY WIRE CONNECTED TO THE
CONTROL PRIOR TO DISCHARGING YOUR BODY’S
ELECTROSTATIC CHARGE TO GROUND.

2. Firmly touch a clean, unpainted, metal surface of the
furnace chassis which is close to the control. Tools held in
a person’s hand during grounding will be satisfactorily
discharged.

3. After touching the chassis you may proceed to service the
control or connecting wires as long as you do nothing that

—3—

recharges your body with static electricity (for example; DO
NOT move or shuffle your feet, DO NOT touch un­grounded objects, etc.).

4. If you touch ungrounded objects (and recharge your body
with static electricity), firmly touch furnace again before
touching control or wires.

5. Use this procedure for installed and uninstalled (un­grounded) furnaces.

6. Before removing a new control from its container, dis­charge your body’s electrostatic charge to ground to protect
the control from damage. If the control is to be installed in
a furnace, follow items 1 through 5 before bringing the
control or yourself into contact with the furnace. Put all
used AND new controls into containers before touching
ungrounded objects.

7. An ESD service kit (available from commercial sources)
may also be used to prevent ESD damage.

LOCATION

I. GENERAL

CAUTION: Do not install furnace in a corrosive or

contaminated atmosphere. Make sure all combustion and
circulating air requirements are met, in addition to all
local codes and ordinances.
Do not use this furnace during construction when adhe­sives, sealers, and/or new carpets are being installed. If
the furnace is required during construction, use clean
outside air for combustion and ventilation. Compounds of
chlorine and fluorine when burned with combustion air
form acids which cause corrosion of the heat exchangers
and metal vent system. Some of these compounds are
found in paneling and dry wall adhesives, paints, thin­ners, masonry cleaning materials, and many other sol­vents commonly used in the construction process.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.

III. HAZARDOUS LOCATIONS

18-IN. MINIMUM

TO BURNERS

A93044

WARNING: When furnace is installed in a residential
garage, it must be installed so that burners and ignition
sources are located a minimum of 18 in. above floor. The
furnace must be located or protected to avoid physical
damage by vehicles. When furnace is installed in a public
garage, airplane hangar, or other building having a
hazardous atmosphere, unit must be installed in accor­dance with requirements of National Fire Protection
Association, Inc.

Air For Combustion And Ventilation

Provisions for adequate combustion and ventilation air must be
provided in accordance with Section 5.3 of the NFGC, Air for
Combustion and Ventilation, or applicable provisions of the local
building codes.

Canadian installations must be installed in accordance with NSC­NGPIC and all authorities having jurisdiction.

WARNING: DO NOT install the furnace on its back or
sides. Safety control operation will be adversely affected.
A failure to follow this warning can cause a fire, personal
injury, or death.

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

Locate furnace as close to the chimney/vent and as near the center
of the air distribution system as possible. The furnace should be
installed as level as possible.

Provide ample space for servicing and cleaning. Always comply
with the minimum fire protection clearances shown on the unit
rating plate. This furnace shall not be installed directly on
carpeting, tile, or any combustible material other than wood
flooring. The furnace may be installed on combustible flooring
when installed with the accessory downflow subbase, which is
available from your distributor or branch when required.

II. LOCATION RELATIVE TO COOLING EQUIPMENT

The cooling coil must be installed parallel with or on the
downstream side of the unit to avoid condensation in the heat
exchangers. When installed parallel with a furnace, dampers or
other means used to control the flow of air must prevent chilled air
from entering the unit. If the dampers are manually operated, they
must be equipped with means to prevent operation of either unit
unless the damper is in the full-heat or full-cool position.

CAUTION: Air for combustion must not be contami­nated by halogen compounds, which include fluoride,
chloride, bromide, and iodide. These elements are found
in aerosol sprays, detergents, bleaches, cleaning solvents,
salts, air fresheners, and other household products.

CAUTION: The operation of exhaust fans, kitchen ven­tilation fans, clothes dryers, or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make-up air MUST be provided for the ventilation
devices, in addition to that required by the furnace.

All fuel-burning equipment must be supplied with air for combus­tion of the fuel. Sufficient air MUST be provided to ensure there
will not be a negative pressure in the equipment room or space. In
addition, a positive seal MUST be made between the furnace
cabinet and the return-air duct to avoid pulling air from the burner
area and blocked vent safeguard opening.

The requirements for combustion and ventilation air depend upon
whether the furnace is located in an unconfined or confined space.

IV. UNCONFINED SPACE

An unconfined space has volume of at least 50 cu ft for each 1000
Btuh of total input for all appliances (such as furnaces, clothes
dryers, water heaters, etc.) in the space.

—4—

For Example:

376CAV FURNACE

INPUT BTUH

46,000 307
69,000 460

92,000 613
115,000 767
135,000 920

MINIMUM SQ FT WITH

7–1/2 FT CEILING

If the unconfined space is of unusually tight construction, air for
combustion and ventilation MUST come from either the outdoors
or spaces freely communicating with the outdoors. Combustion
and ventilation openings must be sized the same as for a confined
space as defined below. Return air must not be taken from the
room unless an equal or greater amount of air is supplied to the
room.

V. CONFINED SPACE

A confined space is defined as a space whose volume is less than
50 cu ft per 1000 Btuh of total input ratings of all appliances
installed in that space. A confined space MUST have provisions
for supplying air for combustion, ventilation, and dilution of flue
gases using 1 of the following methods. (See Figs. 3, 4, and Table

2.)
NOTE: In determining free area of an opening, the blocking

effect of louvers, grilles, and screens must be considered. If free
area of louver or grille design is unknown, assume that wood
louvers have a 20 percent free area and metal louvers or grilles
have a 60 percent free area. Screens, when used, must not be
smaller than 1/4-in. mesh. Louvers and grilles must be constructed
so they cannot be closed.

The size of the openings depends upon whether air comes from
outside of the structure or an unconfined space inside the structure.

1. All air from inside the structure requires 2 openings (for
structures not usually tight):

a. Each opening MUST have at least 1 sq in. of free area

per 1000 Btuh of total input for all equipment within the
confined space, but not less than 100 sq in. per opening.
(See Fig. 3 and Table 2.) The minimum dimension of air
openings shall not be less than 3 in.

b. If building is constructed unusually tight, a permanent

opening directly communicating with the outdoors shall
be provided. See item 2 below.

c. If furnace is installed on a raised platform to provide a

return-air plenum, and return air is taken directly from
hallway or space adjacent to furnace, all air for combus­tion must come from outdoors.

2. Air from outside the structure requires 1 of the following
methods:

a. If combustion air is taken from outdoors through 2

vertical ducts, the openings and ducts MUST have at
least 1 sq in. of free area per 4000 Btuh of total input for
all equipment within the confined space. (See Figs. 3, 4,
and Table 2.)

b. If combustion air is taken from outdoors through 2

horizontal ducts, the openings and ducts MUST have at
least 1 sq in. of free area per 2000 Btuh of total input for
all equipment within the confined space. (See Fig. 4 and
Table 2.)

c. If combustion air is taken from outdoors through a single

opening or duct (horizontal or vertical) commencing
within 12 in. of the top of the confined space, opening
and duct MUST have at least 1 sq in. of free area per

3000 Btuh of the total input for all equipment within the
confined space and not less than the sum of the areas of
all vent connectors in the confined space. (See Fig. 4 and
Table 2.) Equipment clearances to the structure shall be
at least 1 in. from the sides and back and 6 in. from the
front of the appliances.

When ducts are used, they must be of the same cross-sectional area
as the free area of the openings to which they connect. The
minimum dimension of ducts must not be less than 3 in. (See Fig.

4.)

AIR DUCTS

This section covers installation of the 376CAV Series H and J
furnace.

I. GENERAL REQUIREMENTS

The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal and
Air Conditioning Contractors National Association (SMACNA) or
American Society of Heating, Refrigerating and Air Conditioning
Engineers (ASHRAE). Or consult factory The Air Systems Design
Guidelinesreference tables available from your local distributor.
The duct system should be sized to handle the required system
design airflow CFM at the design external static pressure.

When a furnace is installed so that the supply ducts carry air to
areas outside the space containing the furnace, the return air must
also be handled by a duct(s) sealed to the furnace casing and
terminating outside the space containing the furnace.

Secure ductwork with proper fasteners for type of ductwork used.
Seal supply- and return-duct connections to furnace with code
approved tape or duct sealer.

Flexible connections should be used between ductwork and
furnace to prevent transmission of vibration. Ductwork passing
through unconditioned space should be insulated to enhance
system performance. When air conditioning is used, a vapor
barrier is recommended.

Maintain a 1-in. clearance from combustible materials to supply air
ductwork for a distance of 36 in. horizontally from the furnace. See
NFPA 90B or local code for further requirements.

II. DUCTWORK ACOUSTICAL TREATMENT

Metal duct systems that do not have a 90 degree elbow and 10 ft
of main duct to the first branch take-off may require internal
acoustical lining. As an alternative, fibrous ductwork may be used
if constructed and installed in accordance with the latest edition of
SMACNA construction standard on fibrous glass ducts. Both
acoustical lining and fibrous ductwork shall comply with NFPA
90B as tested by UL Standard 181 for Class 1 Rigid air ducts.

III. SUPPLY AIR CONNECTIONS
A. Downflow Furnaces

Connect supply-air duct to supply-air opening on furnace. The
supply-air ducts attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used), when
installed on non-combustible material. When installed on combus­tible material, supply-air duct attachment must ONLY be con­nected to an accessory subbase or factory approved air condition­ing coil casing. DO NOT cut main furnace casing to attach supply
side air duct, humidifier, or other accessories. All accessories
MUST be connected external to the furnace main casing.

B. Horizontal Furnaces

Connect supply-air duct to supply-air opening on furnace. The
supply-air ducts attachment must ONLY be connected to furnace
supply/outlet or air conditioning coil casing (when used). DO NOT
cut main furnace casing to attach supply side air duct, humidifier,
or other accessories. All accessories MUST be connected external
to the furnace main casing.

—5—

VENT THROUGH ROOF
(CATEGORY I)

DUCTS TO

OUTDOORS

1 SQ IN.
PER 4000
BTUH

*

RETURN

AIR

INTERIOR

HEATED

SPACE

SUPPLY AIR

* Minimum opening size is 100 sq in. with
minimum dimensions of 3 in.

†

Minimum of 3 in. when type B-1 vent is used.

Fig. 3—Confined Space: Air for Combustion and Ventilation

12″ MAX

1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL

UNCONFINED
SPACE

6″ MIN
(FRONT)

1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL

†

12″ MAX

A93387

from an Unconfined Indoor Space

12″ MAX

1 SQ IN.
PER 2000
BTUH

*

DUCTS

TO

OUTSIDE

1 SQ IN.
PER 2000
BTUH

*

12″ MAX

SUPPLY AIR

Minimum dimensions of 3 in.

*

NOTE:

Use any of the following
combinations of openings:
A & B C & D D & E F & G

RETURN

A

B

AIR

Fig. 4—Confined Space: Air for Combustion and Ventilation

D

VENT
THROUGH
ROOF
(CATEGORY I)

CONFINED

C

DUCT

TO

OUTDOORS

F

SPACE

G

E

12″ MAX

12

″

MAX

1 SQ IN.
PER 4000
BTUH

OUTDOORS
1 SQ IN.

PER 4000
BTUH

12

″

MAX

1 SQ IN.
PER 4000
BTUH

*

*

A93388

from Outdoors

TABLE 2—MINIMUM FREE AREA OF COMBUSTION AIR OPENING*

376CAV

FURNACE

INPUT

(BTUH)

46,000 100 11.50 4 23.0 6 15.33 5
69,000 100 17.25 5 34.5 7 23.00 6

92,000 100 23.00 6 46.0 8 30.67 7
115,000 115 28.75 7 57.5 9 38.33 7
135,000 135 33.75 7 67.5 10 45.00 8

* Free area shall be equal to or greater than the sum of the areas of all vent connectors in the confined space. Opening area must be increased if other gas appliances in
the space require combustion air.

AIR FROM INDOOR

UNCONFINED SPACE

Free Area

of Opening

(Sq. In.)

IV. RETURN AIR CONNECTIONS

The return-air duct must be connected to return air opening as
shown in Fig. 1. DO NOT cut into casing sides or back to attach
any portion of return-air duct. Bypass humidifier connections
should be made at ductwork or coil casing sides exterior to
furnace.

WARNING: Do not install furnace on its back. Safety
control operation will be adversely affected. Never con­nect return-air ducts to back of furnace. Failure to follow
this warning could result in fire, personal injury, or death.

OUTDOOR AIR THROUGH

VERTICAL DUCTS

Free Area of

Opening and Duct

(Sq. In.)

Round

Pipe

(In. Dia.)

OUTDOOR AIR THROUGH

HORIZONTAL DUCTS

Free Area

of Opening and Duct

(Sq. In.)

Round

Pipe

(In. Dia)

OUTDOOR AIR THROUGH

SINGLE DUCT

Free Area

of Opening and Duct

(Sq. In.)

Round

(In. Dia)

rating plate, MUST be used. A factory accessory floor base is not
required when this furnace is installed on manufacturer’s Coil
Assembly Part No. CD5 or CK5, or when Coil Box Part No.
KCAKC is used.

1. Determine application being installed from Table 3.

2. Construct hold in floor per dimensions specified in Table 3
and Fig. 5.

3. Construct plenum to dimensions specified in Table 3.

4. If downflow subbase (KGASB) is used, install as shown in
Fig. 6.

Pipe

If coil assembly CD5, CK5 or Coil Box KCAKC is used,
install as shown in Fig. 7.

V. DOWNFLOW INSTALLATION

This furnace is approved for use on combustible materials or wood
flooring. A factory accessory floor base, as listed on the furnace

VI. HORIZONTAL ATTIC INSTALLATION

The furnace can be installed on either the left-hand (LH) or
right-hand (RH) side. A typical attic installation is shown in Fig. 8.

—6—

FRONT

BACK

FRONT

A. Construct a Working Platform

Constructs a working platform, on location, where all required
furnace clearances are met. (See Fig. 2 and 8.)

B. Install Furnace

1. Position furnace in desired location.

B
A
C
K

2. Connect gas supply pipe. See Fig. 8 for typical piping entry.

3. Install field-supplied filter retainers as indicated in Fig. 11
and Table 4 before connecting return-air duct to furnace.

4. Connect supply- and return-air ducts.

5. Install 24- X 24–in. sheet metal shield on platform in front
of louvered control panel as shown in Fig. 8.

VII. HORIZONTAL CRAWLSPACE INSTALLATION

A93043

The furnace can be installed horizontally with either LH or RH
side up. In a crawlspace, furnace can either be hung from floor
joist (see Fig. 10) or installed on suitable blocks or pad. (See Fig.

A

PLENUM

OPENING

B

D

FURNACE

CASING

WIDTH

14–3/16

17–1/2

21

24–1/2

FLOOR

OPENING

C

Fig. 5—Floor and Plenum Opening Dimensions

TABLE 3—OPENING DIMENSIONS (IN.)

APPLICATION

Non-Combustible Flooring 12–11/16 19 13–3/8 19–5/8

Combustible Flooring Using KGASB Subbase 11–13/16 19 13–7/16 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 16 19 16–5/8 19–5/8

Combustible Flooring Using KGASB Subbase 15–1/8 19 16–3/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 19–1/2 19 20–1/8 19–5/8

Combustible Flooring Using KGASB Subbase 18–5/8 19 20–1/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

Non-Combustible Flooring 23 19 23–5/8 19–5/8

Combustible Flooring Using KGASB Subbase 22–1/8 19 23–3/4 20–3/8

Combustible Flooring with CD5 or CK5 Coil Assembly or

KCAKC Coil Box

PLENUM OPENING FLOOR OPENING

ABCD

12–5/16 19 13–5/16 20

15–1/2 19 16–1/2 20

19 19 20 20

22–1/2 19 23–1/2 20

A96283

—7—

FURNACE

(OR COIL CASING

WHEN USED)

COMBUSTIBLE

FLOORING

FURNACE

CD5 OR CK5

COIL ASSEMBLY

OR KCAKC

COIL BOX

COMBUSTIBLE

FLOORING

DOWNFLOW

SUBBASE

SHEET METAL

PLENUM

FLOOR

OPENING

Fig. 6—Furnace, Plenum, and Subbase Installed on a Com-

A96285

bustible Floor

9.) The furnace can be suspended from each corner by hanger bolts
(4 each 3/8-in. all-thread rod) cut to desired length, 1- X 3/8–in.
flat washer, 3/8–in. lockwasher, and 3/8–in. nut. Dimples are
provided for hole locations. (See Fig. 1.)

Since horizontal crawlspace installation is very similar to attic
installation, refer to Section VI, “Horizontal Attic Installation”.
The installation of a sheet metal shield in front of louvered control
panel is covered in Section VI.

For crawlspace installation, this same sheet metal shield must be
installed above louvered control panel. Extend sheet metal shield
over furnace top far enough to cover gas pipe entry hole.

SHEET METAL

PLENUM

FLOOR

OPENING

Fig. 7—Furnace, Plenum, and Coil Assembly or Coil Box

A96284

Installed on a Combustible Floor

VIII. FILTER ARRANGEMENT

WARNING: Never operate unit without filter access

door removed. Failure to follow this warning could result
in fire, personal injury, or death.

LINE CONTACT ONLY PERMISSIBLE BETWEEN
LINES FORMED BY INTERSECTIONS OF
THE TOP AND TWO SIDES OF THE FURNACE
JACKET AND BUILDING JOISTS,
STUDS, OR FRAMING.

MANUAL SHUTOFF

GAS VALVE

SEDIMENT

TRAP

GAS
ENTRY

″

6

24

24

″

″

SHEET
METAL

Fig. 8—Typical Attic Installation

—8—

MIN

TYPE-B
VENT

30-IN. MIN
WORK AREA

A97516