International comfort products F8MXN, G8MXN, G8MXL, F8MXL, R8MXL Installation Instructions Manual
INSTALLATION INSTRUCTIONS
80% Single Stage, ECM Motor
Category I, Gas Furnace
F8MXN, G8MXN, F8MXL, G8MXL
These instructions must be read and understood completely before attempting installation.
Safety Labeling and Signal Words
DANGER, WARNING, CAUTION, and NOTE Signal Words in Manuals
The signal words DANGER, WARNING, CAUTION, and NOTE
are used to identify levels of hazard seriousness. The signal word
DANGER is only used on product labels to signify an immediate
hazard. The signal words WARNING, CAUTION, and NOTE will
be used on product labels and throughout this manual and other
manual that may apply to the product.
DANGER − Immediate hazards which will result in severe person-
al injury or death.
WARNING − Hazards or unsafe practices which could result in
severe personal injury or death.
CAUTION − Hazards or unsafe practices which may result in
minor personal injury or product or property damage.
NOTE − Used to highlight suggestions which will result in en-
hanced installation, reliability, or operation.
The signal word WARNING is used throughout this manual in
the following manner:
!
WARNING
The signal word CAUTION is used throughout this manual in
the following manner:
!
CAUTION
Signal Words on Product Labeling
Signal words are used in combination with colors and/or pictures
or product labels.
Safety−alert symbol
When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS 3...............................
INTRODUCTION 4.........................................
CODES AND STANDARDS 4................................
SAFETY 4.................................................
GENERAL INSTALLATION 5.................................
COMBUSTION AND VENTILATION AIR 5.....................
DUCT SYSTEMS 5.........................................
ACOUSTICAL LINING AND FIBROUS GLASS DUCT 5..........
GAS PIPING AND GAS PIPE PRESSURE TESTING 5..........
ELECTRICAL CONNECTIONS 5.............................
VENTING 5...............................................
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS PROCEDURE 5.............................
LOCATION 6..............................................
AIR FOR COMBUSTION AND VENTILATION 8.................
INSTALLATION 10..........................................
UPFLOW INSTALLATION 10.................................
DOWNFLOW INSTALLATION 11.............................
HORIZONTAL INSTALLATION 12.............................
FILTER ARRANGEMENT 13.................................
AIR DUCTS 13.............................................
GAS PIPING 16............................................
ELECTRICAL CONNECTIONS 19............................
SERVICE AND MAINTENANCE PROCEDURES 40.............
SEQUENCE OF OPERATION 44.............................
WIRING DIAGRAM 46......................................
TROUBLESHOOTING GUIDE 47.............................
Use of the AHRI Certified TM Mark indicates a manufacturer’s participation in the
program. For verification of certification for
individual products, go to www.ahridirectory.org .
!
WARNING
PERSONAL INJURY, AND/OR PROPERTY
DAMAGE HAZARD
Failure to carefully read and follow this warning could
result in equipment malfunction, property damage,
personal injury and/or death.
Installation or repairs made by unqualified persons
could result in equipment malfunction, property
damage, personal injury and/or death.
The information contained in this manual is intended for
use by a qualified service technician familiar with safety
procedures and equipped with proper tools and test
instruments.
Installation must conform with local building codes and
with the Natural Fuel Gas Code (NFCG) NFPA
54/ANSI Z223.1
INSTALLER: Affix these instructions on or adjacent to the furnace.
CONSUMER: Retain these instructions for future reference.
Portions of the text and tables are reprinted from NFPA 54 /ANSI Z223.1−2012©, with permission of National Fire Protection Association, Quincy, MA 02269 and American Gas Association, Washing-
ton, DC 20001. This reprinted material is not the complete and official position of the NFPA or ANSI, on the referenced subject, which is represented only by the standard in its entirety.
Printed in U.S.A. 441 01 1411 04 July 2013
Figure 1 − Dimensional Drawing
VENT
NOTES:
1. Two additional 7/8−in. (22 mm) diameter holes are located in the top plate.
2. 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. (406 mm) round or 14 1/2 x 12−in. (368 x 305 mm) rectangle. ....
b. For 1200 CFM−20−in. (508 mm) round or 14 1/2 x 19 1/2−in. (368 x 495 mm) rectangle. ....
c. For 1600 CFM−22−in. (559 mm) round or 14 1/2 x 22 1/16−in. (368 x 560mm) rectangle. ....
d. For airflow requirements above 1800 CFM, see Air Delivery table in Product Data literature for specific use of single side inlets. The use of both side inlets, a ....
combination of 1 side and the bottom, or the bottom only will ensure adequate return air openings for airflow requirements above 1800 CFM.....
A B C D
FURNACE SIZE
0451408 14−3/16 (360) 12−9/16 (319) 9−5/16 (237) 12−11/16 (322) 4 (102) 104 (47)
0701716 17−1/2 (445) 15−7/8 (403) 11−9/16 (294) 16 (406) 4 (102) 126 (57)
0902116 21 (533) 19−3/8 (492) 13−5/16 (338) 19−1/2 (495) 4 (102) 140 (64)
1102120 21 (533) 19−3/8 (492) 13−5/16 (338) 19−1/2 (495) 4 (102) 152 (69)
1352420 24−1/2 (622) 22−7/8 (581) 15−1/16 (383) 23 (584) 4 (102)* 163 (74)
* 135 size furnaces require a 5 in. or 6 in. (127 or 152 mm) vent. Use a vent adapter between furnace and vent stack.
2
CABINET WIDTH
IN. (MM)
OUTLET WIDTH
IN. (MM)
Specifications are subject to change without notice.
Table 1 – Dimensions
TOP AND BOTTOM
FLUE COLLAR
IN. (MM)
BOTTOM WIDTH
IN. (MM)
VENT
CONNECTION
SIZE*
IN. (MM)
441 01 1411 04
SHIP WT
(LB / KG)
SAFETY CONSIDERATIONS
!
FIRE, EXPLOSION, ELECTRICAL SHOCK, AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in dangerous
operation, serious injury, death, or property damage.
Improper installation, adjustment, alteration, service,
maintenance, or use could cause carbon monoxide
poisoning, explosion, fire, electrical shock, or other
conditions which may cause personal injury or property
damage. Consult a qualified service agency, local gas
supplier, or your distributor or branch for information or
assistance. The qualified service agency must use only
factory−authorized and listed kits or accessories when
modifying this product.
FURNACE RELIABILITY HAZARD
Improper installation or misapplication of furnace may
require excessive servicing or cause premature
component failure.
Application of this furnace should be indoors with
special attention given to vent sizing and material,
gas input rate, air temperature rise, unit leveling, and
unit sizing.
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical
shock, or other conditions which may cause death, personal
injury, or property damage. Consult a qualified installer,
service agency, or your distributor or branch for information or
assistance. The qualified installer or agency must use
factory−authorized kits or accessories when modifying this
product. Refer to the individual instructions packaged with
the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective
clothing, and work gloves. Have a fire extinguisher available.
Read these instructions thoroughly and follow all warnings or
cautions include in literature and attached to the unit. Consult
local building codes, the current editions of the National Fuel
Gas Code (NFGC) NFPA 54/ANSI Z223.1 and the National
Electrical Code (NEC) NFPA 70.
Recognize safety information. This is the safety−alert symbol
. When you see this symbol on the unit and in instructions
or manuals, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and
CAUTION. These words are used with the safety−alert
symbol. DANGER identifies the most serious hazards which
will result in severe personal injury or death. WARNING
signifies hazards which could result in personal injury or
death. CAUTION is used to identify unsafe practices which
may result in minor personal injury or product and property
damage. NOTE is used to highlight suggestions which will
result in enhanced installation, reliability, or operation.
441 01 1411 04
WARNING
!
CAUTION
Specifications are subject to change without notice.
!
CAUTION
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs.
Use care and wear appropriate protective clothing,
safety glasses and gloves when handling parts and
servicing furnaces.
1. Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.
2. Install this furnace only in a location and position as
specified in the “Location” section of these instructions.
3. Provide adequate combustion and ventilation air to the
furnace space as specified in “Air for Combustion and
Ventilation” section.
4. Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system only,
as specified in the “Venting” section of these instructions.
5. Never test for gas leaks with an open flame. Use a
commercially available soap solution made specifically
for the detection of leaks to check all connections, as
specified in the “Gas Piping” section.
6. Always install furnace to operate within the furnace’s
intended temperature−rise range with a duct system
which has an external static pressure within the allowable range, as specified in the “Start−Up, Adjustments,
and Safety Check” section. See furnace rating plate.
7. When a furnace is installed so that supply ducts carry
air circulated by the furnace to areas outside the space
containing the furnace, the return air shall also be
handled by duct(s) sealed to the furnace casing and
terminating outside the space containing the furnace.
See “Air Ducts” section.
8. A gas−fired furnace for installation in a residential gar-
age must be installed as specified in the warning box in
the “Location” section.
9. The furnace may be used for construction heat
provided that the furnace installation and operation
complies with the first CAUTION in the LOCATION section of these instructions.
10. These Multipoise Gas−Fired Furnaces are CSA
(formerly A.G.A. and C.G.A). design−certified for use
with natural and propane gases (see furnace rating
plate) and for installation in alcoves, attics, basements,
closets, utility rooms, crawlspaces, and garages. The
furnace is factory−shipped for use with natural gas. A
CSA listed accessory gas conversion kit is required to
convert furnace for use with propane gas.
11. See Figure 2 for required clearances to combustible
construction.
12. Maintain a 1−in. (25 mm) clearance from combustible
materials to supply air ductwork for a distance of 36
inches (914 mm) horizontally from the furnace. See
NFPA 90B or local code for further requirements.
13. These furnaces SHALL NOT be installed directly on
carpeting, tile, or any other combustible material other
than wood flooring. In downflow installations, factory
accessory floor base MUST be used when installed on
combustible materials and wood flooring. Special base
is not required when this furnace is installed on manufacturer’s coil model numbers END4X, ENW4X or coil
casing model number NAEA. See Figure 2 for clearance to combustible construction information.
3
INTRODUCTION
F8MXN, G8MXN, F8MXL, and G8MXL, 4−way multipoise
Category I fan−assisted furnace is CSA design−certified. A
Category I fan−assisted furnace is an appliance equipped
with an integral mechanical means to either draw or force
products of combustion through the combustion chamber
and/or heat exchanger. The furnace is factory−shipped for
use with natural gas.
This furnace is not approved for installation in mobile homes,
recreational vehicles, or outdoors. This furnace is designed
for minimum continuous return−air temperature of 60_F
Figure 2 − Clearances to Combustibles
(16_C)db or intermittent operation down to 55_F (13_C) db
such as when used with a night setback thermostat.
Return−air temperature must not exceed 85_F (29_C) db.
Failure to follow these return−air temperature limits may affect
reliability of heat exchangers, motors, and controls. (See
Figure 3).
For accessory installation details, refer to the applicable
instruction literature.
NOTE: Remove all shipping brackets and materials before
operating the furnace.
CODES AND STANDARDS
Follow all national and local codes and standards in addition
to these instructions. The installation must comply with
regulations of the serving gas supplier, local building, heating,
plumbing, and other codes. In absence of local codes, the
installation must comply with the national codes listed below
and all authorities having jurisdiction.
4
In the United States, follow all codes and standards for the
following:
Safety
S USA: National Fuel Gas Code (NFGC) NFPA
Specifications are subject to change without notice.
54−2012/ANSI Z223.1−2012 and the Installation
Standards, Warm Air Heating and Air Conditioning
Systems ANSI/NFPA 90B
441 01 1411 04
Figure 3 − Return Air Temperature
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS PROCEDURE
80_F/27_C
60_F/16_C
General Installation
S Current edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association Inc., Batterymarch Park, Quincy, MA 02269;
(www.NFPA.org) or for only the NFGC, contact the
American Gas Association, 400 N. Capitol Street,
N.W., Washington, DC 20001 (www.AGA.org).
Combustion and Ventilation Air
S NFGC NFPA54/ANSI Z223.1−2012 Section 9.3, Air
for Combustion and Ventilation.
Duct Systems
S Air Conditioning Contractors Association (ACCA)
Manual D, Sheet Metal and Air Conditioning Contractors National Association (SMACNA), or American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) 2005 Fundamentals
Handbook Chapter 35 or 2004 HVAC Systems and
Equipment Handbook Chapters 9 and 16.
Acoustical Lining and Fibrous Glass Duct
S Current edition of SMACNA and NFPA 90B as
tested by UL Standard 181 for Class I Rigid Air
Ducts
Gas Piping and Gas Pipe Pressure Testing
S NFGC NFPA54/ANSI Z223.1−2012; chapters 5, 6,
7, and 8 and National Plumbing Codes.
Electrical Connections
S National Electrical Code (NEC) ANSI/NFPA
70−2011.
Venting
S NFGC NFPA 54 / ANSI Z223.1−2012; Chapters 12
and 13.
A06745
!
CAUTION
FURNACE RELIABILITY HAZARD
Improper installation or service of furnace may cause
premature furnace component failure.
Electrostatic discharge can affect electronic
components. Follow the Electrostatic Discharge
Precautions Procedure listed below during furnace
installation and servicing to protect the furnace
electronic control. Precautions will prevent electrostatic
discharges from personnel and hand tools which are
held during the procedure. These precautions will help
to avoid exposing the control to electrostatic discharge
by putting the furnace, the control, and the person at the
same electrostatic potential.
1. Disconnect all power to the furnace. Multiple disconnects may be required. DO NOT TOUCH THE
CONTROL OR ANY WIRE CONNECTED TO THE
CONTROL PRIOR TO DISCHARGING YOUR BODY’S
ELECTROSTATIC CHARGE TO GROUND.
2. Firmly touch the clean, unpainted, metal surface of the
furnace chassis which is close to the control. Firmly
touch the clean, unpainted, metal surface of the furnace chassis which is close to the control. Tools held in
a person’s hand during grounding will be satisfactorily
discharged.
3. After touching the chassis, you may proceed to service
the control or connecting wires as long as you do nothing to recharge your body with static electricity (for example; DO NOT move or shuffle your feet, do not touch
ungrounded objects, etc.).
4. If you touch ungrounded objects (and recharge your
body with static electricity), firmly touch a clean, unpainted metal surface of the furnace again before
touching control or wires.
5. Use this procedure for installed and uninstalled (ungrounded) furnaces.
6. Before removing a new control from its container, discharge your body’s electrostatic charge to ground to
protect the control from damage. If the control is to be
installed in a furnace, follow items 1 through 4 before
bringing the control or yourself in contact with the furnace. Put all used and new controls into containers before touching ungrounded objects.
7. An ESD service kit (available from commercial
sources) may also be used to prevent ESD damage.
441 01 1411 04
Specifications are subject to change without notice.
5
THE BLOWER IS LOCATED
TO THE RIGHT OF THE
BURNER SECTION, AND
AIR CONDITIONED AIR IS
DISCHARGED TO THE LEFT.
Figure 4 − Multipoise Orientations
THE BLOWER IS
LOCATED BELOW THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED UPWARD.
THE BLOWER IS
LOCATED ABOVE THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED DOWNWARD
LOCATION
GENERAL
This multipoise furnace is shipped in packaged configuration.
Some assembly and modifications are required when used in
any of the four applications shown in Figure 4.
This furnace must:
S be installed so the electrical components are protec-
ted from water.
S not be installed directly on any combustible material
other than wood flooring for upflow applications.
Downflow installations require use of a factory−approved floor base or coil model numbers END4X,
ENW4X or coil casing model number NAEA when
installed on combustible materials or wood flooring
(refer to SAFETY CONSIDERATIONS).
S be located as close to the chimney or vent and at-
tached to an air distribution system. Refer to Air
Ducts section.
S be provided ample space for servicing and cleaning.
Always comply with minimum fire protection clearances shown on the furnace clearance to combustible label.
The following types of furnace installations may require
OUTDOOR AIR for combustion due to chemical exposures:
S Commercial buildings
S Buildings with indoor pools
S Laundry rooms
S Hobby or craft rooms, and
S Chemical storage areas
THE BLOWER IS
LOCATED TO THE LEFT
OF THE BURNER SECTION,
AND CONDITIONED AIR IS
DISCHARGED TO THE RIGHT.
A02097
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death, and unit component damage.
Corrosive or contaminated air may cause failure of
parts containing flue gas, which could leak into the
living space. Air for combustion must not be
contaminated by halogen compounds, which include
fluoride, chloride, bromide, and iodide. These
elements can corrode heat exchangers and shorten
furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents,
salts, air fresheners, and other household products.
Do not install furnace in a corrosive or contaminated
atmosphere. Make sure all combustion and
circulating air requirements are met, in addition to all
local codes and ordinances.
If air is exposed to the following substances, it should not be
used for combustion air, and outdoor air may be required for
combustion:
WARNING
S Permanent wave solutions
S Chlorinated waxes and cleaners
S Chlorine based swimming pool chemicals
S Water softening chemicals
S De−icing salts or chemicals
S Carbon tetrachloride
S Halogen type refrigerants
S Cleaning solvents (such as perchloroethylene)
S Printing inks, paint removers, varnishes, etc.
S Hydrochloric acid
S Cements and glues
S Antistatic fabric softeners for clothes dryers
S Masonry acid washing materials
6
Specifications are subject to change without notice.
441 01 1411 04
All fuel−burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal
must be made between the furnace cabinet and the
return−air duct to prevent pulling air from the burner area and
from draft safeguard opening.
Figure 5 − Installation in a Garage
18−IN. (457.2 mm)
MINIMUM TO BURNERS
A93044
!
WARNING
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
When the furnace is installed in a residential garage,
the burners and ignition sources must be located at
least 18 inches above the floor. The furnace must be
located or protected to avoid damage by vehicles.
When the furnace is installed in a public garage,
airplane hangar, or other building having a hazardous
atmosphere, the furnace must be installed in
accordance with the NFGC.
!
CAUTION
PERSONAL INJURY AND/OR PROPERTY
DAMAGE HAZARD
Improper use or installation of this furnace may cause
premature furnace component failure.
This gas furnace may be used for heating buildings
under construction provided that:
−The furnace is permanently installed with all electrical
wiring, piping, venting and ducting installed according to
these installation instructions. A return air duct is
provided, sealed to the furnace casing, and terminated
outside the space containing the furnace. This prevents a
negative pressure condition as created by the circulating
air blower, causing a flame rollout and/or drawing
combustion products into the structure.
−The furnace is controlled by a thermostat. It may not be
“hot wired” to provide heat continuously to the structure
without thermostatic control.
−Clean outside air is provided for combustion. This is to
minimize the corrosive effects of adhesives, sealers and
other construction materials. It also prevents the
entrainment of drywall dust into combustion air, which
can cause fouling and plugging of furnace components.
−The temperature of the return air to the furnace is
maintained between 55_F (13_C) and 80_F (27_C), with
no evening setback or shutdown. The use of the furnace
while the structure is under construction is deemed to be
intermittent operation per our installation instructions.
−The air temperature rise is within the rated rise range on
the furnace rating plate, and the gas input rate has been
set to the nameplate value.
−The filters used to clean the circulating air during the
construction process must be either changed or
thoroughly cleaned prior to occupancy.
−The furnace, ductwork and filters are cleaned as
necessary to remove drywall dust and construction
debris from all HVAC system components after
construction is completed. −Verify proper furnace
operating conditions including ignition, gas input rate, air
temperature rise, and venting according to these
installation instructions.
Table 2 – Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
TWO HORIZONTAL DUCTS
FURNACE
INPUT
(BTUH)
44,000 22 (14193) 6 (152) 14.7 (9484) 5 (127) 11 (7097) 4 (102)
66,000 33 (21290) 7 (178) 22 (14193) 6 (152) 16.5 (10645) 5 (127)
88,000 44 (28387) 8 (203) 29.3 (18903) 7 (178) 22 (14193) 6 (152)
110,000 55 (35484) 9 (229) 36.7 (23677) 7 (178) 27.5 (17742) 6 (152)
132,000 66 (42581) 10 (254) 44 (28387) 8 (203) 33 (21290) 7 (178)
FURNACE
110,000 + 30,000 = (140,000 divided by 4,000) = 35.0 Sq. In. for each two Vertical Ducts or Openings
66,000 + 40,000 = (106,000 divided by 3,000) = 35.3 Sq. In. for a Single Duct or Opening
88,000 + 30,000 = (118,000 divided by 2,000) = 59.0 Sq. In. for each of two Horizontal Ducts
(1 SQ. IN./2,000 BTUH)
(1,100 SQ. MM/KW)
Free Area of Open-
ing and Duct
(sq. in. / sq. mm)
WATER
HEATER
Round Duct
Diameter
(in./mm)
441 01 1411 04
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH)
(734 SQ. MM/KW)
Free Area of Open-
ing and Duct
(sq. In. / sq. mm)
Round Duct
Diameter
(in. / mm)
EXAMPLES: Determining Free Area
TOTAL INPUT
Specifications are subject to change without notice.
TWO OPENINGS OR VERTICAL
Free Area of
Opening and Duct
(sq. In. / sq. mm)
DUCTS
(1 SQ. IN./4,000 BTUH)
(550 SQ. MM/KW)
Round Duct
Diameter
(In./mm)
7
Table 3 – Minimum Space volumes for 100% combustion, Ventilation, and Dilution from Indoors
OTHER THAN FAN−ASSISTED TOTAL
ACH
0.60 1,050 1,400 1,750 1,100 1,650 2,200 2,750 3,300
0.50 1,260 1,680 2,100 1,320 1,980 2,640 3,300 3,960
0.40 1,575 2,100 2,625 1,650 2,475 3,300 4,125 4,950
0.30 2,100 2,800 3,500 2,200 3,300 4,400 5,500 6,600
0.20 3,150 4,200 5,250 3,300 4,950 6,600 8,250 9,900
0.10 6,300 8,400 10,500 6,600 9,900 13,200 16,500 19,800
0.00 NP NP NP NP NP NP NP NP
ACH = Air Changes/Hour
NP = Not Permitted
(1,000’S BTUH GAS INPUT RATE
30 40 50 44 66 88 110 132
Space Volume (ft.3)
FAN −ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
AIR FOR COMBUSTION AND
!
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
Do not install the furnace on its back or hang furnace
with control compartment facing downward. Safety
control operation will be adversely affected. Never
connect return−air ducts to the back of the furnace.
(See Figure 6)
Figure 6 − Prohibit Installation on Back
WARNING
VENTILATION
Provisions for adequate combustion, ventilation, and dilution
air must be provided in accordance with:
S U.S. installations: Section 9.3 of the NFGC
NFPA54/ANSI Z223.1−2012, Air for Combustion and
Ventilation, and applicable provisions of the local
building codes.
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal
injury or death.
The operation of exhaust fans, kitchen ventilation
fans, clothes dryers, attic exhaust fans or fireplaces
could create a NEGATIVE PRESSURE CONDITION
at the furnace. Make−up air MUST be provided for the
ventilation devices, in addition to that required by the
furnace. Refer to Carbon Monoxide Poisoning Hazard
warning in venting section of these instructions to
determine if an adequate amount of make−up air is
available.
WARNING
A02054
!
CAUTION
FURNACE CORROSION HAZARD
Failure to follow this caution may result in furnace
damage.
Air for combustion must not be contaminated by
halogen compounds, which include fluoride, chloride,
bromide, and iodide. These elements can corrode
heat exchangers and shorten furnace life. Air
contaminants are found in aerosol sprays,
detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
LOCATION RELATIVE TO COOLING EQUIPMENT
The cooling coil must be installed parallel with, or on the
downstream side of the unit to avoid condensation in the heat
exchangers. When installed parallel with the furnace,
dampers or other flow control must prevent chilled air from
entering the furnace. If the dampers are manually operated,
they must be equipped with means to prevent operation of
either unit unless the damper is in the full−heat or full−cool
position.
8
Specifications are subject to change without notice.
The requirements for combustion and ventilation air depend
upon whether or not the furnace is located in a space having
a volume of at least 50 cubic feet per 1,000 Btuh input rating
for all gas appliances installed in the space.
S Spaces having less than 50 cubic feet per 1,000
Btuh require the OUTDOOR COMBUSTION AIR
METHOD.
S Spaces having at least 50 cubic feet per 1,000 Btuh
may use the INDOOR COMBUSTION AIR,
STANDARD or KNOWN AIR INFILTRATION
METHOD.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper combustion, ventilation, and dilution of flue gases using permanent horizontal or vertical duct(s) or opening(s) directly communicating with the outdoors or spaces that
freely communicate with the outdoors.
2. Figure 7 illustrates how to provide TWO OUTDOOR
OPENINGS, one inlet and one outlet combustion and
ventilation air opening, to the outdoors.
a. One opening MUST commence within 12−in. (300
mm) of the ceiling and the second opening MUST
commence within 12−in. (300 mm) of the floor.
b. Size openings and ducts per Figure 7 and Table 2.
441 01 1411 04
c. TWO HORIZONTAL DUCTS require 1 square inch of
free area per 2,000 Btuh (1,100 mm
2
/kW) of combined
input for all gas appliances in the space per Figure 7
and Table 2.
d. TWO OPENINGS OR VERTICAL DUCTS require 1
square inch of free area per 4,000 Btuh (550 mm2/kW)
for combined input of all gas appliances in the space
per Figure 7 and Table 2.
3. ONE OUTDOOR OPENING requires:
a. 1 square inch of free area per 3,000 Btuh (734
2
mm
/kW) for combined input of all gas appliances in
the space per Table 2 and
b. Not less than the sum of the areas of all vent connect-
ors in the space.
The opening shall commence within 12” (300 mm) of the
ceiling. Appliances in the space shall have clearances of at
least 1” (25 mm) from the sides and back and 6” (150 mm)
from the front. The opening shall directly communicate with
the outdoors or shall communicate through a vertical or
horizontal duct to the outdoors or spaces (crawl or attic) that
freely communicate with the outdoors.
Figure 7 − Air for Combustion, Ventilation, and Dilution
from Outdoors
1 SQ IN.
E
12 ″ MAX
(305mm)
1 SQ IN.
PER 4000
BTUH*
PER 4000
BTUH*
F
1 SQ IN .
BTUH*
1 SQ IN .
BTUH*
G
12 ″
(305mm)
MAX
PER
4000
OUTDOORS
PER
4000
12 ″
(305mm)
MAX
A03174
DUCTS
TO
O UTDOORS
(305mm)
12 ″ MAX
1 SQ IN.
PER 2000
BTUH*
DUCT S
TO
OUTDOORS
1 SQ IN.
PER 2000
BTUH*
(305mm)
12 ″ MAX
CIRCULA TING AIR DUCT S
*Minimum dimensions of 3 in. (76 mm).
NOTE: Use any of the following combinations of openings:
A&B, C&D, D&E, F&G
B
AIR DUCTS
C IRCULA TING
A
OF COMB USTION AIR
CLEARANCE IN FRONT
D
VENT
THR OUGH
R OOF
(76mm)
AT LEAST 3 IN .
OPENINGS SHALL BE
C
DUCT
TO
OUTDOORS
Indoor Combustion Air − NFPA & AGA
Standard and Known−Air−Infiltration Rate Methods
Indoor air is permitted for combustion, ventilation, and
dilution, if the Standard or Known−Air−Infiltration Method is
used.
!
WARNING
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in death
and/or personal injury.
Many homes require air to be supplied from outdoors
for furnace combustion, ventilation, and dilution of flue
gases. The furnace combustion air supply must be
provided in accordance with this instruction manual.
The Standard Method:
1. The space has no less volume than 50 cubic feet per
1,000 Btuh of the maximum input ratings for all gas appliances installed in the space and
2. The air infiltration rate is not known to be less than 0.40
air changes per hour (ACH).
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH
Infiltration rates greater than 0.60 ACH shall not be used. The
minimum required volume of the space varies with the
number of ACH and shall be determined per Table 3 or
Equations 1 and 2. Determine the minimum required volume
for each appliance in the space and add the volumes
together to get the total minimum required volume for the
space.
Table 3 − Minimum Space Volumes were determined by
using the following equations from the National Fuel Gas
Code ANSI Z223.1−2012/NFPA 54−2012, 9.3.2.2:
1. For other than fan−assisted appliances, such as a
draft hood−equipped water heater:
Volume
Other
=
21ft
ACH
3
I
other
1000 Btu/hr
A04002
2. For fan−assisted appliances such as this furnace:
Volume
Fan
=
15ft
ACH
3
I
fan
1000 Btu/hr
A004003
If:
Iother = combined input of all other than fan−assisted
appliances
in Btuh/hr
Ifan = combined input of all fan−assisted appliances in
Btuh/hr
ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the Standard Method
and to the Known Air Infiltration Rate Method.
1. Adjoining rooms can be considered part of a space if:
a. There are no closeable doors between rooms.
b. Combining spaces on same floor level. Each opening
shall have free area of at least 1 in.
2
mm
/kW) of the total input rating of all gas appliances
in the space, but not less than 100 in.
2
/1,000 Btuh (2,000
2
(0.06 m2). One
opening shall commence within 12” (300 mm) of the
ceiling and the second opening shall commence with-
441 01 1411 04
Specifications are subject to change without notice.
9
in 12” (300 mm) of the floor. The minimum dimension
of air openings shall be at least 3 in. (80 mm). (See
Figure 8)
c. Combining space on different floor levels. The
volumes of spaces on different floor levels shall be
considered as communicating spaces if connected by
one or more permanent openings in doors or floors
having free area of at least 2 in.
2
mm
/kW) of total input rating of all gas appliances.
2
/1,000 Btuh (4,400
Figure 8 − Air for Combustion, Ventilation, and Dilution
from Indoors
Combination of Indoor and Outdoor Air
1. Indoor openings shall comply with the Indoor Combustion Air Method below and,
2. Outdoor openings shall be located as required in the
Outdoor Combustion Air Method mentioned previously and,
3. Outdoor openings shall be sized as follows:
a. Calculate the Ratio of all Indoor Space volume divided
by required volume for Indoor Combustion Air Method below.
Figure 9 − Removing Bottom Closure Panel
CIRCULATING AIR
DUCTS
INTERIOR
HEATED
SPACE
CIRCULATING AIR DUCTS
2
*Minimum opening size is 100 in.
*Minimum of 3 in. (76 mm), when type −B1 vent is used.
VENT THROUGH ROOF
12" MAX
(305mm)
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
UNCONFINED
SPACE
(152mm)
6" MIN
Ü
(FRONT)
1 SQ IN.
PER 1000
BTUH* IN DOOR
OPENINGS SHALL BE AT LEAST 3 IN.
OR WALL
CLEARANCE IN FRONT OF COMBUSTION AIR
with minimum dimensions of 3 in. (76 mm).
12" MA X
(305mm)
A03175
2. An attic or crawlspace may be considered a space that
freely communicates with the outdoors provided there
are adequate permanent ventilation openings directly
to outdoors having free area of at least 1−in.
2
/4,000
Btuh of total input rating for all gas appliances in the
space.
3. In spaces that use the Indoor Combustion Air Meth-
od, infiltration should be adequate to provide air for
combustion, permanent ventilation and dilution of flue
gases. However, in buildings with unusually tight construction, additional air MUST be provided using the
methods described in the Outdoor Combustion Air
Method section.
Unusually tight construction is defined as construction with:
a. Walls and ceilings exposed to the outdoors have a
continuous, sealed vapor barrier. Openings are gasketed or sealed and
b. Doors and openable windows are weatherstripped
and
c. Other openings are caulked or sealed. These include
joints around window and door frames, between sole
plates and floors, between wall−ceiling joints, between
wall panels, at penetrations for plumbing, electrical
and gas lines, etc.
BOTTOM
CLOSURE
PANEL
BOTTOM
FILLER PANEL
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. The minimum dimension of air openings shall be not less than
3 in. (80 mm).
INSTALLATION
UPFLOW INSTALLATION
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel
installed in bottom return−air opening. Remove and discard
this panel when bottom return air is used. To remove bottom
closure panel, perform the following:
1. Tilt or raise furnace and remove two screws holding
bottom filler panel. (See Figure 9)
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
Side Return Air Inlet
These furnaces are shipped with bottom closure panel
installed in bottom return−air opening. This panel MUST be in
place when only side return air is used.
NOTE: Side return−air openings can be used in UPFLOW
and most HORIZONTAL configurations. Do not use side
return−air openings in DOWNFLOW configuration.
Leveling Legs (If Desired)
In upflow position with side return inlet(s), leveling legs may
be used. (See Figure 10) Install field−supplied, 5/16 x 1−1/2
in. (8 x 38 mm) (max) corrosion−resistant machine bolts,
washers and nuts.
NOTE: Bottom closure must be used when leveling legs are
used. It may be necessary to remove and reinstall bottom
10
Specifications are subject to change without notice.
441 01 1411 04
closure panel to install leveling legs. To remove bottom
closure panel, see Item 1. in Bottom Return Air Inlet section.
To install leveling legs:
1. Position furnace on its back. Locate and drill a hole in
each bottom corner of furnace. (See Figure 10)
2. For each leg, install nut on bolt and then install bolt and
nut in hole. (Install flat washer if desired.)
3. Install another nut on other side of furnace base. (Install flat washer if desired.)
Figure 10 − Leveling Legs
5/
16″
(8mm)
(8mm)
5/
16″
1 3/ 4″
(44mm)
Figure 11 − Floor and Plenum Opening Dimensions
A
B D
C
3
/ 4″
1
(44mm)
(8mm)
5
/ 16″
(8mm)
5/
16″
1
(44mm)
3/
4″
3/
4″
1
A89014
(44mm)
4. Adjust outside nut to provide desired height, and tighten inside nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
DOWNFLOW INSTALLATION
NOTE: For downflow applications, this furnace is approved
for use on combustible flooring when any one of the following
two accessories are used:
S Downflow combustible floor subbase
S Coil model numbers END4X, ENW4X
S Coil casing model number NAEA
1. Determine application being installed from Table 4.
2. Construct hole in floor per Table 4 and Figure 11.
3. Construct plenum to dimensions specified in Table 4
and Figure 11.
4. If downflow subbase is used, install as shown in
Figure 12. If coil model numbers END4X, ENW4X or
coil casing model number NAEA are used, install as
shown in Figure 13.
NOTE: It is recommended that the perforated supply−air duct
flanges be completely folded over or removed from furnace
when installing the furnace on a factory−supplied cased coil
or coil casing. To remove the supply−air duct flange, use wide
duct pliers or hand seamers to bend flange back and forth
until it breaks off. Be careful of sharp edges. (See Figure 14)
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel
installed in
this panel when
closure panel,
1. Tilt or raise furnace and remove two screws holding
2. Rotate bottom filler panel downward to release holding
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws
441 01 1411 04
bottom return−air opening. Remove and discard
bottom return air is used. To remove bottom
perform the following:
bottom filler panel. (See Figure 9)
tabs.
Specifications are subject to change without notice.
A96283
Figure 12 − Furnace, Plenum, and Subbase Installed
on a Combustible Floor
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
A96285
Figure 13 − Furnace, Plenum, and Coil or
Coil Casing Installed on a Combustible Floor
FURNACE
APPROVED
COIL ASSEMBLY
OR
COIL BOX
COMBUSTIBLE
FLOORING
SHEET METAL
PLENUM
FLOOR
OPENING
A08556
11
Table 4 – Opening Dimensions − In. (mm)
FURNACE
CASING
WIDTH
14–3/16
(360)
17–1/2
(445)
21
(533)
24−1/2
(622)
APPLICATION
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow Applications on Combustible Flooring (subbase required)
Downflow Applications on Combustible Flooring with Coil END4X,
ENW4X or Coil Casing NAEA (subbase not required)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow Applications on Combustible Flooring (subbase required)
Downflow Applications on Combustible Flooring Coil with Coil
END4X, ENW4X or Coil Casing NAEA (subbase not required)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow Applications on Combustible Flooring (subbase required)
Downflow Applications on Combustible Flooring with Coil END4X,
ENW4X or Coil Casing NAEA (subbase not required)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
Downflow Applications on Noncombustible Flooring
(subbase not required)
Downflow Applications on Combustible Flooring (subbase required)
Downflow Applications on Combustible Flooring with Coil END4X,
ENW4X or Coil Casing NAEA (subbase not required)
PLENUM OPENING FLOOR OPENING
A B C D
12−11/16
(322)
12−9/16
(319)
11−13/16
(284)
12−5/16
(313)
16
(406)
15−7/8
(403)
15−1/8
(384)
15−1/2
(394)
19−1/2
(495)
19−3/8
(492)
18−5/8
(473)
19
(483)
23
(584)
22−7/8
(581)
22−1/8
(562)
22−1/2
(572)
21−5/8
(549)
19
(483)
19
(483)
19
(483)
21−5/8
(549)
19
(483)
19
(483)
19
(483)
21−5/8
(549)
19
(483)
19
(483)
19
(483)
21−1/8
(537)
19
(483)
19
(483)
19
(483)
13−5/16
(338)
13−3/16
(335)
13−7/16
(341)
13−5/16
(338)
16−5/8
(422)
16−1/2
(419)
16−3/4
(425)
16−1/2
(419)
20−1/8
(511)
20
(508)
20−1/4
(514)
20
(508)
23−5/8
(600)
23−1/2
(597)
23−3/4
(603)
23−1/2
(597)
22−1/4
19−5/8
20−5/8
22−1/4
19−5/8
20−5/8
22−1/4
19−5/8
20−5/8
22−1/4
19−5/8
20−5/8
(565)
(498)
(600)
20
(508)
(565)
(498)
(600)
20
(508)
(565)
(498)
(600)
20
(508)
(565)
(498)
(600)
20
(508)
HORIZONTAL INSTALLATION
!
WARNING
FIRE, EXPLOSION, AND CARBON MONOXIDE
POISONING HAZARD
Failure to follow this warning could result in personal
injury, death, and/or property damage.
Do not install the furnace on its back or hang furnace
with control compartment facing downward. Safety
control operation will be adversely affected. Never
connect return−air ducts to the back of the furnace.
The furnace can be installed horizontally in an attic or crawl
space on either the left−hand (LH) or right−hand (RH) side.
The furnace can be hung from floor joists, rafters or trusses or
installed on a non−combustible platform, blocks, bricks or
pad.
Suspended Furnace Support
The furnace may be supported under each end with threaded
rod, angle iron or metal plumber’s strap as shown. (See
Figure 15 and Figure 16) Secure angle iron to bottom of
furnace as shown. Heavy−gauge sheet metal straps
(plumber’s straps) may be used to suspend the furnace from
each bottom corner. To prevent screws from pulling out, use 2
#8 x 3/4−in. (19 mm) screws into the side and 2 #8 x 3/4−in.
(19 mm) screws in the bottom of the furnace casing for each
strap. (See Figure 15 and Figure 16) If the screws are
attached to ONLY the furnace sides and not the bottom, the
straps must be vertical against the furnace sides and not pull
away from the furnace sides, so that the strap attachment
12
Specifications are subject to change without notice.
screws are not in tension (are loaded in shear) for reliable
support.
Platform Furnace Support
Construct working platform at location where all required
furnace clearances are met. (See Figure 2 and Figure 17) For
furnaces with 1−in. (25 mm) clearance requirement on side,
set furnace on noncombustible blocks, bricks or angle iron.
For crawl space installations, if the furnace is not suspended
from the floor joists, the ground underneath furnace must be
level and the furnace set on blocks or bricks.
Roll−Out Protection
Provide a minimum 17−3/4 in. x 22 in. (451 mm x 559 mm)
piece of sheet metal for flame roll−out protection in front of
burner area for furnaces closer than 12 inches (305 mm)
above the combustible deck or suspended furnaces closer
than 12 inches (305 mm) to joists. The sheet metal MUST
extend underneath the furnace casing by 1 in. (25 mm) with
the door removed.
The bottom closure panel on furnaces of widths 17−1/2 in.
(445 mm) and larger may be used for flame roll−out
protection when bottom of furnace is used for return air
connection. See Figure 17 for proper orientation of roll−out
shield.
Bottom Return Air Inlet
These furnaces are shipped with bottom closure panel
installed in bottom return−air opening. Remove and discard
this panel when bottom return air is used. To remove bottom
closure panel, perform the following:
1. Tilt or raise furnace and remove two screws holding
bottom filler panel. (See Figure 9)
441 01 1411 04
2. Rotate bottom filler panel downward to release holding
tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws. Side Return
Air Inlet
Side Return Air Inlet
These furnaces are shipped with bottom closure panel
installed in bottom return−air opening. This panel MUST be in
place when side return air inlet(s) is used without a bottom
return air inlet.
Not all horizontal furnaces are approved for side return air
connections. (See Figure 20).
FILTER ARRANGEMENT
!
CARBON MONOXIDE AND POISONING
HAZARD
Failure to follow this warning could result in personal
injury, or death.
Never operate a furnace without a filter or with filter
access door removed.
There are no provisions for an internal filter rack in these
furnaces.
A field−supplied accessory external filter is required.
Refer to the instructions supplied with the external filter rack
for assembly and installation options.
AIR DUCTS
General Requirements
The duct system should be designed and sized according to
accepted national standards such as those published by: Air
Conditioning Contractors Association (ACCA), Sheet Metal
and Air Conditioning Contractors National Association
(SMACNA) or American Society of Heating, Refrigerating and
Air Conditioning Engineers (ASHRAE) or consult The Air
Systems Design Guidelines reference tables available from
your local distributor. The duct system should be sized to
handle the required system design CFM at the design
external static pressure. The furnace airflow rates are
provided in Table 5 − AIR DELIVERY−CFM (With Filter).
When a furnace is installed so that the supply ducts carry air
circulated by the furnace to areas outside the space
containing the furnace, the return air shall also be handled by
duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace.
Secure ductwork with proper fasteners for type of ductwork
used. Seal supply− and return−duct connections to furnace
with code approved tape or duct sealer.
WARNING
NOTE: Flexible connections should be used between
ductwork and furnace to prevent transmission of vibration.
Ductwork passing through unconditioned space should be
insulated and sealed to enhance system performance. When
air conditioning is used, a vapor barrier is recommended.
Maintain a 1−in. (25 mm) clearance from combustible
materials to supply air ductwork for a distance of 36 in. (914
mm) horizontally from the furnace. See NFPA 90B or local
code for further requirements.
Ductwork Acoustical Treatment
NOTE: Metal duct systems that do not have a 90 degree
elbow and 10 ft. (3 M) of main duct to the first branch take−off
may require internal acoustical lining. As an alternative,
fibrous ductwork may be used if constructed and installed in
accordance with the latest edition of SMACNA construction
standard on fibrous glass ducts. Both acoustical lining and
fibrous ductwork shall comply with NFPA 90B as tested by UL
Standard 181 for Class 1 Rigid air ducts.
Supply Air Connections
For a furnace not equipped with a cooling coil, the outlet duct
shall be provided with a removable access panel. This
opening shall be accessible when the furnace is installed and
shall be of such a size that the heat exchanger can be
viewed for possible openings using light assistance or a
probe can be inserted for sampling the airstream. The cover
attachment shall prevent leaks.
Upflow and Horizontal Furnaces
Connect supply−air duct to flanges on furnace supply−air
outlet. Bend flange upward to 90_ with wide duct pliers. (See
Figure 14) The supply−air duct must be connected to ONLY
the furnace supply−outlet−air duct flanges or air conditioning
coil casing (when used). DO NOT cut main furnace casing
side to attach supply air duct, humidifier, or other accessories.
All accessories MUST be connected to duct external to
furnace main casing.
NOTE: For horizontal applications, the top−most flange may
be bent past 90 degrees to allow the evaporator coil to hang
on the flange temporarily while the remaining attachment and
sealing of the coil are performed.
Downflow Furnaces
Connect supply−air duct to supply−air outlet on furnace. Bend
flange inward past 90_ with wide duct pliers. (See Figure 14)
The supply−air duct must be connected to ONLY the furnace
supply outlet or air conditioning coil casing (when used).
When installed on combustible material, supply−air duct must
be connected to ONLY the accessory subbase or a factory
approved air conditioning coil casing. DO NOT cut main
furnace casing to attach supply side air duct, humidifier, or
other accessories. All accessories MUST be connected to
duct external to furnace casing.
441 01 1411 04
Specifications are subject to change without notice.
13
Figure 14 − Duct Flanges
UPFLOW DOWNFLOW HORIZONTAL
120°
MIN
90°
YES
YES
NO
120°
MIN
YES
YES
NO
Figure 15 − Horizontal Unit Suspension
1
/
4 " (6mm) THREADED ROD
4 REQ.
120°
MIN
90°
YES
YES
NO
A02020
OUTER DOOR
A S SEMBLY
8" (203mm)
FOR DOOR REMOVAL
(2) HEX NUTS, (2) WASHERS & (2) LOCK WASHERS
REQ. PER ROD
MIN
SECURE ANGLE
IRON TO BOTTOM
OF FURNACE WITH
3
/4" (19mm) SCREWS
3 #8 x
TYPICAL FOR 2 SUPPORTS
1” (25mm) SQUARE, 1-1/4”x1-1/4”x1/8” (32x32x3mm)
ANGLE IRON OR UNI-STRUT MAY BE USED
A10130
14
Specifications are subject to change without notice.
441 01 1411 04
Figure 16 − Horizontal Suspension with Straps
METHOD 1
FOLD ALL STRAPS UNDER
FURNACE AND SECURE WTH
(4) #8 x 3/4 (19 mm) SHEET METAL SCREWS
(2 SCREWS IN SIDE AND 2 SCREWS
IN BOTTOM).
METHOD 2
USE (4) #8 x 3/4 (19 mm) SHEET
METAL SCREWS FOR EACH
STRAP. THE STRAPS
SHOULD BE VERTICAL
AGAINST THE FURNACE
SIDES AND NOT PULL AWAY
FROM THE FURNACE
SIDES.
Figure 17 − Typical Attic Installation
LINE CONT A CT ONL Y PERMISSIBLE BETWEEN
LINES FORMED BY INTERSECTIONS OF
THE T OP AND TW O SIDES OF THE FURNA CE
JA CKET AND BUILDING JOISTS ,
STUDS , OR FRAMING.
EQUIPMENT MANU AL
SHUT -OFF GAS VA LV E
SEDIMENT
TRAP
UNION
Return Air Connections
!
WARNING
FIRE HAZARD
Failure to follow this warning could cause personal
injury, death and/or property damage.
Never connect return−air ducts to the back of the
furnace. Refer to the following instructions.
441 01 1411 04
GAS
ENTR Y
M IN
6 ″
(451mm)
17 3 / 4
22
″
(559mm)
″
SHEET
MET AL
Downflow Furnaces
The return−air duct must be connected to return−air opening
(bottom inlet) as shown in Figure 21. DO NOT cut into casing
sides (left or right). Side opening is permitted for only upflow
and most horizontal furnaces. (See Figure 21) Bypass
humidifier connections should be made at ductwork or coil
casing sides exterior to furnace.
Upflow and Horizontal Furnaces
The return−air duct must be connected to bottom, sides (left
or right), or a combination of bottom and side(s) of main
Specifications are subject to change without notice.
TYPE-B
VENT
(152mm)
*
30-IN . (762mm)
MIN WORK AREA
17 3 / 4 ″ (451mm)
4 3 / 4 ″ (121mm)
1 ″
(25mm)
EXTEND OUT 12 ″
FR OM FA CE OF DOOR
* WHEN USED W ITH
SINGLE W ALL VEN T
CONNECTIONS
OVERALL
UNDER DOOR
UNDER FURNACE
(305mm)
A10131
A10164
15
Loading...