Variable Speed Induced-Combustion Deluxe 4-Way Multipoise Furnace Installation, Start-up, Operating, and

Variable Speed Induced-Combustion Deluxe 4-Way Multipoise Furnace Installation, Start-up, Operating, and
Variable Speed
Induced-Combustion Deluxe
4-Way Multipoise Furnace
Cancels: II 315A-70-4
II 315A-70-5
4-06
Installation, Start-up, Operating, and
Service and Maintenance Instructions
Series 120/C
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
Portions of the text and tables are reprinted from NFPA 54/ANSI Z223.1-2006©, with
permission of National Fire Protection Association, Quincy, MA 02269 and American
Gas Association, Washington DC 20001. This reprinted material is not the complete
and official position of the NFPA or ANSI on the referenced subject, which is
represented only by the standard in its entirety.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS .....................................................2
INTRODUCTION ..........................................................................2
CODES AND STANDARDS........................................................4
Safety.........................................................................................4
General Installation...................................................................4
Combustion and Ventilation Air ..............................................4
Duct Systems ............................................................................4
Acoustical Lining and Fibrous Glass Duct..............................4
Gas Piping and Gas Pipe Pressure Testing..............................4
Electrical Connections ..............................................................4
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
PROCEDURE ................................................................................4
LOCATION....................................................................................5
General ......................................................................................5
Location Relative to Cooling Equipment ................................7
AIR FOR COMBUSTION AND VENTILATION ......................7
INSTALLATION .........................................................................10
Upflow Installation .................................................................10
Bottom Return Air Inlet ....................................................10
Side Return Air Inlet.........................................................10
Leveling Legs (If Desired)................................................10
Downflow Installation ............................................................10
Bottom Return Air Inlet ....................................................11
Horizontal Installation ............................................................11
Suspended Furnace Support ..............................................11
Platform Furnace Support .................................................11
Roll-Out Protection............................................................11
Bottom Return Air Inlet ....................................................14
Side Return Air Inlet.........................................................14
Filter Arrangement..................................................................12
Air Ducts.................................................................................12
General Requirements .......................................................12
Ductwork Acoustical Treatment .......................................13
Supply Air Connections ....................................................13
Return Air Connections.....................................................15
Gas Piping...............................................................................18
Electrical Connections ............................................................19
115-V Wiring.....................................................................19
J-Box Relocation ...............................................................20
Electrical Connection to J-Box .........................................19
Power Cord Installation.....................................................20
BX Cable Installation ........................................................21
24-V Wiring.......................................................................21
Accessories ........................................................................21
Venting ....................................................................................21
General Venting Requirements .........................................24
Masonry Chimney Requirements......................................29
Appliance Application Requirements ...............................29
Additional Venting Requirements.....................................30
Sidewall Venting ...............................................................33
START-UP, ADJUSTMENT, AND SAFETY CHECK ............33
General ....................................................................................33
Start-Up Procedures ...............................................................35
Adjustments ...........................................................................36
Check Safety Controls ............................................................43
Checklist..................................................................................43
SERVICE AND MAINTENANCE PROCEDURES..................43
Introduction .............................................................................46
General...............................................................................46
Electrical Controls and Wiring .........................................46
Care and Maintenance ............................................................47
Cleaning and/or Replacing Air Filter ...............................47
Blower Motor and Wheel..................................................48
Cleaning Heat Exchanger..................................................49
Sequence of Operation............................................................50
Wiring Diagrams.....................................................................54
Troubleshooting ......................................................................54
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Printed in U.S.A.
Pg 1
4-06
Tab 6a 8a
SAFETY CONSIDERATIONS
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.
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.
3. Provide adequate combustion and ventilation air to the furnace
space as specified in “Air for Combustion and Ventilation”
section.
Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, explosion, fire, electrical shock, or other conditions which may
cause personal injury or property damage. Consult a qualified
service agency, local gas supplier, or your distributor or
branch for information or assistance. The qualified service
agency must use only factory-authorized and listed kits or
accessories when modifying this product.
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.
FURNACE RELIABILITY HAZARD
Improper installation or misapplication of furnace may require excessive servicing or cause premature component
failure.
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.
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.
8. A gas-fired furnace for installation in a residential garage must
be installed as specified in the warning box in the “Location”
section.
Installing and servicing heating equipment can be hazardous due to
gas and electrical components. Only trained and qualified
personnel should install, repair, or service heating equipment.
Untrained personnel can perform basic maintenance functions
such as cleaning and replacing air filters. All other operations must
be performed by trained service personnel. When working on
heating equipment, observe precautions in literature, on tags, and
on labels attached to or shipped with furnace and other safety
precautions that may apply.
→
9. The furnace may be used for construction heat provided that
the furnace installation and operation complies with the first
CAUTION in the LOCATION section of these instructions.
10. These Multipoise Gas-Fired Furnaces are CSA (formerly
A.G.A. and C.G.A.) design-certified for use with natural and
propane gases (see furnace rating plate) and for installation in
alcoves, attics, basements, closets, utility rooms, crawlspaces,
and garages. The furnace is factory-shipped for use with
natural gas. A CSA (A.G.A. and C.G.A.) listed gas conversion
kit is required to convert furnace for use with propane gas.
These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept up with changing residential construction practices. We require these instructions as a
minimum for a safe installation.
11. See Fig. 1 for required clearances to combustible construction.
12. Maintain a 1-in. clearance from combustible materials to
supply air ductwork for a distance of 36 inches horizontally
from the furnace. See NFPA 90B or local code for further
requirements.
CUT HAZARD
Failure to follow this caution may result in personal injury.
13. These furnaces SHALL NOT be installed directly on carpeting, tile, or any other combustible material other than wood
flooring. In downflow installations, factory accessory floor
base MUST be used when installed on combustible materials
and wood flooring. Special base is not required when this
furnace is installed on manufacturer’s Coil Assembly Part No.
CD5 or CK5, or when Coil Box Part No. KCAKC is used. See
Fig. 1 for clearance to combustible construction information.
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.
Wear safety glasses and work gloves. Have fire extinguisher
available during start-up and adjustment procedures and service
calls.
. When you see this symbol on
This is the safety-alert symbol
the furnace and in instructions or manuals, be alert to the potential
for personal injury.
INTRODUCTION
The Series 120/C 4–way multipoise Category I fan-assisted
furnace is CSA (formerly A.G.A. and C.G.A.) design-certified. A
Category I fan-assisted furnace is an appliance equipped with an
integral mechanical means to either draw or force products of
combustion through the combustion chamber and/or heat exchanger. The furnace is factory-shipped for use with natural gas.
This furnace is not approved for installation in mobile homes,
recreational vehicles, or outdoors.
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies a hazard which
could result in personal injury or death. CAUTION is used to
identify hazards which may result in minor personal injury or
product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or
operation.
2
INSTALLATION
TOP / PLENUM
DESSUS / CHAMBRED'AIR
MINIMUM INCHES CLEARANCE TO COMBUSTIBLE CONSTRUCTION
DISTANCE MINIMALE EN POUCES AUX CONSTRUCTIONS COMBUSTIBLES
This forced air furnace is equipped for use with This furnace is approved for UPFLOW, DOWNFLOW, and
HORIZONTAL installations.
natural gas at altitudes 0-10,000 ft (0-3,050m).
Cette fournaise est approuvée pour l 'installation HORIZONTALE
An accessory kit, supplied by the
et la circulation d 'air VERS LE HAUT et VERS LE BAS.
manufacturer, shall be used to convert to propane
gas use or may be required for some natural gas
1"
Clearance arrows
applications.
Les fléches de dégagement
ne change pas avec
do
not
change
with
This furnace is for indoor installation in a
l 'orientation de la fournaise.
furnace
orientation.
building constructed on site.
This furnace may be installed on combustible
flooring in alcove or closet at minimum clearance
0"
as indicated by the diagram from combusitble
0"
B
E
material.
AR AC
ID È *
S
K
T
RI
This furnace may be used with a Type B-1 Vent
E
ÈR
CÔ
AC SE
E
and may be vented in common with other gas
RN A I
F U URN
fired appliances.
FO
NT
O
F R AN T
AV
FR
A V ON
T
A
N
T
S
E
EN R V
I
TR
ET C E
IE
N
3"MIN
BOTTOM
DESSOUS
* 0"
DE
SI
É
ÔT
C
0"
Cette fournaise à air pulsé est équipée
pour utilisation avec gaz naturel et altitudes
comprises entre 0-3,050m (0-10,000 pi).
Utiliser une trousse de conversion, fournie par
le fabricant, pour passer au gaz propane ou pour
certaines installations au gaz naturel.
Cette fournaise est prévue pour être
installée dans un bâtiment construit sur place.
Cette fournaise peut être installée sur
un plancher combustible dans une alcôve ou
dans un garde-robe en respectant le minimum
d'espace libre des matériaux combustibles, tel
qu´indiqué sur le diagramme.
Cette fournaise peut être utilisée avec un
conduit d´évacuation de Type B-1 ou connectée
au conduit ommun d 'autres appareils à gaz.
†
24"
MIN
Ø
Clearance in inches
Dégagement (po).
Vent Clearance to combustibles:
For Single Wall vents 6 inches (6 po).
For Type B-1 vent type 1 inch (1 po).
Dégagement de l´évent avec combustibles:
Pour conduit d´évacuation à paroi simple 6 po (6 inches).
Pour conduit d´évacuation de Type B-1 1 po (1 inch).
MINIMUM INCHES CLEARANCE TO COMBUSTIBLE CONSTRUCTION
DOWNFLOW POSITIONS:
† Installation on non-combusibible floors only.
Ø
*
For Installation on combustible flooring only when installed on special base, Part No. KGASB0201ALL,
Coil Assembly, Part No. CD5 or CK5, or Coil Casing, Part No. KCAKC.
18 inches front clearance required for alcove.
Indicates supply or return sides when furnace is in the horizontal position. 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.
DÉGAGEMENT MINIMUM EN POUCES AVEC ÉLÉMENTS
DE CONSTRUCTION COMBUSTIBLES
POUR LA POSITION COURANT DESCENDANT:
† Pour l´installation sur plancher non combustible seulement.
Ø
*
Pour l´installation sur un plancher combustible seulement quand on utilise la base spéciale, pièce
nº KGASB0201ALL, l´ensemble serpentin, pièce nº CD5 ou CK5, ou le carter de serpentin, pièce
nº KCAKC.
Dans une alcôve, on doit maintenir un dégagement à l´avant de 18 po (450mm).
La poistion indiquée concerne le côté d´entrée ou de retour quand la fournaise est dans la
position horizontale.
Le contact n´est permis qu´entre les lignes formées par les intersections du dessus et des
deux côtés de la cherrise de la fournaise et les solives, montant sous cadre de charpente.
327590-101 REV. C
Fig. 1—Clearances to Combustibles
3
Step 4—Duct Systems
•
80
US and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning Contractors National Association (SMACNA), or American Society of Heating, Refrigeration, and Air Conditioning Engineers
(ASHRAE) 2001 Fundamentals Handbook Chapter 34 or 2000
HVAC Systems and Equipment Handbook Chapters 9 and 16.
Step 5—Acoustical Lining and Fibrous Glass Duct
•
US and CANADA: current edition of SMACNA and NFPA
90B as tested by UL Standard 181 for Class I Rigid Air Ducts
Step 6—Gas Piping and Gas Pipe Pressure Testing
60
•
US: NFGC; chapters 5, 6, 7, and 12 and National Plumbing
Codes
•
CANADA: NSCNGPIC Parts 3, 4, and 5, and Appendices A,
B, E and H.
Step 7—Electrical Connections
A04036
Fig. 2—Return Air Temperature
•
US: National Electrical Code (NEC) ANSI/NFPA 70–2002
•
CANADA: Canadian Electrical Code CSA C22.1
Step 8—Venting
This furnace is designed for minimum continuous return-air
temperature of 60°F db or intermittent operation down to 55°F db
such as when used with a night setback thermostat. Return-air
temperature must not exceed 80°F db. Failure to follow these
return-air temperature limits may affect reliability of heat exchangers, motors, and controls. (See Fig. 2.)
CODES AND STANDARDS
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.
In the United States and Canada, follow all codes and standards for
the following:
Step 1—Safety
US: National Fuel Gas Code (NFGC) NFPA 54–2002/ANSI
Z223.1–2002 and the Installation Standards, Warm Air Heating
and Air Conditioning Systems ANSI/NFPA 90B
2. Firmly touch the clean, unpainted, metal surface of the furnace
chassis which is close to the control. Tools held in a person’s
hand during grounding will be satisfactorily discharged.
CANADA: CSA B149.1-00 National Standard of Canada
Natural Gas and Propane Installation Code (NSCNGPIC)
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.).
Step 2—General Installation
•
US: 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.)
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.
CANADA: NSCNGPIC. For a copy, contact Standard Sales,
CSA International, 178 Rexdale Boulevard, Etobicoke (Toronto), Ontario, M9W 1R3 Canada
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.
Step 3—Combustion and Ventilation Air
•
US: Section 8.3 of the NFGC, Air for Combustion and
Ventilation
•
CANADA: Part 7 of NSCNGPIC, Venting Systems and Air
Supply for Appliances
CANADA: NSCNGPIC Part 7 and Appendix C
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.
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.
•
•
FURNACE RELIABILITY HAZARD
Improper installation or service of furnace may cause premature furnace component failure.
NOTE: Remove all shipping brackets and materials before operating the furnace.
•
US: NFGC; chapters 10 and 13
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS
PROCEDURE
For accessory installation details, refer to the applicable instruction
literature.
•
•
4
28-7/8"
26-1/8"
(FLUE COLLAR)
25-1/4"
2-7/16"
A
22-9/16"
JUNCTION BOX
LOCATION
D
F
5-15/16"
AIRFLOW
1-5/16"
1-1/8"
OUTLET
4-13/16"
1/2" DIA. K.O.THERMOSTAT
WIRE ENTRY
1-3/4" DIA.RIGHT HAND
GAS ENTRY
8-9/16"
7/8" DIA
ACCESSORY
13/16"
19"
13/16"
1/2" DIA THERMOSTAT
WIRE ENTRY
11/16"
7-3/4"
9-5/8"
11-1/2"
3-15/16"
LEFT HAND GAS
ENTRY
7/8" DIA. K.O. WIRE ENTRY
33-5/16"
ALTERNATE
JUNCTION BOX
LOCATIONS (TYP)
24-7/8"
VENT OUTLET
5 PLACES (TYP)
14-7/8"
7/8" DIA. ACCESSORY
7/8" DIA. ACCESSORY
5-1/2"
5-1/2"
11/16"
21-5/8"
BOTTOM INLET
11/16"
E
1-11/16"
1-1/2"
3-3/4"
1-1/4"
1"
22-1/16"
SIDE INLET
24"
CASING
A04037
NOTES:
1. Two additional 7/8-in. 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. round or 14 1/2 x 12-in. rectangle.
b. For 1200 CFM-20-in. round or 14 1/2 x 19 1/2-in. rectangle.
c. For 1600 CFM-22-in. round or 14 1/2 x 22 1/16-in. 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.
Fig. 3—Dimensional Drawing
Table 1—Dimensions (IN.)
FURNACE SIZE
A
CABINET WIDTH
(IN.)
D
SUPPLY-AIR
WIDTH
(IN.)
E
RETURN-AIR
WIDTH
(IN.)
070-12/036070
14-3/16
12-9/16
12-11/16
9-5/16
4
127
16
090-16/048090
17-1/2
15-7/8
16
11-9/16
4
151
16
110-20/060110
21
19-3/8
19-1/2
13-5/16
4
163
20
135-22/066135
24-1/2
22-7/8
23
15-1/16
4†
177
24
155-22/066155
24-1/2
22-7/8
23
15-1/16
4†
183
24
F
C.L. TOP AND
BOTTOM FLUE COLLAR
(IN.)
FLUE COLLAR*
(IN.)
SHIP WT. (LB)
FILTER MEDIA
CABINET SIZE
(IN.)
* 5” or 6” vent connector may be required in some cases.
†5″ or larger vent is required. Use a 4-5 or 4-6 inch vent adapter between furnace and vent connector.
This furnace must:
7. An ESD service kit (available from commercial sources) may
also be used to prevent ESD damage.
•
LOCATION
GENERAL
be installed so the electrical components are protected from
water.
• not be installed directly on any combustible material other than
wood flooring (refer to SAFETY CONSIDERATIONS).
This multipoise furnace is shipped in packaged configuration.
Some assembly and modifications are required when used in any
of the four applications shown in Fig. 4.
NOTE: For high-altitude installations, the high-altitude conversion kit MUST be installed at or above 5500 ft above sea level.
Obtain high-altitude conversion kit from your area authorized
distributor.
5
•
be located close to the chimney or vent and attached to an air
distribution system. Refer to Air Ducts section.
•
be provided ample space for servicing and cleaning. Always
comply with minimum fire protection clearances shown on the
furnace clearance to combustible construction label.
THE BLOWER IS
LOCATED BELOW THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED UPWARD.
THE BLOWER IS LOCATED
TO THE RIGHT OF THE
BURNER SECTION, AND
AIR CONDITIONED AIR IS
DISCHARGED TO THE LEFT.
THE BLOWER IS
LOCATED TO THE LEFT
OF THE BURNER SECTION,
AND CONDITIONED AIR IS
DISCHARGED TO THE RIGHT.
THE BLOWER IS
LOCATED ABOVE THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED DOWNWARD
A02097
Fig. 4—Multipoise Orientations
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.
Commercial buildings
Buildings with indoor pools
•
Laundry rooms
•
•
•
•
•
De-icing salts or chemicals
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
•
Hydrochloric acid
•
Cements and glues
•
Antistatic fabric softeners for clothes dryers
•
Masonry acid washing materials
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
• Hobby or craft rooms, and
• Chemical storage areas
If air is exposed to the following substances, it should not be used
for combustion air, and outdoor air may be required for combustion:
•
•
•
Water softening chemicals
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.
The following types of furnace installations may require OUTDOOR AIR for combustion due to chemical exposures:
•
•
•
When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least 18 in.
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 or NSCNGPIC. (See Fig. 5.)
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine based swimming pool chemicals
6
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
Do not install the furnace on its back or hang furnace with
control compartment facing downward. Safety control operation will be adversely affected. Never connect return-air ducts
to the back of the furnace. (See Fig. 6.)
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.
18-IN. MINIMUM
TO BURNERS
A93044
Fig. 5—Installation in a Garage
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.
A02054
Fig. 6—Prohibit Installation on Back
AIR FOR COMBUSTION AND VENTILATION
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
• U.S. Installations: Section 8.3 of the NFGC, Air for Combustion and Ventilation and applicable provisions of the local
building codes.
• Canadian Installations: Part 7 of the NSCNGPIC, Venting
Systems and Air Supply for Appliances and all authorities
having jurisdiction.
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.
7
Table 2–Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
TWO HORIZONTAL DUCTS
SINGLE DUCT OR OPENING
TWO OPENINGS OR VERTICAL DUCTS
FURNACE (1 SQ. IN./2,000 BTUH) (1,100 SQ. MM/KW) (1 SQ. IN./3,000 BTUH) (734 SQ. MM/KW) (1 SQ. IN./4,000 BTUH) (550 SQ. MM/KW)
INPUT
Free Area of
Free Area of
Free Area of
Round Duct
Round Duct
Round Duct
(BTUH)
Opening and Duct
Opening and Duct
Opening and Duct
(in. Dia)
(in. Dia)
(In. Dia)
(Sq. In.)
(sq In.)
(Sq In.)
44,000
22
6
14.7
5
11
4
66,000
33
7
22
6
16.5
5
88,000
44
8
29.3
7
22
6
110,000
55
9
36.7
7
27.5
6
132,000
66
10
44
8
33
7
154,000
77
10
51.3
9
38.5
8
EXAMPLES: Determining Free Area
FURNACE
110,000
66,000
88,000
+
+
+
WATER HEATER
30,000
40,000
30,000
=
=
=
TOTAL INPUT
(140,000 divided by 4,000)
(106,000 divided by 3,000)
(118,000 divided by 2,000)
=
=
=
35.0 Sq. In. for each two Vertical Ducts or Openings
35.3 Sq. In. for a Single Duct or Opening
59.0 Sq. In. for each of two Horizontal Ducts
Table 3–Minimum Space Volumes for 100% Combustion, Ventilation, and
Dilution from Indoors
ACH
0.60
0.50
0.40
0.30
0.20
0.10
0.00
OTHER THAN FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
30
40
50
1,050
1,260
1,575
2,100
3,150
6,300
NP
1,400
1,680
2,100
2,800
4,200
8,400
NP
1,750
2,100
2,625
3,500
5,250
10,500
NP
FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
44
66
88
110
132
Space Volume (ft3)
1,100
1,650
2,200
2,750
3,300
1,320
1,980
2,640
3,300
3,960
1,650
2,475
3,300
4,125
4,950
2,200
3,300
4,400
5,500
6,600
3,300
4,950
6,600
8,250
9,900
6,600
9,900
13,200
16,500
19,800
NP
NP
NP
NP
NP
154
3,850
4,620
5,775
7,700
11,550
23,100
NP
NP = Not Permitted
zontal or vertical duct(s) or opening(s) directly communicating with the outdoors or spaces that freely communicate with
the outdoors.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
The operation of exhaust fans, kitchen ventilation fans,
clothes dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make-up air MUST be provided for the ventilation devices, in
addition to that required by the furnace. Refer to the Carbon
Monoxide Poisoning Hazard warning in the venting section
of these instructions to determine if an adequate amount of
make-up air is available.
2. Fig. 7 illustrates how to provide TWO OUTDOOR OPENINGS, one inlet and one outlet combustion and ventilation air
opening, to the outdoors.
a. One opening MUST commence within 12″ (300 mm) of
the ceiling and the second opening MUST commence
within 12″ (300 mm) of the floor.
b. Size openings and ducts per Fig. 7 and Table 2.
c. TWO HORIZONTAL DUCTS require 1 square inch of
free area per 2,000 Btuh (1,100 mm2/kW) of combined
input for all gas appliances in the space per Fig. 7 and Table
2.
The requirements for combustion and ventilation air depend upon
whether or not the furnace is located in a space having a volume
of at least 50 cubic feet per 1,000 Btuh input rating for all gas
appliances installed in the space.
•
Spaces having less than 50 cubic feet per 1,000 Btuh require
the OUTDOOR COMBUSTION AIR METHOD.
•
Spaces having at least 50 cubic feet per 1,000 Btuh may use the
INDOOR COMBUSTION AIR, STANDARD or KNOWNAIR INFILTRATION METHOD.
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 Fig.
7 and Table 2.
3. ONE OUTDOOR OPENING requires:
a. 1 square inch of free area per 3,000 Btuh (734 mm2/kW)
for combined input of all gas appliances in the space per
Table 2 and
Outdoor Combustion Air Method
b. Not less than the sum of the areas of all vent connectors in
the space.
1. Provide the space with sufficient air for proper combustion,
ventilation, and dilution of flue gases using permanent hori-
8
1 SQ IN.
PER 4000
BTUH*
1 SQ IN.
PER 2000
BTUH*
12″ MAX
A
VENT THROUGH ROOF
CLEARANCE IN FRONT OF COMBUSTION AIR
OPENINGS SHALL BE AT LEAST 3 IN.
DUCTS
TO
OUTDOORS
CIRCULATING AIR
DUCTS
12″
MAX
F
1 SQ IN.
PER
4000
BTUH*
OUTDOORS
B
D
VENT
THROUGH
ROOF
CLEARANCE IN FRONT
OF COMBUSTION AIR
OPENINGS SHALL BE
AT LEAST 3 IN.
12″ MAX
1 SQ IN.
PER 2000
BTUH*
CIRCULATING
AIR DUCTS
DUCTS
TO
OUTDOORS
INTERIOR
HEATED
SPACE
1 SQ IN.
PER
4000
BTUH*
E
G
12″
MAX
C
12″ MAX
CIRCULATING AIR DUCTS
DUCT
TO
OUTDOORS
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
CIRCULATING AIR DUCTS
1 SQ IN.
PER 4000
BTUH*
* Minimum opening size is 100 sq in. with
minimum dimensions of 3 in.
† Minimum of 3 in. . when type-B1 vent is used.
*Minimum dimensions of 3 in.
NOTE: Use any of the following
combinations of openings:
A&B C&D D&E F&G
A03175
Fig. 8—Air for Combustion, Ventilation, and
Dilution from Indoors
A03174
Fig. 7—Air for Combustion, Ventilation, and
Dilution for Outdoors
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.
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.
Table 3-Minimum Space Volumes were determined by using the
following equations from the National Fuel Gas Code ANSI
Z223.1-2002/NFPA 54-2002,8.3.2.2:
Indoor Combustion Air© NFPA & AGA
Standard and Known-Air-Infiltration Rate Methods
1. For other than fan-assisted appliances, such as a draft
hood-equipped water heater:
Indoor air is permitted for combustion, ventilation, and dilution,
if the Standard or Known-Air-Infiltration Method is used.
Volume
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.
Other
3
I other
= 21ft
ACH 1000 Btu/hr
A04002
2. For fan-assisted appliances such as this furnace:
Volume
Fan
3
I fan
= 15ft
ACH 1000 Btu/hr
A04003
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
If:
Iother = combined input of all other than fan-assisted appliances in Btu/hr
2. The air infiltration rate is not known to be less than 0.40 air
changes per hour (ACH).
Ifan = combined input of all fan-assisted appliances in Btu/hr
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
ACH = air changes per hour (ACH shall not exceed 0.60.)
9
INSTALLATION
UPFLOW INSTALLATION
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:
Bottom Return Air Inlet
a. There are no closable doors between rooms.
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:
b. Combining spaces on same floor level. Each opening shall
have free area of at least 1 in.2/1,000 Btuh (2,000 mm2/kW)
of the total input rating of all gas appliances in the space,
but not less than 100 in.2 (0.06 m2). One opening shall
commence within 12″ (300 mm) of the ceiling and the
second opening shall commence within 12″ (300 mm) of
the floor. The minimum dimension of air openings shall be
at least 3 in. (80 mm). (See Fig. 8.)
1. Tilt or raise furnace and remove 2 screws holding bottom filler
panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
c. Combining space on different floor levels. The volumes of
spaces on different floor levels shall be considered as
communicating spaces if connected by one or more permanent openings in doors or floors having free area of at least
2 in.2/1,000 Btuh (4,400 mm2/kW) of total input rating of
all gas appliances.
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.
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.
Leveling Legs (If Desired)
In upflow position with side return inlet(s), leveling legs may be
used. (See Fig. 10.) Install field-supplied, 5/16 X 1-1/2 in. (max)
corrosion-resistant machine bolts, washers and nuts.
3. In spaces that use the Indoor Combustion Air Method,
infiltration should be adequate to provide air for combustion,
permanent ventilation and dilution of flue gases. However, in
buildings with unusually tight construction, additional air
MUST be provided using the methods described in the
Outdoor Combustion Air Method section.
Unusually tight construction is defined as
Construction with:
NOTE: Bottom closure must be used when leveling legs are used.
It may be necessary to remove and reinstall bottom closure panel
to install leveling legs. To remove bottom closure panel, see Item
1 in Bottom Return Air Inlet section in Step 1 above.
To install leveling legs:
1. Position furnace on its back. Locate and drill a hole in each
bottom corner of furnace. (See Fig. 10.)
a. Walls and ceilings exposed to the outdoors have a continuous, sealed vapor barrier. Openings are gasketed or sealed
and
2. For each leg, install nut on bolt and then install bolt with nut
in hole. (Install flat washer if desired.)
b. Doors and openable windows are weatherstripped and
3. Install another nut on other side of furnace base. (Install flat
washer if desired.)
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.
4. Adjust outside nut to provide desired height, and tighten inside
nut to secure arrangement.
5. Reinstall bottom closure panel if removed.
Combination of Indoor and Outdoor Air
1. Indoor openings shall comply with the Indoor Combustion
Air Method below and,
2. Outdoor openings shall be located as required in the Outdoor
Combustion Air Method mentioned previously and,
3. Outdoor openings shall be sized as follows:
a. Calculate the Ratio of all Indoor Space volume divided by
required volume for Indoor Combustion Air Method
below.
b. Outdoor opening size reduction Factor is 1 minus the
Ratio in a. above.
c. Minimum size of Outdoor openings shall be the size
required in Outdoor Combustion Air Method above
multiplied by reduction Factor in b. above. The minimum
dimension of air openings shall be not less than 3 in. (80
mm).
A02098
Fig. 9—Removing Bottom Closure Panel
DOWNFLOW INSTALLATION
NOTE: For downflow applications, this furnace is approved for
use on combustible flooring when any one of the following 3
accessories are used:
10
5⁄16″
HORIZONTAL INSTALLATION
5⁄16″
FIRE, EXPLOSION, AND CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
1 3⁄4″
1 3⁄4″
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.
5⁄16″
The furnace can be installed horizontally in an attic or crawlspace
on either the left-hand (LH) or right-hand (RH) side. The furnace
can be hung from floor joists, rafters or trusses or installed on a
non-combustible platform, blocks, bricks or pad.
5⁄16″
1
Suspended Furnace Support
3⁄4″
1 3⁄4″
The furnace may be supported under each end with threaded rod,
angle iron or metal plumber’s strap as shown. (See Fig. 15 and 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 ¾-in. screws into the side and 2 #8 x ¾-in. screws
in the bottom of the furnace casing for each strap. (See Fig. 15 and
16.)
A02071
Fig. 10—Leveling Legs
•
Special Base, KGASB
•
Cased Coil Assembly Part No. CD5 or CK5
•
Coil Box Part No. KCAKC
If the screws are attached to ONLY the furnace sides and not the
bottom, the straps must be vertical against the furnace sides and
not pull away from the furnace sides, so that the strap attachment
screws are not in tension (are loaded in shear) for reliable support.
Platform Furnace Support
Construct working platform at location where all required furnace
clearances are met. (See Fig. 2 and 17.) For furnaces with 1-in.
clearance requirement on side, set furnace on non-combustible
blocks, bricks or angle iron. For crawlspace installations, if the
furnace is not suspended from the floor joists, the ground underneath furnace must be level and the furnace set on blocks or bricks.
1. Determine application being installed from Table 4.
2. Construct hole in floor per Table 4 and Fig. 11.
3. Construct plenum to dimensions specified in Table 4 and Fig.
11.
Roll-Out Protection
4. If downflow subbase, KGASB is used, install as shown in Fig.
12. If Coil Assembly Part No. CD5 or CK5 or Coil Box Part
No. KCAKC is used, install as shown in Fig. 13.
Provide a minimum 17-3/4″ X 22″ piece of sheet metal for flame
roll-out protection in front of burner area for furnaces closer than
12 inches above the combustible deck or suspended furnaces
closer than 12 inches to joists. The sheet metal MUST extend
underneath the furnace casing by 1 in. with the door removed.
NOTE: It is recommended that the perforated supply-air duct
flanges be completely folded over or removed from furnace when
installing the furnace on a factory-supplied cased coil or coil box.
To remove the supply-air duct flange, use wide duct pliers or hand
seamers to bend flange back and forth until it breaks off. Be careful
of sharp edges. (See Fig. 14.)
The bottom closure panel on furnaces of widths 17-1/2 in. and
larger may be used for flame roll-out protection when bottom of
furnace is used for return air connection. See Fig. 17 for proper
orientation of roll-out shield.
Bottom Return Air Inlet
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:
These furnaces are shipped with bottom closure panel installed in
bottom return-air opening. Remove and discard this panel when
bottom return air is used. To remove bottom closure panel,
perform the following:
1. Tilt or raise furnace and remove 2 screws holding bottom filler
panel. (See Fig. 9.)
1. Tilt or raise furnace and remove 2 screws holding bottom filler
panel. (See Fig. 9.)
2. Rotate bottom filler panel downward to release holding tabs.
2. Rotate bottom filler panel downward to release holding tabs.
3. Remove bottom closure panel.
3. Remove bottom closure panel.
4. Reinstall bottom filler panel and screws.
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 side
return air inlet(s) are used without a bottom return air inlet.
11
FURNACE
(OR COIL CASING
WHEN USED)
A
COMBUSTIBLE
FLOORING
PLENUM
OPENING
B
D
DOWNFLOW
SUBBASE
FLOOR
OPENING
SHEET METAL
PLENUM
FLOOR
OPENING
C
A96283
Fig. 11—Floor and Plenum Opening Dimensions
A96285
Fig. 12—Furnace, Plenum, and Subbase Installed on
a Combustible Floor
FURNACE
CD5 OR CK5
COIL ASSEMBLY
OR KCAKC
COIL BOX
COMBUSTIBLE
FLOORING
SHEET METAL
PLENUM
FLOOR
OPENING
A04140
A04140
Fig. 13—Furnace, Plenum, and Coil Assembly or Coil
Box Installed on a Combustible Floor
This furnace is shipped with a factory-supplied Media Filter
Cabinet. The Media Filter Cabinet uses either a factory-supplied
standard 1-inch filter or 4-inch wide Media Filter which can be
purchased separately.
Not all horizontal furnaces are approved for side return air
connections (See Fig. 20.)
FILTER ARRANGEMENT
Refer to the instructions supplied with Media Cabinet for assembly
and installation options.
AIR DUCTS
General Requirements
CARBON MONOXIDE 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.
An external filter rack is required.
12
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
Table 4—Opening Dimensions (In.)
FURNACE
CASING
WIDTH
14–3/16
17–1/2
21
24-1/2
PLENUM OPENING
APPLICATION
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
Downflow applications on combustible flooring (KGASB
subbase required)
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
Downflow applications on combustible flooring (KGASB
subbase required)
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
Downflow applications on combustible flooring (KGASB
subbase required)
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
Upflow Applications on Combustible or Noncombustible
Flooring (KGASB subbase not required)
Downflow Applications on Noncombustible Flooring
(KGASB subbase not required)
Downflow applications on Combustible flooring (KGASB
subbase required)
Downflow Applications on Combustible Flooring with CD5 or
CK5 Coil Assembly or KCAKC coil box (KGASB subbase
not required)
FLOOR OPENING
A
B
C
D
12-11/16
21-5/8
13-5/16
22-1/4
12-9/16
19
13-3/16
19-5/8
11-13/16
19
13-7/16
20-5/8
12-5/16
19
13-5/16
20
16
21-5/8
16-5/8
22-1/4
15-7/8
19
16-1/2
19-5/8
15-1/8
19
16-3/4
20-5/8
15-1/2
19
16-1/2
20
19-1/2
21-5/8
20-1/8
22-1/4
19-3/8
19
20
19-5/8
18-5/8
19
20-1/4
20-5/8
19
19
20
20
23
21-1/8
23-5/8
22-1/4
22-7/8
19
23-1/2
19-5/8
22-1/8
19
23-3/4
20-5/8
22-1/2
19
23-1/2
20
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.
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.
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 air
stream. The cover attachment shall prevent leaks.
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.
NOTE: Flexible connections should be used between ductwork
and furnace to prevent transmission of vibration.
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 Fig. 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.
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.
Ductwork Acoustical Treatment
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.
NOTE: 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
Downflow Furnaces
13
DOWNFLOW
UPFLOW
HORIZONTAL
90˚
90˚
PREFERRED
PREFERRED
120˚
MIN
PREFERRED
PREFERRED
120˚
MIN
PERMITTED
PREFERRED
120˚
MIN
PERMITTED
PREFERRED
PERMITTED
A02329
Fig. 14—Duct Flanges
1/4" THREADED ROD
4 REQ.
OUTER DOOR
ASSEMBLY
SECURE ANGLE
IRON TO BOTTOM
OF FURNACE WITH
3 #8 x 3/4" SCREWS
TYPICAL FOR 2 SUPPORTS
8" MIN FOR DOOR
REMOVAL
1" SQUARE, 11/4" x 11/4" x 1/4" ANGLE IRON
OR UNI-STRUT MAY BE USED
(2) HEX NUTS, (2) WASHERS & (2) LOCK WASHERS
REQ. PER ROD
A02345
Fig. 15—Horizontal Unit Suspension
14
METHOD 2
USE (4) #8 x 3/4 SHEET
METAL SCREWS FOR EACH
STRAP. THE STRAPS
SHOULD BE VERTICAL
AGAINST THE FURNACE
SIDES AND NOT PULL AWAY
FROM THE FURNACE
SIDES.
METHOD 1
FOLD ALL STRAPS UNDER
FURNACE AND SECURE WTH
(4) #8 x 3/4 SHEET METAL SCREWS
(2 SCREWS IN SIDE AND 2 SCREWS
IN BOTTOM).
A03176
Fig. 16—Horizontal Suspension with Straps
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.
17 3/4″ OVER ALL
4 3/4″ UNDER DOOR
1″ UNDER FURNACE
GAS
ENTRY
TYPE-B
VENT
IN*
6″ M
EXTEND OUT 12″ OUT
FROM FACE OF DOOR
30-IN. MIN
WORK AREA
* WHEN USED WITH
SINGLE WALL VENT
CONNECTIONS
17 3/4″
SHEET
METAL
22″
EQUIPMENT MANUAL
SHUT-OFF GAS VALVE
SEDIMENT
TRAP
UNION
A03177
Fig. 17—Typical Attic Installation
Return Air Connections
Connect supply-air duct to supply-air outlet on furnace. Bend
flange inward past 90° with wide duct pliers (See Fig. 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, KGASB0201ALL, 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.
FIRE HAZARD
A 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.
Follow instructions below.
Downflow Furnaces
15
A02075
Fig. 18—Upflow Return Air Configurations and Restrictions
A02163
Fig. 19—Downflow Return Air Configurations and Restrictions
A02162
Fig. 20—Horizontal Return Air Configurations and Restrictions
16
Table 5—Air Delivery - CFM (With Filter)*
FURNACE
SIZE
036070
††
††
††
EXTERNAL STATIC PRESSURE (In. wc)**
CFM Airflow
Setting
External Static
Pressure Range
0.1
0.2
0.3
0.4
Low Heat
High Heat
1-1/2 Tons Cooling
2 Tons Cooling
2-1/2 Tons Cooling
3 Tons Cooling
3-1/2 Tons Cooling
Maximum
735 (615)†
1180 (1060)†
525
700
875
1050
1225
1400
0 – 0.5
0 – 1.0
0 – 0.5‡
0 – 0.5‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0
0 – 1.0
735
1160
525
700
875
1050
1205
1395
735
1165
525
700
875
1050
1215
1400
735
1175
525
700
875
1050
1225
1400
735
1180
525
695
875
1050
1225
1400
Low Heat
High Heat
1-1/2 Tons Cooling
2 Tons Cooling
2-1/2 Tons Cooling
3 Tons Cooling
3-1/2 Tons Cooling
4 Tons Cooling
Maximum
985 (825)†
1210 (1090)†
525
700
875
1050
1225
1400
1600
0 – 1.0
0 – 1.0
0 – 0.5‡
0 – 0.5‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0
0 – 1.0
950
1190
525
690
830
1005
1205
1370
1565
970
1205
525
695
855
1025
1220
1385
1580
985
1210
525
700
875
1040
1215
1395
1585
985
1210
525
700
875
1050
1225
1400
1595
985
1210
500
690
875
1050
1225
1400
1600
Low Heat
High Heat
2 Tons Cooling
2-1/2 Tons Cooling
3 Tons Cooling
3-1/2 Tons Cooling
4 Tons Cooling
5 Tons Cooling
6 Tons Cooling
Maximum
1320 (1110)†
1475 (1330)†
700
875
1050
1225
1400
1750
2100
2200
0 – 1.0
0 – 1.0
0 – 0.5‡
0 – 0.5‡
0 – 0.5‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0
0 – 1.0
1275
1460
700
860
1050
1185
1385
1710
2090
2200
1295
1465
700
875
1050
1195
1395
1730
2100
2200
1315
1475
700
865
1045
1215
1400
1745
2100
2200
1320
1475
685
855
1050
1225
1400
1745
2100
2190
Low Heat
High Heat
2 Tons Cooling
2-1/2 Tons Cooling
3 Tons Cooling
3-1/2 Tons Cooling
4 Tons Cooling
5 Tons Cooling
6 Tons Cooling
Maximum
1700 (1430)†
1915 (1725)†
700
875
1050
1225
1400
1750
2100
2200
0 – 1.0
0 – 1.0
0 – 0.5‡
0 – 0.5‡
0 – 0.5‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0
0 – 1.0
1700
1900
700
870
1010
1155
1395
1740
2075
2180
1700
1905
700
870
1030
1180
1400
1750
2085
2195
1700
1915
700
865
1050
1200
1400
1750
2090
2200
Low Heat
High Heat
2 Tons Cooling
2-1/2 Tons Cooling
3 Tons Cooling
3-1/2 Tons Cooling
4 Tons Cooling
5 Tons Cooling
6 Tons Cooling
Maximum
1715 (1440)†
1970 (1775)†
700
875
1050
1225
1400
1750
2100
2200
0 – 1.0
0 – 1.0
0 – 0.5‡
0 – 0.5‡
0 – 0.5‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0‡
0 – 1.0
0 – 1.0
1715
1955
700
865
1015
1160
1385
1745
2055
2175
1715
1965
700
875
1020
1185
1400
1750
2070
2190
1715
1965
700
875
1035
1215
1400
1750
2080
2200
Operating Mode
0.5
0.6
0.7
0.8
0.9
1.0
1180
1180
1180
1175
865
1050
1225
1400
855
1050
1225
1385
845
1045
1225
1360
840
1035
1210
1310
985
1210
985
1210
985
1210
985
1210
980
1200
875
1050
1225
1400
1600
870
1050
1225
1400
1560
865
1050
1225
1400
1520
850
1050
1225
1400
1480
820
1050
1220
1380
1430
1320
1475
660
840
1050
1225
1400
1750
2095
2185
1320
1475
1320
1475
1320
1475
1320
1465
1315
1465
1225
1400
1750
2085
2175
1225
1400
1750
2065
2155
1225
1400
1750
2045
2130
1225
1400
1745
2020
2085
1225
1400
1740
1990
2015
1700
1915
700
865
1050
1210
1400
1750
2100
2200
1700
1915
665
865
1050
1220
1400
1735
2100
2200
1695
1915
1700
1915
1695
1915
1685
1915
1670
1915
1225
1400
1740
2100
2200
1225
1400
1735
2090
2185
1225
1390
1730
2080
2165
1225
1375
1715
2055
2140
1225
1355
1700
2025
2095
1715
1970
700
865
1045
1225
1400
1750
2085
2200
1715
1970
680
865
1050
1225
1400
1745
2095
2200
1705
1970
1710
1970
1705
1970
1705
1970
1695
1960
1225
1400
1740
2100
2200
1225
1395
1745
2100
2200
1225
1395
1745
2100
2200
1225
1380
1740
2090
2180
1225
1360
1735
2065
2160
AIRFLOW (CFM)
725
1180
1180
510
685
875
875
1050
1050
1225
1225
1400
1400
048090
††
††
060110***
††
††
††
066135
††
††
††
066155
††
††
††
*
**
†
‡
††
***
Actual external static pressure (ESP) can be determined by using the fan laws (CFM 2 is proportional to ESP); such as a
system with heating airflow of 1180 CFM at 0.5 ESP would operate at cooling airflow of 1050 CFM at 0.4 ESP and low-heating
airflow of 735 CFM at 0.19 ESP.
A filter is required for each return-air connection to the furnace. Airflow performance includes 1" washable filter media such as
contained in factory-authorized accessory filter rack. To determine airflow performance without this filter, assume an additional 0.1"
available external static pressure.
"Comfort mode" airflow values are shown in (parenthesis). "Comfort mode" airflow is selected when the low-heat rise
adjustment switch (SW1-3) is OFF and the comfort/efficiency switch (SW1-4) is ON. Furnaces are shipped in this configuration.
Ductwork must be sized for the highest airflow, which is high-heating CFM and is greater than cooling CFM in this case.
Note also that heating ESP will be higher than cooling ESP for this system.
Operation within the blank areas of the chart is not recommended because high-heat airflow will be above 1.0 ESP.
All airflows on 110 size furnace are 5% less on side return only installations.
17
A04016
The return-air duct must be connected to return-air opening
(bottom inlet) as shown in Fig. 3. DO NOT cut into casing sides
(left or right). Side opening is permitted for only upflow and
certain horizontal furnaces. Bypass humidifier connections should
be made at ductwork or coil casing sides exterior to furnace. (See
Fig. 19.)
Table 6—Maximum Capacity of Pipe*
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 furnace
casing as shown in Fig. 3. Bypass humidifier may be attached into
unused return air side of the furnace casing. (See Fig. 18 and 20.)
NOMINAL
IRON
PIPE
SIZE
(IN.)
INTERNAL
DIAMETER
(IN.)
10
20
1/2
0.622
175
120
97
82
73
3/4
0.824
360
250
200
170
151
LENGTH OF PIPE (FT)
30
40
50
1
1.049
680
465
375
320
285
1-1/4
1.380
1400
950
770
660
580
1-1/2
1.610
2100
1460
1180
990
900
* Cubic ft of natural gas per hr for gas pressures of 0.5 psig (14–in. wc) or less
and a pressure drop of 0.5–in wc (based on a 0.60 specific gravity gas).
Ref: Table 12.2 ANSI Z223-2002/NFPA 54-2002.
Not all horizontal furnace models are approved for side return air
connections. (See Fig. 20.)
GAS PIPING
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
FIRE OR EXPLOSION HAZARD
A failure to follow this warning could result in personal
injury, death, and/or property damage.
Never purge a gas line into a combustion chamber. 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.
If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not use a
connector which has previously served another gas appliance.
Black iron pipe shall be installed at the furnace gas control
valve and extend a minimum of 2 in. outside the furnace.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in furnace damage.
Use proper length of pipe to avoid stress on gas control
manifold and a gas leak.
Connect gas pipe to furnace using a backup wrench to avoid
damaging gas controls and burner misalignment.
An accessible manual equipment shutoff valve MUST be installed
external to furnace casing and within 6 ft of furnace. A 1/8-in. NPT
plugged tapping, accessible for test gauge connection, MUST be
installed immediately upstream of gas supply connection to
furnace and downstream of manual equipment shutoff valve.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Gas valve inlet and/or inlet pipe must remain capped until gas
supply line is permanently installed to protect the valve from
moisture and debris. Also, install a sediment trap in the gas
supply piping at the inlet to the gas valve.
NOTE: The furnace gas control valve inlet pressure tap connection is suitable to use as test gauge connection providing test
pressure DOES NOT exceed maximum 0.5 psig (14-in. wc) stated
on gas control valve. (See Fig. 53.)
Gas piping must be installed in accordance with national and local
codes. Refer to current edition of NFGC in the U.S. and the
NSCNGPIC in Canada.
Some installations require gas entry on right side of furnace (as
viewed in upflow). (See Fig. 21a and 21b.)
Install a sediment trap in riser leading to furnace as shown in Fig
21c. Connect a capped nipple into lower end of tee. Capped nipple
should extend below level of furnace gas controls. Place a ground
joint union between furnace gas control valve and exterior manual
equipment gas shutoff valve.
Installations must be made in accordance with all authorities
having jurisdiction. If possible, the gas supply line should be a
separate line running directly from meter to furnace.
NOTE: In the state of Massachusetts:
1. Gas supply connections MUST be performed by a licensed
plumber or gas fitter.
2. When flexible connectors are used, the maximum length
shall not exceed 36 inches (915 mm).
3. When lever handle type manual equipment shutoff valves are
used, they shall be T-handle valves.
4. The use of copper tubing for gas piping is NOT approved by
the state of Massachusetts.
A 1/8-in. NPT plugged tapping, accessible for test gauge connection, MUST be installed immediately upstream of gas supply
connection to furnace and downstream of manual equipment
shutoff valve.
Piping should be pressure and leak tested in accordance with
NFGC in the United States or NSCNGPIC in Canada, local, and
national plumbing and gas codes before the furnace has been
connected. After all connections have been made, purge lines and
check for leakage at furnace prior to operating furnace.
Refer to Table 6 for recommended gas pipe sizing. Risers must be
used to connect to furnace and to meter. Support all gas piping
with appropriate straps, hangers, etc. Use a minimum of 1 hanger
every 6 ft. Joint compound (pipe dope) should be applied sparingly
and only to male threads of joints. Pipe dope must be resistant to
the action of propane gas.
If pressure exceeds 0.5 psig (14-in. wc), gas supply pipe must be
disconnected from furnace and capped before and during supply
pipe pressure test. If test pressure is equal to or less than 0.5 psig
(14-in. wc), turn off electric shutoff switch located on furnace gas
18
ELECTRICAL CONNECTIONS
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower access panel door switch opens 115-v power to
control. No component operation can occur. Do not bypass or
close switch with panel removed.
See Fig. 24 for field wiring diagram showing typical field 115-v
wiring. Check all factory and field electrical connections for
tightness.
Field-supplied wiring shall conform with the limitations of 63°F
(33°C) rise.
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
The cabinet MUST have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-2002 and Canadian Electrical Code CSA C22.1 or local codes to minimize personal
injury if an electrical fault should occur. This may consist of
electrical wire, conduit approved for electrical ground or a
listed, grounded power cord (where permitted by local code)
when installed in accordance with existing electrical codes.
Refer to the power cord manufacturer’s ratings for proper
wire gauge. Do not use gas piping as an electrical ground.
A05028
Fig. 21a—Right Side Gas Entry Example 1
90° Elbow
2" Nipple
Street Elbow
Gas Valve
A02327
Fig. 21b—Right Side Gas Entry Example 2
FURNACE MAY NOT OPERATE
Failure to follow this caution may result in intermitent
furnace operation.
GAS
SUPPLY
MANUAL
SHUTOFF
VALVE
(REQUIRED
SEDIMENT
TRAP
UNION
Furnace control must be grounded for proper operation or else
control will lock out. Control must remain grounded through
green/yellow wire routed to gas valve and manifold bracket
screw.
115-V WIRING
Verify that the voltage, frequency, and phase correspond to that
specified on unit rating plate. Also, check to be sure that service
provided by utility is sufficient to handle load imposed by this
equipment. Refer to rating plate or Table 7 for equipment electrical
specifications.
U.S. Installations: Make all electrical connections in accordance
with National Electrical Code (NEC) ANSI/NFPA 70-2002 and
any local codes or ordinances that might apply.
Canadian Installations: Make all electrical connections in accordance with Canadian Electrical Code CSA C22.1 or authorities
having jurisdiction.
A02035
Fig. 21c—Typical Gas Pipe Arrangement
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
control valve and accessible manual equipment shutoff valve
before and during supply pipe pressure test. After all connections
have been made, purge lines and check for leakage at furnace prior
to operating furnace.
Use a separate, fused branch electrical circuit with a properly sized
fuse or circuit breaker for this furnace. See Table 7 for wire size
and fuse specifications. A readily accessible means of electrical
disconnect must be located within sight of the furnace.
The gas supply pressure shall be within the maximum and
minimum inlet supply pressures marked on the rating plate with
the furnace burners ON and OFF.
19
Table 7—Electrical Data
FURNACE SIZE
VOLTSHERTZPHASE
070-12/036070
090-16/048090
110-20/060110
135-22/066135
155-22/066155
115-60-1
115-60-1
115-60-1
115-60-1
115-60-1
OPERATING
MAXIMUM
MAXIMUM
UNIT
MAXIMUM
MINIMUM
VOLTAGE RANGE
FUSE OR CKT BKR
UNIT AMPS AMPACITY# WIRE LENGTH (FT)‡
WIRE GAUGE
AMPS†
Maximum* Minimum*
127
104
9.0
11.99
30
15
14
127
104
9.6
12.56
29
15
14
127
104
15.1
19.33
29
20
12
127
104
14.9
19.13
30
20
12
127
104
15.0
19.23
29
20
12
* Permissible limits of the voltage range at which the unit operates satisfactorily.
# Unit ampacity = 125 percent of largest operating component’s full load amps plus 100 percent of all other potential operating components’ (EAC, humidifier, etc.) full load
amps.
† Time-delay type is recommended.
‡ Length shown is as measured 1 way along wire path between furnace and service panel for maximum 2 percent voltage drop.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control LED status indicator light will flash
rapidly and furnace will NOT operate.
J-BOX RELOCATION
NOTE: If factory location of J-Box is acceptable, go to next
section (ELECTRICAL CONNECTION to J-Box).
TWO
NOTE: On 14″ wide casing models, the J-Box shall not be
relocated to other side of furnace casing when the vent pipe is
routed within the casing.
1. Remove and save two screws holding J-Box. (See Fig. 22.)
NOTE: The J-Box cover need not be removed from the J-Box in
order to move the J-Box. Do NOT remove green ground screw
inside J-Box. The ground screw is not threaded into the casing
flange and can be lifted out of the clearance hole in casing while
swinging the front edge of the J-Box outboard of the casing.
A02099
2. Cut wire tie on loop in furnace wires attached to J-Box.
Fig. 22—Relocating J-Box
3. Move J-Box to desired location.
4. Fasten J-Box to casing with the two screws removed in Step
1.
FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
death, or property damage.
If field-supplied manual disconnect switch is to be mounted
on furnace casing side, select a location where a drill or
fastener cannot damage electrical or gas components.
5. Route J-Box wires within furnace away from sharp edges,
rotating parts and hot surfaces.
ELECTRICAL CONNECTION TO J-BOX
Field-Supplied Electrical Box on Furnace J-Box Bracket
See Fig. 24.
1. Select and remove a hole knockout in the casing where the
electrical box is to be installed.
1. Remove cover from furnace J-Box.
2. Attach electrical box to furnace J-Box bracket with at least
two field-supplied screws through holes in electrical box into
holes in bracket. Use blunt-nose screws that will not pierce
wire insulation.
NOTE: Check that duct on side of furnace will not interfere with
installed electrical box.
2. Remove the desired electrical box hole knockout and position
the hole in the electrical box over the hole in the furnace
casing.
3. Route furnace power wires through holes in electrical box and
J-Box bracket, and make field-wire connections in electrical
box. Use best practices (NEC in U.S. and CSA C22.1 in
Canada) for wire bushings, strain relief, etc.
3. Fasten the electrical box to casing by driving two fieldsupplied screws from inside electrical box into casing steel.
4. Route and secure field ground wire to green ground screw on
J-Box bracket.
4. Remove and save two screws holding J-Box. (See Fig. 22.)
5. Pull furnace power wires out of 1/2-inch diameter hole in
J-Box. Do not loosen wires from strain-relief wire-tie on
outside of J-Box.
5. Connect line voltage leads as shown in Fig. 24.
6. Reinstall cover to J-Box. Do not pinch wires between cover
and bracket.
Electrical Box on Furnace Casing Side
6. Route furnace power wires through holes in casing and
electrical box and into electrical box.
See Fig. 23.
7. Pull field power wires into electrical box.
8. Remove cover from furnace J-Box.
9. Route field ground wire through holes in electrical box and
casing, and into furnace J-Box.
20
6. Reinstall cover to J-Box. Do not pinch wires between cover
and bracket.
BX CABLE INSTALLATION IN FURNACE J-BOX
1. Remove cover from J-Box.
2. Route BX cable into 7/8-inch diameter hole in J-Box.
3. Secure BX cable to J-Box bracket with connectors approved
for the type of cable used.
4. Secure field ground wire to green ground screw on J-Box
bracket.
5. Connect line voltage leads as shown in Fig. 24.
6. Reinstall cover to J-Box. Do not pinch wires between cover
and bracket.
24-V WIRING
Make field 24-v connections at the 24-v terminal strip. (See Fig.
25.) Connect terminal Y/Y2 as shown in Fig. 26-33 for proper
cooling operation. Use only AWG No. 18, color-coded, copper
thermostat wire.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control. Any direct shorts during installation, service, or
maintenance could cause this fuse to blow. If fuse replacement is
required, use ONLY a 3-amp fuse of identical size.
ACCESSORIES
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used) using
1/4-in female quick connect terminals to the two male 1/4-in
quick-connect terminals on the control board marked EAC-1
and EAC-2. The terminals are rated for 115VAC, 1.0 amps
maximum and are energized during blower motor operation.
(See Fig. 25.)
A03221
Fig. 23—Field-Supplied Electrical Box on
Furnace Casing
10. Reattach furnace J-Box to furnace casing with screws removed in Step 4.
2. Humidifier (HUM)
Connect an accessory 24 VAC, 0.5 amp maximum humidifer
(if used) to the 1/4-in male quick-connect HUM terminal and
COM-24V screw terminal on the control board thermostat strip.
The HUM terminal is energized when blower is energized in
heating. (See Fig. 25.)
11. Secure field ground wire to J-Box green ground screw.
12. Complete electrical box wiring and installation. Connect line
voltage leads as shown in Fig. 24. Use best practices (NEC in
U.S. and CSA C22.1 in Canada) for wire bushings, strain
relief, etc.
13. Reinstall cover to J-Box. Do not pinch wires between cover
and bracket.
NOTE: DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat, Zone Controller or similiar
device. See Thermidistat™, Zone Controller, thermostat, or controller manufacturer’s instructions for proper connection.
POWER CORD INSTALLATION IN FURNACE J-BOX
NOTE: Power cords must be able to handle the electrical requirements listed in Table 7. Refer to power cord manufacturer’s
listings.
VENTING
The furnace shall be connected to a listed factory built chimney or
vent, or a clay-tile lined masonry or concrete chimney. Venting
into an unlined masonry chimney or concrete chimney is prohibited.
1. Remove cover from J-Box.
2. Route listed power cord through 7/8-inch diameter hole in
J-Box.
When an existing Category I furnace is removed or replaced, the
original venting system, may no longer be sized to properly vent
the attached appliances. An improperly sized Category I venting
system could cause the formation of condensate in the furnace and
vent, leakage of condensate and combustion products, and spillage
of combustion products into the living space.
3. Secure power cord to J-Box bracket with a strain relief
bushing or a connector approved for the type of cord used.
4. Secure field ground wire to green ground screw on J-Box
bracket.
5. Connect line voltage leads as shown in Fig. 24.
21
FIELD 24-VOLT WIRING
FIELD 115-, 208/230-, 460-VOLT WIRING
FACTORY 24-VOLT WIRING
FACTORY 115-VOLT WIRING
NOTE 2
W
FIVE
WIRE
C
Y
R
G
1-STAGE
THERMOSTAT
TERMINALS
FIELD-SUPPLIED
FUSED DISCONNECT
THREE-WIRE
HEATINGONLY
BLK
BLK
WHT
WHT
208/230- OR
460-VOLT
THREE
PHASE
W2
COM
W/W1
GND
Y/Y2
115-VOLT FIELD- JUNCTION
SUPPLIED
BOX
FUSED
CONTROL
DISCONNECT
BOX
NOTE 1
R
GND
CONDENSING
UNIT
G
24-VOLT
TERMINAL
BLOCK
FURNACE
208/230VOLT
SINGLE
PHASE
NOTES: 1. Connect Y/Y2-terminal as shown for proper operation.
2. Some thermostats require a "C" terminal connection as shown.
3. If any of the original wire, as supplied, must be replaced, use
same type or equivalent wire.
A95236
Fig. 24—Field Wiring Diagram
22
MODEL PLUG
CONNECTOR
COMMUNICATION
CONNECTOR
CONTINUOUS FAN
(CF) AIRFLOW
SETUP SWITCHES
FUTURE
APPLICATIONS
SW1 SETUP
SWITCHES AND
BLOWER OFFDELAY
AIR CONDITIONING
(A/C) AIRFLOW
SETUP SWITCHES
HUMIDIFIER
TERMINAL (24-VAC
0.5 AMP MAX.
ACRDJ – AIR
CONDITIONING
RELAY DISABLE
JUMPER
24-V THERMOSTAT
TERMINALS
FLASH
UPGRADE
CONNECTOR
(FACTORY
ONLY)
STATUS AND COMM
LED LIGHTS
PL3 – ECM BLOWER
HARNESS
CONNECTOR
3-AMP FUSE
TRANSFORMER 24-VAC
CONNECTIONS
115-VAC (L2) NEUTRAL
CONNECTIONS
EAC-1 TERMINAL
(115-VAC 1.0 AMP MAX.)
115-VAC (L1) LINE
VOLTAGE CONNECTIONS
PL1 – LOW VOLTAGE MAIN
HARNESS CONNECTOR
PL2 – HOT SURFACE
IGNITER & INDUCER
MOTOR CONNECTOR
A02018
Fig. 25—Variable Speed Furnace Control for ECM Blower Motor
23
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into operation,
while all other appliances connected to the venting system are
not in operation:
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223.1-2002/NFPA 54 or the CSA B149.1, Natural Gas
and Propane Installation Code and these instructions.
Determine that there is no blockage or restriction, leakage,
corrosion and other deficiencies, which could cause an
unsafe condition.
3. As far as practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other
spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected to
the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they are operating
at maximum speed. Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance being
inspected into operation. Adjust the thermostat so
appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances at the
draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle.
8. If improper venting is observed during any of the above
tests, the venting system must be corrected in accordance
with the National Fuel Gas Code, ANSI Z223.12002/NFPA 54 and/or CSA B149.1, Natural Gas and
Propane Installation Code.
9. After it has been determined that each appliance connected
to the venting system properly vents when tested as
outlined above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-fired burning
appliance to their previous conditions of use.
A00275
Fig. 26—Two-Stage Furnace with Single-Speed
Air Conditioner
The following information and warning must be considered in
addition to the requirements defined in the NFGC or the NSCNGPIC.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Do not bypass the draft safeguard switch, as an unsafe
condition could exist which must be corrected.
1. If a vent (common or dedicated) becomes blocked, the furnace
will be shut off by the draft safeguard switch located on the
vent elbow.
Vent system or vent connectors may need to be resized. Vent
systems or vent connectors must be sized to approach minimum
size as determined using appropriate table found in the NFGC or
NSCNGPIC.
GENERAL VENTING REQUIREMENTS
2. Two-stage furnaces require Type B vent connectors outside
the casing in all configurations. Single wall vent connector
may be used inside the furnace casing with the transition to
Type B vent outside the furnace casing. Size the connector so
that the FAN-Min vent connector capacity is equal to or lower
than the low fire rate of the furnace and the FAN-Max vent
connector capacity is equal to or higher than the furnace high
fire rate.
Follow all safety codes for proper vent sizing and installation
requirements, including local building codes, the National Fuel
Gas Code ANSI Z223.1-2002/NFPA 54-2002 (NFGC), Parts 10
and 13 in the United States or the National Standard of Canada,
Natural Gas and Propane Installation Code CSA-B149.1-00
(NSCNGPIC) Section 7 and Appendix C in Canada, the local
building codes, and furnace and vent manufacturers’ instructions.
These furnaces are design-certified as Category I furnaces in
accordance with ANSI Z21.47-2003/CSA 2.3-2003 and operate
with a non-positive vent static pressure to minimize the potential
for vent gas leakage. Category I furnaces operate with a flue loss
not less than 17 percent to minimize the potential for condensation
in the venting system. These furnaces are approved for common
venting and multi-story venting with other fan assisted or draft
hood equipped appliances in accordance with the NFCG or the
NSCNGPIC, the local building codes, and furnace and vent
manufacturers’ instructions.
3. Do not vent this Category I furnace into a single wall
dedicated or common vent. The dedicated or common vent is
considered to be the vertical portion of the vent system that
terminates outdoors.
4. Vent connectors serving Category I furnaces shall not be
connected into any portion of a mechanical draft system
operating under positive pressure.
5. In the US: Do not vent this appliance with any solid fuel
burning appliance.
In Canada: Check with the authority having jurisdiction for
approval on use with solid fuel burning appliance.
24
See notes 2, 5, 8, 10, 11 and 12
on the page following these figures
See notes 1, 2, 4, 6, 7, 9, 10, 11, and 15
on the page following these figures
A03179
A03180
Fig. 27—Two-Stage Furnace with Two-Speed
Air Conditioner
Fig. 28—Two-Stage Furnace with Single-Speed
Heat Pump (Dual Fuel)
See notes 1, 2, 3, 4, 6, 8, 9, 10, 12, 13 and 15
on the page following these figures
A03178
Fig. 29—Two-Stage Furnace with Two-Speed Heat Pump (Dual Fuel)
25
See notes 2, 11, and 12 on the
page following these figures
A03183
Fig. 32—Two-Stage Thermostat with Two-Stage
Furnace and Two-Speed Air Conditioner
See notes 1, 2, 4, 11, 14, 15, and 16
on the page following these figures
A03181
Fig. 30—Dual Fuel Thermostat with Two-Stage
Furnace and Single-Speed Heat Pump
1
See notes 1 and 2 on the page
following these figures
A03184
Fig. 33—Single-Stage Thermostat with
Two-Stage Furnace and Two-Speed Air Conditioner
See notes 1, 2, 3, 4, 12, 13, 14, 15, and 17
on the page following these figures
A03182
Fig. 31—Dual Fuel Thermostat with Two-Stage
Furnace and Two-Speed Heat Pump
26
NOTES FOR FIGURES 26-33
1. Heat pump MUST have a high pressure switch for dual fuel applications.
2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
3. If the heat pump date code is 1501E or earlier, select the ″ZONE″ position on the two-speed heat pump control. Heat pumps having date
codes 1601E and later do not have or require a ″ZONE″ selection.
4. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
5. Dip switch No. 1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default.
6. Dip switch No. 1 on Thermidistat should be set in ON position for heat pump installations.
7. Dip switch No. 2 on Thermidistat should be set in OFF position for single-speed compressor operation. This is factory default.
8. Dip switch No. 2 on Thermidistat should be set in ON position for two-speed compressor operation.
9. Configuration Option No. 10 “Dual Fuel Selection” must be turned ON in all dual fuel applications.
10. NO connection should be made to the furnace HUM terminal when using a Thermidistat.
11. Optional connection: If wire is connected, dip switch SW1-2 on furnace control should be set in ON position to allow
Thermidistat/Thermostat to control furnace staging.
12. Optional connection: If wire is connected, ACRDJ jumper on furnace control should be removed to allow Thermidistat/Thermostat to
control outdoor unit staging.
13. Furnace must control its own high-stage heating operation via furnace control algorithm.
14. The RVS Sensing terminal “L” should not be connected. This is internally used to sense defrost operation.
15. DO NOT SELECT the “FURNACE INTERFACE” or “BALANCE POINT” option on the two-speed heat pump control board. This is
controlled internally by the Thermidistat/Dual Fuel Thermostat.
16. Dip switch D on Dual Fuel Thermostat should be set in OFF position for single-speed compressor operation. This is factory default.
17. Dip switch D on Dual Fuel Thermostat should be set in ON position for two-speed compressor operation.
27
CHIMNEY INSPECTION CHART
For additional requirements refer to the National Fuel Gas Code NFPA 54/ANSI Z223.1 and ANSI/NFPA 211
Chimneys, Fireplaces, Vents, and Solid Fuel Burning Appliances in the U.S.A. or to the Canadian
installation Code CSA-B149.1 in Canada.
Crown
condition:
Missing mortar
or brick?
Rebuild
crown.
Yes
No
Is chimney
property lined with
clay tile liner?
No
Yes
Is
liner and top
seal in good
condition?
No
Repair
liner or top seal
or reline chimney as
necessary.
Reline
Repair
Yes
Debris
in cleanout?
Yes
Mortar, tile, metal vent,
fuel oil residue?
Mortar
or tile
debris?
No Remove metal vent
or liner.
Clay
tile misalignment,
missing sections,
gaps?
Yes
Remove mortar
and tile debris
No
Yes
No
No
Consult
Part B of
chimney adapter venting
instructions for
application
suitability.
Is chimney
lined with properly
sized, listed liner or
Type-B vent?
Condensate
drainage at bottom
of chimney?
Yes
Install chimney
adapter per
instructions.
No
Yes
Yes
Is chimney
to be dedicated to
a single
furnace?
Line chimney with property
sized, listed flexible metal
liner or Type-B vent per
NFGC or NSCNGPIC Vent
Sizing Tables and liner or
vent manufacturer’s
Installation instructions.
Suitable
Yes
Chimney
exposed to
outdoors below
roof line?
Not Suitable
No
Not Suitable
Consult
Part C of
chimney adapter venting
instructions for
application
suitability
Suitable
Install chimney
adapter per
instructions.
No
Chimney is
acceptable for use.
A03206
Fig. 34—Chimney Inspection Chart
28
b. Indicates the chimney exceeds the maximum permissible
size in the tables, the chimney should be rebuilt or relined
to conform to the requirements of the equipment being
installed and the authority having jurisdiction.
6. Category I furnaces must be vented vertically or nearly
vertically unless equipped with a listed mechanical venter. See
SIDEWALL VENTING section.
7. Do not vent this appliance into an unlined masonry chimney.
Refer to Chimney Inspection Chart, Fig. 34.
A chimney without a clay tile liner, which is otherwise in good
condition, shall be rebuilt to conform to ANSI/NFPA 211 or be
lined with a UL listed (ULC listed in Canada) metal liner or UL
listed Type-B vent. Relining with a listed metal liner or Type-B
vent is considered to be a vent-in-a-chase.
MASONRY CHIMNEY REQUIREMENTS
NOTE: These furnaces are CSA design-certified for use in
exterior tile-lined masonry chimneys with a factory accessory
Chimney Adapter Kit. Refer to the furnace rating plate for correct
kit usage. The Chimney Adapter Kits are for use with ONLY
furnaces having a Chimney Adapter Kit number marked on the
furnace rating plate.
If a metal liner or Type-B vent is used to line a chimney, no other
appliance shall be vented into the annular space between the
chimney and the metal liner.
If a clay tile-lined masonry chimney is being used and it is exposed
to the outdoors below the roof line, relining might be required.
Chimneys shall conform to the Standard for Chimneys, Fireplaces,
Vents, and Soild Fuel Burning Appliances ANSI/NFPA 211-2003
in the United States and to a Provincial or Territorial Building
Code in Canada (in its absence, the National Building Code of
Canada) and must be in good condition.
Exterior Masonry Chimney FAN + NAT
Installations with Type-B Double-Wall Vent
Connectors ©NFPA & AGA
Table A—Combined Appliance Maximum Input
Rating in Thousands of BTU per Hour
U.S.A.-Refer to Sections 13.1.9 and 13.2.20 of the NFGC or the
authority having jurisdiction to determine whether relining is
required. If relining is required, use a properly sized listed metal
liner, Type-B vent, or a listed alternative venting design.
NOTE: See the NFGC 13.1.9 and 13.2.20 regarding alternative
venting design and the exception, which cover installations such as
our
Chimney
Adapter
Kits
KGACA02014FC
and
KGACA02015FC, which are listed for use with these furnaces.
VENT HEIGHT (FT)
6
8
10
15
20
30
The Chimney Adapter Kit is a listed alternative venting system for
these furnaces. See the kit instructions for complete details.
INTERNAL AREA OF CHIMNEY
(SQ. IN.)
12
19
28
38
74
119
178
257
80
130
193
279
84
138
207
299
NR
152
233
334
NR
NR
250
368
NR
NR
NR
404
APPLIANCE APPLICATION REQUIREMENTS
Canada (and U.S.A.)-This furnace is permitted to be vented into
a clay tile-lined masonry chimney that is exposed to the outdoors
below the roof line, provided:
Appliance operation has a significant impact on the performance
of the venting system. If the appliances are sized, installed,
adjusted, and operated properly, the venting system and/or the
appliances should not suffer from condensation and corrosion. The
venting system and all appliances shall be installed in accordance
with applicable listings, standards, and codes.
1. Vent connector is Type-B double-wall, and
2. This furnace is common vented with at least 1 draft hoodequipped appliance, and
3. The combined appliance input rating is less than the maximum
capacity given in Table A, and
The furnace should be sized to provide 100 percent of the design
heating load requirement plus any margin that occurs because of
furnace model size capacity increments. Heating load estimates
can be made using approved methods available from Air Conditioning Contractors of America (Manual J); American Society of
Heating, Refrigerating, and Air-Conditioning Engineers; or other
approved engineering methods. Excessive oversizing of the furnace could cause the furnace and/or vent to fail prematurely.
4. The input rating of each space heating appliance is greater
than the minimum input rating given in Table B for the local
99% Winter Design Temperature. Chimneys having internal
areas greater than 38 square inches require furnace input
ratings greater than the input ratings of these furnaces. See
footnote at bottom of Table B, and
5. The authority having jurisdiction approves.
When a metal vent or metal liner is used, the vent must be in good
condition and be installed in accordance with the vent manufacturer’s instructions.
If all of these conditions cannot be met, an alternative venting
design shall be used, such as the listed chimney adapter kit with a
furnace listed for use with the kit, a listed chimney-lining system,
or a Type-B common vent.
To prevent condensation in the furnace and vent system, the
following precautions must be observed:
Inspections before the sale and at the time of installation will
determine the acceptability of the chimney or the need for repair
and/or (re)lining. Refer to the Fig. 34 to perform a chimney
inspection. If the inspection of a previously used tile-lined chimney:
1. The return-air temperature must be at least 60°F db except for
brief periods of time during warm-up from setback at no lower
than 55°F db or during initial start-up from a standby
condition.
2. Adjust the gas input rate per the installation instructions. Low
gas input rate causes low vent gas temperatures, causing
condensation and corrosion in the furnace and/or venting
system. Derating is permitted only for altitudes above 2000 ft.
a. Shows signs of vent gas condensation, the chimney should
be relined in accordance with local codes and the authority
having jurisdiction. The chimney should be relined with a
listed metal liner, Type-B vent, or a listed chimney adapter
kit shall be used to reduce condensation. If a condensate
drain is required by local code, refer to the NFGC, Section
10.9 for additional information on condensate drains.
3. Adjust the air temperature rise to the midpoint of the rise range
or slightly above. Low air temperature rise can cause low vent
gas temperature and potential for condensation problems.
4. Set the thermostat heat anticipator or cycle rate to reduce short
cycling.
29
3 screws that secure vent elbow to furnace, rotate furnace vent
elbow to position desired, re-install screws. The factory-supplied
vent elbow does NOT count as part of the number of vent
connector elbows.
Table B—Minimum Alowable Input Rating of
Space-Heating Appliance in
Thousands of BTU per Hour
VENT
HEIGHT (FT)
The vent connector can exit the door through one of 5 locations on
the door.
INTERNAL AREA OF CHIMNEY
(SQ. IN.)
12
19
28
38
1. Attach the single wall vent connector to the furnace vent
elbow, and fasten the vent connector to the vent elbow with at
least two field-supplied, corrosion-resistant, sheet metal
screws located 180° apart.
17 to 26°F
Local 99% Winter Design
Temperature: 17 to 26 degrees F*
6
0
55
99
141
8
52
74
111
154
10
NR
90
125
169
15
NR
NR
167
212
20
NR
NR
212
258
30
NR
NR
NR
362
NOTE: An accessory flue extension KGAFE0112UPH is available to extend from the furnace elbow to outside the furnace
casing. If flue extension is used, fasten the flue extension to the
vent elbow with at least two field-supplied, corrosion-resistant,
sheet metal screws located 180° apart. Fasten the vent connector to
the flue extension with at least two field-supplied, corrosionresistant sheet metal screws located 180° apart.
5 to 16 F
Local 99% Winter Design
Temperature: 5 to 16 degrees F*
6
NR
78
121
166
8
NR
94
135
182
10
NR
111
149
198
15
NR
NR
193
247
20
NR
NR
NR
293
30
NR
NR
NR
377
2. Vent the furnace with the appropriate connector as shown in
Fig 35-47.
-10 to 4 F
Local 99% Winter Design
Temperature: -10 to 4 degrees F*
6
NR
NR
145
196
8
NR
NR
159
213
10
NR
NR
175
231
15
NR
NR
NR
283
20
NR
NR
NR
333
30
NR
NR
NR
NR
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.
3. Orient the door to determine the correct location of the door
knockout to be removed.
-11 F or lower
Local 99% Winter Design
Temperature: -11 degrees F or lower*
4. Use aviation-type tin snips to remove the correct U-shaped
knockout in door.
NOTE: A number of techniques can be used to remove these
knockouts as seen in Fig. 48 through 52. The knockout in the
bottom of the door is unique due to its flanging and is not easily
removed by first cutting the two tie points at the edge of the door,
using aviation-type tin snips. (See Fig. 48.) A sharp blow to the
rounded end of the knockout (See Fig. 49.) will separate more tie
points and allow the knockout to be pulled loose. (See Fig. 50.)
Remove any burrs and sharp edges.
For the rectangular J-box knockout, use tin snips along the door
edge and use a sharp blow with a hammer to remove the knockout.
Remove any burrs and sharp edges.
For the knockouts in the other locations on the door (top and
sides), tin snips can also be used along the door edges; however,
the preferred method is to use a hammer and screwdriver to strike
a sharp blow (See Fig. 51.) directly to the knockout tie points or
use a hammer in the upper left corner of the desired knockout. (See
Fig. 52.) Remove any burrs and sharp edges.
Not recommended for any vent
configuration
*The 99% Winter Design Dry-Bulb (db) temperatures are found in the 1993
ASHRAE Fundamentals Handbook, Chapter 24, Table 1 (United States) and
2 (Canada), or use the 99.6% heating db temperatures found in the 1997 or
2001 ASHRAE Fundamentals Handbook, Climatic Design Information chapter, Table 1A (United States) and 2A (Canada).
Air for combustion must not be contaminated by halogen compounds which include chlorides, fluorides, bromides, and iodides.
These compounds are found in many common home products such
as detergent, paint, glue, aerosol spray, bleach, cleaning solvent,
salt, and air freshener, and can cause corrosion of furnaces and
vents. Avoid using such products in the combustion-air supply.
Furnace use during construction of the building could cause the
furnace to be exposed to halogen compounds, causing premature
failure of the furnace or venting system due to corrosion.
NOTE: If a knockout does not come out after two sharp blows,
pull and snip as needed to remove the knockout. Additional blows
may cause damage to the door.
Vent dampers on any appliance connected to the common vent can
cause condensation and corrosion in the venting system. Do not
use vent dampers on appliances common vented with this furnace.
ADDITIONAL VENTING REQUIREMENTS
BURN HAZARD
Failure to follow this caution may result in personal injury.
A 4″ round vent elbow is supplied with the furnace. A 5-inch or 6inch vent connector may be required for some model furnaces. A
field-supplied 4-inch to 5-inch or 4-inch to 6-inch sheet metal
increaser fitting is required when 5-inch or 6-inch vent connector
is used. See Fig. 35-47, Venting Orientation for approved vent
configurations.
Hot vent pipe is within reach of small children when installed
in downflow position.
See the following instruction.
An accessory Vent Guard Kit, KGAVG0101DFG is REQUIRED
for downflow applications for use where the vent exits through the
lower portion of the furnace casing door. Refer to the Vent Guard
Kit Instructions for complete details.
NOTE: Vent connector length for connector sizing starts at
furnace vent elbow. The 4-inch vent elbow is shipped for upflow
configuration and may be rotated for other positions. Remove the
30
SEE NOTES: 1,2,4,7,8,9
on the page following
these figures
SEE NOTES: 1,2,4,5,7,8,9
on the page following
these figures
A03208
A03211
Fig. 35—Upflow Application-Vent Elbow Up
Fig. 38—Downflow Application-Vent Elbow Up
SEE NOTES: 1,2,4,5,6,7,8,9,10
on the page following these figures
SEE NOTES: 1,2,3,4,7,8,9
on the pages following
these figures
A03209
A03207
Fig. 36—Upflow Application-Vent Elbow Right
SEE NOTES:1,2,3,4,5,7,8,9
on the page following
these figures
Fig. 39—Downflow ApplicationVent Elbow Left then Up
SEE NOTES:1,2,3,4,5,7,8,9
on the page following
these figures.
A03210
A03212
Fig. 37—Downflow ApplicationVent Elbow Up then Left
Fig. 40—Downflow ApplicationVent Elbow Up then Right
31
SEE NOTES: 1,2,4,7,8,9 on the page
following these figures
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
A03213
Fig. 41—Horizontal Left Application-Vent Elbow Left
A03215
Fig. 43—Horizontal Left Application-Vent Elbow Up
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
A03214
Fig. 44—Horizontal Left Application-Vent Elbow Right
Fig. 42—Horizontal Left ApplicationVent Elbow Right then Up
SEE NOTES: 1,2,4,7,8,9 on the page
following these figures
A03216
A03218
SEE NOTES: 1,2,4,5,7,8,9 on the page
following these figures
Fig. 45—Horizontal Right ApplicationVent Elbow Right
A03219
Fig. 46—Horizontal Right ApplicationVent Elbow Left then Up
SEE NOTES: 1,2,4,5,7,8,9
A02068
Fig. 47—Horizontal Right Application-Vent Elbow Left
32
Caution!! For the following applications, use the minimum vertical heights as specified below
For all other applications, follow exclusively the National Fuel Gas Code
FURNACE ORIENTATION
VENT ORIENTATION
FURNACE INPUT(BTU/HR)
MINIMUM
VENT DIAMETER (IN.)*
MINIMUM VERTICAL VENT HEIGHT (FT)**
Downflow
Vent elbow left, then up
Fig. 37
154,000
132,000
110,000(036/-12 only)
5
12
Horizontal Left
Vent elbow right,
then up
Fig. 40
154,000
132,000
5
7
Horizontal Left
Vent Elbow up
Fig. 41
154,000
132,000
5
7
Horizontal Left
Vent elbow right
Fig. 42
154,000
5
7
Downflow
Vent elbow up then left
Fig. 35
110,000
(036/-12 only)
5
10
Downflow
Vent elbow up, then right
Fig. 38
110,000
(036/-12 only)
5
10
NOTE: All vent configurations must also meet National Fuel Gas Code venting requirements NFGC.
*4 in. inside casing or vent guard
**Including 4 in. vent section(s)
Venting Notes for Fig. 35-47
1. For common vent, vent connector sizing and vent material:
United States--use the NFGC
Canada--use the NSCNGPIC
2. Immediately increase to 5-inch or 6-inch vent connector outside furnace casing when 5-inch vent connector is required, refer to Note 1
above.
3. Side outlet vent for upflow and downflow installations must use Type B vent immediately after exiting the furnace, except when
KGAVG0101DFG, Downflow Vent Guard Kit, is used in the downflow position.
4. Type-B vent where required, refer to Note 1 above.
5. Four-inch single-wall (26 ga. min.) vent must be used inside furnace casing and when the KGAVG0101DFG Downflow Vent Guard Kit
is used external to the furnace.
6. Accessory Downflow Vent Guard Kit, KGAVG0101DFG required in downflow installations with lower vent configuration.
7. Chimney Adapter Kit may be required for exterior masonry chimney applications. Refer to Chimney Adapter Kit, KGACA02014FC or
KGACA02015FC, for sizing and complete application details.
8. Secure vent connector to furnace elbow with (2) corrosion-resistant sheet metal screws, spaced approximately 180° apart.
9. Secure all other single wall vent connector joints with (3) corrosion resistant screws spaced approximately 120° apart. Secure Type-B vent
connectors per vent connector manufacturer’s recommendations.
10. The total height of the vent and connector shall be at least seven feet for the 154,000 Btuh gas input rate model when installed in a
downflow application with furnace elbow turned to left side with the connector elbow outside furnace casing pointing upward. (See Fig.
39.)
START-UP, ADJUSTMENT, AND SAFETY CHECK
Step 1—General
The horizontal portion of the venting system shall slope upwards
not less than 1/4-in. per linear ft (21 mm/m) from the furnace to the
vent and shall be rigidly supported every 5 ft or less with metal
hangers or straps to ensure there is no movement after installation.
SIDEWALL VENTING
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death or property damage.
This furnace is equipped with manual reset limit switches in
the gas control area. The switches open and shut off power to
the gas valve, if a flame rollout or overheating condition
occurs in the gas control area. DO NOT bypass the switches.
Correct problem before resetting the switches.
This furnace is not approved for direct sidewall horizontal venting.
In the U.S.: Per section 10.3.4 of the NFGC, any listed mechanical
venter may be used, when approved by the authority having
jurisdiction.
In Canada: Per section 7.24.2 of the NSCNGPIC, any listed
mechanical venter may be used, when approved by the authority
having jurisdiction.
1. Maintain 115-v wiring and ground. Improper polarity will
result in rapid flashing LED and no furnace operation.
Select the listed mechanical venter to match the Btuh input of the
furnace being vented. Follow all manufacturer’s installation requirements for venting and termination included with the listed
mechanical venter.
2. Make thermostat wire connections at the 24-v terminal block
on the furnace control. Failure to make proper connections
33
A04127
Fig. 48—Using Tin Snips to Cut Tie Points
A04130
Fig. 51—Hammer and Screwdriver Used for
Knockout
A04128
Fig. 49—Rounded End of Knockout
A04131
Fig. 52—Remove Knockout with Hammer
A04129
Fig. 50—Knockout Pulled Loose
will result in improper operation. (See Fig. 24.)
3. Gas supply pressure to the furnace must be greater than 4.5-in.
wc (0.16 psig ) but not exceed 14-in. wc (0.5 psig).
5. Replace blower compartment door. Door must be in place to
operate furnace.
6. Setup switch descriptions
The variable speed furnace control has DIP switches to select
thermostat staging, blower off delay timings, air flow selection
and other operational or service related functions. (See Fig.
25, 57 and Table 8.)
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.
4. Check all manual-reset switches for continuity.
34
Step 2—Start-Up Procedures
REGULATOR COVER SCREW
PLASTIC ADJUST SCREW
ON/OFF SWITCH
REGULATOR SPRING
1/2˝ NPT INLET
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could cause personal injury,
death or property damage.
Never purge a line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition for the
purpose of checking leakage. Use a soap-and-water solution
to check for leakage.
HIGH STAGE GAS
PRESSURE REGULATOR
ADJUSTMENT
LOW STAGE
GAS PRESSURE
REGULATOR ADJUSTMENT
INLET
PRESSURE TAP
1. Purge gas lines after all connections have been made.
MANIFOLD
PRESSURE TAP
2. Check gas lines for leaks.
1/2˝ NPT OUTLET
A04167
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
or death.
Blower access door switch opens 115-v power to control. No
component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch for
service purposes.
Fig. 53—Redundant Automatic Gas Control Valve
3. To Begin Component Self-Test:
Remove Blower Access Door. Disconnect the thermostat R
lead from furnace control board. Manually close blower door
switch. Turn Setup DIP switch SW1-6 ON. (See Fig. 25, 57
and Table 8.)
BURNER
ORIFICE
NOTE: The furnace control allows all components, except the gas
valve, to be run for short period of time. This feature helps
diagnose a system problem in case of a component failure.
Component test feature will not operate if any thermostat signal is
present at the control.
A93059
Fig. 54—Orifice Hole
Refer to service label attached to furnace or See Fig. 56.
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
(ANITICIPATOR, CLOCK, ETC.,
MUST BE OUT OF CIRCUIT.)
Component test sequence is as follows:
a. Inducer motor starts on high-speed and continues to run
until Step d. of component test sequence.
b. Hot surface igniter is energized for 15 sec., then off.
HOOK-AROUND
AMMETER
c. Blower motor operates for 15 sec.
d. Inducer motor goes to low-speed for 10 sec., then stops.
e. After component test is completed, one or more status
codes (11, 25, or 41) will flash. See component test section
of service label (Fig. 56) in furnace for explanation of
status codes.
R Y W G
NOTE: To repeat component test, turn setup switch SW1-6 OFF,
then back ON.
4. Turn setup DIP switch SW1-6 OFF. Reconnect R lead to
furnace control board, release blower door switch and reinstall
blower access door.
10 TURNS
5. Operate furnace per instruction on inner door.
FROM UNIT 24-V
CONTROL TERMINALS
EXAMPLE: 5.0 AMPS ON AMMETER
10 TURNS AROUND JAWS
6. Verify furnace shut down by lowering thermostat setting
below room temperature.
= 0.5 AMPS FOR THERMOSTAT
ANTICIPATOR SETTING
7. Verify furnace restarts by raising thermostat setting above
room temperature.
A96316
Fig. 55—Amp Draw Check With Ammeter
35
Table 8—Furnace Setup Switch Description
SETUP
SWITCH NO.
SWITCH
NAME
NORMAL
POSITION
DESCRIPTION
OF USE
SW1-1
Status Code Recovery
OFF
Turn ON to retrieve up to 7 stored status codes for troubleshooting
assistance when R thermostat lead is disconnected.
SW1-2
Adaptive Heat Mode
OFF
Allows 2-stage operation with a single stage thermostat.
Turn ON when using 2 stage thermostat to allow Low Heat operation when R to W/W1 closes and High Heat operation when R to
W/W1 and W2 close.
SW1-3
Low Heat
Rise Adjust
OFF
Turn ON to increase Low Heat airflow by 18 percent. This compensates for increased return air temperature caused with bypass humidifier.
SW1-4
Comfort/Efficiency Adjustment
ON
Turn ON to decrease Low Heat airflow by 16 percent and High Heat
airflow 10 percent for maximum comfort.
SW1-5
CFM per ton adjust
OFF
Turn ON for 400 CFM per ton. Turn OFF for 350 CFM per ton.
SW1-6
Component Self-Test
OFF
Turn ON to initiate Component Self-Test for troubleshooting assistance when R thermostat lead is disconnected.
Turn OFF when Self-Test is completed.
SW1-7
Blower OFF delay
ON or OFF
Control blower Off Delay time. Used in conjunction with SW1-8. See
Table 10.
SW1-8
Blower OFF delay
ON or OFF
Control blower Off Delay time. Used in conjunction with SW1-7. See
Table 10.
SERVICE
LED CODE
STATUS
If status code recall is needed disconnect the "R" thermostat lead, reset power, and put setup switch "SW1-1" in the ON
position. To clear the status code history put setup switch "SW1-1" in the ON position and jumper thermostat terminals "R",
CONTINUOUS OFF - Check for 115VAC at L1 and L2, and 24VAC at SEC-1 and SEC-2.
"W/W1", and "Y/Y2" simultaneously until status code #11 is flashed.
CONTINUOUS ON - Control has 24VAC power.
RAPID FLA SHING - Line voltage (115VAC) polarity reversed.
EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY THE NUMBER OF LONG FLASHES.
11 NO PREVIOUS CODE - Stored status codes are erased automatically after 72
hours or as specified above.
12 BL OWER ON AFTER POWER UP (115 VAC or 24 VAC) -Blower runs for 90
seconds, if unit is powered up during a call for heat (R-W/W1 closed) or
(R-W/W1 opens) during blower on-delay period.
13 LIMIT CIRCUIT LOCKOUT - Lockout occurs if a limit, draft safeguard, flame
rollout, or blocked vent switch (if used) is open longer than 3 minutes or 10
successive limit trips occurred during high-heat. Control will auto reset after
three hours. Refer to status code #33.
14 IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to status
code #34.
15 BL OWER MOTOR LOCKOUT - Indicates the blower failed to reach 250 RPM or
the blower failed to communicate within 30 seconds after being turned ON in two
successive heating cycles. Control will auto reset after 3 hours.
Refer to status code #41.
21 GAS HEATING LOCKOUT - Control will NOT auto reset. Check for:
- Mis-wired gas valve
-Defective control (valve relay)
22 ABNO RMAL FLAME-PROVING SIGNAL - Flame is proved while gas valve is
de-energized. Inducer will run until fault is cleared. Check for:
- Leaky gas valve
- Stuck-open gas valve
23 PRESSURE SWITCH DID NOT OPEN Check for:
- Obstructed pressure tubing
- Pressure switch stuck closed
24 SECONDARY VOLTAGE FUSE IS OPEN Check for: - Short circuit in secondary
voltage (24VAC) wiring.
25 INVAL ID MODEL SELECTION OR SETUP ERROR - Indicates either the model
plug is missing or incorrect or, setup switch "SW1-1" or "SW1-6" is positioned
improperly. If code flashes 4 times on power-up control is defaulting to model
selection stored in memory.Check for: -Thermostat call with SW1-1, SW1-6 or
both SW1-1 & SW1-6 ON. - Board date code 2103 or later required to recognize model
plug 007. - Proper model plug number and resistance values per wiring diagram
31 HIGH-HEAT PRESSURE SWITCH OR RELAY DID NOT CLOSE OR
REOPENED - Control relay may be defective. Refer to status code #32.
32 LOW-HEAT PRESSURE SWITCH DID NOT CLOSE OR REOPENED - If open
longer than five minutes, inducer shuts off for 15 minutes before retry. If opens
during blower on-delay period, blower will come on for the selected blower
off-delay. Check for: - Excessive wind
- Restricted vent - Proper vent sizing
32 Cont in ued: Check for:
- Low inducer voltage (115 VAC)
- Defective inducer motor
- Inadequate combustion air supply
- Defective pressure switch
- Low inlet gas pressure (if LGPS used)
- Low inducer voltage (115 VAC)
- Disconnected or obstructed pressure tubing
33 LIMIT CIRCUIT FAULT - Indicates a limit, draft safeguard, flame rollout, or
blocked vent switch (if used) is open or the furnace is operating in high-heat
only mode due to 2 successive low heat limit trips. Blower will run for 4
minutes or until open switch remakes whichever is longer. If open longer
than 3 minutes, code changes to lockout #13. If open less than 3 minutes
status code #33 continues to flash until blower shuts off. Flame rollout switch
and BVSS require manual reset.
Check for: - Loose blower wheel
- Restricted vent
- Proper vent sizing
- Excessive wind
- Dirty filter or restricted duct system
- Defective switch or connections
- Inadequate combustion air supply (Flame Roll-out Switch open)
34 IGNITION PROVING FAILURE - Control will try three more times before
lockout #14 occurs. If flame signal lost during blower on-delay period, blower
will come on for the selected blower off-delay. Check for:
- Oxide buildup on flame sensor (clean with fine steel wool)
- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal)
- Manual valve shut-off - Low inlet gas pressure - Control ground continuity
- Gas valve defective or turned off
- Flame sensor must not be grounded
- Inadequate flame carryover or rough ignition
- Green/Yellow wire MUST be connected to furnace sheet metal
41 BL OWER MOTOR FAUL T - Indicates the blower failed to reach 250 RPM
or the blower failed to communicate within the prescribed times limits. Thirty
seconds after being turned ON or ten seconds during steady-state operation.
43 LOW-HEAT PRESSURE SWITCH OPEN WHILE HIGH-HEAT PRESSURE
SWITCH IS CLOSED - Check for: - Mis-wired pressure switches
- Low-heat pressure switch stuck open - Low inlet gas pressure (if LGPS used)
- Disconnected or obstructed pressure tubing
45 CONTROL CIRCUITRY LOCKOUT Auto-reset after one hour lockout due to;
- Gas valve relay stuck open - Flame sense circuit failure - Software check error
Reset power to clear lockout. Replace control if status code repeats.
Fig. 56—Service Label
COMPONENT TEST
To initiate the component test sequence, shut
OFF the room thermostat or disconnect the "R"
thermostat lead. Reset power and then put setup
switch "SW1-6" in the ON position to start the
component test sequence. Once initiated the
furnace control will turn the inducer ON at highheat speed. The inducer motor will run for the
entire test. The hot surface igniter and blower
motor will be turned ON for 15 seconds each.
When the blower is turned OFF the inducer will
be switched to low-speed for 10 seconds. When
the component test is completed one or more of
the following codes will flash.
CODE
DESCRIPTION
11
Indicates the blower motor tested
OK. Visual check of inducer motor
and hot surface igniter required.
25
SETUP ERROR - Same as code 25 above.
41
BLOWER MOTOR FAUL T - Indicates
blower motor failed test. Check
blower, wiring, and furnace control.
To repeat component test turn setup switch
"SW1-6" OFF and then back ON. After component
test is completed put setup switch "SW1-6" in the
OFF position and reconnect the "R" thermostat
lead.
328787-101 REV. A
A04015
Step 3—Adjustments
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in reduced furnace
life.
DO NOT redrill orifices. Improper drilling (burrs, out-ofround holes, etc.) can cause excessive burner noise and
misdirection of burner flames. This can result in flame
impingement of heat exchangers, causing failures. (See Fig.
54.)
FIRE HAZARD
Failure to follow this warning could result in injury, death
and/or property damage.
DO NOT bottom out gas valve regulator adjusting screw.
This can result in unregulated manifold pressure and result in
excess overfire and heat exchanger failures.
Furnace gas input rate on rating plate is for installations at altitudes
up to 2000 ft. Furnace input rate must be within ±2 percent of
furnace rating plate input. For altitudes above 5500 ft., a fieldsupplied high altitude pressure switch is required.
36
1. Determine the correct gas input rate.
In the U.S.A.:
The input rating for altitudes above 2,000 ft. must be reduced
by 4 percent for each 1,000 ft. above sea level.
For installations below 2000 ft., refer to the unit rating plate.
For installations above 2000 ft., multiply the input on the
rating plate by the de-rate multiplier in Table 9 for the correct
HI
BRN
PRINTED CIRCIUT BOARD
37
1
AB CD
OAT
OFF
123
OFF
123
OFF
123
W2
Y1 DHUM G Com W/W1 Y/Y2 R
24V
Air Conditioning (Adjustable Airflow -CFM)
Air Conditioning Relay, SPST (N.O.)
Air Conditioning Relay Defeat Jumper
Blower Motor (ECM)
Blocked Vent Safety Switch, Manual Reset,
SPST (N.C.)
CF
Continuous Fan (Adjustable Airflow -CFM)
COMMR Communication Relay, SPDT
CPU
Microprocessor 7 Circuitry
DHUM DHUM Connection (24VAC 0.02 Amps)
DSS
Draft Safeguard Sw., Auto-Reset, SPST (N.C.)
EAC-1 Electronic Air Cleaner Connection
(115VAC 1.0 Amp Max.)
EAC-2 Electronic Air Cleaner Connection (Common)
FRS
Flame Rollout Switch, Man. Reset, SPST(N.C.)
FSE
Flame-Proving Sensor Electrode
FUSE
Fuse, 3 Amp, Automotive Blade Type,
Factory Installed
GV
Gas Valve
GVR
Gas Valve Relay, DPST (N.O.)
HPS
High-Heat Pressure Switch, SPST (N.O.)
HPSR
High-Heat Pressure Switch Relay, SPST (N.C.)
HSI
Hot Surface Igniter (115VAC)
HSIR
Hot Surface Igniter Relay, SPST (N.O.)
HUM
24VAC Humidifier Connection (0.5 Amp Max.)
HUMR Humidifier Relay, SPST (N.O.)
IDM
Inducer Draft Motor, 2-Speed, Shaded Pole
IDR
Inducer Motor Relay, SPST (N.O.)
IHI/LOR Inducer Motor Speed Change Relay, SPDT
AC
OFF
A/C
ACR
ACRDJ
BLWM
BVSS
PL1
OFF
123
1
1 CF
1
HUM
PL7
4
1
OFF
123
FRS1
1
YEL
LPS
RED
NOTE #13
NEUTRAL - L2
BLK
L1
PL2
WHT
DSS
ORN
1
BLK
WHT
WHT
WHT
BLU
PL12
IND
NOTE #7
BLK
4
BLK
WHT
COM
HI
BLWM
PL10
HSI
PL14
ILK
JB
GRN/YEL
CONDUCTOR ON
WIRING (24VAC)
FIELD CONTROL
WIRING (24VAC)
Y/Y2
G
Y1
13.
14.
PLUG RECEPTACLE
10.
1.
2.
3.
4.
5.
6.
7.
8.
9.
TRAN
Fig. 57—Wiring Diagram
2
NOTE #5
PCB
CPU
HUMR
GVR
HPSR
PL12
10
16
1
7
PL1-6
2
1
PL14
EAC-2
4
PL1-1
NOTE #3
C
PL1-10 M
GV
PL1-4
LGPS
(WHEN USED)
PL1-3
FU1
HI
HPS
LPS
IDM
L2
L2
24VAC
TRAN
FSE
PL1-5
SEC1
SEC2
115VAC L2
BLWM
L1
NOTE #6
NOTE #8
PL1-2
PL1-12
PL1-8
FRS1
5
3
PL13
PL11
3 COM
LO
HI
4
HSI
PL10
2
1
2
1
SCHEMATIC DIAGRAM
1
2
3
EAC-1
PL2
DSS
L2
EQUIPMENT
GROUND
IND
NOTE #7
BVSS
4
PCB
IHI/LOR
HSIR
L2
(WHEN USED)
NOTE #12
PL12
3
CPU
ACR
EAC
L1
1
(WHEN USED)
LS2
IDR
NOTE #5
PL3
ILK
TO 115VAC FIELD-DISCONNECT SWITCH
A04014
If any of the original equipment wire is replaced use wire rated for 105˚C.
Use only copper wire between the disconnect switch and the furnace junction box (JB).
This wire must be connected to furnace sheet metal for control to prove flame.
Symbols are electrical representation only.
Solid lines inside PCB are printed circuit board conductors and are not included in legend.
Replace only with a 3 amp fuse.
Inductor is used with 3/4 hp and 1 hp ECM Blower motors.
Factory connected when (LGPS) not used.
Blower off-delay, gas heating selections are (90, 120, 150, 180) seconds, cooling or heat pump
90 seconds or 5 seconds when dehumidify call is active.
Ignition lockout will occur after four consecutive unsuccessful trials for ignition. Control will
auto-reset after three hours.
Inducer motor (IDM) contains internal auto-reset thermal overload switch.
Factory connected when BVSS is not used. BVSS used when Chimney Adapter Accessory Kit is
installed.
Any of the 5 wires shown within the NEUTRAL L2 box can be connected to any terminal within the box.
Blower motor (BLWM) is locked-rotor overload protected by redundant electronic control circuits.
NOTES:
COM
11.
12.
GROUND
COMMR
R
HUM
LS1
GND
DHUM
W2
EQUIPMENT
SCREW TERMINAL
FIELD WIRING
CONTROL
RED
W/W1
FRS2
PRINTED CIRCIUT BOARD
FACTORY CONTROL
WIRING (115VAC)
FACTORY POWER
CONTROL TERMINAL
TERMINAL
JUNCTION
FRS2
BLK WHT
FU2
54 3 2 1
2
1
LO
GRN/YEL
RED
FUSED OR CIRCUIT
BREAKER DISCONNECT
SWITCH (WHEN REQ'D)
NOTE #2
NEUTRAL
L1
LS1
10 16 1 7
PL13
BLK
BLK
RED
RED
2
BLK
ORN
IDM
PL11 WHT
3
WHT
RED
FSE
RED
LS2
(WHEN USED)
RED
LGPS (WHEN USED)
BVSS
(WHEN USED)
NOTE #8
ORN
NOTE #12
Blower Door Interlock Switch, SPST (N.O.)
Inductor (Note #7)
Light Emitting Diode for Status Codes
Low Gas Pressure Switch, SPST (N.O.)
Low-Heat Pressure Switch, SPST (N.O.)
Limit Switch, Auto-Reset, SPST (N.C.)
Printed Circuit Board
12-Circuit Connector
4-Circuit HSI & IDM Connector
4-Circuit ECM BLWM Connector
4-Circuit Model Plug Connector
4-Circuit Communication Connector
2-Circuit OAT Connector
2-Circuit HSI Connector
IDM Connector (3-Circuit)
1-Circuit Inductor Splice Connector
16-Circuit ECM Blower Ctrl. Connector
5-Circuit ECM Blower Power Connector
Manual Switch, Status Code Recall, SPST (N.O.)
Manual Switch, Low-Heat Only, SPST(N.O.)
Manual Switch, Low-Heat Rise Adj. SPST (N.O.)
Manual Switch, Comfort/Efficiency Adjustment,
SPST (N.O.)
SW1-5 Manual Switch, Cooling CFM/Ton, SPST (N.O.)
SW1-6 Manual Switch, Component Test, SPST (N.O.)
SW1-7,8 Manual Switches, Blower Off-Delay, SPST(N.O.)
SW4-1 Manual Switch, Twinning Main (OFF) / Sec. (ON)
SW4-2&3 FOR FUTURE USE
TRAN Transformer, 115VAC / 24VAC
ILK
IND
LED
LGPS
LPS
LS 1, 2
PCB
PL1
PL2
PL3
PL4
PL7
PL9
PL10
PL11
PL12
PL13
PL14
SW1-1
SW1-2
SW1-3
SW1-4
STATUS
CODE
LEDS
COMM
MODEL
SIZE
070
DEF. 525 2 700
875 1050 1 1225 1225 1225
090
DEF.
525
700 2 875 1050 1225 1400 1 1400
110,135,
DEF.
700
875 2 1050 1225 1400 1750 1 2100
155
1. Default A/C airflow when A/C switches are in OFF position
2. Default cont. fan airflow when CF switches are in OFF position
OFF
123
ACRDJ
PL9
PL3
RED
A/C OR CF AIRFLOW SELECTION CHART BASED ON 350 CFM/TON
PL8
GRY
GRN/YEL
BRN
HPS
BLU
PL12
L
E
G
E
N
D
NOTE #3
C
GRN/YEL
GV
PL4 - MODEL PLUG CHART
MODEL COOLING MODEL PIN RESISTANCE K
PLUG
SIZE
SIZE
1-4
2-3
HK70EZ
----070
001
5.1
11
----090
003
5.1
24
066/-22
110
004
5.1
33
110
060/-20
007
62
5.1
----135
005
5.1
39
----5.1
155
006
51
90
SEC
120
SEC
150
SEC
180
SEC
M
CONNECTION DIAGRAM
OFF
123
FUSE 3-AMP
EAC-1
SW1-7,8
BLOWER OFF DELAY
SELECTION
123
SEC-2 SEC-1
RED
GRN
YEL
BLU
EAC-2
YEL
PL4
SW1
VS HSI HI LO
OFF OFF OFF OFF
SW4
328782-101 REV. A
7 8 7 8 7 8 7 8
RED
GRN
YEL
BLU
ACRDJ
Table 9–Altitude Derate Multiplier for U.S.A.
ALTITUDE
(FT)
0–2000
2001–3000
3001–4000
4001–5000
5001–6000
6001–7000
7001–8000
8001–9000
9001–10,000
PERCENT
OF DERATE
0
8–12
12–16
16–20
20–24
24–28
28–32
32–36
36–40
EXAMPLE 2: (0–2000 ft altitude)
For 22,000 Btuh per burner application use Table 12.
Heating value = 1000 Btu/cu ft
Specific gravity = 0.62
Therefore: Orifice No. 43*
Manifold pressure: 3.7-in. wc for high-heat
1.6-in. wc for low-heat
* Furnace is shipped with No. 43 orifices. In this example
all main burner orifices are the correct size and do not need
to be changed to obtain proper input rate.
DERATE MULTIPLIER
FACTOR*
1.00
0.90
0.86
0.82
0.78
0.74
0.70
0.66
0.62
3. Adjust manifold pressure to obtain low fire input rate. (See
Fig. 53.)
* Derate multiplier factors are based on midpoint altitude for altitude range.
a. Turn gas valve ON/OFF switch to OFF.
b. Remove manifold pressure tap plug from gas valve.
c. Connect a water column manometer or similar device to
manifold pressure tap.
input rate.
In Canada:
The input rating for altitudes from 2,000 to 4,500 ft above sea
level must be derated 10 percent by an authorized Gas
Conversion Station or Dealer.
To determine correct input rate for altitude, see example and
use 0.90 as derate multiplier factor.
d. Turn gas valve ON/OFF switch to ON.
e. Move setup SW1–2 on furnace control to ON position to
lock furnace in low-heat operation. (See Table 8 and Fig.
25.)
f. Manually close blower door switch.
EXAMPLE:
88,000 BTUH INPUT FURNACE INSTALLED AT 4300 FT.
Derate
Furnace Input Rate
Furnace Input Rate X Multiplier =
at Installation
at Sea Level
Factor
Altitude
88,000
X
0.90
=
79,200
g. Jumper R and W/W1 thermostat connections on control to
start furnace. (See Fig. 25.)
h. Remove regulator adjustment cap from low heat gas valve
pressure regulator (See Fig. 53.) and turn low-heat adjusting screw (3/16 or smaller flat-tipped screwdriver) counterclockwise (out) to decrease input rate or clockwise (in)
to increase input rate.
2. Determine the correct orifice and manifold pressure adjustment. All models in all positions except Low NOx models in
downflow and horizontal positions use Table 12 (22,000 Btuh
per burner.) Low NOx models in downflow or horizontal
positions must use Table 13 (21,000 Btuh per burner.)
See input listed on rating plate.
NOTE: DO NOT set low-heat manifold pressure less than 1.4-in
wc or more than 1.7-in. wc for natural gas. If manifold pressure is
outside this range, change main burner orifices.
a. Obtain average yearly gas heat value (at installed altitude)
from local gas supplier.
j. Leave manometer or similar device connected and proceed
to Step 4.
b. Obtain average yearly gas specific gravity from local gas
supplier.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check orifice hole with a numbered drill bit of
correct size. Never redrill an orifice. A burr-free and squarely
aligned orifice hole is essential for proper flame characteristics.
i. Install low-heat regulator adjustment cap.
c. Find installation altitude in Table 12 or 13.
d. Find closest natural gas heat value and specific gravity in
Table 12 or 13.
4. Verify natural gas low-heat input rate by clocking meter.
NOTE: Gas valve regulator adjustment caps must be in place for
proper input to be clocked.
e. Follow heat value and specific gravity lines to point of
intersection to find orifice size and low-and high-heat
manifold pressure settings for proper operation.
a. Turn off all other gas appliances and pilots served by the
meter.
f. Check and verify burner orifice size in furnace. NEVER
ASSUME ORIFICE SIZE. ALWAYS CHECK AND
VERIFY.
b. Run furnace for 3 minutes in low-heat operation.
c. Measure time (in sec) for gas meter to complete 1 revolution and note reading. The 2 or 5 cubic feet dial provides a
more accurate measurement of gas flow.
g. Replace orifice with correct size, if required by Table 12 or
13. Use only factory-supplied orifices. See EXAMPLE 2.
d. Refer to Table 11 for cubic ft of gas per hr.
e. Multiply gas rate cu ft/hr by heating value (Btu/cu ft) to
obtain input.
Table 10—Blower Off Delay Setup Switch
If clocked rate does not match required input from Step 1,
increase manifold pressure to increase input or decrease
manifold pressure to decrease input. Repeat steps b through
e until correct low-heat input is achieved. Re-install lowheat regulator seal cap on gas valve.
DESIRED HEATING MODE
SETUP SWITCH (SW-7 AND -8) POSITION
BLOWER OFF DELAY (SEC.)
SW1-7
SW1-8
90
OFF
OFF
120
ON
OFF
150
OFF
ON
180
ON
ON
5. Set low heat temperature rise.
The furnace must operate within the temperature rise ranges
38
specified on the furnace rating plate. Do not exceed temperature rise ranges specified on furnace rating plate for high-and
low-fire. Determine the temperature rise as follows:
Table 11—GAS RATE (CU FT/HR)
SIZE OF TEST DIAL
SIZE OF TEST DIAL
SECONDS
SECONDS
FOR 1
FOR 1
1
2
5
1
2
5
REVOLUTION Cu Ft Cu Ft Cu Ft REVOLUTION Cu Ft Cu Ft Cu Ft
NOTE: Blower access door must be installed when taking temperature rise reading. Leaving blower access door off will result in
incorrect temperature measurements.
10
360
720
1800
50
72
144
360
11
327
655
1636
51
71
141
355
12
300
600
1500
52
69
138
346
13
277
555
1385
53
68
136
340
14
257
514
1286
54
67
133
333
15
240
480
1200
55
65
131
327
16
225
450
1125
56
64
129
321
17
212
424
1059
57
63
126
316
18
200
400
1000
58
62
124
310
19
189
379
947
59
61
122
305
20
180
360
900
60
60
120
300
21
171
343
857
62
58
116
290
22
164
327
818
64
56
112
281
23
157
313
783
66
54
109
273
24
150
300
750
68
53
106
265
25
144
288
720
70
51
103
257
26
138
277
692
72
50
100
250
27
133
267
667
74
48
97
243
28
129
257
643
76
47
95
237
29
124
248
621
78
46
92
231
30
120
240
600
80
45
90
225
31
116
232
581
82
44
88
220
32
113
225
563
84
43
86
214
33
109
218
545
86
42
84
209
34
106
212
529
88
41
82
205
35
103
206
514
90
40
80
200
36
100
200
500
92
39
78
196
37
97
195
486
94
38
76
192
When setup switch SW1-4 is ON, operation will be near the high
end of the rise range for improved comfort.
38
95
189
474
96
38
75
188
39
92
185
462
98
37
74
184
This furnace is capable of automatically providing proper airflow
to maintain the temperature rise within the range specified on unit
rating plate.
40
90
180
450
100
36
72
180
41
88
176
439
102
35
71
178
42
86
172
429
104
35
69
173
43
84
167
419
106
34
68
170
44
82
164
409
108
33
67
167
45
80
160
400
110
33
65
164
46
78
157
391
112
32
64
161
47
76
153
383
116
31
62
155
48
75
150
375
120
30
60
150
49
73
147
367
a. Verify unit is running in low-heat per Step 4. Place
thermometers in return and supply ducts as close to furnace
as possible. Be sure thermometers do not see radiant heat
from heat exchangers. Radiant heat affects temperature rise
readings. This practice is particularly important with
straight-run ducts.
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect 115-v electrical power before changing speed tap.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in shorten furnace
life. Set air temperature rise within limits specified on the
rating plate to prevent reduced life of furnace components.
Operation is within a few degrees of the mid-point of rise
range when setup switch SW1-4 is OFF.
NOTE: If the temperature rise is outside this range, first check:
1.) Gas input for low heat operation.
2.) Derate for altitude if applicable.
3.) Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50-in. wc.
4.) Ensure low-heat rise adjust switch SW1-3 is in ON
position when bypass humidifier is used. Refer to Table
8 and Fig. 25 and 57.
5.) Make sure proper model plug is installed.
b. Run for 3 minutes in high-heat operation.
c. Measure time (in sec) for gas meter to complete 1 revolution and note reading.
6. Adjust Manifold Pressure to Obtain High Heat Rate
a. Remove high heat regulator adjustment cap from gas valve
pressure regulator.
d. Refer to Table 11 for cubic ft of gas per hr.
b. Jumper R, W/W1 and W2 thermostat connections on
control to run furnace in high heat. (See Fig. 25 and 57.)
e. Multiply gas rate cu ft/hr by heating value (Btu/cu ft) to
obtain input.
c. Turn high-heat adjusting screw (3/16 or smaller flat-tipped
screwdriver)) counterclockwise (out) to decrease input rate
or clockwise (in) to increase rate.
NOTE: Using the 2 cu. ft. or 5 cu. ft. gas meter dial provides
greater accuracy in verifying gas input rate.
If clocked rate does not match required input from Step 1, increase
manifold pressure to increase input or decrease manifold pressure
to decrease input. Repeat steps b through e until correct high heat
input is achieved. Re-install high-heat regulator seal cap on gas
valve.
d. Re-install high-heat adjustment caps.
NOTE: DO NOT set high-heat manifold pressure less than 3.2-in.
wc or more than 3.8-in. wc for natural gas. If manifold pressure is
outside this range, change main burner orifices.
8. Set high heat temperature rise.
Jumper R to W/W1 and W2 to check high-gas-heat temperature rise. Do not exceed temperature rise ranges specified on
furnace rating plate for high heat. The furnace must operate
within the temperature rise ranges specified on the furnace
rating plate.
7. Verify natural gas high heat input rate by clocking meter.
NOTE: Gas valve regulator adjustment caps must be in place for
proper input to be clocked.
a. Turn off all other gas appliances and pilots served by the
meter.
39
Determine the air temperature rise as follows:
NOTE: Blower access door must be installed when taking temperature rise reading. Leaving blower access door off will result in
incorrect temperature measurements.
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace
life. Recheck temperature rise.It must be within limits specified on the rating plate. Recommended operation is at the
mid-point of rise range or slightly above.
a. Verify the unit is operating in high heat per Step 6. Place
thermometers in return and supply ducts as close to furnace
as possible. Be sure thermometers do not see radiant heat
from heat exchangers. Radiant heat affects temperature rise
readings. This practice is particularly important with
straight-run ducts.
9. Set Blower Off Delay
a. Remove blower access door if installed.
b. Turn Dip switch SW-7 or SW-8 ON or OFF for desired
blower off delay. (See Table 10 and Fig. 25 and 57.)
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
10. Set thermostat heat anticipator.
a. Mechanical thermostat—Set thermostat heat anticipator to
match the amp draw of the electrical components in the
R-W/W1 circuit. Accurate amp draw readings can be
obtained at the wires normally connected to thermostat
subbase terminals, R and W. The thermostat anticipator
should NOT be in the circuit while measuring current.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in shorten furnace
life. Set air temperature rise within limits specified on the
rating plate to prevent reduced life of furnace components.
Operation is within a few degrees of the mid-point of rise
range when setup switch SW1-4 is OFF.
(1.) Set SW1-2 switch on furnace control board to ON.
(2.) Remove thermostat from subbase or from wall.
(3.) Connect an amp meter as shown in Fig. 55 across the
R and W subbase terminals or R and W wires at wall.
When setup switch SW1-4 is ON, operation will be near the high
end of the rise range for improved comfort.
(4.) Record amp draw across terminals when furnace is in
low heat and after blower starts.
This furnace is capable of automatically providing proper airflow
to maintain the temperature rise within the range specified on unit
rating plate.
(5.) Set heat anticipator on thermostat per thermostat
instructions and install on subbase or wall.
(6.) Turn SW1-2 switch OFF.
NOTE: If the temperature rise is outside this range, first check:
1.) Gas input for low-and high-heat operation.
2.) Derate for altitude if applicable.
3.) Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50-in. wc.
4.) Make sure proper model plug is installed.
(7.) Install blower access door.
b. Electronic thermostat: Set cycle rate for 3 cycles per hr.
11. Set Airflow for Air Conditioning -Single Stage and High
Stage Cooling
The ECM blower can be adjusted for a range of airflows for
Low Speed or High Speed cooling. See Table 5-Air Delivery
- CFM (With Filter ). Depending on the model size, the
cooling airflow can be adjusted from 1½ tons nominal cooling
to 3 ½, to 4 or to 6 tons of nominal cooling based on 350 cfm
ton.
The cooling airflow is adjusted by turning Setup switches
SW2-1, SW2-2 and SW2-3 either ON or OFF. Select the
required airflow from Fig. 61. Fig. 61 is based on 350 CFM
per ton. For airflow at 400 CFM per ton, turn Setup SW1-5
ON (See Table 8 and Fig. 25 and 57.)
NOTE: 6 ton airflow will truncate at 2200 cfm on applicable
models. For a complete explanation of cooling airflow, refer to the
section titled ″Sequence of Operation.″
c. Remove thermostat jumpers and release blower access door
switch.
d. Repeat Steps a through c as required to adjust for proper
rise.
e. When correct high heat input rate and temperature rise is
achieved, turn gas valve ON/OFF switch to OFF.
f. Release blower access door switch.
g. Remove manometer or similar device from gas valve.
h. Re-install manifold pressure tap plug in gas valve. (See
Fig. 53.)
FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage. Reinstall manifold pressure
tap plug in gas valve to prevent gas leak.
i. Remove thermostat jumper wire from furnace control
board.
j. Turn gas valve ON/OFF switch to ON.
k. Proceed to Step 9, ″Set Blower Off Delay″ before installing
blower access door.
40
12. Set Airflow For Continuous Fan/Low Speed Cooling Airflow
The ECM blower motor can be adjusted for continuous fan
speeds different than heating or cooling fan speed. See Table
5 - Air Delivery - CFM (With Filter). Select the required
continuous fan airflow from Fig. 61.
The continuous fan speed is also the fan speed for low speed
cooling when furnace is used with a 2-speed cooling unit.
Adjust the Continuous Fan CFM to match the airflow required
for low speed cooling. Select the required airflow from Fig.
61. For airflow at 400 CFM per ton, turn Setup SW1-5 ON
(See Fig. 61.) The airflow selected for low speed cooling will
also be the airflow used for continuous fan.
The continuous fan speed can be further adjusted at the
thermostat using the ″Comfort Fan″ select function. Changing
the continuous fan speed at the thermostat DOES NOT change
the low speed cooling airflow selected at the control board.
TABLE 12—Orifice Size and Manifold Pressure for Gas Input Rate
(Tabulated Data Based On 22,000 Btuh High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
0
to
2000
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
U.S.A.
Altitudes
2001
to
3000
or
Canada
Altitudes
2001
to
4500
U.S.A. Only
ALTITUDE
RANGE
(FT)
3001
to
4000
U.S.A. Only
ALTITUDE
RANGE
(FT)
4001
to
5000
AVG GAS
HEAT VALUE
(BTU/CU FT)
900
925
950
975
1000
1025
1050
1075
1100
AVG GAS
HEAT VALUE
(BTU/CU FT)
800
825
850
875
900
925
950
975
1000
AVG GAS
HEAT VALUE
(BTU/CU FT)
775
800
825
850
875
900
925
950
AVG GAS
HEAT VALUE
(BTU/CU FT)
750
775
800
825
850
875
900
925
0.58
Orifice
Manifold
no.
Pressure
42
3.5/1.5
42
3.3/1.4
43
3.8/1.7
43
3.6/1.6
43
3.5/1.5
43
3.3/1.4
44
3.6/1.6
44
3.4/1.5
44
3.3/1.4
Orifice
no.
42
42
43
43
43
44
44
44
45
0.58
Manifold
Pressure
3.4/1.5
3.2/1.4
3.7/1.6
3.5/1.5
3.3/1.4
3.5/1.5
3.4/1.5
3.2/1.4
3.7/1.6
Orifice
no.
42
43
43
43
44
44
45
46
0.58
Manifold
Pressure
3.2/1.4
3.6/1.6
3.4/1.5
3.2/1.4
3.5/1.5
3.3/1.4
3.8/1.6
3.8/1.6
Orifice
no.
43
43
43
44
44
45
46
46
0.58
Manifold
Pressure
3.6/1.6
3.4/1.5
3.2/1.4
3.4/1.5
3.2/1.4
3.7/1.6
3.7/1.6
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
42
3.6/1.6
42
3.7/1.6
42
3.4/1.5
42
3.5/1.5
42
3.3/1.4
42
3.4/1.5
43
3.8/1.6
42
3.2/1.4
43
3.6/1.6
43
3.7/1.6
43
3.4/1.5
43
3.5/1.5
43
3.2/1.4
43
3.4/1.5
44
3.5/1.5
43
3.2/1.4
44
3.4/1.5
44
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
42
3.5/1.5
42
3.6/1.6
42
3.3/1.4
42
3.4/1.5
43
3.8/1.6
42
3.2/1.4
43
3.6/1.6
43
3.7/1.6
43
3.4/1.5
43
3.5/1.5
43
3.2/1.4
43
3.3/1.4
44
3.5/1.5
44
3.6/1.6
44
3.3/1.4
44
3.4/1.5
45
3.8/1.7
44
3.2/1.4
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
42
3.3/1.4
42
3.4/1.5
43
3.8/1.6
42
3.2/1.4
43
3.5/1.5
43
3.7/1.6
43
3.3/1.4
43
3.4/1.5
44
3.6/1.6
43
3.3/1.4
44
3.4/1.5
44
3.5/1.5
44
3.2/1.4
44
3.3/1.5
45
3.7/1.6
45
3.8/1.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
43
3.8/1.6
42
3.2/1.4
43
3.5/1.5
43
3.6/1.6
43
3.3/1.4
43
3.4/1.5
44
3.6/1.5
43
3.2/1.4
44
3.4/1.5
44
3.5/1.5
45
3.8/1.7
44
3.3/1.4
46
3.8/1.7
45
3.7/1.6
46
3.6/1.6
46
3.7/1.6
* Orifice numbers 43 are factory installed
41
Orifice
no.
41
42
42
42
43
43
43
43
43
0.64
Manifold
Pressure
3.5/1.5
3.7/1.6
3.5/1.5
3.3/1.4
3.8/1.7
3.6/1.6
3.5/1.5
3.3/1.4
3.2/1.4
Orifice
no.
42
42
42
43
43
43
43
44
44
0.64
Manifold
Pressure
3.7/1.6
3.5/1.5
3.3/1.4
3.8/1.7
3.6/1.6
3.4/1.5
3.2/1.4
3.5/1.5
3.4/1.5
Orifice
no.
42
42
43
43
43
43
44
44
0.64
Manifold
Pressure
3.5/1.5
3.3/1.4
3.8/1.6
3.6/1.5
3.4/1.5
3.2/1.4
3.4/1.5
3.3/1.4
Orifice
no.
42
43
43
43
44
44
44
46
0.64
Manifold
Pressure
3.3/1.4
3.8/1.6
3.5/1.5
3.3/1.4
3.6/1.6
3.4/1.5
3.2/1.4
3.8/1.7
TABLE 12—Orifice Size and Manifold Pressure for Gas Input Rate
(Tabulated Data Based On 22,000 Btuh High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)(Continued)
U.S.A. Only
ALTITUDE
RANGE
(FT)
5001
to
6000
U.S.A. Only
ALTITUDE
RANGE
(FT)
6001
to
7000
U.S.A. Only
ALTITUDE
RANGE
(FT)
7001
to
8000
U.S.A. Only
ALTITUDE
RANGE
(FT)
8001
to
9000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
725
750
775
800
825
850
875
900
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
675
700
725
750
775
800
825
850
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
650
675
700
725
750
775
800
825
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
625
650
675
700
725
750
775
0.58
Orifice
Manifold
No.
Pressure
43
3.4/1.5
43
3.2/1.4
44
3.4/1.5
44
3.2/1.4
46
3.8/1.7
46
3.6/1.6
47
3.8/1.7
47
3.6/1.6
Orifice
No.
43
44
44
45
46
46
47
47
0.58
Manifold
Pressure
3.4/1.5
3.6/1.6
3.4/1.5
3.8/1.7
3.7/1.6
3.5/1.5
3.7/1.6
3.5/1.5
Orifice
No.
44
44
45
46
46
47
47
48
0.58
Mainifold
Pressure
3.6/1.6
3.3/1.5
3.8/1.6
3.7/1.6
3.4/1.5
3.6/1.6
3.4/1.5
3.7/1.6
Orifice
No.
44
45
46
47
47
48
48
0.58
Manifold
Pressure
3.3/1.5
3.7/1.6
3.6/1.6
3.8/1.7
3.6/1.6
3.8/1.7
3.6/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
43
3.5/1.5
43
3.6/1.6
43
3.3/1.4
43
3.4/1.5
44
3.5/1.5
43
3.2/1.4
44
3.3/1.4
44
3.4/1.5
45
3.8/1.6
44
3.2/1.4
46
3.7/1.6
46
3.8/1.7
46
3.5/1.5
46
3.6/1.6
47
3.8/1.6
46
3.4/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
43
3.5/1.5
43
3.6/1.6
43
3.3/1.4
43
3.4/1.5
44
3.5/1.5
44
3.6/1.6
44
3.3/1.4
44
3.4/1.5
45
3.7/1.6
45
3.8/1.7
46
3.6/1.6
46
3.8/1.6
46
3.4/1.5
46
3.5/1.5
47
3.6/1.6
47
3.8/1.6
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
43
3.2/1.4
43
3.4/1.5
44
3.5/1.5
44
3.6/1.6
44
3.2/1.4
44
3.3/1.4
46
3.8/1.7
45
3.7/1.6
46
3.6/1.5
46
3.7/1.6
47
3.8/1.6
46
3.4/1.5
47
3.5/1.5
47
3.7/1.6
48
3.8/1.6
47
3.4/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
44
3.5/1.5
44
3.6/1.6
44
3.2/1.4
44
3.3/1.4
46
3.8/1.6
45
3.7/1.6
46
3.5/1.5
46
3.6/1.6
47
3.7/1.6
47
3.8/1.7
47
3.5/1.5
47
3.6/1.6
48
3.7/1.6
48
3.8/1.7
* Orifice numbers 43 are factory installed
42
Orifice
No.
43
43
43
44
44
45
46
46
0.64
Manifold
Pressure
3.7/1.6
3.5/1.5
3.3/1.4
3.5/1.5
3.3/1.4
3.8/1.6
3.7/1.6
3.5/1.5
Orifice
No.
43
43
43
44
44
45
46
46
0.64
Manifold
Pressure
3.7/1.6
3.5/1.5
3.2/1.4
3.5/1.5
3.2/1.4
3.7/1.6
3.6/1.6
3.4/1.5
Orifice
No.
43
43
44
44
46
46
47
47
0.64
Manifold
Pressure
3.5/1.5
3.2/1.4
3.4/1.5
3.2/1.4
3.8/1.6
3.6/1.5
3.8/1.6
3.6/1.5
Orifice
No.
43
44
45
46
46
47
47
0.64
Manifold
Pressure
3.2/1.4
3.4/1.5
3.8/1.7
3.7/1.6
3.5/1.5
3.7/1.6
3.5/1.5
TABLE 12—Orifice Size and Manifold Pressure for Gas Input Rate
(Tabulated Data Based On 22,000 Btuh High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)(Continued)
U.S.A. Only
ALTITUDE
RANGE
(FT)
9001
to
10,000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
600
625
650
675
700
725
0.58
Orifice
Manifold
No.
Pressure
45
3.7/1.6
46
3.6/1.6
47
3.8/1.6
47
3.5/1.5
48
3.7/1.6
48
3.5/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
45
3.8/1.7
44
3.3/1.4
46
3.7/1.6
46
3.8/1.7
46
3.4/1.5
46
3.6/1.5
47
3.6/1.6
47
3.7/1.6
48
3.8/1.7
47
3.5/1.5
48
3.6/1.6
48
3.7/1.6
Orifice
No.
44
45
46
46
47
48
0.64
Manifold
Pressure
3.4/1.5
3.8/1.6
3.7/1.6
3.4/1.5
3.6/1.6
3.8/1.7
* Orifice numbers 43 are factory installed
d. Set thermostat to ″call for heat″ and wait 1 minute. When
pressure switch is functioning properly, hot surface igniter
should NOT glow and control diagnostic light flashes a
status code 32. If hot surface igniter glows when inducer
motor is disconnected, shut down furnace immediately.
Step 4—Check Safety Controls
The flame sensor, gas valve, and pressure switch were all checked
in the Start-up procedure section as part of normal operation.
1. Check Main Limit Switch
This control shuts off combustion system and energizes
air-circulating blower motor, if furnace overheats. By using
this method to check limit control, it can be established that
limit is functioning properly and will operate if there is a
restricted return-air supply or motor failure. If limit control
does not function during this test, cause must be determined
and corrected.
e. Determine reason pressure switch did not function properly
and correct condition.
f. Turn off 115-v power to furnace.
g. Reconnect inducer motor wires, replace outer door, and
turn on 115-v power.
a. Run furnace for at least 5 minutes.
h. Blower will run for 90 seconds before beginning the call
for heat again.
b. Gradually block off return air with a piece of cardboard or
sheet metal until the limit trips.
i. Furnace should ignite normally.
c. Unblock return air to permit normal circulation.
Step 5—Checklist
d. Burners will re-light when furnace cools down.
1. Put away tools and instruments. Clean up debris.
2. Check draft safeguard switch.
The purpose of this control is to cause the safe shutdown of the
furnace during certain blocked vent conditions.
a. Verify vent pipe is cool to the touch.
2. Verify that switches SW1-1 and SW1-6 are OFF and other
setup switches are set as desired. Verify that switches SW1-7
and SW1-8 for the blower OFF DELAY are set as desired per
Table 10.
b. Disconnect power to furnace and remove vent connector
from furnace vent elbow.
3. Verify that blower and burner access doors are properly
installed.
c. Restore power to furnace and set room thermostat above
room temperature.
4. Cycle test furnace with room thermostat.
5. Check operation of accessories per manufacturer’s instructions.
d. After normal start-up, allow furnace to operate for 2
minutes, then block vent elbow in furnace 80 percent of
vent area with a piece of flat sheet metal.
6. Review User’s Guide with owner.
7. Attach literature packet to furnace.
e. Furnace should cycle off within 2 minutes. If gas does not
shut off within 2 minutes, determine reason draft safeguard
switch did not function properly and correct condition.
SERVICE AND MAINTENANCE PROCEDURES
f. Remove blockage from furnace vent elbow.
g. Switch will auto-reset when it cools.
h. Re-install vent connector.
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
NOTE: Should switch remain open longer than 3 minutes,
furnace control board will lockout the furnace for 3 hours. To reset
furnace control board, turn thermostat below room temperature or
from HEAT to OFF and turn 115-v power OFF, then back ON.
The ability to properly perform maintenance on this equipment requires certain knowledge, mechanical skills, tools, and
equipment. If you do not possess these, do not attempt to
perform any maintenance on this equipment other than those
procedures recommended in the User’s Manual.
3. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 115-v power to furnace.
b. Disconnect inducer motor lead wires from wire harness.
c. Turn on 115-v power to furnace.
43
TABLE 13–Orifice Size and Manifold Pressure for Gas Input Rate (Tabulated Data Based On 21,000 Btuh
High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
0
to
2000
U.S.A. and Canada
ALTITUDE
RANGE
(FT)
U.S.A.
Altitudes
2001
to
3000
or
Canada
Altitudes
2001
to
4500
U.S.A. Only
ALTITUDE
RANGE
(FT)
3001
to
4000
U.S.A. Only
ALTITUDE
RANGE
(FT)
4001
to
5000
AVG GAS
HEAT VALUE
(BTU/CU FT)
900
925
950
975
1000
1025
1050
1075
1100
AVG GAS
HEAT VALUE
(BTU/CU FT)
800
825
850
875
900
925
950
975
1000
AVG GAS
HEAT VALUE
(BTU/CU FT)
775
800
825
850
875
900
925
950
AVG GAS
HEAT VALUE
(BTU/CU FT)
750
775
800
825
850
875
900
925
0.58
Orifice
Manifold
no.
Pressure
42
3.2/1.5
43
3.7/1.8
43
3.5/1.7
43
3.3/1.6
44
3.6/1.7
44
3.4/1.6
44
3.3/1.6
45
3.8/1.8
46
3.8/1.8
Orifice
no.
43
43
43
43
44
44
45
46
46
0.58
Manifold
Pressure
3.8/1.8
3.5/1.7
3.3/1.6
3.2/1.5
3.4/1.6
3.2/1.5
3.7/1.8
3.7/1.8
3.5/1.7
Orifice
no.
43
43
44
44
45
46
46
46
0.58
Manifold
Pressure
3.5/1.7
3.3/1.6
3.6/1.7
3.4/1.6
3.8/1.8
3.8/1.8
3.6/1.7
3.4/1.6
Orifice
no.
43
44
44
45
46
46
47
47
0.58
Manifold
Pressure
3.3/1.6
3.6/1.7
3.3/1.6
3.8/1.8
3.8/1.8
3.5/1.7
3.8/1.8
3.6/1.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
42
3.3/1.6
42
3.4/1.6
43
3.8/1.8
42
3.2/1.5
43
3.6/1.7
43
3.7/1.8
43
3.4/1.6
43
3.5/1.7
43
3.3/1.6
43
3.4/1.6
44
3.6/1.7
43
3.2/1.5
44
3.4/1.6
44
3.5/1.7
44
3.2/1.5
44
3.3/1.6
45
3.7/1.8
44
3.2/1.5
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
42
3.2/1.5
42
3.3/1.6
43
3.7/1.7
43
3.8/1.8
43
3.5/1.6
43
3.6/1.7
43
3.3/1.6
43
3.4/1.6
44
3.5/1.7
43
3.2/1.5
44
3.3/1.6
44
3.5/1.6
45
3.8/1.8
44
3.3/1.6
46
3.8/1.8
45
3.8/1.8
46
3.6/1.7
46
3.8/1.8
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
43
3.7/1.7
43
3.8/1.8
43
3.4/1.6
43
3.5/1.7
43
3.2/1.5
43
3.3/1.6
44
3.5/1.7
44
3.6/1.7
44
3.3/1.6
44
3.4/1.6
45
3.8/1.8
44
3.2/1.5
46
3.7/1.8
45
3.7/1.8
46
3.5/1.7
46
3.7/1.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
no.
Pressure
no.
Pressure
43
3.4/1.6
43
3.5/1.7
43
3.2/1.5
43
3.3/1.6
44
3.4/1.6
44
3.6/1.7
44
3.2/1.5
44
3.4/1.6
45
3.7/1.8
45
3.8/1.8
46
3.7/1.7
46
3.8/1.8
46
3.5/1.7
46
3.6/1.7
47
3.7/1.8
47
3.8/1.8
* Orifice numbers 43 are factory installed
44
Orifice
no.
42
42
43
43
43
43
43
44
44
0.64
Manifold
Pressure
3.5/1.7
3.3/1.6
3.8/1.8
3.7/1.7
3.5/1.7
3.3/1.6
3.2/1.5
3.4/1.6
3.3/1.6
Orifice
no.
42
42
43
43
43
44
44
44
45
0.64
Manifold
Pressure
3.4/1.6
3.2/1.5
3.7/1.8
3.5/1.7
3.3/1.6
3.6/1.7
3.4/1.6
3.2/1.5
3.7/1.8
Orifice
no.
42
43
43
43
44
44
45
46
0.64
Manifold
Pressure
3.2/1.5
3.7/1.7
3.4/1.6
3.2/1.5
3.5/1.7
3.3/1.6
3.8/1.8
3.8/1.8
Orifice
no.
43
43
43
44
44
45
46
46
0.64
Manifold
Pressure
3.6/1.7
3.4/1.6
3.2/1.5
3.5/1.6
3.3/1.6
3.7/1.8
3.7/1.8
3.5/1.7
TABLE 13–Orifice Size and Manifold Pressure for Gas Input Rate (Tabulated Data Based On 21,000 Btuh
High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)(Continued)
U.S.A. Only
ALTITUDE
RANGE
(FT)
5001
to
6000
U.S.A. Only
ALTITUDE
RANGE
(FT)
6001
to
7000
U.S.A. Only
ALTITUDE
RANGE
(FT)
7001
to
8000
U.S.A. Only
ALTITUDE
RANGE
(FT)
8001
to
9000
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
725
750
775
800
825
850
875
900
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
675
700
725
750
775
800
825
850
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
650
675
700
725
750
775
800
825
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
625
650
675
700
725
750
775
0.58
Orifice
Manifold
No.
Pressure
44
3.5/1.7
44
3.3/1.6
45
3.7/1.8
46
3.7/1.8
46
3.5/1.7
47
3.7/1.8
47
3.5/1.7
48
3.8/1.8
Orifice
No.
44
44
45
46
46
47
47
48
0.58
Manifold
Pressure
3.5/1.7
3.3/1.6
3.7/1.8
3.6/1.7
3.4/1.6
3.6/1.7
3.4/1.6
3.7/1.7
Orifice
No.
44
45
46
47
47
48
48
48
0.58
Manifold
Pressure
3.3/1.6
3.7/1.8
3.6/1.7
3.8/1.8
3.5/1.7
3.8/1.8
3.6/1.7
3.3/1.6
Orifice
No.
45
46
47
47
48
48
49
0.58
Manifold
Pressure
3.7/1.8
3.6/1.7
3.8/1.8
3.5/1.7
3.7/1.8
3.5/1.7
3.8/1.8
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
43
3.2/1.5
43
3.3/1.6
44
3.4/1.6
44
3.5/1.7
44
3.2/1.5
44
3.3/1.6
46
3.8/1.8
45
3.8/1.8
46
3.6/1.7
46
3.7/1.8
47
3.8/1.8
46
3.5/1.7
47
3.6/1.7
47
3.7/1.8
47
3.4/1.6
47
3.5/1.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
43
3.2/1.5
43
3.3/1.6
44
3.4/1.6
44
3.5/1.7
45
3.8/1.8
44
3.3/1.6
46
3.8/1.8
45
3.7/1.8
46
3.5/1.7
46
3.6/1.7
47
3.8/1.8
46
3.4/1.6
47
3.5/1.7
47
3.6/1.7
48
3.8/1.8
47
3.4/1.6
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
44
3.4/1.6
44
3.5/1.7
45
3.8/1.8
44
3.3/1.6
46
3.7/1.8
46
3.8/1.8
46
3.5/1.7
46
3.6/1.7
47
3.7/1.8
47
3.8/1.8
47
3.4/1.6
47
3.6/1.7
48
3.7/1.8
48
3.8/1.8
48
3.5/1.6
48
3.6/1.7
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
45
3.8/1.8
44
3.3/1.6
46
3.7/1.8
46
3.8/1.8
46
3.4/1.6
46
3.5/1.7
47
3.6/1.7
47
3.7/1.8
48
3.8/1.8
47
3.5/1.7
48
3.6/1.7
48
3.7/1.8
48
3.4/1.6
48
3.5/1.7
* Orifice numbers 43 are factory installed
45
Orifice
No.
43
43
44
44
46
46
46
47
0.64
Manifold
Pressure
3.4/1.6
3.2/1.5
3.4/1.6
3.2/1.5
3.8/1.8
3.6/1.7
3.4/1.6
3.7/1.7
Orifice
No.
43
43
44
45
46
46
47
47
0.64
Manifold
Pressure
3.4/1.6
3.2/1.5
3.4/1.6
3.8/1.8
3.8/1.8
3.5/1.7
3.8/1.8
3.5/1.7
Orifice
No.
43
44
45
46
46
47
47
48
0.64
Manifold
Pressure
3.2/1.5
3.4/1.6
3.8/1.8
3.7/1.8
3.5/1.6
3.7/1.7
3.4/1.6
3.7/1.8
Orifice
No.
44
45
46
46
47
48
48
0.64
Manifold
Pressure
3.4/1.6
3.8/1.8
3.7/1.7
3.4/1.6
3.6/1.7
3.8/1.8
3.6/1.7
TABLE 13–Orifice Size and Manifold Pressure for Gas Input Rate (Tabulated Data Based On 21,000 Btuh
High-Heat/14,500 Btuh for Low-Heat Per Burner,
Derated 4 Percent For Each 1000 Ft Above Sea Level)(Continued)
U.S.A. Only
ALTITUDE
RANGE
(FT)
AVG GAS
HEAT VALUE
AT ALTITUDE
(BTU/CU FT)
9001
to
10,000
600
625
650
675
700
725
0.58
Orifice
Manifold
No.
Pressure
46
3.6/1.7
47
3.7/1.8
47
3.4/1.6
48
3.6/1.7
48
3.4/1.6
49
3.7/1.8
SPECIFIC GRAVITY OF NATURAL GAS
0.60
0.62
Orifice
Manifold
Orifice
Manifold
No.
Pressure
No.
Pressure
46
3.7/1.8
46
3.8/1.8
47
3.8/1.8
46
3.5/1.7
47
3.6/1.7
47
3.7/1.8
48
3.8/1.8
47
3.4/1.6
48
3.5/1.7
48
3.6/1.7
49
3.8/1.8
48
3.4/1.6
Orifice
No.
45
46
47
47
48
48
0.64
Manifold
Pressure
3.7/1.8
3.6/1.7
3.8/1.8
3.5/1.7
3.7/1.8
3.5/1.7
* Orifice numbers 43 are factory installed
installation, service, or maintenance will cause this fuse to blow. If
fuse replacement is required, use ONLY a 3-amp fuse. The control
LED will display status code 24 when fuse needs to be replaced.
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow this warning could result in personal injury
or death, or property damage.
Proper instrumentation is required to service electrical controls.
The control in this furnace is equipped with a Status Code LED
(Light-Emitting Diode) to aid in installation, servicing, and
troubleshooting. It can be viewed through the sight glass in blower
access door. The amber furnace control LED is either ON
continuously, rapid flashing, or a code composed of 2 digits. The
first digit is the number of short flashes, the second digit is the
number of long flashes.
Before servicing, disconnect all electrical power to furnace.
Verify proper operation after servicing.
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper furnace
operation or failure of furnace.
For an explanation of status codes, refer to service label located on
blower access door or Fig. 56, and the troubleshooting guide which
can be obtained from your distributor.
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous
operation.
See Fig. 62, a brief Troubleshooting Guide.
For 2-Stage Variable Speed ECM Controls the stored status codes
will NOT be erased from the control memory, when 115- or 24-v
power is interrupted. The control will store up to the last 7 Status
Codes in order of occurence.
Step 1—Introduction
GENERAL
1. To retrieve status codes, proceed with the following:
NOTE: NO thermostat signal may be present at control, and all
blower-OFF delays must be completed.
These instructions are written as if the furnace is installed in an
upflow application. An upflow furnace application is where the
blower is located below the combustion and controls section of the
furnace, and conditioned air is discharged upward. Since this
furnace can be installed in any of the 4 positions shown in Fig. 4,
you must revise your orientation to component location accordingly.
a. Leave 115-v power to furnace turned on.
b. Remove outer access door.
c. Look into blower access door sight glass for current amber
LED status. Removing blower access door will open
blower access door switch and terminate 115-v power to
control so that status code is not displayed.
ELECTRICAL CONTROLS AND WIRING
d. Remove blower access door.
NOTE: The Status Codes cannot be retrieved by disconnecting
the limit switch or draft safeguard switch. To retrieve Status
Codes, follow the procedure below.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
There may be more than 1 electrical supply to the furnace.
Check accessories and cooling unit for additional electrical
supplies that must be shut off during furnace servicing.
2. Turn Setup Switch, SW1-1 “ON.”
3. Manually close blower access door switch.
4. Control will flash up to 7 Status Codes.
The electrical ground and polarity for 115-v wiring must be
properly maintained. Refer to Fig. 24 for field wiring information
and to Fig. 57 for furnace wiring information.
5. The last Status Code, or 8th Code, will be Code 11.
6. Turn SW1-1 “OFF.”
7. A continuously-lit Amber LED will appear and indicates
proper operation.
NOTE: If the polarity is not correct, the STATUS LED on the
control will flash rapidly and prevent the furnace from heating.
The control system also requires an earth ground for proper
operation of the control and flame-sensing electrode.
8. Release blower access door switch, install blower access door
and replace outer door or refer to the SERVICE label on the
front of the blower access door for more information.
The 24-v circuit contains an automotive-type, 3-amp fuse located
on the control. (See Fig. 25.) Any shorts of the 24-v wiring during
Component Self-Test
46
Consult your local dealer about proper frequency of maintenance
and the availability of a maintenance contract.
Component Test can ONLY be initiated by performing the
following:
1. Remove outer access door.
2. Remove blower access door.
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury,
death, and/or property damage.
Turn off the gas and electrical supplies to the furnace before
performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
3. Remove the wire from the “R” terminal of the control board.
4. Turn Setup Switch, SW-1-6 “ON.”
5. Manually close blower access door switch.
Blower access door switch opens 115-v power to control. No
component operation can occur unless switch is closed. Caution
must be taken when manually closing this switch for service
purposes.
CARBON MONOXIDE POISONING AND FIRE
HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
Never operate furnace without a filter or with filter access
door removed.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur unless switch is
closed. Exercise caution to avoid electrical shock from
exposed electrical components when manually closing this
switch for service purposes.
CUT HAZARD
Failure to follow this caution may result in personal injury.
6. Component Test sequence will function as follows:
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.
a. Inducer motor starts on high-speed and continues to run
until Step (d.) of component test sequence.
b. Hot surface igniter is energized for 15 sec, then deenergized.
The minimum maintenance on this furnace is as follows:
c. Blower operates for 10 sec, then turns off.
1. Check and clean air filter each month or more frequently if
required. Replace if torn.
d. Inducer motor goes to low-speed for 10 seconds, then turns
off.
2. Check blower motor and wheel for cleanliness each heating
and cooling season. Clean as necessary.
e. After component test is completed, one or more status
codes (11, 25, or 41) will flash. See component test section
of service label for explanation of status codes.
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as necessary.
4. Inspect burner compartment before each heating season for
rust, corrosion, soot or excessive dust. If necessary, have
furnace and burner serviced by a qualified service agency.
NOTE: To repeat component test, turn setup switch SW1-6 OFF
then back ON.
f. Turn setup switch SW1-6 OFF.
5. Inspect the vent pipe/vent system before each heating season
for rust, corrosion, water leakage, sagging pipes or broken
fittings. Have vent pipes/vent system serviced by a qualified
service agency.
7. RELEASE BLOWER ACCESS DOOR SWITCH, reattach
wire to “R” terminal on furnace control board, replace blower
access door, and replace outer access door.
6. Inspect any accessories attached to the furnace such as a
humidifier or electronic air cleaner. Perform any service or
maintenance to the accessories as recommended in the accessory instructions.
Step 2—Care and Maintenance
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
Never store anything on, near, or in contact with the furnace,
such as:
1. Spray or aerosol cans, rags, brooms, dust mops, vacuum
cleaners, or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning compounds, plastic or plastic containers, gasoline, kerosene,
cigarette lighter fluid, dry cleaning fluids, or other volatile
fluids.
3. Paint thinners and other painting compounds, paper bags,
or other paper products.
Exposure to these materials could lead to corrosion of the
heat exchangers.
CLEANING AND/OR REPLACING AIR FILTER
The air filter arrangement will vary depending on the application.
NOTE: If the filter has an airflow direction arrow, the arrow must
point towards the blower.
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.
Media cabinet filter procedures:
NOTE: Media cabinet is included with variable speed furnace.
For continuing high performance and to minimize possible furnace
failure, periodic maintenance must be performed on this furnace.
1. Turn off electrical supply to furnace before removing filter
access door.
47
6. Remove 2 screws holding control box to blower shelf.
Table 14—Filter Size Information (In.)
FILTER SIZE
FURNACE
CASING WIDTH
Side Return
Bottom Return
FILTER
TYPE
14-1/2
16 X 25 X 1
14 X 25 X 1
Cleanable*
17-1/2
16 X 25 X 1
16 X 25 X 1
Cleanable*
21
16 X 25 X 1
20 X 25 X 1
Cleanable*
24
16 X 25 X 1
24 X 25 X 1
Cleanable*
7. Hang control box from front of furnace casing and away from
blower compartment.
8. Remove 2 screws holding blower assembly to blower deck
and slide blower assembly out of furnace.
9. Clean blower wheel and motor using a vacuum with soft brush
attachment. Blower wheel blades may be cleaned with a small
paint or flux brush. Do not remove or disturb balance weights
(clips) on blower wheel blades.
* Recommended
10. Vacuum any loose dust from blower housing, wheel and
motor.
2. Remove filter cabinet door.
3. Slide filter out of cabinet.
11. If a greasy residue is present on blower wheel, remove wheel
from the blower housing and wash it with an appropriate
degreaser. To remove wheel:
4. If equipped with permanent, washable 1-inch filter, clean filter
by spraying cold tap water through filter in opposite direction
of airflow. Rinse filter and let dry. Oiling or coating of the
filter is not recommended. See Table 14 for size information.
NOTE: Before disassembly, mark blower mounting arms, motor,
and blower housing so motor and each arm is positioned at the
same location during reassembly.
5. If equipped with factory-specified disposable media filter,
replace only with media filter having the same part number
and size. For expandable replacement media, refer to the
instructions included with the replacement media. If equipped
with accessory KGAFR0301ALL external filter rack, See
Table 14.
a. Disconnect ground wire attached to blower housing.
b. Remove screws securing cutoff plate and remove cutoff
plate from housing.
c. Loosen set screw holding blower wheel on motor shaft
(160+/-20 in.-lb. when assembling).
6. Slide filter into cabinet.
d. Remove bolts holding motor to blower housing and slide
motor out of wheel (40+/-10 in.-lb. when reassembling).
7. Replace filter cabinet door.
8. Turn on electrical supply to furnace.
e. Remove blower wheel from housing.
BLOWER MOTOR AND WHEEL
f. Clean wheel and housing.
12. Reassemble motor and blower by reversing steps 11e, through
11a. Be sure to reattach ground wire to the blower housing.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Blower access door switch opens 115-v power to control. No
component operation can occur unless switch is closed.
Caution must be taken when manually closing this switch for
service purposes.
13. Verify that blower wheel is centered in blower housing and set
screw contacts the flat portion of the motor shaft. Loosen set
screw on blower wheel and reposition if necessary.
14. Spin the blower wheel by hand to verify that the wheel does
not rub on the housing.
15. Reinstall blower assembly in furnace.
16. Reinstall control box assembly in furnace.
NOTE: The blower wheel should not be dropped or bent as
balance will be affected.
NOTE: Refer to Fig. 57 if leads were not identified before
disconnection.
The following steps should be performed by a qualified service
agency.
17. Reconnect blower leads to furnace control. Refer to furnace
wiring diagram, and connect thermostat leads if previously
disconnected.
To ensure long life and high efficiency, clean accumulated dirt and
grease from blower wheel and motor annually.
The inducer and blower motors are pre-lubricated and require no
additional lubrication. These motors can be identified by the
absence of oil ports on each end of the motor.
18. To check blower for proper rotation:
a. Turn on electrical supply.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury,
or death.
Blower access door switch opens 115-v power to furnace
control. No component operation can occur unless switch is
closed. Exercise caution to avoid electrical shock from
exposed electrical components when manually closing this
switch for service purposes.
2. Loosen the thumbscrew on outer door and then remove outer
door.
3. For downflow or horizontal furnaces having vent pipes within
the furnace that pass in front of the blower access door:
a. Disconnect vent connector from furnace vent elbow.
b. Disconnect and remove short piece of vent pipe from
within furnace.
b. Manually close blower access door switch.
4. Remove 2 screws from blower access door and remove blower
access door.
NOTE: If R-W/W1 thermostat terminals are jumpered at the time
blower access door switch is closed, blower will run for 90 sec
before beginning a heating cycle.
5. Disconnect blower leads from furnace control. Record wire
color and location for reassembly. All other factory wires can
be left connected, but field thermostat connections may need
to be disconnected depending on their length and routing.
c. Perform component self-test as shown at the bottom of the
SERVICE label, located on the front of blower access door.
48
d. Verify blower is rotating in the correct direction
9/32˝
19. If furnace is operating properly, RELEASE BLOWER ACCESS DOOR SWITCH. Remove any jumpers or reconnect
any disconnected thermostat leads. Replace blower access
door.
5/16˝
20. Downflow or horizontal furnaces with vent pipe through
furnace only:
a. Install and connect short piece of vent pipe inside furnace
to existing vent.
b. Connect vent connector to vent elbow.
21. Turn on gas supply and cycle furnace through one complete
heating and cooling cycle. Verify the furnace temperature rise
as shown in Adjustments Section. Adjust temperature rise as
shown in Adjustments Section. If outdoor temperature is
below 70°F, turn off circuit breaker to outdoor unit before
running furnace in the cooling cycle. Turn outdoor circuit
breaker on after completing cooling cycle.
A05025
Fig. 58—Igniter Position-Side View
CLEANING HEAT EXCHANGER
The following steps should be performed by a qualified service
agency:
1-7/8”
NOTE: If the heat exchangers get a heavy accumulation of soot
and carbon, they should be replaced rather than trying to clean
them thoroughly. A build-up of soot and carbon indicates that a
problem exists which needs to be corrected, such as improper
adjustment of manifold pressure, insufficient or poor quality
combustion air, incorrect size or damaged manifold orifice(s),
improper gas, or a restricted heat exchanger. Action must be taken
to correct the problem.
A05026
Fig. 59—Igniter Position-Top View
If it becomes necessary to clean the heat exchangers because of
dust or corrosion, proceed as follows:
reversible electric drill, and vacuum cleaner, clean cells as
follows:
1. Turn OFF gas and electrical power to furnace.
2. Remove outer access door.
a. Remove metal screw fitting from wire brush to allow
insertion into cable.
3. Disconnect vent connector from furnace vent elbow.
4. For downflow or horizontal furnace having an internal vent
pipe, remove internal vent pipe within the casing.
b. Insert the twisted wire end of brush into end of spring
cable, and crimp tight with crimping tool or crimp by
striking with ball-peen hammer. TIGHTNESS IS VERY
IMPORTANT.
5. Disconnect wires to the following components. Mark wires to
aid in reconnection (be careful when disconnecting wires from
switches because damage may occur):
NOTE: The materials needed in item 9 can usually be purchased
at local hardware stores.
a. Draft safeguard switch.
b. Inducer motor.
(1.) Attach variable-speed, reversible drill to the end of
spring cable (end opposite brush).
c. Pressure switches.
d. Limit overtemperature switch.
(2.) Insert brush end of cable into the outlet opening of cell
and slowly rotate with drill. DO NOT force cable.
Gradually insert cable into upper pass of cell. (See Fig.
60.)
e. Gas valve.
f. Hot surface igniter.
g. Flame-sensing electrode
(3.) Work cable in and out of cell 3 or 4 times to obtain
sufficient cleaning. DO NOT pull cable with great
force. Reverse drill and gradually work cable out.
h. Flame rollout switches.
6. Remove screws that fasten the collector box assembly to the
cell panel. Be careful not to damage the collector box. Inducer
assembly and elbow need not be removed from collector box.
(4.) Insert brush end of cable in burner inlet opening of
cell, and proceed to clean 2 lower passes of cell in
same manner as upper pass.
7. Disconnect gas line from gas manifold.
8. Remove the 4 screws that attach the burner assembly to the
cell panel. The gas valve and individual burners need not be
removed from support assembly. Remove NOx baffles, if
installed.
(5.) Repeat foregoing procedures until each cell in furnace
has been cleaned.
(6.) Using vacuum cleaner, remove residue from each cell.
(7.) Using vacuum cleaner with soft brush attachment,
clean burner assembly.
NOTE: Be very careful when removing burner assembly to avoid
breaking igniter. See Fig. 58 and 59 for correct igniter location.
(8.) Clean flame sensor with fine steel wool.
9. Using field-provided 25-caliber rifle cleaning brush, 36 in.
long, 1/4″ diameter steel spring cable, a variable speed,
(9.) Install NOx baffles (if removed).
49
Step 3—Sequence of Operation
NOTE: Furnace control must be grounded for proper operation or
else control will lock out. Control is grounded through
green/yellow wire routed to gas valve and burner box screw.
Using the schematic diagram in Fig. 57, follow the sequence of
operation through the different modes. Read and follow the wiring
diagram very carefully.
NOTE: If a power interruption occurs during a call for heat
(W/W1 or W/W1-and-W2), the control will start a 90-second
blower-only ON period two seconds after power is restored, if the
thermostat is still calling for gas heating. The amber LED light will
flash code 12 during the 90-second period, after which the LED
will be ON continuous, as long as no faults are detected. After the
90-second period, the furnace will respond to the thermostat
normally.
A91252
Fig. 60—Cleaning Heat Exchanger Cell
The blower door must be installed for power to be conducted
through the blower door interlock switch ILK to the furnace
control CPU, transformer TRAN, inducer motor IDM, blower
motor BLWM, hot-surface igniter HSI, and gas valve GV.
(10.) Reinstall burner assembly. Center burners in cell
openings.
10. Remove old sealant from cell panel and collector box flange.
1. Two-Stage Heating (Adaptive Mode) with Single-Stage
Thermostat
See Fig. 24 or 33 for thermostat connections
11. Spray releasing agent on the heat exchanger cell panel where
collector box assembly contacts cell panel.
NOTE: The low-heat only switch SW1-2 selects either the
low-heat only operation mode when ON, (see item 2. below) or the
adaptive heating mode when OFF in response to a call for heat.
(See Table 8.) When the W2 thermostat terminal is energized it
will always cause high-heat operation when the R-to-W circuit is
closed, regardless of the setting of the low-heat only switch.
This furnace can operate as a two-stage furnace with a single-stage
thermostat because the furnace control CPU includes a programmed adaptive sequence of controlled operation, which selects
low-heat or high-heat operation. This selection is based upon the
stored history of the length of previous gas-heating periods of the
single-stage thermostat.
The furnace will start up in either low- or high-heat. If the furnace
starts up in low-heat, the control CPU determines the low-heat
on-time (from 0 to 16 minutes) which is permitted before switching to high-heat.
If the power is interrupted, the stored history is erased and the
control CPU will select low-heat for up to 16 minutes and then
switch to high-heat, as long as the thermostat continues to call for
heat. Subsequent selection is based on stored history of the
thermostat cycle times.
The wall thermostat ″calls for heat″, closing the R-to-W circuit.
The furnace control performs a self-check, verifies the low-heat
and high-heat pressure switch contacts LPS and HPS are open, and
starts the inducer motor IDM in high-speed.
NOTE: A releasing agent such as cooking spray or equivalent
(must not contain corn or canola oil, aromatic or halogenated
hydrocarbons or inadequate seal may occur) and RTV sealant
(G.E. 162, 6702, or Dow-Corning 738) are needed before starting
installation. DO NOT substitute any other type of RTV sealant.
G.E. 162 (P771-9003) is available through RCD in 3-oz tubes.
12. Apply new sealant to flange of collector box and attach to cell
panel using existing screws, making sure all screws are secure.
13. Reconnect wires to the following components (Use connection
diagram on wiring label, if wires were not marked for
reconnection locations.):
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switches.
d. Limit overtemperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame-sensing electrode.
h. Flame rollout switches.
14. Reinstall internal vent pipe, if applicable.
15. Reinstall vent connector on furnace vent elbow. Securely
fasten vent connector to vent elbow with 2 field-supplied,
corrosion-resistant, sheet metal screws located 180° apart.
a. Inducer Prepurge Period
16. Replace blower access door only if it was removed.
(1.) If the furnace control CPU selects low-heat operation
the inducer motor IDM comes up to speed, the
low-heat pressure switch LPS closes, and the furnace
control CPU begins a 15-second prepurge period. If
the low-heat pressure switch LPS fails to remain
closed the inducer motor IDM will remain running at
high-speed. After the low-heat pressure switch recloses the furnace control CPU will begin a 15-second
prepurge period, and continue to run the inducer motor
IDM at high-speed.
17. Set thermostat above room temperature and check furnace for
proper operation.
18. Verify blower airflow and speed changes between heating and
cooling.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
(2.) If the furnace control CPU selects high-heat operation,
the inducer motor IDM remains running at high-speed,
and the high-heat pressure switch relay HPSR is
de-energized to close the NC contact. When sufficient
pressure is available the high-heat pressure switch
Never use a match or other open flame to check for gas leaks.
Use a soap-and-water solution.
19. Check for gas leaks.
50
Cooling Tonnage vs. Airflow (CFM)
AIR CONDITIONING
TONS (12,000 BTU/HR)
AIRFLOW
(CFM)
070 MODEL
090 MODEL
110, 135,
& 155 MODELS
1-1/2
525
X2
X
2
700
X
X2
X
2-1/2
875
X
X
X2
3
1050
X1
X
X
3-1/2
1225
X1
X1
X
4
1400
X1
X
5
1750
X1
6
2100
X
X-INDICATES AN ALLOWABLE SELECTION.
070
DEF
5252
700
875
10501
1225
1225
1225
090
DEF
525
7002
875
1050
1225
14001
1400
110,135,155
DEF
700
8752
1050
1225
1400
17501
2100
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
MODEL
SIZE
OFF
AIR CONDITIONING (A/C) OR CONTINUOUS-FAN (CF) AIRFLOW SELECTION CHART
BASED ON 350 CFM/TON
SW1-5 ON
SWITCH SW3 POSITIONS
070
DEF
600 2
800
1000
12001
1400
1400
1400
090
DEF
600
8002
1000
1200
1400
16001
1600
110,135,155
DEF
800
10002
1200
1400
1600
20001
2200
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
OFF
3 2 1
MODEL
SIZE
OFF
BASED ON 400 CFM/TON
SW1-5 ON
SWITCH SW3 POSITIONS
1.DEFAULT A/C AIRFLOW WHEN A/C SWITCHES ARE IN OFF POSITION (FACTORY SETTING)
2.DEFAULT CONT. FAN AIRFLOW WHEN CF SWITCHES ARE IN OFF POSITION (FACTORY SETTING)
3. SWITCH POSITIONS ARE ALSO SHOWN ON FURNACE WIRING DIAGRAM
Fig. 61—Cooling (A/C) or Continuous-Fan (CF) Airflow Selection Chart
A03220
HPS closes, and the high-heat gas valve solenoid
GV-HI is energized. The furnace control CPU begins
a 15-second prepurge period after the low-heat pressure switch LPS closes. If the high-heat pressure
switch HPS fails to close and the low-heat pressure
switch LPS closes, the furnace will operate at low-heat
gas flow rate until the high-heat pressure switch closes
for a maximum of 2 minutes after ignition.
two seconds, the control CPU will close the gas valve
GV-M, and the control CPU will repeat the ignition
sequence for up to three more Trials-For-Ignition before
going to Ignition-Lockout. Lockout will be reset automatically after three hours, by momentarily interrupting
115 vac power to the furnace, or by interrupting 24 vac
power at SEC1 or SEC2 to the furnace control CPU (not at
W/W1, G, R, etc.).
If flame is proved when flame should not be present, the
furnace control CPU will lock out of Gas-Heating mode
and operate the inducer motor IDM on high speed until
flame is no longer proved.
b. Igniter Warm-Up -At the end of the prepurge period, the
Hot-Surface Igniter HSI is energized for a 17-second
igniter warm-up period.
c. Trial-For-Ignition Sequence -When the igniter warm-up
period is completed the main gas valve relay contact GVR
closes to energize the gas valve solenoid GV-M. The gas
valve solenoid GV-M permits gas flow to the burners
where it is ignited by the HSI. Five seconds after the GVR
closes, a 2-second flame proving period begins. The HSI
igniter will remain energized until the flame is sensed or
until the 2-second flame proving period begins.
If the furnace control CPU selects high-heat operation, the
high-heat gas valve solenoid GV-HI is also energized.
e. Blower-On delay - If the burner flame is proven the
blower-ON delays for low-heat and high-heat are as follows:
Low-heat - 45 seconds after the gas valve GV-M is opened
the blower motor BLWM is turned ON at low-heat airflow.
High-heat - 25 seconds after the gas valve GV-M is
opened the BLWM is turned ON at high-heat airflow.
Simultaneously, the humidifier terminal HUM and electronic air cleaner terminal EAC-1 are energized and remain
energized throughout the heating cycle.
f. Switching from Low- to High-Heat - If the furnace
control CPU switches from low-heat to high-heat, the
furnace control CPU will switch the inducer motor IDM
speed from low to high. The high-heat pressure switch relay
HPSR is de-energized to close the NC contact. When
d. Flame-Proving - When the burner flame is proved at the
flame-proving sensor electrode FSE, the inducer motor
IDM switches to low-speed unless the furnace is operating
in high-heat, and the furnace control CPU begins the
blower-ON delay period and continues to hold the gas
valve GV-M open. If the burner flame is not proved within
51
airflow. Cooling airflow is based on the A/C selection
shown in Fig. 61. The electronic air cleaner terminal
EAC-1 is energized with 115 vac when the blower motor
BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y circuits
are opened. The outdoor unit will stop, and the furnace
blower motor BLWM will continue operating at cooling
airflow for an additional 90 seconds. Jumper Y/Y2 to
DHUM to reduce the cooling off-delay to 5 seconds. (See
Fig. 25.)
sufficient pressure is available the high-heat pressure
switch HPS closes, and the high-heat gas valve solenoid
GV-HI is energized. The blower motor BLWM will transition to high-heat airflow five seconds after the furnace
control CPU switches from low-heat to high-heat.
g. Switching from High- to Low-Heat -The furnace control
CPU will not switch from high-heat to low-heat while the
thermostat R-to-W circuit is closed when using a singlestage thermostat.
h. Blower-Off Delay - When the thermostat is satisfied, the R
to W circuit is opened, de-energizing the gas valve GV-M,
stopping gas flow to the burners, and de-energizing the
humidifier terminal HUM. The inducer motor IDM will
remain energized for a 5-second post-purge period. The
blower motor BLWM and air cleaner terminal EAC-1 will
remain energized at low-heat airflow or transition to
low-heat airflow for 90, 120, 150, or 180 seconds (depending on selection at blower-OFF delay switches). The
furnace control CPU is factory-set for a 120-second
blower-OFF delay.
b. Single-Stage Thermostat and Two-Speed Cooling
(Adaptive Mode) See Fig. 33 for thermostat connections
This furnace can operate a two-speed cooling unit with a
single-stage thermostat because the furnace control CPU
includes a programmed adaptive sequence of controlled
operation, which selects low-cooling or high-cooling operation. This selection is based upon the stored history of
the length of previous cooling period of the single-stage
thermostat.
NOTE: The air conditioning relay disable jumper ACRDJ must
be connected to enable the adaptive cooling mode in response to a
call for cooling. (See Fig. 25.) When ACRDJ is in place the
furnace control CPU can turn on the air conditioning relay ACR to
energize the Y/Y2 terminal and switch the outdoor unit to
high-cooling.
2. Two-Stage Thermostat and Two-Stage Heating
See Fig. 32 for thermostat connections.
NOTE: In this mode the low-heat only switch SW1-2 must be ON
to select the low-heat only operation mode in response to closing
the thermostat R-to-W1 circuit. Closing the thermostat R-toW1-and-W2 circuits always causes high-heat operation, regardless
of the setting of the low-heat only switch.
The wall thermostat ″calls for heat″, closing the R-to-W1 circuit
for low-heat or closing the R-to-W1-and-W2 circuits for high-heat.
The furnace control performs a self-check, verifies the low-heat
and high-heat pressure switch contacts LPS and HPS are open, and
starts the inducer motor IDM in high-speed.
The start up and shut down functions and delays described in item
1. above apply to the 2-stage heating mode as well, except for
switching from low- to high-Heat and vice versa.
The furnace control CPU can start up the cooling unit in either
low- or high-cooling. If starting up in low-cooling, the furnace
control CPU determines the low-cooling on-time (from 0 to 20
minutes) which is permitted before switching to high-cooling.
If the power is interrupted, the stored history is erased and the
furnace control CPU will select low-cooling for up to 20 minutes
and then energize the air conditioning relay ACR to energize the
Y/Y2 terminal and switch the outdoor unit to high-cooling, as long
as the thermostat continues to call for cooling. Subsequent
selection is based on stored history of the thermostat cycle times.
a. Switching from Low- to High-Heat - If the thermostat Rto-W1 circuit is closed and the R-to-W2 circuit closes, the
furnace control CPU will switch the inducer motor IDM
speed from low to high. The high-heat pressure switch
relay HPSR is de-energized to close the NC contact. When
sufficient pressure is available the high-heat pressure
switch HPS closes, and the high-heat gas valve solenoid
GV-HI is energized. The blower motor BLWM will transition to high-heat airflow five seconds after the R-to-W2
circuit closes.
The wall thermostat ″calls for cooling″, closing the R-to-G-and-Y
circuits. The R-to-Y1 circuit starts the outdoor unit on low-cooling
speed, and the R-to-G-and-Y1 circuits starts the furnace blower
motor BLWM at low-cooling airflow which is the true on-board
CF selection as shown in Fig. 61.
If the furnace control CPU switches from low-cooling to highcooling, the furnace control CPU will energize the air conditioning
relay ACR. When the air conditioning relay ACR is energized the
R-to-Y1-and-Y2 circuits switch the outdoor unit to high-cooling
speed, and the R-to-G-and-Y1-and-Y/Y2 circuits transition the
furnace blower motor BLWM to high-cooling airflow. Highcooling airflow is based on the A/C selection shown in Fig. 61.
NOTE: When transitioning from low-cooling to high-cooling the
outdoor unit compressor will shut down for 1 minute while the
furnace blower motor BLWM transitions to run at high-cooling
airflow.
b. Switching from High- to Low-Heat -If the thermostat Rto-W2 circuit opens, and the R-to-W1 circuit remains
closed, the furnace control CPU will switch the inducer
motor IDM speed from high to low. The high-heat pressure
switch relay HPSR is energized to open the NC contact and
de-energize the high-heat gas valve solenoid GV-HI. When
the inducer motor IDM reduces pressure sufficiently, the
high-heat pressure switch HPS will open. The gas valve
solenoid GV-M will remain energized as long as the
low-heat pressure switch LPS remains closed. The blower
motor BLWM will transition to low-heat airflow five
seconds after the R-to-W2 circuit opens.
The electronic air cleaner terminal EAC-1 is energized with 115
vac whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y circuit are
opened. The outdoor unit stops, and the furnace blower BLWM
and electronic air cleaner terminal EAC-1 will remain energized
for an additional 90 seconds. Jumper Y1 to DHUM to reduce the
cooling off-delay to 5 seconds. (See Fig. 25.)
3. Cooling mode
The thermostat ″calls for cooling″.
c. Two-Stage Thermostat and Two-Speed Cooling
See Fig. 32 for thermostat connections
NOTE: The air conditioning relay disable jumper ACRDJ must
be disconnected to allow thermostat control of the outdoor unit
staging. (See Fig. 25.)
a. Single-Speed CoolingSee Fig. 24 for thermostat connections
The thermostat closes the R-to-G-and-Y circuits. The R-toY circuit starts the outdoor unit, and the R-to-G-and-Y/Y2
circuits start the furnace blower motor BLWM on cooling
52
b. When the R-to-Y/Y2 circuit is closed, R-to-G circuit is
open, and there is a demand for dehumidification, the
furnace blower motor BLWM will drop the blower airflow
to 65 percent of high-cooling airflow for a maximum of 10
minutes each cooling cycle or until the R-to-G circuit
closes or the demand for dehumidification is satisfied.
High-cooling airflow is based on the A/C (air conditioning)
selection shown in Fig. 61.
The thermostat closes the R-to-G-and-Y1 circuits for low-cooling
or closes the R-to-G-and-Y1-and-Y2 circuits for high-cooling. The
R-to-Y1 circuit starts the outdoor unit on low-cooling speed, and
the R-to-G-and-Y1 circuit starts the furnace blower motor BLWM
at low-cooling airflow which is the true on-board CF (continuous
fan) selection as shown in Fig. 61. The R-to-Y1-and-Y2 circuits
start the outdoor unit on high-cooling speed, and the R-toG-and-Y/Y2 circuits start the furnace blower motor BLWM at
high-cooling airflow. High-cooling airflow is based on the A/C (air
conditioning) selection shown in Fig. 61.
The electronic air cleaner terminal EAC-1 is energized with 115
vac whenever the blower motor BLWM is operating.
When the thermostat is satisfied, the R-to-G-and-Y1 or R-toG-and-Y1-and-Y2 circuits are opened. The outdoor unit stops, and
the furnace blower BLWM and electronic air cleaner terminal
EAC-1 will remain energized for an additional 90 seconds. Jumper
Y1 to DHUM to reduce the cooling off-delay to 5 seconds. (See
Fig. 25.)
c. When the ″call for cooling″ is satisfied and there is a
demand for dehumidification, the cooling blower-off delay
is decreased from 90 seconds to 5 seconds.
6. Continuous Blower Mode
When the R-to-G circuit is closed by the thermostat, the
blower motor BLWM will operate at continuous blower
airflow. Continuous blower airflow selection is initially based
on the CF (continuous fan) selection shown in Fig. 61. Factory
default is shown in Fig. 61. Terminal EAC-1 is energized as
long as the blower motor BLWM is energized.
During a call for heat, the furnace control CPU will transition
the blower motor BLWM to continuous blower airflow,
low-heat airflow, or the midrange airflow, whichever is
lowest. The blower motor BLWM will remain ON until the
main burners ignite then shut OFF and remain OFF for the
blower-ON delay (45 seconds in low-heat, and 25 seconds in
high-heat), allowing the furnace heat exchangers to heat up
more quickly, then restarts at the end of the blower-ON delay
period at low-heat or high-heat airflow, respectively.
The blower motor BLWM will revert to continuous-blower
airflow after the heating cycle is completed. In high-heat, the
furnace control CPU will drop the blower motor BLWM to
low-heat airflow during the selected blower-OFF delay period
before transitioning to continuous-blower airflow.
When the thermostat ″calls for low-cooling″, the blower motor
BLWM will switch to operate at low-cooling airflow. When
the thermostat is satisfied, the blower motor BLWM will
operate an additional 90 seconds at low-cooling airflow before
transitioning back to continuous-blower airflow.
When the thermostat ″calls for high-cooling″, the blower
motor BLWM will operate at high cooling airflow. When the
thermostat is satisfied, the blower motor BLWM will operate
an additional 90 seconds at high-cooling airflow before
transitioning back to continuous-blower airflow.
When the R-to-G circuit is opened, the blower motor BLWM
will continue operating for an additional 5 seconds, if no other
function requires blower motor BLWM operation.
Continuous Blower Speed Selection from Thermostat -To
select different continuous-blower airflows from the room
thermostat, momentarily turn off the FAN switch or pushbutton on the room thermostat for 1-3 seconds after the blower
motor BLWM is operating. The furnace control CPU will shift
the continuous-blower airflow from the factory setting to the
next highest CF selection airflow as shown in Fig. 61.
Momentarily turning off the FAN switch again at the thermostat will shift the continuous-blower airflow up one more
increment. If you repeat this procedure enough you will
eventually shift the continuous-blower airflow to the lowest
CF selection as shown in Table 1. The selection can be
changed as many times as desired and is stored in the memory
to be automatically used following a power interruption.
NOTE: If the blower-off delay is set to the maximum, the
adjustable continuous-fan feature is locked (i.e., fan speed cannot
be changed from its current setting).
4. Thermidistat Mode
See Fig. 26-29 for thermostat connections
The dehumidification output, DHUM on the Thermidistat
should be connected to the furnace control thermostat terminal
DHUM. When there is a dehumidify demand, the DHUM
input is activated, which means 24 vac signal is removed from
the DHUM input terminal. In other words, the DHUM input
logic is reversed. The DHUM input is turned ON when no
dehumidify demand exists. Once 24 vac is detected by the
furnace control on the DHUM input, the furnace control
operates in Thermidistat mode. If the DHUM input is low for
more than 48 hours, the furnace control reverts back to
non-Thermidistat mode.
The cooling operation described in item 3. above also applies
to operation with a Thermidistat. The exceptions are listed
below:
a. Low cooling-When the R-to-G-and-Y1 circuit is closed
and there is a demand for dehumidification, the furnace
blower motor BLWM will drop the blower airflow to 86
percent of low-cooling airflow which is the true on-board
CF (continuous fan) selection as shown in Fig. 61.
b. High cooling-When the R-to-G-and Y/Y2 circuit is closed
and there is a demand for dehumidification, the furnace
blower motor BLWM will drop the blower airflow to 86
percent of high-cooling airflow. High-cooling airflow is
based on the A/C (air conditioning) selection shown in Fig.
61.
c. Cooling off-delay-When the ″call for cooling″ is satisfied
and there is a demand for dehumidification, the cooling
blower-off delay is decreased from 90 seconds to 5
seconds.
5. Super-Dehumidify Mode
Super-Dehumidify mode can only be entered if the furnace
control is in the Thermidistat mode and there is a demand for
dehumidification. The cooling operation described in item 3.
above also applies to operation with a Thermidistat. The
exceptions are listed below:
a. When the R-to-Y1 circuit is closed, R-to-G circuit is open,
and there is a demand for dehumidification, the furnace
blower motor BLWM will drop the blower airflow to 65
percent of low-cooling airflow for a maximum of 10
minutes each cooling cycle or until the R-to-G circuit
closes or the demand for dehumidification is satisfied.
Low-cooling airflow is the true on-board CF (continuous
fan) selection as shown in Fig. 61.
53
The component test sequence is as follows:
7. Heat pump
See Fig. 28-31 for thermostat connections.
When installed with a heat pump, the furnace control automatically changes the timing sequence to avoid long blower
off times during demand defrost cycles. Whenever W/W1 is
energized along with Y1 or Y/Y2, the furnace control CPU
will transition to or bring on the blower motor BLWM at
cooling airflow, low-heat airflow, or the midrange airflow,
whichever is lowest. The blower motor BLWM will remain on
until the main burners ignite then shut OFF and remain OFF
for 25 seconds before coming back on at heating airflow.
When the W/W1 input signal disappears, the furnace control
begins a normal inducer post-purge period while changing the
blower airflow. If Y/Y2 input is still energized the furnace
control CPU will transition the blower motor BLWM airflow
to cooling airflow. If Y/Y2 input signal disappears and the Y1
input is still energized the furnace control CPU will transition
the blower motor BLWM to low-cooling airflow. If both the
Y1 and Y/Y2 signals disappear at the same time, the blower
motor BLWM will remain on at low-heat airflow for the
selected blower-OFF delay period. At the end of the blowerOFF delay, the blower motor BLWM will shut OFF unless G
is still energized, in which case the blower motor BLWM will
operate at continuous blower airflow.
a. The furnace control CPU turns the inducer motor ON at
high-heat speed and keeps it ON through step c.
b. After waiting 10 seconds the furnace control CPU turns the
hot surface igniter ON for 15 seconds, then OFF.
c. The furnace control CPU then turns the blower motor
BLWM on at midrange airflow for 15 seconds, then OFF.
d. After shutting the blower motor OFF the furnace control
CPU switches the inducer to low-heat speed for 10 seconds, then OFF.
NOTE: The EAC terminals are energized when the blower is
operating.
After the component test is completed, 1 or more status codes (11,
25, or 41) will flash. See component test section or Service Label
(Fig. 56.) for explanation of status codes.
NOTE: To repeat component test, turn setup switch SW1-6 to
OFF and then back ON.
Step 4—Wiring Diagram
Refer to wiring diagram Fig. 57.
Step 5—Troubleshooting
Refer to the service label. (See Fig. 56—Service Label.)
8. Component test
The furnace features a component test system to help diagnose
a system problem in the case of a component failure. To
initiate the component test procedure, ensure that there are no
thermostat inputs to the control and all time delays have
expired. Turn on setup switch SW1-6. (See Fig. 25.)
NOTE: The component test feature will not operate if the control
is receiving any thermostat signals or until all time delays have
expired.
The Troubleshooting Guide (See Fig. 62.) can be a useful tool in
isolating furnace operation problems. Beginning with the word
“Start,” answer each question and follow the appropriate arrow to
the next item.
The Guide will help to identify the problem or failed component.
After replacing any component, verify correct operation sequence.
A more detailed Troubleshooting Guide is available from your
distributor.
54
55
Go to section below for the status code
that was flashed.
Determine status code. The status code is
a 2 digit number with the first digit determined
by the number of short flashes and the
second digit by the number of long flashes?
YES
Is AMBER LED status light blinking ON/OFF
slowly with a combination of short and
long flashes?
NO
Is AMBER LED status light blinking
rapidly without a pause?
YES
Is AMBER LED status light on?
START
YES
NO
YES
NO
Was there a previous status code other
than #11?
YES
Replace furnace control.
Run system through a low-heat, high-heat,
or cooling cycle to check operation. Status
codes are erased after 72 hours or can be
manually erased by putting setup switch
SW1-1 in the ON position and jumpering R,
W/W1, and Y/Y2 simultaneously until status
code #11 is flashed.
YES
Does the control respond to W/W1, W2, Y1,
Y/Y2, and G (24V) thermostat signals?
Replace transformer.
Check for correct line voltage polarity.
If units are twinned, check for proper
low-voltage (24V) transformer phasing.
To recall previous status codes disconnect
the R thermostat connection, reset power,
and put setup switch SW1-1 in the ON
position. The AMBER LED will flash the
status codes in the order of occurrence.
Record status codes until status code #11
flashes (1 short and 1 long flash). After status
code #11 flashes the status codes will repeat.
Status codes are erased after 72 hours or
can be manually erased by putting setup
switch SW1-1 in the ON position and
jumpering R, W/W1, and Y/Y2 simultaneously
until status code #11 is flashed. When done
put setup switch SW1-1 in the OFF position.
YES
Is there 115V going to switch?
Is door switch closed?
Replace door switch.
NO
NO
NO
Replace furnace control.
YES
Is there 24V at SEC-1 and SEC-2?
YES
Is there 115V at L1 and L2?
Fig. 62—Troubleshooting Guide-Variable Speed
YES
NO
NO
NO
The thermostat is not compatible with the
furnace control. Either install a ballast resistor,
connect the Com24V thermostat terminal to
the thermostat, or replace the thermostat.
NO
Does the problem repeat when using
a jumper wire?
Disconnect all the thermostat wires from the
furnace control.
YES
Is 24V present at W/W1, W2, Y1, Y/Y2 or G
thermostat terminals on the furnace control?
NO
Check room thermostat or
interconnecting cable.
Close circuit breaker and go back to START.
Check for continuity in wire from circuit
breaker to furnace.
YES
Is circuit breaker closed?
Is door switch closed?
NO
A02108b
Copyright 2006 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Printed in U.S.A.
Pg 56
4-06
Tab 6a 8a
24 SECONDARY VOLTAGE FUSE IS OPEN
Check for:
- Short circuit in secondary voltage
(24V) wiring including thermostat
leads. Disconnect thermostat leads
to isolate short circuit.
23 PRESSURE SWITCH DID NOT OPEN
Check for:
- Obstructed pressure tube.
- Pressure switch stuck closed.
22 ABNORMAL FLAME-PROVING SIGNAL
Flame is proved while gas valve is deenergized. Inducer will run until fault is
cleared. Check for:
- Stuck open or leaky gas valve.
21 GAS HEATING LOCKOUT – Turn off
power and wait 5 minutes to retry.
Check for:
- Stuck closed gas valve relay on control.
- Miswire or short to gas valve wire.
15 BLOWER MOTOR LOCKOUT – Indicates
the blower failed to reach 250 RPM or
the blower failed to communicate within
30 seconds after being turned ON in two
successive heating cycles. Control will
auto-reset after 3 hours. See code 41.
14 IGNITION LOCKOUT – System failed to
ignite gas and prove flame in 4 attempts.
Control will auto-reset after 3 hours.
See status code 34.
13 LIMIT CIRCUIT LOCKOUT – Lockout
occurs if the limit, draft safeguard, flame
rollout, or blocked vent switch* (if used)
is open longer than 3 minutes or 10
successive limit trips occurred during
high-heat. Control will auto-reset after 3
hours. See code 33.
12 BLOWER ON AFTER POWER UP –
(115V OR 24V) – Normal operation.
Blower runs for 90 seconds, if unit is
powered up during a call for heat (RW/W1 closed) or when (R-W/W1 opens)
during the blower on-delay period.
11 NO PREVIOUS CODE – Status codes
are erased after 72 hours or can be
manually erased by putting setup switch
SW1-1 in the ON position and jumpering
R, W/W1, and Y/Y2 simultaneously until
status code #11 is flashed. Run system
through a low-heat, high-heat, or cooling
cycle to check system.
Fixed.
YES
Will main burners ignite and stay on?
YES
Is current near typical value?
Clean flame sensor with fine steel wool and
recheck current. Nominal current is 4.0 to
6.0 microamps.
YES
Repeat call for heat and check flame sensor
current during trial for ignition period. Is the
DC microamps below 0.5?
NO
Do the main burners stay on?
YES
Do the main burners ignite?
YES
Does gas valve open and allow gas to flow?
YES
Reconnect the R thermostat lead and set
thermostat to call for heat. Connect voltmeter
across gas valve connections. Does gas
valve receive 24V?
Unplug igniter harness from control and
repeat component test by turning setup switch
SW1-6 OFF and then back ON. Check for
115V between pin 3 and NEUTRAL-L2 on
the control. Was 115V present for the 15
second period?
43 LOW-HEAT PRESSURE SWITCH OPEN
WHILE HIGH-HEAT PRESSURE
SWITCH IS CLOSED - Check for:
- Low-heat pressure switch stuck open.
- Disconnected or obstructed pressure
tube.
- Miswired pressure switches.
- Low inlet gas pressure (if LGPS used).
* Blocked vent shut off switch used in Chimney Adapter Kit
34 IGNITION PROVING FAILURE – If flame
is not sensed during the trial for ignition
period, the control will repeat the ignition
sequence 3 more times before lockout
#14 occurs. If flame signal is lost during
NO
the blower on-delay period, blower will
come on for the selected blower off-delay.
Check the following items first before
proceeding to the next step.
- Gas valve turned off.
- Manual shut-off valve.
- Green/Yellow wire MUST be connected
to furnace sheet metal.
- Flame sensor must not be grounded.
To determine whether the problem is in
the gas valve, igniter, or flame sensor the YES
system can be operated in component
test mode. To check the igniter remove
the R thermostat connection from the
control, reset power, and put setup switch
SW1-6 in the ON position to start the
component test. Does the igniter glow
orange/white by the end of the 15 second
warm-up period?
33 LIMIT CIRCUIT FAULT – Indicates the
limit, draft safeguard, flame rollout, or
blocked vent shut off switch* (if used)
is open or the furrnace is operating in
high-heat only mode due to 2 successive low-heat limit trips. Blower will run
for 4 min. or until open switch remakes
whichever is longer. If open longer than
3 min., code changes to lockout
#13. If open less than 3 min. status code
#33 continues to flash until blower shuts
off. Flame rollout switch and BVSS
requires manual reset. Check for:
- Dirty filter or restricted duct system.
- Loose blower wheel.
.
- Defective switch or connections
- Inadequate combustion air supply
(flame rollout switch open).
- Restricted vent.
- Proper vent sizing.
- Excessive wind.
32 LOW-HEAT PRESSURE SWITCH DID
NOT CLOSE OR REOPENED – If open
longer than 5 minutes, inducer shuts off
for 15 minutes before retry. If opens
during blower on-delay period, blower will
come on for the selected blower off-delay.
Check for:
- Proper vent sizing.
- Low inducer voltage (115V).
- Low inlet gas pressure (if LGPS used).
- Inadequate combustion air supply.
- Disconnected or obstructed pressure
tubing.
- Defective inducer motor.
- Defective pressure switch.
- Excessive wind.
- Restricted vent.
NO
NO
NO
YES
NO
NO
NO
YES
NO
Replace furnace control.
Replace electrode.
A02108b
Check connections and retry. If current is
near typical value (4.0-6.0 nominal) and
burners will not stay on, repeat check in highheat. If burners will still not stay on replace
control. If burners operate in high-heat then
switch to low-heat,check manifold pressure.
If OK, check burner carryover and flame
sensor location.
Allow blower to come on and repeat test
to check for intermittent operation.
Check for:
- Inadequate flame carryover or rough
ignition.
- Low inlet gas pressure.
- Proper firing rate.
- Blocked or incorrect carry- over gap.
(.045” nominal)
Check that all gas valves are turned on.
Replace valve.
Check connections. If OK, replace control.
Check for continuity in the harness and
igniter. Replace defective component.
Replace furnace control.
45 CONTROL CIRCUITRY LOCKOUT
Auto-reset after 1 hour lockout due to:
- Flame circuit failure.
- Gas valve relay stuck open.
- Software check error.
Reset power to clear lockout.
Replace control if code repeats.
57
31 HIGH-HEAT PRESSURE SWITCH OR
RELAY DID NOT CLOSE OR
REOPENED - Check for:
- Control relay may be defective.
- Gas valve is miswired.
- See status code 32.
25 INVALID MODEL SELECTION OR
SETUP ERROR – If status code 25 only
flashes 4 times on power-up the control
is missing its model plug PL4 and is
defaulting to the model selection stored
in memory. If status code 25 flashes
continuously it could indicate any of the
following:
- Model plug PL4 is missing and there
is no valid model stored in permanent
memory. This will happen if you forget
to install the model plug PL4 on a
service replacement control.
- Thermostat call with SW1-1 ON.
- Thermostat call with SW1-6 ON.
- SW1-1 and SW1-6 both ON.
YES
Replace the blower control module attached
to the blower motor. Follow the instructions
with the blower control module to make sure
the entire blower motor does not need to be
replaced.
YES
Does the voltage fluctuate as described in the
previous step?
NO
Connect a DC voltmeter across PL3-4 BLUE
(+) and PL3-2 GREEN (-). Does the voltage
fluctuate as described two steps back?
NO
Replace the furnace control.
You have an open wire or bad terminal on the
BLUE wire between the furnace control and
the blower motor.
Replace the blower control module attached
to the blower motor. Follow the instructions
with the blower control module to make sure
the entire blower motor does not need to be
replaced.
NO
41 BLOWER MOTOR FAULT – Indicates the
blower failed to reach 250 RPM or the
blower failed to communicate within the
prescribed time limits. Thirty seconds
after being turned ON or ten seconds
during steady-state operation. Turn power
off and check the following items first
before proceeding to the next step.
- Rubbing blower wheel.
- Loose blower wheel.
- Wiring from furnace control to blower
motor.
Remove the R thermostat connection
from the furnace control, disconnect both
connectors from the blower motor PL13
and PL14. Does the blower wheel turn
freely?
YES
YES
YES
Turn power off, disconnect PL13 and PL14
from the blower motor, then turn power back
on. Connect a DC voltmeter across PL1316 BLUE (+) and PL13-1 GREEN (-). The
voltage should be near 0-VDC but it will
fluctuate briefly several times a second. If
you have an analog voltmeter the needle will
briefly go high several times a second. If you
have a digital voltmeter with a bar graph it
will show a large change in magnitude on
the bar graph several times a second. If you
have a standard digital voltmeter it will show
a brief fluctuation in voltage and the
magnitude may vary depending on the
voltmeter used.
NO
Turn power off, reconnect PL13 and PL14 to
the blower motor, then turn power back on.
Connect a DC voltmeter across PL3-3
YELLOW (+) and PL3-2 GREEN (-). Does
the voltage fluctuate more than it did in the
previous step?
The voltage just measured should be very
stable and should not fluctuate more than
.02-VDC. If the voltage fluctuates more than
this get a different voltmeter before
proceeding.
YES
Is there 5-VDC at PL13-16 YELLOW (+) and
PL13-1 GREEN (-)?
Replace the furnace control.
NO
Is there 12-VDC at PL3-1 RED (+) and PL32 GREEN (-)?
NO
Is there 12-VDC at PL13-7 RED (+) and PL131 GREEN (-)?
YES
Turn power back on. Is there 115VAC at
PL14-5 and PL14-4?
NO
YES
NO
A02108c
You have an open wire or bad terminal on the
YELLOW wire between the furnace control
and the blower motor.
YES
Is there 5-VDC at PL3-3 YELLOW (+) and
PL3-2 GREEN (-)?
NO
You have an open wire or bad terminal on
either the RED or GREEN wire between the
furnace control and the blower motor.
You have an open wire or bad terminal on
either the BLACK or WHITE power leads
between the furnace control and the blower
motor. If you have a power choke disconnect
it and check continuity.
Copyright 2006 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 101
Printed in U.S.A.
Pg 58
4-06
Tab 6a 8a
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