RESIDENTIAL GAS FURNACE MODELS
TG8S*MP, TGLS*MP, GG8S*MP, GGLS*MP
(Single Stage Multi-position / Low NOx)
LIST OF SECTIONS
SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
ELECTRICAL POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
TWINNING AND STAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
VENT SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
START-UP AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . .19
SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
REPLACEMENT PART CONTACT INFORMATION . . . . . . . . . . . .28
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
LIST OF FIGURES
Duct Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Vertical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Coil Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Horizontal Right Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Horizontal Left Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
PC Series Upflow Coil Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Horizontal Left or Right application (Right Shown) . . . . . . . . . . . . . . 7
Combustible Floor Base Accessory . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Horizontal Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical Attic Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Typical Suspended Furnace / Crawl Space Installation . . . . . . . . . . . 8
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Side Return Cutout Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Gas Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Thermostat Chart - Single Stage AC with
Single Stage PSC Furnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Thermostat Chart - Single Stage HP with
Single Stage PSC Furnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Typical Twinned Furnace Application . . . . . . . . . . . . . . . . . . . . . . . .15
Single Wire Twinning Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . .16
Single Wire Staging Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . .16
Combustion Air Inducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Combustion Airflow Path Through The Furnace
Casing to the Burner Compartment . . . . . . . . . . . . . . . . . . . . . . . . .17
Outside and Ambient Combustion Air . . . . . . . . . . . . . . . . . . . . . . . .18
Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Reading Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Furnace Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
LIST OF TABLES
Unit Clearances to Combustibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Coil Projection Dimensions - PC Series Coils . . . . . . . . . . . . . . . . . . 7
Cabinet and Duct Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Recommended Filter Sizes (High Velocity 600 FPM) . . . . . . . . . . . . 9
Nominal Manifold Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Ratings & Physical / Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . 12
Estimated Free Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Unconfined Space Minimum Area . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Free Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Gas Rate (CU FT/HR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Inlet Gas Pressure Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Nominal Manifold Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Blower Performance CFM - Any Position
(without filter) - Bottom Return . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Blower Performance CFM - Any Position
(without filter) - Left Side Return . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
These high efficiency, compact units employ induced combustion, reli-
able hot surface ignition and high heat transfer aluminized tubular heat
exchangers. The units are factory shipped for installation in upflow or
horizontal applications and may be converted for downflow applica-
tions.
DANGER indicates an imminently hazardous situation, which, if not
avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation, which, if not
avoided, could result in death or serious injury.
CAUTION indicates a potentially hazardous situation, which, if not
avoided may result in minor or moderate injury. It is also used to
alert against unsafe practices and hazards involving only property dam-
age.
These furnaces are designed for residential installation in a basement,
closet, alcove, attic, recreation room or garage and are also ideal for
commercial applications. All units are factory assembled, wired and
tested to assure safe dependable and economical installation and oper-
ation.
These units are Category I listed and may be common vented with
another gas appliance as allowed by the National Fuel Gas Code.
Improper installation may create a condition where the operation of
the product could cause personal injury or property damage.
Improper installation, adjustment, alteration, service or mainte-
nance can cause injury or property damage. Failure to carefully
read and follow all instructions in this manual can result in fur-
nace malfunction, death, personal injury and/or property dam-
age. Only a qualified contractor, installer or service agency should
install this product.
SECTION I: SAFETY
This is a safety alert symbol. When you see this symbol on
labels or in manuals, be alert to the potential for personal
injury.
Understand and pay particular attention to the signal words DANGER,
WARNING, or CAUTION.
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COMBUSTION AIR QUALITY
(LIST OF CONTAMINANTS)
The furnace requires OUTDOOR AIR for combustion when the furnace
is located in any of the following environments.
CODES AND STANDARDS
Follow all national, local codes and standards in addition to this installa-
tion manual. The installation must comply with regulations of the serv-
ing 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.
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•
•
•
•
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Restricted Environments
Commercial buildings
In the United States and Canada, follow all codes and standards for the
following, using the latest edition available:
Buildings with indoor pools
Furnaces installed in laundry rooms
Furnaces installed in hobby or craft rooms
Furnaces installed near chemical storage areas
Chemical exposure
STEP 1 -Safety
•
US: National Fuel Gas Code (NFGC) NFPA 54/ANSI Z223.1 and
the Installation Standards, Warm Air Heating and Air Conditioning
Systems ANSI/NFPA 90B
The furnace requires OUTDOOR AIR for combustion when the furnace
is located in an area where the furnace is being exposed to the follow-
ing substances and / or chemicals.
•
CANADA: CAN/CGA-B149.1 National Standard of Canada. Natu-
ral Gas and Propane Installation Codes (NSCNGPIC)
STEP 2 -General Installation
•
•
•
•
•
•
•
•
•
•
•
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•
Permanent wave solutions
•
US: Current edition of the NFGC and NFPA 90B. For copies, con-
tact the
Chlorinated waxes and cleaners
Chlorine based swimming pool chemicals
Water softening chemicals
National Fire Protection Association Inc.
Batterymarch Park
Quincy, MA 02269
De-icing salts or chemicals
or for only the NFGC, contact the
American Gas Association,
400 N. Capital, N.W.
Carbon tetrachloride
Halogen type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Hydrochloric acid
Washington DC 20001
•
CANADA: NSCNGPIC. For a copy contact:
Standard Sales, CSA International
178 Rexdale Boulevard
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
Etobicoke, (Toronto) Ontario Canada M9W 1RS
When outdoor air is used for combustion, the combustion air intake duct
system termination must be located external to the building and in an
area where there will be no exposure to the substances listed above.
STEP 3 -Combustion and Ventilation Air
•
•
US: Section 5.3 of the NFGC, air for Combustion and Ventilation
CANADA: Part 7 of NSCNGPIC, Venting Systems and Air Supply
for Appliances
STEP 4 -Duct Systems
•
US and CANADA: Air Conditioning Contractors Association
The furnace area must not be used as a broom closet or for any
other storage purposes, as a fire hazard may be created. Never
store items such as the following on, near or in contact with the fur-
nace.
1. Spray or aerosol cans, rags, brooms, dust mops, vacuum
cleaners or other cleaning tools.
(ACCA) Manual D, Sheet Metal and Air Conditioning Contractors
Association National Association (SMACNA), or American Soci-
ety of Heating, Refrigeration, and Air Conditioning Engineers
(ASHRAE) 1997 Fundamentals Handbook Chapter 32.
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
2. Soap powders, bleaches, waxes or other cleaning com-
pounds; plastic items or containers; gasoline, kerosene, ciga-
rette lighter fluid, dry cleaning fluids or other volatile fluid.
3. Paint thinners and other painting compounds.
STEP 6 -Gas Piping and Gas Pipe Pressure Testing
•
•
US: NFGC; chapters 2, 3, 4, & 9 and National Plumbing Codes
CANADA: NSCNGPIC Part 5
4. Paper bags, boxes or other paper products
STEP 7 -Electrical Connections
Never operate the furnace with the blower door removed. To
do so could result in serious personal injury and/or equipment
damage.
•
•
US: National Electrical Code (NEC) ANSI/NFPA 70
CANADA: Canadian Electrical Code CSA C22.1
These instructions cover minimum requirements and conform to exist-
ing national standards and safety codes. In some instances these
instructions exceed certain local codes and ordinances, especially
those who have not kept up with changing residential and non-HUD
modular home construction practices. These instructions are required
as a minimum for a safe installation.
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INSPECTION
FOR FURNACES INSTALLED IN THE COMMON-
WEALTH OF MASSACHUSETTS ONLY
As soon as a unit is received, it should be inspected for possible dam-
age during transit. If damage is evident, the extent of the damage
should be noted on the carrier’s freight bill. A separate request for
inspection by the carrier’s agent should be made in writing. Also, before
installation, the unit should be checked for screws or bolts which may
have loosened in transit. There are no shipping or spacer brackets
which need to be removed from the interior of this unit.
For all side wall horizontally vented gas fueled equipment installed in
every dwelling, building or structure used in whole or in part for resi-
dential purposes, including those owned or operated by the Com-
monwealth and where the side wall exhaust vent termination is less
than seven (7) feet above finished grade in the area of the venting,
including but not limited to decks and porches, the following require-
ments shall be satisfied:
FURNACE LOCATION AND CLEARANCES
1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At
the time of installation of the side wall horizontal vented gas
fueled equipment, the installing plumber or gasfitter shall
observe that a hard wired carbon monoxide detector with an
alarm and battery back-up is installed on the floor level where
the gas equipment is to be installed. In addition, the installing
plumber or gasfitter shall observe that a battery operated or
hard wired carbon monoxide detector with an alarm is installed
on each additional level of the dwelling, building or structure
served by the side wall horizontal vented gas fueled equipment.
It shall be the responsibility of the property owner to secure the
services of qualified licensed professionals for the installation of
hard wired carbon monoxide detectors
The furnace shall be located using the following guidelines:
1. Where a minimum amount of air intake/vent piping and elbows will
be required.
2. As centralized with the air distribution as possible.
3. Where adequate combustion air will be available (particularly
when the appliance is not using outdoor combustion air).
4. Where it will not interfere with proper air circulation in the confined
space.
Installation in freezing temperatures:
1. Furnace shall be installed in an area where ventilation facilities
provide for safe limits of ambient temperature under normal oper-
ating conditions.
a. In the event that the side wall horizontally vented gas
fueled equipment is installed in a crawl space or an attic,
the hard wired carbon monoxide detector with alarm and
battery back-up may be installed on the next adjacent floor
level.
Improper installation in an ambient below 32ºF (0.0° C) could create
a hazard, resulting in damage, injury or death.
b. In the event that the requirements of this subdivision can
not be met at the time of completion of installation, the
owner shall have a period of thirty (30) days to comply with
the above requirements; provided, however, that during
said thirty (30) day period, a battery operated carbon mon-
oxide detector with an alarm shall be installed.
2. Do not allow return air temperature to be below 55º F (13° C) for
extended periods. To do so may cause condensation to occur in
the main heat exchanger, leading to premature heat exchanger
failure.
Clearances for access/service:
Ample clearances should be provided to permit easy access to the unit.
The following minimum clearances are recommended:
2. APPROVED CARBON MONOXIDE DETECTORS. Each car-
bon monoxide detector as required in accordance with the
above provisions shall comply with NFPA 720 and be ANSI/UL
2034 listed and IAS certified.
1. Twenty-four (24) inches (61 cm) between the front of the furnace
and an adjacent wall or another appliance, when access is
required for servicing and cleaning.
3. SIGNAGE. A metal or plastic identification plate shall be perma-
nently mounted to the exterior of the building at a minimum
height of eight (8) feet above grade directly in line with the
exhaust vent terminal for the horizontally vented gas fueled
heating appliance or equipment. The sign shall read, in print
size no less than one-half (1/2) inch in size, "GAS VENT
DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUC-
TIONS".
2. Eighteen (18) inches (46 cm) at the side where access is required
for passage to the front when servicing or for inspection or
replacement of flue/vent connections.
In all cases, accessibility clearances shall take precedence over clear-
ances for combustible materials where accessibility clearances are
greater.
Installation in a residential garage:
4. INSPECTION. The state or local gas inspector of the side wall
horizontally vented gas fueled equipment shall not approve the
installation unless, upon inspection, the inspector observes car-
bon monoxide detectors and signage installed in accordance
with the provisions of 248 CMR 5.08(2)(a)1 through 4.
A gas-fired furnace for installation in a residential garage must be
installed so the burner(s) and the ignition source are located not less
than 18 inches (46 cm) above the floor, and the furnace must be located
or protected to avoid physical damage by vehicles.
Table 1: Unit Clearances to Combustibles (All Dimensions in Inches, and All Surfaces Identified with the Unit in an Upflow Configuration)
Top
Front
Rear
Left Side
In. (cm)
0 (0.0)
Right Side
In. (cm)
0 (0.0)
Flue
Floor/
Bottom
Line
Contact
Application
Closet
Alcove
Attic
In. (cm) In. (cm) In. (cm)
In. (cm)
Upflow
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
0 (0.0)
0 (0.0)
0 (0.0)
6 (15.2) Combustible
1 (2.5) Combustible
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Upflow B-Vent
Downflow
0 (0.0)
0 (0.0)
1 (25.4)1
6 (15.2)
0 (0.0)
0 (0.0)
1 (25.4)1
1 (2.5)
Downflow B-Vent
Horizontal
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
1 (2.5)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
0 (0.0)
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes2
Yes2
6 (15.2) Combustible
1 (2.5) Combustible
Horizontal B-Vent
1. Special floor base or air conditioning coil required for use on combustible floor.
2. Line contact only permitted between lines formed by the intersection of the rear panel and side panel (top in horizontal position) of the furnace jacket and building
joists, studs or framing.
4
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On all installations without a coil, a removable access panel is recom-
mended in the outlet duct such that smoke or reflected light would be
observable inside the casing to indicate the presence of leaks in the
heat exchanger. This access cover shall be attached in such a manner
as to prevent leaks.
SECTION II: DUCTWORK
DUCTWORK GENERAL INFORMATION
The duct system’s design and installation must:
1. Handle an air volume appropriate for the served space and within
the operating parameters of the furnace specifications.
DUCT FLANGES
2. Be installed in accordance of National Fire Protection Association
as outlined in NFPA standard 90B (latest editions) or applicable
national, provincial, state, and local fire and safety codes.
3. Create a closed duct system. For residential and Non-HUD Modu-
lar Home installations, when a furnace is installed so that the sup-
ply ducts carry air circulated by the furnace to areas outside the
space containing the furnace, the return air shall also be handled
by a duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace.
Four flanges are provided to attach ductwork to the furnace. These
flanges are rotated down for shipment. In order to use the flanges,
remove the screw holding an individual flange, rotate the flange so it is
in the upward position and reinstall the screw then repeat this for all 4
flanges.
If the flanges are not used, they must remain in the rotated down posi-
tion as shipped.
Factory
installed
For duct attachment,
if needed.
4. Complete a path for heated or cooled air to circulate through the
air conditioning and heating equipment and to and from the condi-
tioned space.
The cooling coil must be installed in the supply air duct, down-
stream of the furnace. Cooled air may not be passed over the heat
exchanger.
When the furnace is used with a cooling coil, the coil must be installed
parallel with, or in the supply air side of the furnace to avoid condensa-
tion in the primary heat exchanger. When a parallel flow arrangement is
used, dampers or other means used to control airflow must be ade-
quate to prevent chilled air from entering the furnace. If manually oper-
ated, the damper must be equipped with means to prevent the furnace
or the air conditioner from operating unless the damper is in full heat or
cool position.
FIGURE 1: Duct Attachment
DUCTWORK INSTALLATION AND SUPPLY PLENUM
CONNECTION - UPFLOW/HORIZONTAL
Attach the supply plenum to the furnace outlet. The use of
an approved flexible duct connector is recommended on all
installations. This connection should be sealed to prevent
air leakage. The sheet metal should be crosshatched to
eliminate any popping of the sheet metal when the indoor
fan is energized.
When replacing an existing furnace, if the existing plenum is not the
same size as the new furnace then the existing plenum must be
removed and a new plenum installed that is the proper size for the new
furnace. If the plenum is shorter than 12” (30.5 cm) the turbulent air flow
may cause the limit controls not to operate as designed, or the limit con-
trols may not operate at all.
FLOOR BASE AND DUCTWORK INSTALLATION -
DOWNFLOW
The duct system is a very important part of the installation. If the duct
system is improperly sized the furnace will not operate properly.
The ducts attached to the furnace plenum, should be of sufficient size
so that the furnace operates at the specified external static pressure
and within the air temperature rise specified on the nameplate.
Installations on combustible material or directly on any
floors must use a combustible floor base shown in Figure 8.
Follow the instructions supplied with the combustible floor
base accessory. This combustible floor base can be
replaced with a matching cooling coil, properly sealed to
prevent leaks. Follow the instructions supplied with the
cooling coil cabinet for installing the cabinet to the duct con-
nector. Plug intake and vent pipe holes in bottom panel and
move grommet to desired vent side exit.
The minimum plenum height is 12” (30.5 cm). The furnace will not
operate properly on a shorter plenum height. The minimum recom-
mended rectangular duct height is 4 inches (10 cm) attached to the
plenum.
Downflow Air Conditioning Coil Cabinet
The furnace should be installed with coil cabinet part number specifi-
cally intended for downflow application. If a matching cooling coil is
used, it may be placed directly on the furnace outlet and sealed to pre-
vent leakage. For details of the coil cabinet dimensions and installation
requirements, refer to the installation instructions supplied with the coil
cabinet.
The duct system must be properly sized to obtain the correct airflow
for the furnace size that is being installed.
Refer to Table 6 or the furnace rating plate for the correct rise range
and static pressures.
If the ducts are undersized, the result will be high duct static pres-
sures and/or high temperature rises which can result in a heat
exchanger OVERHEATING CONDITION. This condition can result
in premature heat exchanger failure, which can result in personal
injury, property damage, or death.
Attach the air conditioning coil cabinet to the duct connector, and then
position the furnace on top of the coil cabinet. The connection to the fur-
nace, air conditioning coil cabinet, duct connector, and supply air duct
must be sealed to prevent air leakage.
COIL INSTALLATION
If a matching cooling coil is used, it may be placed directly on the fur-
nace outlet and sealed to prevent leakage. If thermoplastic evaporator
‘A’ coil drain pans are to be installed in the upflow/horizontal configura-
tion, then extra 2” minimum spacing may be needed to ensure against
drain pan distortion.
On all installations without a coil, a removable access panel is rec-
ommended in the outlet duct such that smoke or reflected light
would be observable inside the casing to indicate the presence of
leaks in the heat exchanger. This access cover shall be attached in
such a manner as to prevent leaks.
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For horizontal left hand applications no conversion is required to an MC
coil when used with a downflow/horizontal furnace. A mounting plate,
supplied with every coil should always be installed on the side desig-
nated as top side. See Figures 4 & 5.
COIL/FURNACE ASSEMBLY - MC/FC/PC SERIES
COILS
Mounting Plate
Furnace
FIGURE 5: Horizontal Left Application
FURNACE ASSEMBLY - PC SERIES COILS
These upflow coils are designed for installation on top of upflow fur-
naces only.
UPFLOW
DOWNFLOW
If the coil is used with a furnace of a different size, use a 45° transition
to allow proper air distribution through the coil.
FIGURE 2: Vertical Applications
FURNACE ASSEMBLY - MC & FC SERIES COILS
These coils are factory shipped for installation in either upflow or down-
flow applications with no conversion.
1. Position the coil casing over the furnace opening as shown in Fig-
ure 6.
2. Place the ductwork over the coil casing flange and secure.
Position the coil casing over or under the furnace opening as shown in
Figure 2 after configuring coil flanges as required see “Coil Flange” sec-
tion below.
3. Check for air leakage between the furnace and coil casing and
seal appropriately.
COIL FLANGE INSTALLATION
The coils include removable flanges to allow proper fit up with furnaces
having various inlet and outlet flange configurations. The two flanges
are attached to the top of the coil in the factory during production. For
proper configuration of flanges refer to Figure 3.
Do not drill any holes or drive any screws into the front duct flange
on the coil in order to prevent damaging coil tubing. See Figure 6
C
(Min)
D
Flexible
Duct Collar
Field
Fabricated
Ductwork
Do not drill
or Screw
this flange
FACTORY
FLANGE
LOCATION
(Used for upflow
or horizontal
Upflow
Coil
right installations)
ALTERNATE
FLANGE LOCATION
Upflow
Furnace
(Used for downflow or
horizontal left installations)
Alternate
Drain Location
Primary
Drain
Secondary
Drain
FIGURE 3: Coil Flange
FIGURE 6: PC Series Upflow Coil Installation
Table 2: Coil Projection Dimensions - PC Series Coils
FURNACE ASSEMBLY - MC SERIES COILS ONLY
MC coils are supplied ready to be installed in a horizontal position. A
horizontal pan is factory installed. MC coils should be installed in all hor-
izontal applications with the horizontal drain pan side down.
COIL SIZE
DIMENSION “C” INCH
PC18
PC24
3-1/2
4-1/2
4-1/2
5-1/2
6-1/2
9
Mounting Plate
PC30, PC32, PC35
PC42, PC43, PC36, PC37
PC48
Furnace
PC60
Dimension “C” should be at least 2/3 of dimension “D”. See Figure 6
FIGURE 4: Horizontal Right Application
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CRITICAL COIL PROJECTION
The coil assembly must be located in the duct such that a minimum dis-
tance is maintained between the top of the coil and the top of the duct.
Refer to Table 2.
RESIDENTIAL AND MODULAR HOME UPFLOW
RETURN PLENUM CONNECTION
Return air may enter the furnace through the side(s) or bottom depend-
ing on the type of application. Return air may not be connected into the
rear panel of the unit.
COIL / FURNACE ASSEMBLY - HC SERIES COILS
SIDE RETURN APPLICATION
These coils are supplied ready to be installed in a right hand position or
a left hand position. When used in conjunction with a horizontal furnace
(blow through) application, the coil should be oriented with the opening
of the “A” coil closest to the furnace. See Figure 7.
Side return applications pull return air through an opening cut in the
side of the furnace casing. This furnace is supplied with a bottom block-
off panel that should be left in place if a side return is to be used. If the
furnace is to be installed on a flat, solid surface, this bottom panel will
provide an adequate seal to prevent air leakage through the unused
bottom opening. However, if the furnace is to be installed on a surface
that is uneven, or if it is to be installed on blocks or otherwise raised off
the floor, it will be necessary to seal the edges of the bottom panel
to the casing using tape or other appropriate gasket material to
prevent air leakage.
NOTICE
Each coil is shipped with an external tie plate that should be used to
secure the coil to the furnace. It should be installed on the back side
of the coil using the dimpled pilot holes. See Figure 7.
BOTTOM RETURN AND ATTIC INSTALLATIONS
Bottom return applications normally pull return air through a base plat-
form or return air plenum. Be sure the return platform structure or return
air plenum is suitable to support the weight of the furnace.
Use tie plate
supplied with coil
The internal bottom panel must be removed for this application.
Attic installations must meet all minimum clearances to combustibles
and have floor support with required service accessibility.
DOWNFLOW APPLICATION
Gas Furnace
For downflow applications, the furnace must be turned upside-down so
that the circulating air enters at the top and exits the furnace at the bot-
tom. The combustion air inducer must be rotated 90° as shown in Fig-
ure 22. DO NOT BLOCK COMBUSTION AIR INLET OPENINGS.
FIGURE 7: Horizontal Left or Right application (Right Shown)
DOWNFLOW DUCT CONNECTORS
HORIZONTAL APPLICATION
All downflow installations must use a suitable duct connector approved
by the furnace manufacturer for use with this furnace. The duct connec-
tors are designed to be connected to the rectangular duct under the
floor and sealed. Refer to the instructions supplied with the duct con-
nector for proper installation. Refer to the separate accessory parts list
at the end of these instructions for the approved accessory duct con-
nectors.
FIGURE 9: Horizontal Application
FURNACE
This furnace may be installed in a horizontal position on either side
as shown above. It must not be installed on its back.
WARM AIR PLENUM
WITH 1” FLANGES
ATTIC INSTALLATION
FIBERGLASS
INSULATION
Line contact only permissible
between lines formed by the
intersection of furnace top
and two sides and building
joists, studs or framing
Supply
Air
Vent (Maintain
required
clearances to
combustibles)
FIBERGLASS TAPE
UNDER FLANGE
Filter rack
must be a minimum
distance
of 18” (45.7 cm)
from the
furnace
Sheet metal in
front of furnace
combustion air
Openings is
Gas Piping
12”
Recommended
COMBUSTIBLE FLOOR
BASE ACCESSORY
12”
30” MIN.
Work Area
FIGURE 8: Combustible Floor Base Accessory
Return
Air
Sediment
Trap
FIGURE 10: Typical Attic Installation
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This appliance is certified for line contact when the furnace is installed
in the horizontal left or right position. The line contact is only permissible
between lines that are formed by the intersection of the top and two
sides of the furnace and the building joists, studs or framing. This line
may be in contact with combustible material. Refer to Figure 10.
All six suspension points must be level to ensure proper and quiet fur-
nace operation. When suspending the furnace, use a secure platform
constructed of plywood or other building materials secured to the floor
or ceiling joists. Refer to Figure 11 for details and additional information.
When a furnace is installed in an attic or other insulated space,
keep all insulating materials at least 12 inches (30.5 cm) away from
furnace and burner combustion air openings.
Support
Rod
Support
Angle (x3)
During installation, doors should remain on the furnace when
moving or lifting.
Maintain 6” minimum
clearance between support
rods and front of furnace
When moving or handling this furnace prior to installation, always leave
the doors on the furnace to provide support and to prevent damage or
warping of the cabinet. When lifting the furnace, support the ends of the
furnace rather than lifting by the cabinet flanges at the return air open-
ings (bottom or sides) or supply air opening.
FIGURE 11: Typical Suspended Furnace / Crawl Space Installation
It is acceptable to use the primary heat exchanger tubes as a lifting
point provided that the tubes are lifted at the front of the heat exchang-
ers where attached to the vestibule panel. Do not use the top return
bend of the heat exchangers as lifting points as the tubes may shift out
of position or their location brackets/baffles.
During installation, doors should remain on the furnace when
moving or lifting.
When moving or handling this furnace prior to installation it is recom-
mended to leave the doors on the furnace to provide support and to
prevent damage or warping of the cabinet. When lifting the furnace,
support the ends of the furnace rather than lifting by the cabinet flanges
at the return air openings (bottom or sides) or supply air opening.
SUSPENDED FURNACE / CRAWL SPACE
INSTALLATION
The furnace can be hung from floor joists or installed on suitable blocks
or pads. Blocks or pad installations shall provide adequate height to
ensure that the unit will not be subject to water damage.
It is acceptable to use the primary heat exchanger tubes as a lifting
point provided that the tubes are lifted at the front of the heat exchang-
ers where attached to the vestibule panel. Do not use the top return
bend of the heat exchangers as lifting points as the tubes may shift out
of position or their location brackets/baffles.
Units may also be suspended from rafters or floor joists using rods, pipe
angle supports or straps. In all cases, the furnace should be supported
with rods, straps, or angle supports at three locations to properly sup-
port the furnace. Place one support at the supply end of the furnace,
one support located approximately in the center of the furnace near the
blower shelf, and the third support should be at the return end of the fur-
nace. Maintain a 6” (15.2 cm) minimum clearance between the front of
the furnace and the support rods or straps.
8
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RIGHT SIDE
FRONT
LEFT SIDE
Vent Connection
Outlet
Electrical
Entry
Vent
Connection
Outlet
Electrical
Entry
Gas Pipe
Entry
Gas Pipe
Entry
33”
23”
Thermostat
Wiring
Thermostat
Wiring
14”
A
28.5”
29.5”
1”
1.5”
4” Diameter
Vent Connection
Outlet
.5”
24.38”
.5”
.5”
B
B
C
.5”
20”
24.25”
SUPPLY END
RETURN END
FIGURE 12: Dimensions
Table 3: Cabinet and Duct Dimensions
Approximate
Operating Weights
Cabinet Dimensions (Inches)
Nominal
CFM (m3/min)
BTUH (kW)
Input
Cabinet
Size
A
A (cm)
36.8
36.8
36.8
44.4
53.3
53.3
44.4
53.3
53.3
53.3
53.3
62.2
B
B (cm)
34.0
34.0
34.0
41.6
50.5
50.5
41.6
50.5
50.5
50.5
50.5
59.4
C
C (cm)
26.2
26.2
26.2
29.9
34.5
34.5
29.9
34.5
34.5
40.1
40.1
44.4
Lbs
89
40 (11.7)
60 (17.6)
60 (17.6)
80 (23.4)
80 (23.4)
80 (23.4)
100 (29.3)
100 (29.3)
100 (29.3)
120 (35.1)
120 (35.1)
130 (38.1)
800 (22.7)
1000 (28.3)
1200 (34.0)
1200 (34.0)
1600 (45.3)
2200 (62.3)
1200 (34.0)
1600 (45.3)
2000 (56.6)
1600 (45.3)
2000 (56.6)
2000 (56.6)
A
A
A
B
C
C
B
C
C
C
C
D
14 1/2
14 1/2
14 1/2
17 1/2
21
13 3/8
13 3/8
13 3/8
16 3/8
19 7/8
19 7/8
16 3/8
19 7/8
19 7/8
19 7/8
19 7/8
23 3/8
10.3
10.3
10.3
11.8
13.6
13.6
11.8
13.6
13.6
15.8
15.8
17.5
91
94
103
114
119
108
118
122
123
129
135
21
17 1/2
21
21
21
21
24 1/2
Table 4: Recommended Filter Sizes (High Velocity 600 FPM)
SECTION III: FILTERS
FILTER INSTALLATION
All applications require the use of a field installed filter. All filters and
mounting provision must be field supplied.
CFM
(m³/min)
Cabinet
Size
Side
(in)
Bottom
(in)
800 (22.7)
1000 (28.3)
1200 (34.0)
1200 (34.0)
1600 (45.3)
1600 (45.3)
2000 (56.6)
2200 (62.3)
2000 (56.6)
A
A
A
B
B
C
C
C
D
16 x 25
16 x 25
14 x 25
14 x 25
14 x 25
16 x 25
16 x 25
20 x 25
20 x 25
20 x 25
22 x 25
Filters must be installed external to the furnace cabinet. DO NOT
attempt to install filters inside the furnace.
16 x 25
16 x 25
16 x 25
NOTICE
Single side return above 1800 CFM is approved as long as the filter
velocity does not exceed filter manufacturer’s recommendation.
16 x 25
(2) 16 x 25
(2) 16 x 25
(2) 16 x 25
1. Air velocity through throwaway type filters may not exceed 300 feet per min-
ute (91.4 m/min). All velocities over this require the use of high velocity fil-
ters.
2. Do not exceed 1800 CFM using a single side return and a 16x25 filter. For
CFM greater than 1800, you may use two side returns or one side and the
bottom or one return with a transition to allow use of a 20x25 filter.
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SIDE RETURN
Locate the “L” shaped corner locators. These indicate the size of the cut-
out to be made in the furnace side panel. Refer to Figure 13.
SECTION IV: GAS PIPING
GAS SAFETY
DANGER
An overpressure protection device, such as a pressure regulator,
must be installed in the gas piping system upstream of the furnace
and must act to limit the downstream pressure to the gas valve so it
does not exceed 0.5 PSI (14" w.c. (3.48 kPa). Pressures exceeding
0.5 PSI (14” w.c. (3.48 kPa) at the gas valve will cause damage to
the gas valve, resulting in a fire or explosion or cause damage to
the furnace or some of its components that will result in property
damage and loss of life.
Front of
Furnace
Side of
Furnace
Corner
Markings
FIGURE 13: Side Return Cutout Markings
Outlet
Pressure
Port
Vent Port
Install the side filter rack following the instructions provided with that
accessory. If a filter(s) is provided at another location in the return air
system, the ductwork may be directly attached to the furnace side
panel.
Inlet
Outlet
Wrench
Boss
Inlet
Pressure
Port
Main Regulator
Adjustment
On/Off Switch
(Shown in ON position)
Some accessories such as electronic air cleaners and pleated
media may require a larger side opening. Follow the instructions
supplied with that accessory for side opening requirements. Do not
cut the opening larger than the dimensions shown in Figure 12.
FIGURE 14: Gas Valve
HORIZONTAL APPLICATION
Horizontal Filters
Plan your gas supply before determining the correct gas pipe entry.
Use 90-degree service elbow(s), or short nipples and conventional
90-degree elbow(s) to enter through the cabinet access holes.
All filters and mounting provision must be field supplied. All installa-
tions must have a filter installed.
GAS PIPING INSTALLATION
Properly sized wrought iron, approved flexible or steel pipe must be
used when making gas connections to the unit. If local codes allow the
use of a flexible gas appliance connection, always use a new listed con-
nector. Do not use a connector that has previously serviced another gas
appliance.
Any branch duct (rectangular or round duct) attached to the plenum
must attach to the vertical plenum before the filter. The use of straps
and / or supports is required to support the weight of the external filter
box.
Some utility companies or local codes require pipe sizes larger than the
minimum sizes listed in these instructions and in the codes. The furnace
rating plate and the instructions in this section specify the type of gas
approved for this furnace - only use those approved gases. The instal-
lation of a drip leg and ground union is required. Refer to Figure 15.
Downflow Filters
Downflow furnaces typically are installed with the filters located above
the furnace, extending into the return air plenum or duct. Any branch
duct (rectangular or round duct) attached to the plenum must attach to
the vertical plenum above the filter height.
Filter(s) may be located in the duct system external to the furnace using
an external duct filter box attached to the furnace plenum or at the end
of the duct in a return filter grille(s). The use of straps and/or supports is
required to support the weight of the external filter box.
NOTE: Ground Union maybe installed inside or outside unit.
To Gas
Supply
Ground
Union
To Gas
Supply
External
Manual
Shut-off
Valve
To Gas
Supply
To Gas
Supply
External
Manual
Shut-off
Valve
Gas
Valve
To Gas
Supply
Ground
Union
Ground
Union
Drip Leg
External
Ground
Union
Manual
Shut-off
Valve
Gas
Valve
Gas
Pipe
Gas
Valve
Drip
Leg
Drip
Leg
Drip
Leg
Drip
Leg
To Gas
Supply
Gas Pipe
Ground
Union
Upflow
Downflow
Horizontal
Drip Leg
Configuration
Configuration
Configuration
FIGURE 15: Gas Piping
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GAS ORIFICE CONVERSION FOR PROPANE (LP)
This furnace is constructed at the factory for natural gas-fired operation,
but may be converted to operate on propane (LP) gas by using a fac-
tory-supplied LP conversion kit. Follow the instructions supplied with
the LP kit.
An accessible manual shutoff valve must be installed upstream of
the furnace gas controls and within 6 feet (1.8 m) of the furnace.
The furnace must be isolated from the gas supply piping system by
closing its individual external manual shutoff valve during any pressure
testing of the gas supply piping system at pressures equal to or less
than 1/2 psig (3.5 kPa).
LoNOx furnaces requiring propane (LP) gas must have the LoNOx
screens removed prior to installation and operation. See propane
instructions.
HIGH ALTITUDE GAS ORIFICE CONVERSION
This furnace is constructed at the factory for natural gas-fired operation
at 0 –5,000 feet (0-m – 1,524 m) above sea level.
The gas valve body is a very thin casting that cannot take any
external pressure. Never apply a pipe wrench to the body of the gas
valve when installing piping. A wrench must be placed on the octa-
gon hub located on the gas inlet side of the valve. Placing a wrench
to the body of the gas valve will damage the valve causing improper
operation and/or the valve to leak.
The manifold pressure must be changed in order to maintain proper
and safe operation when the furnace is installed in a location where the
altitude is greater than 5,000 feet (1,524 m) above sea level. Refer to
Table 5 for proper manifold pressure settings.
Gas piping may be connected from either side of the furnace using any
of the gas pipe entry on both sides of the furnace. Refer to Figure 12.
HIGH ALTITUDE PRESSURE SWITCH CONVERSION
For installation where the altitude is less than 5,000 feet (1,524m), it is
not required that the pressure switch be changed unless you are in an
area subject to low pressure inversions.
Table 5: Nominal Manifold Pressure
Manifold Pressures (in wc)
Manifold Pressures (kpa)
Altitude (feet)
Altitude (m)
0-7999
3.5
8000-8999
3.5
9000-9999
3.5
0-2437
0.87
0.87
0.87
0.87
0.87
0.87
0.80
2.44
2438-2742
0.87
2743-3048
0.87
800
850
29.8
31.7
3.5
3.5
3.5
0.87
0.87
900
3.5
3.5
3.5
33.5
0.87
0.87
950
3.5
3.5
3.3
35.4
0.87
0.81
1000
1050
1100
3.5
3.2
2.9
37.3
0.80
0.73
3.5
2.9
2.7
39.1
0.73
0.67
3.2
2.7
2.4
41.0
0.66
0.61
2500 (LP)
9.8
8.2
7.5
93.2 (LP)
2.03
1.86
DANGER
PROPANE AND HIGH ALTITUDE CONVERSION KITS
It is very important to choose the correct kit and/or gas orifices for the altitude and the type of gas for which the furnace is being installed.
Only use natural gas in furnaces designed for natural gas. Only use propane (LP) gas for furnaces that have been properly converted to use pro-
pane (LP) gas. Do not use this furnace with butane gas.
Incorrect gas orifices or a furnace that has been improperly converted will create an extremely dangerous condition resulting in premature heat
exchanger failure, excessive sooting, high levels of carbon monoxide, personal injury, property damage, a fire hazard and/or death.
High altitude and propane (LP) conversions are required in order for the appliance to satisfactory meet the application.
An authorized distributor or dealer must make all gas conversions.
In Canada, a certified conversion station or other qualified agency, using factory specified and/or approved parts, must perform the conversion.
The installer must take every precaution to insure that the furnace has been converted to the proper gas orifice size when the furnace is installed.
Do not attempt to drill out any orifices to obtain the proper orifice size. Drilling out a gas orifice will cause misalignment of the burner flames,
causing premature heat exchanger burnout, high levels of carbon monoxide, excessive sooting, a fire hazard, personal injury, property damage
and/or death.
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SECTION V: ELECTRICAL POWER
ELECTRICAL POWER CONNECTIONS
Use copper conductors only.
Field wiring to the unit must be grounded. Electric wires that are field
installed shall conform to the temperature limitation for 63°F (35°C) rise
wire when installed in accordance with instructions. Refer to Table 6 in
these instructions for specific furnace electrical data.
Table 6: Ratings & Physical / Electrical Data
Max.
Outlet
Air Temp
Nominal
Airflow
Air Temp.
Rise
Input
MB
Output
MB
Blower
Blower
Max
Over-Current
Protect
Total
Unit
Amps
Min. wire Size
(awg) @ 75 ft
one way
AFU
E
Size
m3/
Amp
s
kW
kW CFM
°F
°C
°F
°C
HP
H
H
min
22.7
28.3
34.0
34.0
45.3
62.3
34.0
45.3
56.6
45.3
56.6
56.6
40 11.7 32
9.4 800
80.0 25-55 14-31 155 68.3 1/5
80.0 25-55 14-31 155 68.3 1/3
80.0 30-60 17-33 170 76.7 1/3
80.0 35-65 19-36 165 73.9 1/3
80.0 25-55 14-31 155 68.3 1/2
2.1
3.8
4.8
4.8
9 x 8
9 x 8
10
10
10
10
15
20
10
15
20
15
20
20
4.5
6.0
14
14
14
14
14
12
14
14
12
14
12
12
60 17.6 48 14.1 1000
60 17.6 48 14.1 1200
80 23.5 64 18.8 1200
80 23.5 64 18.8 1600
80 23.5 64 18.8 2200
100 29.3 80 23.4 1200
100 29.3 80 23.4 1600
100 29.3 80 23.4 2000
120 33.7 96 26.9 1600
120 33.7 96 26.9 2000
130 38.1 104 30.5 2000
11 x 8
11 x 8
7.0
7.5
7.5 11 x 10
14.5 11 x 11
10.0
16.0
7.5
80.0 25-55 14-31 155 68.3
1
80.0 40-70 22-39 170 76.7 1/3
80.0 35-65 19-36 165 73.9 1/2
4.8
9 x 8
7.5 11 x 10
14.5 11 x 11
7.5 11 x 10
14.5 11 x 11
14.5 11 x 11
10.0
17.0
10.0
17.0
17.0
80.0 25-55 14-31 155 68.3
1
80.0 40-70 22-39 170 76.7 1/2
80.0 30-60 17-33 160 71.1
80.0 35-65 19-36 165 73.9
1
1
Annual Fuel Utilization Efficiency (AFUE) numbers are determined in accordance with DOE Test procedures.
Wire size and over current protection must comply with the National Electrical Code (NFPA-70-latest edition) and all local codes.
The furnace shall be installed so that the electrical components are protected from water.
3. The furnace's control system requires correct polarity of the power
supply and a proper ground connection. Refer to Figure 16
SUPPLY VOLTAGE CONNECTIONS
Junction
Box
The power connection leads and wiring box may be relocated to the
left side of the furnace. Remove the screws and cut wire tie holding
excess wiring. Reposition on the left side of the furnace and fasten
using holes provided.
Connect ground
lead to screw
Electrical Entry
BLK
LOW VOLTAGE CONTROL WIRING CONNECTIONS
L1-Hot
Neutral
WHT
Install the field-supplied thermostat by following the instructions that
come with the thermostat. With the thermostat set in the OFF position
and the main electrical source disconnected, connect the thermostat
wiring from the wiring connections on the thermostat to the terminal
board on the ignition module, as shown in Figures 17 or 18. Electronic
thermostats may require the common wire to be connected. Apply
strain relief to thermostat wires passing through cabinet. If air condition-
ing equipment is installed, use thermostat wiring to connect the Y and C
terminals on the furnace control board to the proper wires on the con-
densing unit (unit outside).
FIGURE 16: Electrical Wiring
1. Provide a power supply separate from all other circuits. Install
overcurrent protection and disconnect switch per local/national
electrical codes. The switch should be close to the unit for conve-
nience in servicing. With the disconnect or fused switch in the OFF
position, check all wiring against the unit wiring label. Refer to the
wiring diagram in this instruction.
2. Remove the screws retaining the wiring box cover. Route the
power wiring through the opening in the unit into the junction box
with a conduit connector or other proper connection. In the junc-
tion box there will be 3 wires, a Black Wire, a White Wire. Connect
the power supply as shown on the unit-wiring label on the inside of
the blower compartment door or the wiring schematic in this sec-
tion. The black furnace lead must be connected to the L1 (hot)
wire from the power supply. The white furnace screw must be con-
nected to neutral. Connect the power supply ground to the green
screw (equipment ground) An alternate wiring method is to use a
field provided 2” (5.1 cm) x 4” (10.2 cm) box and cover on the out-
side of the furnace. Route the furnace leads into the box using a
protective bushing where the wires pass through the furnace
panel. After making the wiring connections replace the wiring box
cover and screws. Refer to Figure 16.
Set the heat anticipator in the room thermostat to 0.4 amps. Setting
it lower will cause short cycles. Setting it higher will cause the room
temperature to exceed the set points.
Some electronic thermostats do not have adjustable heat anticipa-
tors. They should be set to six cycles per hour. Follow the thermo-
stat manufacturer's instructions.
The 24-volt, 40 VA transformer is sized for the furnace components
only, and should not be connected to power auxiliary devices such as
humidifiers, air cleaners, etc. The transformer may provide power for an
air conditioning unit contactor.
12
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Product Catalog Section.
AC 5D
Single Stage Air Conditioner – Single Stage PSC Furnace
ID MODELS
G*(8/9)S
G*9F
GF(8/9)
LF8
L(Y/M)8S
G8C
(G,T)G(8/9)S
(G/T)GLS
THERMOSTAT
SINGLE STAGE
SINGLE STAGE
AIR
CONDITIONER
*PP11C70224
PSC
FURNACE
SINGLE STAGE PSC
FURNACE
SINGLE STAGE
1
AIR CONDITIONER
C
C
24 – Volt Common
24 – Volt Common
Y
Y/Y2
Y
Full Stage Compressor
Full Stage Compressor
CompressorContactor
RH
R
24 – Volt Hot
(Heat XFMR)
24 – Volt Hot
G
Fan
G
Fan
W
Full Stage Heat
RC
24 – Volt Hot
(Cool XFMR)
W
Full Stage Heat
24VAC Humidifier
(Optional)
HM1
Humidistat
Clipping Jumper W914 for
electric heat on thermostat
is not necessary
Other Part Numbers:
1
SAP
=
Legacy
265901 = 031-09166
FIGURE 17: Thermostat Chart - Single Stage AC with Single Stage PSC Furnaces
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HP 2C
Single Stage Heat Pump – Single Stage PSC Furnace
ID MODELS
OD MODELS
G*(8/9)S
G*9F
GF(8/9)
LF8
E*R*
*RHS
HP*
E*ZD
E*B*
L(Y/M)8S
G8C
(G,T)G(8/9)S
(G/T)GLS
*HGD
THERMOSTAT
THERMOSTAT
THERMOSTAT
*BP21H50124
*BN21H00124
*DP21H40124
*DN21H00124
SINGLE STAGE
SINGLE STAGE
HEAT PUMP
*DN22U00124
*DP32H70124
PSC
FURNACE
SINGLE STAGE PSC
FURNACE
2
DEMAND DEFROST
CONTROL
1
C
C
C
24 – Volt Common
24 – Volt Common
24 – Volt Common
Y1
Y/Y2
Y
First Stage Compressor
Full Stage Compressor
Compressor
R
R
R
24 – Volt Hot
24 – Volt Hot
24 – Volt Hot
G
Fan
G
Fan
E
W
W1/66(out)
Heat
Emergency Heat
Full Stage Heat
W2
N/A
N/A
Third Stage Heat
O
O
Reversing Valve
Energized in Cool
Reversing Valve
Energized in Cool
L
X/L
Malfunction Light
Malfunction Light
Y2
Second Stage Compressor
W1
W
Second Stage Aux. Heat
Auxiliary Heat
3
External Humidistat
(Optional)
Open on Humidity Rise
24VAC Humidifier
(Optional)
Step 1 of Thermostat
Installer / Configuration
Menu must be set to
Heat Pump 1
Step 9 of Thermostat
Installer / Configuration
Menu must be set to
Pump OFF
Other Part Numbers:
Part Numbers:
3
1
Part Number:
S1-2HU16700124
2
SAP
=
Legacy
SAP
=
Legacy
265901 = 031-09166
67297 = 031-01975
FIGURE 18: Thermostat Chart - Single Stage HP with Single Stage PSC Furnaces
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ACCESSORY CONNECTIONS
Vent Pipe
The furnace control will allow power-switching control of various acces-
sories.
ELECTRONIC AIR CLEANER CONNECTION
Two 1/4” (0.64 cm) spade terminals (EAC and NEUTRAL) for electronic
air cleaner connections are located on the control board. The terminals
provide 115 VAC (1.0 amp maximum) during circulating blower opera-
tion.
Gas Supply
(Both sides)
Electrical
Supply
HUMIDIFIER CONNECTION
Two 1/4” (0.64 cm) spade terminals (HUM and NEUTRAL) for humidi-
fier connections are located on the control board. The terminals provide
115 VAC (1.0 amp maximum) during heating system operation.
1 Coil for
Each Furnace
Supply
Air
A mounting hole is provided on the control panel next to the furnace
control board for mounting a humidifier transformer if required.
FIGURE 19: Typical Twinned Furnace Application
SECTION VI: TWINNING AND STAGING
In applications where more heating capacity or more airflow capacity is
needed than what one furnace can deliver, twinning can be used to
make two furnaces operate in tandem. When two furnaces are installed
using the same duct system, it is very important that the two furnace cir-
culating air blowers operate in unison. If one blower starts before the
second blower, the duct system will become pressurized and the blower
on the second furnace will turn backwards causing the second furnace
to overheat, resulting in damage to the furnace. Twinning is used to
make two furnaces operate in tandem, using one duct system, one
room thermostat and causing both furnaces to turn on and off simulta-
neously.
When two furnaces are twinned, typical system total airflow will be
approximately 85% of additive individual furnaces, i.e., two 2000
CFM units will yield a total 3400 CFM.
If a return duct is connected to only one furnace (with a connection
between the two furnaces) an imbalance in the airflow will occur
and the furnace furthest from the return plenum will overheat.
GAS PIPING
Before installing the relay and wiring, disconnect electrical power to
both furnaces. Failure to cut power could result in electrical shock
or equipment damage.
Furnace gas supplies must be provided as specified with these instruc-
tions. Since the furnaces are side by side, with no space between, gas
supplies must enter on the right and left respectively. All gas piping
must be in accordance with the national fuel gas code, ANSI Z223.1,
latest edition, and/or all local code or utility requirements.
TWINNING
In applications where more heating capacity or more airflow capacity is
needed than what one furnace can deliver, twinning can be used to
make two furnaces operate in tandem, using one duct system and one
room thermostat. When one duct system is used for two furnaces, it is
necessary that the two blowers operate in unison. The twinning function
of the board in this furnace ensures that both blowers turn on and off
simultaneously, and operate on the same blower speed.
The relay must not be installed in any location where it could be
exposed to water. If the relay has been exposed to water in any
way, it must not be used.
TWINNING DUCT SYSTEM
Twinned furnaces must only be applied on a common duct system. A
single air supply plenum must be used for both furnaces and coil(s).
Separate plenums and supply ducts systems cannot be utilized. A sin-
gle return air plenum, common to both furnaces must be used. It is sug-
gested that a return platform be utilized, with bottom air entrance into
each furnace. If a side entrance returns system is used, the common
return duct must be divided equally so as to supply each furnace with
an equal amount of return air.
Single-Wire Twinning
The control in the furnace has the single-wire twinning feature. With this
feature, a single wire is connected between the TWIN terminal on one
furnace board to the TWIN terminal on the second furnace board. The
board then communicates the blower status from one furnace to the
other along this wire. This communication makes the second furnace
blower come on at the same time, and on the same speed, as the first
furnace blower. To ensure stable communication, the common terminal
of each control must be connected.
Both furnaces must be identical models in both heating capacity and
CFM capacity. Both furnaces must be operated on the same motor
speed tap. See typical application, Figure 19.
If furnace staging is desired with two single stage furnaces on a com-
mon duct, where the gas burner on the first furnace operates on W1
and the gas burner on the second furnace operates on W2, then the
use of an air-mixing device in the plenum to mix the air from both fur-
naces is strongly recommended. The mixing device must be installed
before any ducts that supply air to occupied spaces. Twinning causes
both indoor fans to operate simultaneously. If a mixing device is not
used, any ducts that are connected down stream from the furnace that
operates on W2, will be supplying cold air in the Heating mode to the
occupied spaces unless W2 is energized.
Single-Wire Twinning Instructions
Connect the control wiring as shown in Figure 21.
1. Connect the low voltage wiring from the wall thermostat to the ter-
minal strip on the control board of Furnace #1.
2. Connect a wire from the TWIN terminal of Furnace #1 to the TWIN
terminal of Furnace #2.
3. Install a separate 24V relay as shown in the diagram below. Use of
this relay is required, as it ensures that the transformers of the two
furnaces are isolated, thus preventing the possibility of any safety
devices being bypassed.
4. Connect the common wires of furnace #1 to the common terminal
of furnace #2.
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Single-Wire Twinning Operation
Single-Wire Staging Operation
Heating - On a call for heat (W signal) from the wall thermostat, both
furnaces will start the ignition sequence and the burners on both fur-
naces will light. About thirty seconds after the burners light, the blowers
on both furnaces will come on in heating speed. When the thermostat is
satisfied, the burners will all shut off and, after the selected blower off
delay time, both blowers will shut off at the same time. The twinning
control ensures that both blowers come on and shut off at the same
time.
Cooling - On a call for cooling (Y signal) from the wall thermostat, both
furnace blowers will come on at the same time in cooling speed. When
the thermostat is satisfied, both blowers will stay on for 60 seconds,
then will shut off at the same time.
Heating - On a call for first-stage heat (W1 signal) from the wall thermo-
stat, Furnace #1 will start the ignition sequence and the burners will
light. About thirty seconds after the burners light, the blowers on both
furnaces will come on in heating speed. When the thermostat is satis-
fied, the burners will shut off and, after the selected blower off delay
time, both blowers will shut off at the same time. On a call for second
stage of heat, the burners of Furnace #2 will also light and both blowers
will run. The twinning control ensures that both blowers come on and
shut off at the same time.
Cooling - On a call for cooling (Y signal) from the wall thermostat, both
furnace blowers will come on at the same time. When the thermostat is
satisfied, both blowers will stay on for 60 seconds, then will shut off at
the same time.
Continuous Fan - On a thermostat call for continuous fan (G signal),
both furnace blowers will come on at the same time in cooling speed
and will stay on until the G signal is removed.
Continuous Fan - On a thermostat call for continuous fan (G signal),
both furnace blowers will come on at the same time in cooling speed
and will stay on until the G signal is removed.
FURNACE 1
CONTROL BOARD
FURNACE 2
CONTROL BOARD
FURNACE 1
CONTROL BOARD
FURNACE 2
CONTROL BOARD
W
G
C
W
G
C
W
G
C
W
G
C
R
Y
TWIN
R TWIN
Y
ISOLATION
RELAY
TWIN
R
R
Y
TWIN
Y
ISOLATION
RELAY
W
G
R
Y
TO A/C
WALL THERMOSTAT
FIGURE 20: Single Wire Twinning Wiring Diagram
TO A/C
W1
G
R
Y
W2
WALL THERMOSTAT
STAGING
FIGURE 21: Single Wire Staging Wiring Diagram
This control can also be used along with a two-stage wall thermostat to
stage two twinned furnaces, making them operate like a single two-
stage furnace. This allows only one furnace to supply heat during times
when the heat output from one furnace is sufficient to satisfy the
demand. When one duct system is used for two furnaces, it is neces-
sary that the two blowers operate in unison. The twinning function of
this board ensures that both blowers turn on and off simultaneously,
and operate on the same blower speed. Even when only one furnace is
supplying heat, both furnace blowers must run.
SECTION VII: VENT SYSTEM
VENT CONNECTIONS
All models are provided with a flue transition that is sized for 4” diame-
ter vent connections. If a larger size vent connector is required, that
connection must be installed external to the furnace. Figure 22 shows
the furnace as it is shipped from the factory. To convert to a horizontal
or downflow position, remove the four screws that secure the inducer
assembly and rotate 90° being careful not to damage the gasket. Rein-
stall screws. Remove cap from appropriate vent outlet location on the
cabinet, cut insulation in cabinet to same size as the hole provided and
reinstall cap in the hole in the top panel.
Single-Wire Staging
The single-wire twinning feature of this board can also be used for stag-
ing of two furnaces. With this feature, a single wire is connected
between the TWIN terminal on one furnace board to the TWIN terminal
on the second furnace board. The board then communicates the blower
status from one furnace to the other along this wire. This communica-
tion makes the second furnace blower come on at the same time, and
on the same speed, as the first furnace blower. To ensure stable com-
munication, the common terminal of each control must be connected.
In downflow applications, do not block the combustion air inlet. The
furnace must be installed on a coil cabinet or subbase to allow com-
bustion air to enter the burner compartment.
Single-Wire Staging Instructions
Connect the control wiring as shown in Figure 22.
COMBUSTION AIR INDUCER
90°
90°
1. Connect the low voltage wiring from the wall thermostat to the ter-
minal strip on the control board of Furnace #1. For staging applica-
tions, the wire from thermostat W1 is connected to the W
connection on the board on Furnace #1. The wire from thermostat
W2 is connected to Furnace #2 through a separate relay, as
described below.
Mounting Screw
(Remove)
Pressure Switch
Tube Routing
2. Connect a wire from the TWIN terminal of Furnace #1 to the TWIN
terminal of Furnace #2.
Flue Transition
(Do Not Remove)
3. Install a separate 24V relay as shown in the diagram below. Use of
this relay is required, as it ensures that the transformers of the two
furnaces are isolated, thus preventing the possibility of any safety
devices being bypassed.
Pressure
Switch
Mounting Screw
(Remove)
4. Connect the common between furnace #1 and furnace #2.
FIGURE 22: Combustion Air Inducer
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CATEGORY 1 - 450 F. MAX. VENT TEMP.
Combustion Air
The venting system must be installed in accordance with Section 5.3,
Air for Combustion and Ventilation, of the National Fuel Gas Code
Z223.1/NFPA 54 (latest edition), or Sections 7.2, 7.3 or 7.4 of CSA
B149.1, National Gas and Propane Codes (latest edition) or applicable
provisions of the local building code and these instructions.
The furnace shall be connected to any type of B, BW or L vent connec-
tor, and shall be connected to a factory-built or masonry chimney. The
furnace shall not be connected to a chimney flue serving a sepa-
rate appliance designed to burn solid fuel.
It is recommended that the appliance is installed in a location where the
space temperature is 32 °F (0°C) or higher. If the appliance is installed
in a location where the ambient temperature is below 32 °F (0°C), the
combustion byproducts could condense causing damage to the appli-
ance heat exchanger.
FIGURE 23: Combustion Airflow Path Through The Furnace Casing to
This appliance may be common vented with another gas appliance for
residential installations as allowed by the codes and standards listed in
these instructions.
the Burner Compartment
Non-HUD approved Modular Homes must be vented with an approved
roof jack and may not be common vented with other appliances.
This type of installation requires that the supply air to the appli-
ance(s) be of a sufficient amount to support all of the appliance(s)
in the area. Operation of a mechanical exhaust, such as an exhaust
fan, kitchen ventilation system, clothes dryer or fireplace may cre-
ate conditions requiring special attention to avoid unsatisfactory
operation of gas appliances. A venting problem or a lack of supply
air will result in a hazardous condition, which can cause the appli-
ance to soot and generate dangerous levels of CARBON MONOX-
IDE, which can lead to serious injury, property damage and / or
death.
VENTING
Category I venting consists of vertically venting one or more appliances
in B-vent or masonry chimney (as allowed), using single wall metal pipe
or B-vent connectors. Type B-vent system extends in a general vertical
direction and does not contain offsets exceeding 45°. A vent system
having not more than one 60° offset is permitted.
VENTING INTO AN EXISTING CHIMNEY
For Category I installations, the furnace shall be connected to a factory
built chimney or vent complying with a recognized standard, or a
masonry or concrete chimney lined with a material acceptable to the
authority having jurisdiction. Venting into an unlined masonry chimney
or concrete chimney is prohibited.
An unconfined space is not less than 50 cu.ft (1.42 m3) per 1,000 Btu/
hr (0.2928 kW) input rating for all of the appliances installed in that
area.
Rooms communicating directly with the space containing the appli-
ances are considered part of the unconfined space, if doors are fur-
nished with openings or louvers.
Where use of an existing chimney is unavoidable, the following rules
must be followed:
1. The masonry chimney must be built and installed in accordance
with nationally recognized building codes or standards and must
be lined with approved fire clay tile flue liners or other approved
liner material that will resist corrosion, softening, or cracking from
flue gases. THIS FURNACE IS NOT TO BE VENTED INTO AN
UNLINED MASONRY CHIMNEY.
A confined space is an area with less than 50 cu.ft (1.42 m3) per 1,000
Btu/hr (0.2928 kW) input rating for all of the appliances installed in that
area. The following must be considered to obtain proper air for combus-
tion and ventilation in confined spaces.
Combustion Air Source From Outdoors
2. This furnace must be vented into a fire clay tile lined masonry
chimney only if a source of dilution air is provided, such as by com-
mon venting with a draft hood equipped water heater. If no source
of dilution air is available, Type B vent must be used, or masonry
chimney vent kit 1CK0603 or 1CK0604 must be used. Refer to the
instructions with the kit to properly apply these masonry chimney
kits.
The blocking effects of louvers, grilles and screens must be given con-
sideration in calculating free area. If the free area of a specific louver or
grille is not known, refer to Table 7, to estimate free area.
Table 7: Estimated Free Area
Wood or Metal
Louvers or Grilles
Wood 20-25%*
Metal 60-70% *
3. The chimney must extend at least 3 ft (0.91 m) above the highest
point where it passes through a roof of a building and at least two
feet higher than any portion of the building with a horizontal dis-
tance of ten feet.
1/4” (0.635 cm)
mesh or larger 100%
Screens+
* Do not use less than 1/4”(0.635 cm) mesh
+ Free area of louvers and grille varies widely; the installer should follow
louver or grille manufacturer’s instructions.
4. The chimney must extend at least 5 ft (1.5 m) above the highest
equipment draft hood or flue collar.
Dampers, Louvers and Grilles (Canada Only)
FAN-ASSISTED COMBUSTION SYSTEM
This appliance is equipped with an integral mechanical means to either
draw products of combustion through the heat exchanger.
1. The free area of a supply air opening shall be calculated by sub-
tracting the blockage area of all fixed louvers grilles or screens
from the gross area of the opening.
2. Apertures in a fixed louver, a grille, or screen shall have no dimen-
sion smaller than 0.25” (0.64 cm).
Ambient Combustion Air Supply
This type installation will draw the air required for combustion from
within the space surrounding the appliance and from areas or rooms
adjacent to the space surrounding the appliance. This may be from
within the space in a non-confined location or it may be brought into the
furnace area from outdoors through permanent openings or ducts. A
single, properly sized pipe from the furnace vent connector to the out-
doors must be provided. Combustion air is brought into the furnace
through the unit top panel opening.
3. A manually operated damper or manually adjustable louvers are
not permitted for use.
4. A automatically operated damper or automatically adjustable lou-
vers shall be interlocked so that the main burner cannot operate
unless either the damper or the louver is in the fully open position.
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Table 9: Free Area
Minimum Free Area Required for Each Opening
Vertical Duct or
BTUH Input
Rating
When a Category I furnace is removed or replaced, the original
venting system may no longer be correctly sized to properly vent
the attached appliances.
Horizontal Duct
Round Duct
Opening to Outside
(4,000 BTUH)
(2,000 BTUH)
(4,000 BTUH)
20 in2 (129 cm2)
30 in2 (193 cm2)
40 in2 (258 cm2)
50 in2 (322 cm2)
60 in2 (387 cm2)
65 in2 (419 cm2)
10 in2 (64 cm2)
15 in2 (97 cm2)
20 in2 (129 cm2)
25 in2 (161 cm2)
30 in2 (193 cm2)
33 in2 (213 cm2)
An improperly sized vent system can cause CARBON MONOXIDE
to spill into the living space causing personal injury, and or death.
40,000
60,000
4” (10 cm)
5” (13 cm)
5” (13 cm)
6” (15 cm)
7” (18 cm)
7” (18 cm)
80,000
Table 8: Unconfined Space Minimum Area
100,000
120,000
130,000
Minimum Free Area
BTUH Input Rating
Required for Each Opening
40 in2 (258 cm2)
40,000
60 in2 (387 cm2)
60,000
EXAMPLE: Determining Free Area.
Appliance 1 Appliance
80 in2 (516 cm2)
2 Total Input
80,000
100,000 + 30,000 = (130,000 4,000) = 32.5 Sq. In. Vertical
Appliance 1 Appliance 2 Total Input
100,000 + 30,000 = (130,000 2,000) = 65 Sq. In. Horizontal
100 in2 (645 cm2)
100,000
120 in2 (742 cm2)
120,000
130 in2 (838 cm2)
130,000
Gas
Vent
Gas
Vent
Gas
Vent
Gable
Vent
Gable
Vent
Ventilated
Attic
Ventilated
Attic
Optional
Inlet (a)
Top Above
Insulation
Top Above
Insulation
Outlet
Air (a)
Soffit
Vent
Soffit
Vent
Outlet
Air (b)
Outlet
Air (a)
Gas
Water
Heater
Gas
Water
Heater
Gas
Water
Heater
Inlet
Air (b)
Inlet
Air (b)
Inlet
Air (a)
Inlet
Air (a)
Ventilated
Crawl Space
FIGURE 24: Outside and Ambient Combustion Air
2. One permanent openings, commencing within 12 in (30.5 mm) of
the top of the enclosure shall be permitted where the equipment
has clearances of at least 1 in (2.54 cm) from the sides and back
and 6 in (15.24 cm) from the front of the appliance. The opening
shall communicate directly with the outdoors and shall have a min-
imum free area of:
Air Supply Openings and Ducts
1. An opening may be used in lieu of a duct to provide the outside air
supply to an appliance unless otherwise permitted by the authority
having jurisdiction. The opening shall be located within 12” (30.5
cm) horizontally from, the burner level of the appliance. Refer to
“COMBUSTION AIR SOURCE FROM OUTDOORS and VENT
AND SUPPLY AIR SAFETY CHECK” in these instructions for
additional information and safety check procedure.
a. 1 square in per 3000 Btu per hour (6.45 cm3 per 0.879 kW) of
the total input rating of all equipment located in the enclosure.
b. Not less than the sum of all vent connectors in the confined
space.
2. The duct shall be either metal, or a material meeting the class 1
requirements of CAN4-S110 Standard for Air Ducts.
3. The duct shall be least the same cross-sectional area as the free
area of the air supply inlet opening to which it connects.
3. The duct shall be least the same cross-sectional area as the free
area of the air supply inlet opening to which it connects.
4. The duct shall terminate within 12 in (30.5 cm) above, and within
24 in (61 cm) horizontally from, the burner level of the appliance
having the largest input.
4. The blocking effects of louvers, grilles and screens must be given
consideration in calculating free area. If the free area of a specific
louver or grille is not known. Refer to Table 7 to estimate free area.
5. A square or rectangular shaped duct shall only be used when the
Ventilated Combustion Air
required free area of the supply opening is 9 in2 (58.06 cm2) or
larger. When a square or rectangular duct is used, its small dimen-
sion shall not be less than 3 in (7.6 cm).
The ventilated attic space or a crawl space from which the combustion
air is taken must comply with the requirements specified in “AIR
SOURCE FROM OUTDOORS” in this instruction or in Section 5.3, Air
for Combustion and Ventilation of the National Fuel Gas Code, ANSI
Z223.1 (latest edition). This type installation requires two properly sized
pipes. One brings combustion air from a properly ventilated attic space
or crawl space and a second pipe that extends from the furnace vent
connection (top right of unit) to the exterior of the building.
6. An air inlet supply from outdoors shall be equipped with a means
to prevent the direct entry of rain and wind. Such means shall not
reduce the required free area of the air supply opening.
7. An air supply inlet opening from the outdoors shall be located not
less than 12” (30.5 cm) above the outside grade level.
Combustion Air Source from Outdoors
Vent and Supply (Outside) Air Safety Check Procedure
1. Two permanent openings, one within 12 in (30.5 mm) of the top
and one within 12 in (30.5 mm) of bottom of the confined space,
Two permanent openings, shall communicate directly or by means
of ducts with the outdoors, crawl spaces or attic spaces.
For Category I furnaces, vent installations shall be in accordance with
Parts 7 and 11 of the National Fuel Gas Code, ANSI Z223.1/NFPA 54,
and or Section 7 and Appendix B of the CSA B149.1, Natural Gas and
Propane Installation Codes, the local building codes, furnace and vent
manufacture's instructions.
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Multi-story or common venting systems are permitted and must be
installed in accordance with the National Fuel Gas Code, ANSI Z223.1/
NFPA 54 and / or the CSA B149.1, Natural Gas and Propane Installa-
tion Codes, local codes, and the manufacture's instructions.
Horizontal portions of the venting system shall be supported to prevent
sagging using hangers or perforated straps and must slope upwards
not less than 1/4" per foot (0.635 cm/m) from the furnace to the vent ter-
minal.
Vent connectors serving Category I furnaces shall not be connected
into any portion of mechanical draft systems operating under positive
pressure.
It is recommended that you follow the venting safety procedure below.
This procedure is designed to detect an inadequate ventilation system
that can cause the appliances in the area to operate improperly causing
unsafe levels of Carbon Monoxide or an unsafe condition to occur.
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-
monxide 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. Inspect the venting system for proper size and horizontal pitch. Determine that there is no blockage, restriction, leakage, corrosion or other
deficiencies, which could cause an unsafe condition
2. Close all building doors and windows.
3. Turn on clothes dryers and TURN ON any exhaust fans, such as range hoods and bathroom exhausts, so they shall operate at maximum
speed. Open the fireplace dampers. Do not operate a summer exhaust fan.
4. Follow the lighting instructions. Place the appliance being inspected in operation. Adjust thermostat so the appliance shall operate contin-
uously.
5. Test each appliance (such as a water heater) equipped with a draft hood for spillage (down-draft or no draft) at the draft hood relief opening
after 5 minutes of main burner operation. Appliances that do not have draft hoods need to be checked at the vent pipe as close to the
appliance as possible. Use a combustion analyzer to check the CO2 and CO levels of each appliance. Use a draft gauge to check for a
downdraft or inadequate draft condition.
6. After it has been determined that each appliance properly vents when tested as outlined above, return doors, windows, exhaust fans, fire-
place dampers and any other gas burning appliance to their normal condition.
7. If improper venting is observed during any of the above tests, a problem exists with either the venting system or the appliance does not
have enough combustion air (Supply Air from outside) to complete combustion. This condition must be corrected before the appliance can
function safely.
NOTE: An unsafe condition exists when the CO reading exceeds 40 ppm and the draft reading is not in excess of - 0.1 in. W.C. (-25 kPa) with
all of the appliance(s) operating at the same time.
8. Any corrections to the venting system and / or to the supply (outside) air system must be in accordance with the National Fuel Gas Code
Z223.1 or CAN/CGA B149.1 Natural Gas and Propane Installation Code (latest editions). If the vent system must be resized, follow the
appropriate tables in Appendix G of the above codes or for this appliance.
NOx SCREEN REMOVAL (Lo-NOx Models Only)
If the furnace is equipped with NOx screens and is to be used with LP
(propane) gas, the screens must be removed prior to start-up.
SECTION VIII: START-UP AND
ADJUSTMENTS
The initial start-up of the furnace requires the following additional
procedures:
1. Make sure that the electrical power to the unit is turned off and that
the gas supply is turned off at the shut-off valve.
2. Remove the blower compartment and burner compartment access
doors.
All electrical connections made in the field and in the factory should
be checked for proper tightness.
3. Disconnect the gas supply piping at the union to permit removal of
the entire burner and gas control assembly from the vestibule
panel. Use the wrench boss on the gas valve when removing or
installing the piping.
When the gas supply is initially connected to the furnace, the gas piping
may be full of air. In order to purge this air, it is recommended that the
ground union be loosened until the odor of gas is detected. When gas is
detected, immediately retighten the union and check for leaks. Allow
five minutes for any gas to dissipate before continuing with the start-up
procedure. Be sure proper ventilation is available to dilute and carry
away any vented gas.
4. Unplug the igniter from the wire harness. Disconnect the flame
sensor wires located on top of the air shield. Unplug the gas valve
from the wiring harness.
5. Remove the screws holding the burner assembly to the vestibule
panel.
6. Remove the burner assembly. It should be possible to swing the
burner assembly out of the way without disconnecting the remain-
ing wires.
7. With the burner assembly out of the way, simply slide the NOx
screens out of the heat exchanger tubes and discard the screens.
8. Replace all components in reverse order. Reconnect all wiring.
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With furnace in operation, check all of the pipe joints, gas valve connec-
tions and manual valve connections for leakage using an approved gas
detector, a non-corrosive leak detection fluid, or other leak detection
methods. Take appropriate steps to stop any leak. If a leak persists,
replace the component.
GAS PIPING LEAK CHECK
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warnings exactly could result in serious
injury, death or property damage.
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. A fire or explosion may result causing
property damage, personal injury or loss of life.
CALCULATING THE FURNACE INPUT
(NATURAL GAS)
NOTICE
Burner orifices are sized to provide proper input rate using natural
gas with a heating value of 1030 BTU/Ft3 (38.4 MJ/m3). If the heat-
ing value of your gas is significantly different, it may be necessary
to replace the orifices.
Burner ignition may not be satisfactory on first startup due to resid-
ual air in the gas line or until gas manifold pressure is adjusted. The
ignition control will make three attempts to light before locking out.
NOTICE
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 sqaurely aligned orifice hole
is essential for proper flame characteristics.
It is recommended that when the gas supply is first connected to the
furnace, the ground union be loosened until the odor of gas is detected.
When gas is detected, immediately tighten the union and check for gas
leaks. Allow five minutes for any gas to dissipate before continuing with
the start-up procedure. Be sure that proper ventilation is available to
dilute and carry away any vented gas.
With furnace in operation, check all of the pipe joints, gas valve connec-
tions and manual valve connections for leakage using an approved gas
detector, a non-corrosive leak detection fluid or other leak detection
methods. Take appropriate action to stop any leak. If a leak persists,
replace the faulty component.
DO NOT bottom out gas valve regulator adjusting screw. This can
result in unregulated manifold pressure and result in excess over-
fire and heat exchanger failures.
The furnace and its equipment shut-off valve must be disconnected
from the gas supply during any pressure testing of that system at test
pressures in excess of 1/2 PSI (3.45 kPa).
NOTICE
DO NOT set manifold pressure less than 3.2 in wc or more than 3.8
in wc for natural gas at sea level. If manifold pressure is outside this
range, change main burner orifices.
The furnace must be isolated from the gas supply piping system by
closing the equipment shut-off valve during any pressure testing of the
gas supply system.
Verify natural gas input rate by clocking meter.
IGNITION SYSTEM SEQUENCE
1. Turn off all other gas appliances and pilots.
1. Turn the gas supply ON at external valve and main gas valve.
2. Set the thermostat above room temperature to call for heat.
3. System start-up will occur as follows:
2. Run furnace for a minimum of 3 minutes in heating operation.
3. Measure time (in sec) for gas meter to complete 1 revolution and
note reading. The 2 cubic feet dial provides a more accurate mea-
surement of gas flow.
a. The induced draft blower motor will start and come up to
speed. Shortly after inducer start-up, the hot surface igniter
will glow for about 17 seconds.
4. Refer to Table 10 for cubic feet of gas per hour.
5. Multiply cubic feet per hour by heating valve (BTU/cu ft) to obtain
input.
b. After this warm up, the ignition module will energize (open)
the main gas valve.
If clocked rate does not match the input rate from the unit nameplate.
follow steps in next section to adjust the manifold pressure. Repeat
steps 2 - 5 until correct input is achieved.
c. After flame is established, the supply air blower will start in
about 30 seconds.
Be sure to relight any gas appliances that were turned off at the
start of this input check.
Burner ignition may not be satisfactory on first startup due to resi-
dential air in the gas line or until gas manifold pressure is adjusted.
The ignition control will make 3 attempts to light before locking out.
20
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Table 10: Gas Rate (CU FT/HR)
Size of Test Dial
2 Cu Ft
720
Size of Test Dial
Seconds For
1 Revolution
Seconds For
1 Revolution
1 Cu Ft
360
327
300
277
257
240
225
212
200
189
180
171
164
157
150
144
138
133
129
124
120
116
113
109
106
103
100
97
5 Cu Ft
1800
1636
1500
1385
1286
1200
1125
1059
1000
947
900
857
818
783
750
720
692
667
643
621
600
581
563
545
529
514
500
486
474
462
450
439
429
419
409
400
391
383
375
367
1 Cu Ft
72
71
69
68
67
65
64
63
62
61
60
58
56
54
53
51
50
48
47
46
45
44
43
42
41
40
39
38
38
37
36
35
35
34
33
33
32
31
30
2 Cu Ft
144
141
138
136
133
131
129
126
124
122
120
116
112
109
106
103
100
97
5 Cu Ft
360
355
346
340
333
327
321
316
310
305
300
290
281
273
265
257
250
243
237
231
225
220
214
209
205
200
196
192
188
184
180
178
173
170
167
164
161
155
150
10
50
51
11
655
12
600
52
13
555
53
14
514
54
15
480
55
16
450
56
17
424
57
18
400
58
19
379
59
20
360
60
21
343
62
22
327
64
23
313
66
24
300
68
25
288
70
26
277
72
27
267
74
28
257
76
95
29
248
78
92
30
240
80
90
31
232
82
88
32
225
84
86
33
218
86
84
34
212
88
82
35
206
90
80
36
200
92
78
37
195
94
76
38
95
189
96
75
39
92
185
98
74
40
90
180
100
102
104
106
108
110
112
116
120
72
41
88
176
71
42
86
172
69
43
84
167
68
44
82
164
67
45
80
160
65
46
78
157
64
47
76
153
62
48
75
150
60
49
73
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ADJUSTMENT OF MANIFOLD GAS PRESSURE &
INPUT RATE
Inlet and manifold gas pressure may be measured by connecting the
“U” tube manometer to the gas valve with a piece of tubing. Follow the
appropriate section in the instructions below. Refer to Figure 25 for a
drawing of the locations of the pressure ports on the gas valve.
The cap for the pressure regulator must be removed to gain access
to the adjustment screw. Loosening or tightening the cap does not
adjust the flow of gas.
Turn gas off at the ball valve or gas cock on gas supply line
before the gas valve. Find the pressure ports on the gas
valve marked Out P and In P.
NOTICE
The regulated outlet pressures, both low and high, have been cali-
brated at the factory. Additional pressure adjustment should not be
necessary. If adjustment is necessary, set to the following specifica-
tions. After adjustment, check for gas leakage.
1. The manifold pressure must be taken at the port marked OUT P.
2. The gas line pressure must be taken at the port marked IN P.
3. Using a 3/32” (2.4 mm) Allen wrench, loosen the set screw by turn-
ing it 1 turn counter clockwise. DO NOT REMOVE THE SET
SCREW FROM THE PRESSURE PORT.
1. Refer to Figure 25 for location of pressure regulator adjustment
cap and adjustment screws on main gas valve.
2. Turn gas and electrical supplies on and follow the operating
instructions to place the unit back in operation.
Read the inlet gas pressure
Connect the positive side of the manometer to the IN P Tap on the gas
valve. Do not connect any tubing to the negative side of the manometer,
as it will reference atmospheric pressure. Refer to Figure 26 for connec-
tion details.
3. Adjust manifold pressure by adjusting gas valve regulator screw
for the appropriate gas per the following:
Table 12: Nominal Manifold Pressure
1. Turn gas and electrical supplies on and follow the operating
instructions to place the unit back in operation.
NOMINAL MANIFOLD PRESSURE
Natural Gas
3.5" w.c. (0.87 kPa)
Table 11: Inlet Gas Pressure Range
Propane (LP) Gas
10.0" w.c. (2.488 kPa)
INLET GAS PRESSURE RANGE
Natural Gas
Propane (LP)
OUTLET
PRESSURE
PORT
VENT PORT
Minimum*
Maximum
4.5” W.C. (1.12 kPa)
10.5” W.C. (2.61 kPa)
8.0” W.C. (1.99 kPa)
13.0” (3.24 kPa) W.C.
INLET
OUTLET
WRENCH
BOSS
The inlet gas pressure operating range table specifies what the
minimum and maximum gas line pressures must be for the furnace
to operate safely. The gas line pressure MUST BE a minimum of:
INLET
PRESSURE
PORT
MAIN REGULATOR
ADJUSTMENT
ON/OFF SWITCH
(Shown in ON position)
•
•
7” w.c. (1.74 kPA) for Natural Gas
11” w.c. (2.74 kPA) for Propane (LP) Gas
FIGURE 25: Gas Valve
in order to obtain the BTU input specified on the rating plate and/or
the nominal manifold pressure specified in these instructions and
on the rating plate.
If gas valve regulator is turned in (clockwise), manifold pressure is
increased. If screw is turned out (counter clockwise), manifold pres-
sure will decrease.
2. Once the correct gas inlet pressure has been established, see
Table 11, turn the gas valve to OFF and turn the electrical supply
switch to OFF; then remove the flexible tubing from the gas valve
pressure tap and tighten the pressure tap plug using the 3/32” (2.4
mm) allen wrench.
4. After the manifold pressure has been adjusted, re-calculate the
furnace input to make sure you have not exceeded the specified
input on the rating plate. Refer to “CALCULATING THE FURNACE
INPUT (NATURAL GAS)”.
3. Turn the electrical and gas supplies back on, and with the burners
in operation, check for gas leakage around the gas valve pressure
port for leakage using an approved non-corrosive gas leak detec-
tion fluid, or other non-flammable leak detection methods.
5. Once the correct BTU (kW) input has been established, turn the
gas valve to OFF and turn the electrical supply switch to OFF; then
remove the flexible tubing from the gas valve pressure tap and
tighten the pressure tap plug using the 3/32” (2.4 mm) Allen
wrench.
Read the manifold gas pressure
Connect the positive side of the manometer to the adapter previously
installed in the OUT P Tap on the gas valve. Do not connect any tubing
to the negative side of the manometer, as it will reference atmospheric
pressure. Refer to Figure 26 for connection details.
6. Turn the electrical and gas supplies back on, and with the burners
in operation, check for gas leakage around the gas valve pressure
port for leakage using an approved non-corrosive gas leak detec-
tion fluid, or other non-flammable leak detection methods.
22
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After about 5 minutes of operation, determine the furnace temperature
rise. Take readings of both the return air and the heated air in the ducts,
about six feet (1.83 m) from the furnace where they will not be affected
by radiant heat. Increase the blower speed to decrease the temperature
rise; decrease the blower speed to increase the rise.
MANIFOLD PRESSURE “U” TUBE CONNECTION
OUTLET
PRESSURE TAP
GAS VALVE
1/4” TUBING
All direct-drive blowers have multi-speed motors. The blower motor
speed taps are located on the furnace control board in the blower com-
partment. Refer to Figure 27, and the unit-wiring label to change the
blower speed. To use the same speed tap for heating and cooling, the
heat terminal and cool terminal must be connected using a jumper wire
and connected to the desired motor lead. Place all unused motor leads
on park terminals. Two park terminals are provided.
MAINIFOLD
PIPE
FLAME
SENSOR
3.5 IN
WATER
COLUMN
GAS
PRESSURE
SHOWN
GAS
BURNERS
U-TUBE
MANOMETER
Do not energize more than one motor speed at a time or damage to
the motor will result.
FIGURE 26: Reading Gas Pressure
ADJUSTMENT OF FAN CONTROL SETTINGS
ADJUSTMENT OF TEMPERATURE RISE
This furnace is equipped with a time-on/time-off heating fan control. The
fan on delay is fixed at 30 seconds. The fan off delay has 4 settings (60,
90, 120 and 180 seconds). The fan off delay is factory set to 120 sec-
onds. The fan-off setting must be long enough to adequately cool the
furnace, but not so long that cold air is blown into the heated space. The
fan-off timing may be adjusted by positioning the jumper on two of the
four pins as shown in Figure 27.
DANGER
The temperature rise, or temperature difference between the return
air and the supply (heated) air from the furnace, must be within the
range shown on the furnace rating plate and within the application
limitations shown in SECTION 6.
The supply air temperature cannot exceed the “Maximum Supply
Air Temperature” specified in these instructions and on the fur-
nace rating plate. Under NO circumstances can the furnace be
allowed to operate above the Maximum Supply Air Temperature.
Operating the furnace above the Maximum Supply Air Temperature
will cause premature heat exchanger failure, high levels of Carbon
Monoxide, a fire hazard, personal injury, property damage, and/or
death.
TWIN
Blower Off
Delay Timer
(In seconds)
PARK PARK
HI COOL
HEAT
EAC-H
L1
XFMR
HUM
FIGURE 27: Furnace Control Board
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Table 13: Blower Performance CFM - Any Position (without filter) - Bottom Return
Bottom Airflow Data (SCFM)
Ext. Static Pressure (in. H2O)
Models
Speed
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
121
0.9
NA
1.0
NA
High
Medium High
Medium Low
Low
966
923
874
804
717
566
386
813
782
743
687
605
464
280
118
NA
NA
040A08
745
706
667
619
545
413
205
NA
NA
NA
684
655
614
565
489
342
171
NA
NA
NA
High
1292
1203
1043
869
1230
1157
1010
845
1160
1105
962
1088
1035
905
1004
942
891
760
476
129
129
Medium High
Medium Low
Low
846
728
485
133
129
060A10
060A12
080B12
080C16
080C22
100B12
100C16
100C20
120C16
120C20
130D20
823
705
491
305
124
123
811
772
708
579
438
178
145
125
High
1358
1097
935
1341
1083
928
1319
1075
920
1303
1064
899
1275
1042
872
1238
1024
840
1190
997
1130
962
1062
906
943
Medium High
Medium Low
Low
821
809
771
731
659
800
779
763
736
711
687
657
622
584
529
High
1329
994
1307
1004
790
1285
1008
782
1247
984
1195
970
1143
941
1091
893
1027
839
927
806
Medium High
Medium Low
Low
773
669
786
781
761
743
726
685
630
540
655
654
647
629
620
594
560
524
469
399
High
1881
1553
1312
1169
2811
2234
1722
1396
1314
1010
812
1822
1535
1286
1166
2725
2233
1716
1375
1318
1004
805
1783
1492
1288
1128
2638
2147
1690
1348
1292
1003
796
1696
1456
1260
1098
2540
2092
1681
1325
1265
995
1602
1408
1205
1069
2448
2042
1603
1263
1223
992
1539
1343
1143
1032
2339
1974
1553
1200
1177
956
1465
1279
1091
987
1394
1226
1029
909
1267
1113
966
1130
1014
841
Medium High
Medium Low
Low
835
747
High
2224
1907
1489
1150
1119
914
2111
1820
1426
1120
1051
857
1974
1705
1335
1052
971
1831
1575
1241
965
Medium High
Medium Low
Low
High
890
Medium High
Medium Low
Low
798
721
786
777
754
727
685
626
560
661
659
644
623
614
605
568
532
482
399
High
2069
1662
1368
1016
2893
2272
1765
1425
1752
1469
1248
1076
2701
2125
1664
1358
2823
2242
1805
1425
2014
1656
1371
1014
2774
2243
1752
1380
1724
1449
1235
1076
2620
2083
1664
1339
2714
2188
1791
1427
1956
1639
1377
1018
2687
2204
1737
1409
1702
1453
1226
1046
2533
2046
1647
1330
2613
2154
1738
1403
1885
1608
1376
1030
2589
2169
1718
1378
1664
1420
1207
1025
2429
1994
1619
1318
2507
2102
1725
1335
1820
1586
1367
1012
2478
2086
1674
1307
1600
1382
1179
1002
2338
1955
1580
1286
2399
2045
1675
1324
1748
1544
1334
996
1668
1491
1295
975
1577
1421
1250
944
1468
1338
1188
898
1362
1204
1104
852
Medium High
Medium
Low
High
2376
2018
1619
1274
1542
1344
1133
968
2255
1940
1561
1226
1454
1269
1077
927
2120
1842
1493
1180
1372
1197
992
1978
1743
1437
1113
1264
1118
922
1824
1602
1312
1025
1119
1022
841
Medium High
Medium Low
Low
High
Medium High
Medium Low
Low
869
784
707
High
2227
1901
1555
1235
2282
1970
1623
1280
2112
1857
1468
1185
2170
1887
1567
1236
1993
1737
1392
1141
2042
1792
1487
1176
1861
1621
1332
1060
1908
1673
1394
1103
1706
1497
1226
938
Medium High
Medium Low
Low
High
1761
1537
1256
996
Medium High
Medium Low
Low
NOTES:
1. Airflow expressed in standard cubic feet per minute (CFM).
2. Motor voltage at 115 V.
24
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Table 14: Blower Performance CFM - Any Position (without filter) - Left Side Return
Left Side Airflow Data (SCFM)
Ext. Static Pressure (in. H2O)
Models
Speed
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
NA
1.0
NA
High
Medium High
Medium Low
Low
994
971
942
899
829
725
419
120
824
804
777
739
675
489
350
361
NA
NA
040A08
757
733
694
659
575
444
399
NA
NA
NA
707
684
641
604
495
397
282
NA
NA
NA
High
1371
1249
1059
854
1323
1207
1026
836
1251
1158
997
1169
1098
949
1086
1018
889
971
843
521
NA
NA
Medium High
Medium Low
Low
921
669
503
NA
NA
060A10
060A12
080B12
080C16
080C22
100B12
100C16
100C20
120C16
120C20
130D20
793
582
420
NA
NA
809
775
717
576
464
216
NA
NA
High
1406
1129
970
1401
1126
947
1394
1107
933
1379
1094
916
1338
1076
890
1304
1047
863
1261
1010
827
1202
966
1135
921
1040
843
Medium High
Medium Low
Low
789
741
668
834
809
797
768
740
710
677
634
586
534
High
1274
975
1285
974
1255
968
1239
960
1207
948
1158
923
1111
879
1049
823
979
830
Medium High
Medium Low
Low
756
672
777
771
772
762
752
734
695
651
604
529
647
634
623
610
602
588
552
506
457
381
High
1825
1516
1294
1126
2972
2173
1670
1371
1258
986
1781
1493
1297
1115
2863
2146
1667
1339
1278
995
1746
1482
1271
1095
2769
2103
1647
1317
1283
1011
786
1695
1464
1238
1049
2671
2082
1618
1284
1259
1003
783
1641
1442
1187
1027
2571
2036
1585
1259
1240
962
1587
1411
1120
996
1521
1343
1083
957
1429
1275
1028
929
1330
1192
979
1184
1035
851
Medium High
Medium
Low
840
742
High
2465
1966
1549
1199
1204
935
2352
1904
1492
1147
1149
913
2227
1827
1408
1085
1073
861
2095
1738
1350
1024
1015
808
1950
1621
1238
928
Medium High
Medium Low
Low
High
897
Medium High
Medium Low
Low
738
793
786
780
750
733
702
627
567
667
653
640
629
604
583
558
519
469
427
High
2009
1523
1230
1126
2964
2192
1699
1361
1789
1451
1202
1063
2828
2085
1620
1322
2958
2191
1737
1404
1994
1506
1249
1115
2886
2178
1695
1356
1774
1445
1210
1050
2768
2073
1631
1311
2862
2182
1738
1394
1933
1521
1245
1095
2794
2150
1706
1337
1738
1431
1266
1033
2699
2042
1636
1302
2758
2157
1713
1380
1893
1490
1230
1049
2707
2109
1632
1304
1702
1413
1252
1010
2612
2029
1593
1271
2662
2092
1691
1355
1836
1466
1218
1027
2623
2098
1612
1267
1665
1394
1226
1007
2524
1967
1567
1241
2553
2085
1675
1327
1763
1435
1195
996
1691
1393
1161
957
1606
1326
1120
929
1508
1241
1039
840
1389
1119
949
Medium High
Medium Low
Low
742
High
2522
2007
1568
1243
1608
1362
1191
982
2415
1956
1519
1191
1514
1312
1082
941
2281
1888
1460
1149
1431
1235
1028
889
2149
1795
1392
1077
1343
1149
950
2012
1671
1293
994
Medium High
Medium Low
Low
High
1205
1037
852
Medium High
Medium
Low
845
778
High
2423
1896
1557
1201
2447
1997
1590
1276
2308
1893
1520
1162
2328
1932
1531
1220
2219
1816
1476
1101
2203
1844
1467
1163
2118
1717
1407
1042
2056
1741
1389
1095
1982
1635
1263
979
Medium High
Medium Low
Low
High
1893
1608
1276
1013
Medium High
Medium Low
Low
NOTES:
1. Airflow expressed in standard cubic feet per minute (CFM).
2. Return air is through side opposite motor (left side).
3. Motor voltage at 115 V.
4. Airflow through across motor side (right side) may be slightly less than the data shown above.
Johnson Controls Unitary Products
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356485-UIM-G-1211
Heating Cycle
SECTION IX: SAFETY CONTROLS
CONTROL CIRCUIT FUSE
When the thermostat switch is set on HEAT and the fan is set on AUTO,
and there is a call for heat, a circuit is completed between terminals R
and W of the thermostat. When the proper amount of combustion air is
being provided, the pressure switch will close, the ignition control pro-
vides a 17-second ignitor warm-up period, the gas valve then opens,
the gas starts to flow, ignition occurs and the flame sensor begins its
sensing function. The blower motor will energize 30 seconds after the
gas valve opens, if a flame is detected. Normal furnace operation will
continue until the thermostat circuit between R and W is opened, which
causes the ignition system and gas valve to de-energize and the burner
flames to be extinguished. The vent motor will operate for 15 seconds
and the blower motor will operate for the amount of time set by the fan-
off delay jumper located on the control board. See Figure 27. The heat-
ing cycle is now complete, and ready for the start of the next heating
cycle.
A 3-amp fuse is provided on the control circuit board to protect the 24-
volt transformer from overload caused by control circuit wiring errors.
This is an ATO 3, automotive type fuse and is located on the control
board.
BLOWER DOOR SAFETY SWITCH
Main power to the unit must still be interrupted at the main power
disconnect switch before any service or repair work is to be done to
the unit. Do not rely upon the interlock switch as a main power dis-
connect.
Blower and burner must never be operated without the blower
panel in place.
If the flame is not detected within 7 seconds of the gas valve opening,
the gas valve is shut off and a retry operation begins. Also, if the flame
is lost for 2 seconds during the 10-second stabilization period, the gas
valve is shut off and a retry operation begins. During a retry operation,
the vent motor starts a 15 second inter-purge and the ignitor warm-up
time is extended to 27 seconds. If the flame is established for more than
10 seconds after ignition during a retry, the control will clear the ignition
attempt (retry) counter. If three retries occur during a call for heat, the
furnace will shut down for one hour. If at the end of the one hour shut
down there is a call for heat, the furnace will initiate a normal start cycle.
If the problem has not been corrected the furnace will again lockout
after three retries.
This unit is equipped with an electrical interlock switch mounted in the
burner compartment. This switch interrupts all power at the unit when
the panel covering the blower compartment is removed.
Electrical supply to this unit is dependent upon the panel that covers the
blower compartment being in place and properly positioned.
ROLLOUT SWITCH CONTROLS
These controls are mounted on the burner assembly. If the temperature
in the area surrounding the burner exceeds its set point, the gas valve
is de-energized. The operation of this control indicates a malfunction in
the combustion air blower, heat exchanger or a blocked vent pipe con-
nection. Corrective action is required. These are manual reset controls
that must be reset before operation can continue.
A momentary loss of gas supply, flame blowout, or a faulty flame probe
circuit will result in a disruption in the flame and be sensed within 1.0
seconds. The gas valve will de-energize and the control will begin a
recycle operation. A normal ignition sequence will begin after a 15 sec-
ond inter-purge. If during the five recycles the gas supply does not
return, or the fault condition is not corrected the ignition control will lock-
out for 60 minutes.
PRESSURE SWITCHES
This furnace is supplied with a pressure switch, which monitors the flow
through the combustion air/vent piping system. This switch de-ener-
gizes the gas valve if any of the following conditions are present.
During burner operation, a momentary loss of power for 50 milliseconds
or longer will de-energize the gas valve. When the power is restored,
the gas valve will remain de-energized and the ignition sequence will
immediately restart.
1. Blockage of vent piping or terminal.
2. Failure of combustion air blower motor.
LIMIT CONTROLS
There is a high temperature limit control located on the furnace vesti-
bule panel near the gas valve. This is an automatic reset control that
provides over temperature protection due to reduced airflow. This may
be caused by:
Hot Surface Ignition System
1. A dirty filter.
HOT SURFACE IGNITION SYSTEM
Do not attempt to light this furnace by hand (with a match or any
other means). There may be a potential shock hazard from the
components of the hot surface ignition system. The furnace can
only be lit automatically by its hot surface ignition system.
2. If the indoor fan motor should fail.
3. Too many supply or return registers closed or blocked off.
The control module will lockout if the limit trips 5 consecutive times. If
this occurs, control will reset & try ignition again after 1 hour.
TROUBLESHOOTING
The following visual checks should be made before troubleshooting:
SEQUENCE OF OPERATION
The following describes the sequence of operation of the furnace. Refer
to Owners Manual for component location.
1. Check to see that the power to the furnace and the ignition control
module is ON.
2. The manual shut-off valves in the gas line to the furnace must be
open.
3. Make sure all wiring connections are secure.
4. Review the sequence of operation. Start the system by setting the
thermostat above the room temperature. Observe the system’s
response. Then use the troubleshooting section in this manual to
check the system’s operation.
Continuous Blower
Cooling/heating thermostats have a fan switch that has an ON and
AUTO position. In the ON position the thermostat circuit is completed
between terminals R and G. The motor will operate continuously on the
speed tap wire that is connected to the “HI COOL” cooling terminal on
the control board. To obtain a constant air circulation at lower flow rate,
change the high-speed wire to either the medium speed wire or the low
speed wire.
Intermittent Blower - Cooling
Cooling/heating thermostats have a fan switch that has an ON and
AUTO position. In the AUTO position the thermostat circuit is completed
between terminals R and G when there is a call for cooling. The motor
will operate on the speed tap wire that is connected to the “HI COOL”
cooling terminal on the control board. The fan off setting is fixed at 60
seconds to improve cooling efficiency.
Never bypass any safety control to allow furnace operation. To do
so will allow furnace to operate under potentially hazardous condi-
tions.
Do not try to repair controls. Replace defective controls with UPG
Source 1 Parts.
Never adjust pressure switch to allow furnace operation.
26
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5 RED FLASHES: This fault is indicated if the normally closed rollout
switch opens. The rollout control is manually reset. Check for proper
combustion air, proper inducer operation, and primary heat exchanger
failure or burner problem. The control will enter a hard lockout and
power will have to be cycled off and on to reset the control after the
problem has been corrected.
FURNACE CONTROL DIAGNOSTICS
The furnace has built-in, self-diagnostic capability. A blinking LED light
on the control board can flash red, green or amber to indicate various
conditions. The control continuously monitors its own operation and the
operation of the system. If a failure occurs, the LED light will indicate
the failure code.
6 RED FLASHES: This indicates that while the unit was operating, the
pressure switch opened four times during the call for heat. Check for
faulty inducer, blocked vent pipe or faulty pressure switch. The furnace
will lock out for one hour and then restart.
The SLOW flash speed is two seconds on and two seconds off.
The other flash codes listed below have the following timing: LED light
will turn on for 1/3 second and off for 1/3 second. This pattern will be
repeated the number of times equal to the code. There will be a two-
second pause between codes. For example, the six red flash code will
flash the LED light on and off six times, then will be off for two seconds.
This pattern will repeat as long as the fault condition remains. The con-
tinuous flash codes listed below will flash the LED light on and off con-
tinuously, with no breaks or longer pauses.
7 RED FLASHES: This fault code indicates that the flame could not be
established during three trials for ignition. Check that the gas valve
switch is in the ON position. Check for low or no gas pressure, faulty
gas valve, dirty or faulty flame sensor, faulty hot surface ignitor, loose
wires or a burner problem. The furnace will lock out for one hour and
then restart.
SLOW GREEN FLASH: Normal operation, no thermostat calls.
SLOW AMBER FLASH: Normal operation with call for heat.
8 RED FLASHES: This fault is indicated if the flame is lost five times
(four recycles) during the heating cycle. Check for low gas pressure,
dirty or faulty flame sensor or faulty gas valve. The furnace will lock out
for one hour and then restart.
LED STEADY OFF – If the LED light does not flash at all, check for
power to the board and check for a blown fuse on the board. If the
board is properly powered and the fuse is not blown, the control board
may need to be replaced.
9 RED FLASHES: Indicates reversed line voltage polarity, grounding
problem or reversed low voltage transformer wires. Both heating and
cooling operations will be affected. Check polarity at furnace and
branch. Check furnace grounding. Check that flame probe is not
shorted to chassis. The furnace will not start the ignition sequence until
this problem is corrected.
STEADY ON ANY COLOR: Control failure. Turn power to the furnace
off and back on. If the fault code returns, the control board must be
replaced. The control board is not field-repairable.
CONTINUOUS GREEN FLASH: Twinning error, incorrect 24V phasing
or no power to twinned unit. Check twinning wiring. Confirm that both
twinned units have power.
10 RED FLASHES: Gas valve energized with no call for heat. The main
blower and inducer blower will run and no ignition sequence will be
started as long as this condition exists. Check gas valve and gas valve
wiring.
CONTINUOUS AMBER FLASH: Flame sense current is below 1.5
microamps. Check and clean flame sensor. Check for proper gas flow.
Verify that current is greater than 1.5 microamps at flame current test
pad.
11 RED FLASHES: This indicates that the main limit switch has opened
its normally-closed contacts and has remained open for more than five
minutes. This condition is usually caused by a failed blower motor or
blower wheel. The control will enter a hard lockout and power will have
to be cycled off and on to reset the control after the problem has been
corrected.
1 RED FLASH: This indicates that flame was sensed when there was
not a call for heat. The control will turn on both the inducer motor and
supply air blower. Check for a leaking or slow-closing gas valve.
2 RED FLASHES: This indicates that the pressure switch is closed
when it should be open. The control confirms that the pressure switch
contacts are open at the beginning of each heat cycle and will not let
the ignition sequence continue if the pressure switch contacts are
closed when they should be open. Check for a faulty pressure switch or
miswiring.
4 AMBER FLASHES: The control is receiving a “Y” signal from the
thermostat without a “G” signal. The furnace will operate normally in
both heating and cooling, but this fault code will be displayed in order to
alert the user that there is a wiring problem. Verify that the “G” wire from
the thermostat is connected properly.
3 RED FLASHES: This indicates the pressure switch contacts are open
when they should be closed. Check for faulty inducer, blocked vent
pipe, broken pressure switch hose, disconnected pressure switch or
inducer wires or faulty pressure switch.
SOFT LOCKOUT: This control includes a soft lockout that will reset
automatically after one hour. This provides protection to an unoccupied
structure if a temporary condition exists causing a furnace malfunction.
An example of this is a temporary interruption in gas supply that would
prevent the furnace from lighting. The control will keep trying to light
each hour and will resume normal operation if the gas supply is
restored.
4 RED FLASHES: This indicates that the main limit switch has opened
its normally closed contacts. The control will operate the supply air
blower and inducer while the open limit condition exists. Check for a
dirty filter, improperly sized duct system, incorrect blower speed setting,
incorrect firing rate, loose limit switch wiring or faulty blower motor.
HARD LOCKOUT: Some fault conditions result in a hard lockout, which
requires power to the control to be turned off and then back on to reset
the control. The control will not automatically restart.
If the limit switch has not closed within five minutes, the control will
assume that the blower is not functioning, will start a hard lockout and
will begin to flash the 11 Red Flashes error code. Power will have to be
cycled off and on to reset the control after the problem has been cor-
rected. See “11Red Flashes” description below.
IGNITION CONTROL FLAME SENSE LEVELS
Normal flame sense current is approximately
3.7 microamps DC (µa)
Low flame signal warning starts at 1.5 microamps.
Low flame signal control lockout point is
0.1 microamps DC (µa)
If the main limit switch opens five times within a single call for heat, the
control will also indicate 4 Red Flashes and will enter a one-hour soft
lockout.
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356485-UIM-G-1211
To retrieve the error codes, push the LAST ERROR button. The LED on
the control will then flash the error codes that are in memory, starting
with the most recent. There will be a two-second pause between each
flash code. After the error codes have all been displayed, the LED will
resume the normal slow green flash after a five second pause. To
repeat the series of error codes, push the button again.
DIAGNOSTIC FAULT CODE STORAGE AND
RETRIEVAL
The control in this furnace is equipped with memory that will store up to
five error codes to allow a service technician to diagnose problems
more easily. This memory will be retained even if power to the furnace
is lost. This feature should only be used by a qualified service tech-
nician.
If there are no error codes in memory, the LED will flash two green
flashes. To clear the memory, push the LAST ERROR button and hold it
for more than five seconds. The LED will flash three green flashes when
the memory has been cleared, then will resume the normal slow green
flash after a five-second pause.
If more than five error codes have occurred since the last reset, only the
five most recent will be retained. The furnace control board has a but-
ton, labeled "LAST ERROR" that is used to retrieve error codes. This
function will only work if there are no active thermostat signals. So any
call for heating, cooling or continuous fan must be terminated before
attempting to retrieve error codes.
SECTION X: REPLACEMENT PARTS LIST
DESCRIPTION
DESCRIPTION (Continued)
FABRICATED PARTS
MOTOR
BRACKET, BLOWER TRACK (2 Req’d)
HEAT EXCHANGER ASS’Y
MANIFOLD, GAS
MOTOR, DIRECT DRIVE BLOWER
BLOWER, COMBUSTION
ELECTRICAL
PAN, BOTTOM
CAPACITOR, RUN
PANEL, TOP
SWITCH, LIMIT
PANEL, DOOR (2 Req’d)
VENT PAN, COMBUSTION (w/Gasket)
PANEL, BLOCKOFF
CONTROL, FURNACE
IGNITER
SENSOR, FLAME
LO-NOX SCREEN (L-Models Only)
MISCELLANEOUS
SWITCH, PRESSURE
SWITCH, DOOR
ORIFICE, BURNER (Natural #45)
SIGHT GLASS, OVAL (2 Req’d)
GASKET, FOAM (Door) (1.5 ft req’d)
GASKET, INTAKE PAN
PLUG, VENT HOLE
TRANSFORMER
VALVE, GAS
CONTROL, TEMPERATURE
AIR MOVING
HOUSING, BLOWER
HOUSING, BLOWER w/WHEEL
WHEEL, BLOWER
BRACKET, DOOR
WIRING HARNESS
FERRULE (3 Req’d)
FABRICATED PARTS
BAFFLE, FLUE
GROMMET (3 Req’d)
MOTOR MOUNT
BURNER, MAIN GAS
BRACKET, IGNITER
SHELF, BLOWER
TUBING, SILICON
DIAGRAM, WIRING
KNOB, QUARTER TURN (4 Req’d)
RAIL, BLOWER (2 Req’d)
REPLACEMENT PART CONTACT INFORMATION
This is a generic parts list. To request a complete parts list, refer to the contact information below:
1. Search for a part or browse the catalog.
2. Find a dealer or distributor.
3. Customer Service contact information.
a. Click on the “Brand Links” button
b. Click on the “Customer Service” button
• You can contact us by mail. Just send a written request to:
Johnson Controls Unitary Products
Consumer Relations
5005 York Drive
Norman, OK 73069
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356485-UIM-G-1211
SECTION XI: WIRING DIAGRAM
FIGURE 28: Wiring Diagram
Johnson Controls Unitary Products
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NOTES
Subject to change without notice. Published in U.S.A.
356485-UIM-G-1211
Copyright © 2011 by Johnson Controls, Inc. All rights reserved.
Supersedes: 356485-UIM-F-0910
Johnson Controls Unitary Products
5005 York Drive
Norman, OK 73069
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