Rheem Manufacturing 1x2000 User manual

92-24161-12-01
SUPERSEDES 92-24161-12-00
INSTALLATION INSTRUCTIONS
FOR UPFLOW/HORIZONTAL ((-)GPK) AND DOWNFLOW
((-)GLK) TWO STAGE INDUCED DRAFT GAS FURNACES
!
If the information in these instructions is not followed exactly, a
fire or explosion may result, causing property damage, personal
injury or death.
THESE INSTRUCTIONS ARE
INTENDED AS AN AID TO
QUALIFIED SERVICE
PERSONNEL FOR PROPER
INSTALLATION, ADJUSTMENT
AND OPERATION OF THIS
UNIT. READ THESE
INSTRUCTIONS THOROUGHLY
BEFORE ATTEMPTING
INSTALLATION OR
OPERATION. FAILURE TO
FOLLOW THESE
INSTRUCTIONS MAY RESULT
IN IMPROPER INSTALLATION,
ADJUSTMENT, SERVICE OR
MAINTENANCE, POSSIBLY
RESULTING IN FIRE,
ELECTRICAL SHOCK, CARBON
MONOXIDE POISONING,
EXPLOSION, PROPERTY
DAMAGE, PERSONAL INJURY
OR DEATH.
Do Not Destroy this Manual.
Please read carefully and keep
in a safe place for future
reference by a serviceman.
WARNING
Recognize this symbol as an indication of Important Safety Information!
!
— Do not store or use gasoline or other
flammable vapors and liquids, or other
combustible materials in the vicinity of this
or any other appliance.
— WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not
use any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas
supplier’s instructions.
• If you cannot reach your gas supplier,
call the fire department.
• Do not return to your home until
authorized by the gas supplier or fire
department.
— DO NOT RELY ON SMELL ALONE TO
DETECT LEAKS. DUE TO VARIOUS
FACTORS, YOU MAY NOT BE ABLE TO
SMELL FUEL GASES.
• U.L. recognized fuel gas and CO
detectors are recommended in all
applications, and their installation should
be in accordance with the manufacturer’s
recommendations and/or local laws,
rules, regulations, or customs
— Improper installation, adjustment, alteration,
service or maintenance can cause injury,
property damage or death. Refer to this
manual. Installation and service must be
performed by a qualified installer, service
agency or the gas supplier.
WARNING
!
PROPOSITION 65: THIS FURNACE CONTAINS FIBERGLASS
INSULATION. RESPIRABLE PARTICLES OF FIBERGLASS ARE
KNOWN TO THE STATE OF CALIFORNIA TO CAUSE CANCER.
EXHAUST GAS FROM THIS FURNACE CONTAINS CHEMICALS,
INCLUDING CARBON MONOXIDE, KNOWN TO THE STATE OF
CALIFORNIA TO CAUSE BIRTH DEFECTS OR OTHER REPRO-
DUCTIVE HARM.
WARNING
!
FOR YOUR SAFETY
!

2
Before beginning any troubleshooting procedure, complete the following installation checklist. A furnace malfunction is
sometimes caused by an improper installation. By completing this checklist, the problem may be found and corrected. Make
copies of the checklist and complete one for every Low Profile Furnace service call for your records.
INSTALLATION CHECKLIST
(Refer to this manual for specifics.)
GAS SUPPLY
Adequate pipe size
No gas leaks
Proper supply and manifold gas pressure (check with an accurate U-tube manometer with the furnace and all other gas
appliances operating.)
ELECTRICAL
Correct thermostat and subbase Thermostat model Subbase model
Correct thermostat mode and setting
Correct line supply voltage
Correct polarity (important with hot surface ignition)
Correct furnace ground to electrical panel
DC microamp (µA) flame signal (hot surface ignition units)
Correct control voltage
Measure and set heat anticipator amperage
Air conditioning low voltage wires connected to terminals “Y” “C” - not with wire nuts
VENTING
Correct vent pipe diameter and length (according to AGA/GAMA tables) Vent connection size
Correct venting material (according to AGA/GAMA tables)
Correct lining for masonry chimneys
Adequate clearance from combustibles
Proper negative pressure reading in the vent
Vent pipe secured to induced draft blower housing
COMBUSTION AIR
Proper source of combustion air
Correct combustion air opening size
FURNACE INSTALLATION
Adequate clearance from combustibles
Adequate clearance for service
Proper air temperature rise (See furnace rating plate)
External static pressure inches w.c.
Correct filter(s)
Correct cooling coil or accessories (if equipped)
Adequate supply and return air ducting Return Air Duct Size Supply Air Duct Size
Air ducts sealed to prevent leakage

3
IMPORTANT: TO INSURE PROPER INSTALLATION AND OPERATION OF
THIS PRODUCT, COMPLETELY READ ALL INSTRUCTIONS PRIOR TO
ATTEMPTING TO ASSEMBLE, INSTALL, OPERATE, MAINTAIN OR REPAIR
THIS PRODUCT. UPON UNPACKING OF THE FURNACE, INSPECT ALL
PARTS FOR DAMAGE PRIOR TO INSTALLATION AND START-UP.
CONTENTS
Safety Precautions...................................................................................................1
Installation Check List ..............................................................................................2
Location Requirements and Considerations............................................................4
Combustion and Ventilation Air..............................................................................10
Vent Pipe Installation..............................................................................................13
Gas Supply and Piping...........................................................................................16
Electrical Wiring......................................................................................................19
Accessories............................................................................................................20
Air Flow...................................................................................................................26
Maintenance...........................................................................................................29
Troubleshooting......................................................................................................31
Wiring Diagram.......................................................................................................33
➤Installation Instructions are updated on a regular basis. This is done as
product changes occur or if new information becomes available. In this
publication, an arrow (➤) denotes changes from the previous edition or additional
new material.

GENERAL INFORMATION
1. IMPORTANT: If furnace operation
is required during construction, and
air ladened with corrosive
compounds such as chlorine and
fluorine are present, provisions
must be taken to provide clean
outdoor combustion and ventilation
air to the furnace. Compounds of
chlorine and fluorine, when burned
with combustion air, form acids
which will cause corrosion of a heat
exchanger. Some of these
compounds are found in paneling,
dry wall, tile adhesives, paints,
stains and varnishes, solvents and
masonry cleaning materials.
2. NOTE: This furnace is shipped with
heat exchanger support brackets
installed under the back of the heat
exchanger. These may be removed
before installation, but it is not
required.
LOCATION
THIS FURNACE IS NOT APPROVED
FOR INSTALLATION IN A MOBILE
HOME. DO NOT INSTALL THIS
FURNACE IN A MOBILE HOME.
INSTALLATION IN A MOBILE HOME
COULD CAUSE FIRE, PROPERTY
DAMAGE, PERSONAL INJURY OR
DEATH.
3. IMPORTANT: This furnace is not
approved or recommended for
installation on its back, with access
doors facing upwards.
4. This furnace is suitable for
installation in buildings constructed
on-site. This heating unit should be
centralized with respect to the heat
distribution system as much as
practicable. When installed in a
utility room, the door of the room
should be wide enough to allow the
largest part of the furnace to enter,
or to permit the replacement of
another appliance, such as a water
heater.
5. IMPORTANT: If installing the unit
over a finished ceiling or living
area, be certain to install an
auxiliary condensate drain pan
under any evaporator coil installed
with the furnace.
6. NOTE: These furnaces are
approved for installation in attics, as
well as alcoves, utility rooms,
closets and crawlspaces.
7. IMPORTANT: Support this unit
when installed. Since this furnace
is suitable for attic or crawl space
installation, it may be installed on
combustible wood flooring or by
using support brackets. See
Figure 1.
8. IMPORTANT: If installing in a
utility room, be sure the door is
wide enough to:
a. allow the largest part of the
furnace to pass; or
b. allow any other appliance (such
as a water heater) to pass.
CLEARANCE –
ACCESSIBILITY
The design of forced air furnaces with
input ratings as listed in the tables on
the following pages are certified by
A.G.A. Laboratories and CGA for the
clearances to combustible materials
shown in inches.
See name/rating plate and clearance
label for specific model number and
clearance information.
Service clearance of at least 24 inches
is recommended in front of all furnaces.
4
The (-)GPK and (-)GLK series two
stage furnaces are designed certified to
operate at full input and at 70% of full
input. They are equipped with a 2 stage
gas valve, 2 speed draft inducer and
operate with the main blower on
heating speed at full input and low
speed at low input.
These furnaces are design certified by
AGA/CGA for use with natural or
propane gases as Category 1 furnaces
and must be vented vertically only.
They are not designed for horizontal
venting.
This furnace should be installed in
accordance with the American National
Standard Z223.1 - latest edition booklet
entitled “National Fuel Gas Code”
(NFPA 54) (in Canada, CAN/CGA
B149.1 and .2 Installation Codes for
gas burning appliances), and the
requirements or codes of the local utility
or other authority having jurisdiction
including local plumbing or waste water
codes.
Additional helpful publications available
from the “National Fire Protection
Association” are: NFPA-90A –
Installation of Air Conditioning and
Ventilating Systems 1985 or latest
edition. NFPA-90B – Warm Air Heating
and Air Conditioning Systems 1984.
These publications are available from:
National Fire Protection Association,
Inc.
Batterymarch Park
Quincy, MA 02269
Canadian Gas Association
55 Scarsdale Road
Don Mills, Ontario, Canada
M3B, 2R3
GENERAL INFORMATION
LOCATION REQUIREMENTS AND CONSIDERATIONS
WARNING
!
➤FIGURE 1
HORIZONTAL FURNACE INSTALLED W/SUPPORT BRACKETS
EXHAUST
VENT
GAS
PIPE
ELECTRICAL
CONDUIT
ST-A0799-01

5
REDUCED CLEARANCE (IN.)
Model A B C D E Left Right Back Top Front Vent Ship.
Side Side Wgts.
05 14 1227⁄32 103⁄8➀111⁄20 4➁0 1 3 6➂85 lbs.
07 171⁄21611⁄32 121⁄8➀15 0 3➁0 1 3 6➂105 lbs.
10(A) 171⁄21611⁄32 121⁄8➀15 0 3➁0 1 3 6➂115 lbs.
10(B) 21 1927⁄32 137⁄8➀181⁄20 0 0 1 3 6➂120 lbs.
12 241⁄22311⁄32 155⁄8➀22 0 0 0 1 3 6➂140 lbs.
15 241⁄22311⁄32 155⁄8➀22 0 0 0 1 3 6➂150 lbs.
CLEARANCE TO COMBUSTIBLE MATERIAL (INCHES)
UPFLOW AND UPFLOW/HORIZONTAL MODELS
TOP
LEFT SIDE
FRONT
RIGHT SIDE
BOTTOM
241⁄2
2613⁄16
265⁄8
2411⁄32
2411⁄32
19⁄32
9⁄16
247⁄16
281⁄16
265⁄8
143⁄8111⁄2
34
13⁄8DIA.
23
15
20
D
7⁄8DIA.
7⁄8DIA.
19⁄32 19⁄32
3⁄4
143⁄8
111⁄2
11⁄4
2317⁄32
C
GAS CONNECTION
ELECTRICAL CONNECTION
OPTIONAL RETURN AIR CUTOUT
(EITHER SIDE) FOR USE WITH
EXTERNAL SIDE FILTER FRAME
LOW VOLTAGE
E
A
B
R.A.
S.A.
➀May require 3(to 4(or 3(or 5(adapter.
➁May be 0(with type B vent.
➂May be 1(with type B vent.
FIGURE 2 UPFLOW AND UPFLOW/HORIZONTAL DIMENSIONS

6
FIGURE 3
REDUCED CLEARANCE (IN.)
Model A B C D E Left Right Back Top Front Vent Ship.
Side Side Wgts.
05 14 1227⁄32 103⁄8➀13 1⁄80 4➁0 1 3 6➂85 lbs.
07 171⁄21611⁄32 121⁄8➀16 5⁄80 3➁0 1 3 6➂105 lbs.
10(A) 171⁄21611⁄32 121⁄8➀16 5⁄80 3➁0 1 3 6➂115 lbs.
10(B) 21 1927⁄32 137⁄8➀20 1⁄80 0 0 1 6 6➂120 lbs.
12 241⁄22311⁄32 155⁄8➀23 5⁄80 0 0 1 3 6➂140 lbs.
15 241⁄22311⁄32 155⁄8➀23 5⁄80 0 0 1 3 6➂150 lbs.
TOP BOTTOM
241⁄2
193⁄4
CA
BD
LOW VOLTAGE
GAS CONNECTION
ELECTRIC CONNECTION
ES.A.
R.A.
265⁄8
2613⁄16
63⁄16
203⁄8
233⁄8
5⁄85⁄8
3⁄4
5⁄8
34 233⁄8
203⁄8
63⁄16
247⁄16
265⁄8
201⁄8
281⁄16
7⁄8DIA.
1⁄2DIA.
13⁄8DIA.
➀May require 3(to 4(or 3(or 5(adapter.
➁May be 0(with type B vent.
➂May be 1(with type B vent.
CLEARANCE TO COMBUSTIBLE MATERIAL (INCHES)
DOWNFLOW MODELS

ACCESSIBILITY CLEARANCES,
WHERE GREATER, MUST TAKE
PRECEDENCE OVER FIRE
PROTECTION CLEARANCES.
UPFLOW AND HORIZONTAL
INSTALLATION — Certified for use on
combustible floor.
FURNACES MUST NOT BE
INSTALLED DIRECTLY ON
CARPETING, TILE OR OTHER
COMBUSTIBLE MATERIAL OTHER
THAN WOOD FLOORING.
INSTALLATION ON A COMBUSTIBLE
MATERIAL CAN RESULT IN FIRE
CAUSING PROPERTY DAMAGE,
SEVERE PERSONAL INJURY OR
DEATH.
UNIT DESIGN IS CERTIFIED FOR
INSTALLATION ON NON-
COMBUSTIBLE FLOOR. A SPECIAL
COMBUSTIBLE FLOOR SUB-BASE IS
REQUIRED WHEN INSTALLING ON A
COMBUSTIBLE FLOOR. FAILURE TO
INSTALL THE SUB-BASE MAY
RESULT IN FIRE, PROPERTY
DAMAGE, PERSONAL INJURY OR
DEATH. THIS SPECIAL BASE IS
OFFERED AS AN ACCESSORY
FROM THE FACTORY. SEE THE
CLEARANCE LABEL LOCATED
INSIDE THE FURNACE FOR THE
APPROPRIATE MODEL NUMBER.
THE SPECIAL BASE IS NOT
REQUIRED WHEN THE FURNACE IS
INSTALLED ON TOP OF AN AIR
CONDITIONING PLENUM.
A gas-fired furnace for installation in a
residential garage must be installed so
that the burner(s) and the ignition source
are located not less than 18(above the
floor and the furnace is located or
protected to avoid physical damage by
vehicles.
UPFLOW UNIT DESIGN REQUIRES A
SOLID METAL BASE PLATE (SEE
TABLE ON PAGE 8 OR FURNACE
CLEARANCE LABEL FOR PART
NUMBER) MUST BE IN PLACE WHEN
THE FURNACE IS INSTALLED WITH
SIDE OR REAR AIR RETURN DUCTS.
FAILURE TO INSTALL A BASE PLATE
COULD CAUSE PRODUCTS OF
COMBUSTION TO BE CIRCULATED
INTO THE LIVING SPACE AND
CREATE POTENTIALLY
HAZARDOUS CONDITIONS,
INCLUDING CARBON MONOXIDE
POISONING.
furnace equals that which would
normally enter through the return air
intake of the furnace. Any duct opening
pulling return air from the outside must
not be any higher nor closer than 10 feet
to the furnace exhaust vent.
Install plenum chambers and air ducts in
accordance with the Standard for the
Installation of Air Conditioning and
Ventilating Systems, NFPA No. 90A, or
the Standard for the Installation of Warm
Air Heating and Air Conditioning
Systems, NFPA No. 90B.
If the supply ducts carry air circulated by
the furnace to areas outside the space
containing the furnace, the return air
duct or ducts must be sealed to the
furnace casing and terminate outside the
space containing the furnace. If there is
no complete return air duct system, the
return air connection must be sealed to
the furnace casing and run full size to a
location outside the utility room or space
housing the furnace to prevent a
negative pressure on the venting
system. DO NOT take return air from a
confined utility room containing
combustion producing appliances.
Any evaporator cooling coil must be
installed downstream of the furnace (at
the outlet end of the furnace) or in
parallel with the furnace to avoid
condensation on the heat exchanger.
If the furnace is installed parallel with a
cooling unit, a damper or other air flow
control must be installed to prevent
chilled air from entering the furnace. If
this device is manually operated, it must
have a means to prevent operation of
the other unit unless the damper is in the
full heat or cool position.
IMPORTANT: One of the most common
causes of forced air heating problems is
insufficient return air to the furnace. The
return system area should be
approximately equal to or greater than
the area of the warm air discharge.
CONSULT LOCAL CODES FOR
SPECIAL REQUIREMENTS. Adjust the
blower speed to maintain the air
temperature rise range shown on the
rating plate.
NOTE: The outlet duct from the furnace
should have a removable access panel.
It should be accessible after installation
to visually check the heat exchanger. It
also enables a service person to visually
check the air inlet side of an evaporator
coil for dirt, dust or other obstructions.
The total static pressure drop of the
entire system should not exceed 0.5(
w.c.
IMPORTANT: Some high efficiency
filters have a greater than normal
resistance to air flow. This can adversely
affect furnace operation. BE SURE TO
CHECK AIR FLOW if using any filter
other than the factory-provided filter.
When coils are used with air handlers
or furnaces and installed above a
finished ceiling or living area, it is
recommended that an auxiliary sheet
metal condensate drain pan be
fabricated and installed under entire
unit. Failure to do so can result in
property damage.
SITE SELECTION
1. Select a site in the building near the
center of the proposed, or existing,
duct system.
2. Give consideration to the vent
system piping when selecting the
furnace location. Be sure the venting
system can get from the furnace to
the termination with minimal length
and elbows.
3. Locate the furnace near the existing
gas piping. Or, if running a new gas
line, locate the furnace to minimize
the length and elbows in the gas
piping.
4. Locate the furnace to maintain
proper clearance to combustibles as
shown in the preceding tables.
COMBUSTIBLE MATERIAL MUST
NOT BE PLACED ON OR AGAINST
THE FURNACE JACKET OR WITHIN
THE SPECIFIED CLEARANCES OF
THE VENT PIPE. THE AREA
AROUND THE FURNACE MUST BE
KEPT CLEAR AND FREE OF ALL
COMBUSTIBLE MATERIALS
INCLUDING GASOLINE AND OTHER
FLAMMABLE VAPORS AND
LIQUIDS. PLACEMENT OF
COMBUSTIBLE MATERIALS ON,
AGAINST OR AROUND THE
FURNACE JACKET CAN CAUSE AN
EXPLOSION OR FIRE RESULTING IN
PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH. THE
HOMEOWNER SHOULD BE
CAUTIONED THAT THE FURNACE
AREA MUST NOT BE USED AS A
BROOM CLOSET OR FOR ANY
OTHER STORAGE PURPOSES.
RETURN AIR DUCTING
AND SUPPLY
Return air may come from:
(1) outside the building, (2) return air
ducting from several inside rooms, or (3)
a combination of the two. When using
outside air, design and adjust the system
to maintain a return air temperature
above 50°F during the heating season.
If return air comes from both inside and
outside the building, design the ducting
system with a diverting damper so that
the volume of return air entering the
7
CAUTION
!
WARNING
!
WARNING
!
TABLE 1
FURNACE BASE BASE
WIDTH PLATE NO. PLATE SIZE
14(RXGB-D14 115⁄8( x 239⁄16(
171⁄2(RXGB-D17 151⁄8(x 239⁄16(
21(RXGB-D21 185⁄8(x 239⁄16(
241⁄2(RXGB-D24 255⁄8( x 239⁄16(

NEVER ALLOW PRODUCTS OF
COMBUSTION OR THE FLUE
PRODUCTS TO ENTER THE
RETURN AIR DUCTWORK, OR THE
CIRCULATING AIR SUPPLY. ALL
RETURN DUCTWORK MUST BE
ADEQUATELY SEALED AND
SECURED TO THE FURNACE WITH
SHEET METAL SCREWS, AND
JOINTS TAPED. WHEN A FURNACE
IS MOUNTED ON A PLATFORM,
WITH RETURN THROUGH THE
BOTTOM, IT MUST BE SEALED
AIRTIGHT BETWEEN THE FURNACE
AND THE RETURN AIR PLENUM.
THE RETURN AIR PLENUM MUST
BE PERMANENTLY ENCLOSED.
NEVER USE A DOOR AS A PART OF
THE RETURN AIR PLENUM. THE
FLOOR OR PLATFORM MUST
PROVIDE SOUND PHYSICAL
SUPPORT OF THE FURNACE,
WITHOUT SAGGING, CRACKS,
GAPS, ETC., AROUND THE BASE AS
TO PROVIDE A SEAL BETWEEN
THE SUPPORT AND THE BASE.
FAILURE TO PREVENT PRODUCTS
OF COMBUSTION FROM BEING
CIRCULATED INTO THE LIVING
SPACE CAN CREATE POTENTIALLY
HAZARDOUS CONDITIONS,
INCLUDING CARBON MONOXIDE
POISONING THAT COULD RESULT
IN PERSONAL INJURY OR DEATH.
DO NOT, UNDER ANY
CIRCUMSTANCES, CONNECT
RETURN OR SUPPLY DUCTWORK
TO OR FROM ANY OTHER HEAT
PRODUCING DEVICE SUCH AS A
FIREPLACE INSERT, STOVE, ETC.
DOING SO MAY RESULT IN FIRE,
CARBON MONOXIDE POISONING,
EXPLOSION, PERSONAL INJURY
OR PROPERTY DAMAGE.
BLOWER AND BURNERS MUST
NEVER BE OPERATED WITHOUT
THE BLOWER DOOR IN PLACE.
THIS IS TO PREVENT DRAWING
GAS FUMES (WHICH COULD
CONTAIN HAZARDOUS CARBON
MONOXIDE) INTO THE HOME THAT
COULD RESULT IN PERSONAL
INJURY OR DEATH.
UPFLOW UNITS
1. Position the unit to minimize long runs
or runs with many turns and elbows.
2. Open the return air compartment.
a. If using side or back return air,
install the bottom base.
A SOLID METAL BASE PLATE, SEE
TABLE 1, OR FURNACE CLEARANCE
LABEL FOR PART NUMBER MUST
BE IN PLACE WHEN THE FURNACE
IS INSTALLED WITH SIDE OR REAR
AIR RETURN DUCTS. FAILURE TO
INSTALL A BASE PLATE COULD
CAUSE PRODUCTS OF
COMBUSTION TO BE CIRCULATED
INTO THE LIVING SPACE AND
CREATE POTENTIALLY
HAZARDOUS CONDITIONS,
INCLUDING CARBON MONOXIDE
POISONING OR DEATH.
b. Cut an opening in the side or back.
The opening should be cut the full
width of the knockouts on the unit.
NOTE: Where the maximum air flow is
1800 CFM or more, both sides or the
bottom must be used for return air.
3. Connect the return duct or return air
cabinet to the unit. Make the
connection air tight to prevent
entraining combustion gases from an
adjacent fuel-burning appliance.
4. Be sure to have adequate space
for the unit filter.
NOTE: DO NOT take return air from
bathrooms, kitchens, furnace rooms,
garages, utility or laundry rooms, or
cold areas.
5. If summer air conditioning is desired,
position the indoor coil on the top of
the unit. Insure that no air can bypass
this coil.
6. Connect the supply air plenum to the
furnace plenum opening.
DOWNFLOW UNITS
1. Position the unit to minimize long runs
or runs with many turns and elbows.
2. If summer air conditioning is desired,
position the indoor coil on the bottom
of the unit. Insure that no air can
bypass this coil.
3. If installing on a combustible floor and
not using an air conditioning
plenum, install the special
combustible floor base. See Figure 4.
THE DOWNFLOW FURNACE DESIGN
IS CERTIFIED FOR INSTALLATION
ON A NON-COMBUSTIBLE FLOOR.
USE THE SPECIAL BASE SPECIFIED
ON THE FURNACE CLEARANCE
LABEL. FAILURE TO INSTALL THE
SPECIAL BASE MAY RESULT IN
FIRE, PROPERTY DAMAGE,
PERSONAL INJURY OR DEATH. THIS
SPECIAL BASE IS SHIPPED FROM
THE FACTORY AS AN ACCESSORY.
4. Connect the furnace to the supply air
plenum.
5. Connect the return air ducting to the
return air opening at the top of the
unit. Make the connection air tight to
prevent entraining combustion gases
from an adjacent fuel-burning
appliance.
6. Be sure to have adequate space
for the unit filter.
NOTE: DO NOT take return air from
bathrooms, kitchens, furnace rooms,
garages, utility or laundry rooms, or
cold areas.
HORIZONTAL UNITS
1. Position the unit to minimize long
runs or runs with many turns and
elbows.
2. If summer air conditioning is desired,
position the indoor coil on the supply
air side of the unit. Insure that no air
can bypass this coil.
8
FIGURE 4
COMBUSTIBLE FLOOR BASE
WARNING
!
WARNING
!
WARNING
!
WARNING
!

9
3. Connect the furnace to the supply
air plenum.
4. Secure the four angle brackets
shipped with the unit to the return air
opening. See Figure 5. Connect the
return air ducting to the return air
opening at the top of the unit. Make
the connection air tight to prevent
entraining combustion gases from
an adjacent fuel-burning appliance.
5. Be sure to have adequate space
for the unit filter.
NOTE: DO NOT take return air from
bathrooms, kitchens, furnace rooms,
garages, utility or laundry rooms, or
cold areas.
FIGURE 5
HORIZONTAL RETURN AIR DUCT
FIGURE 6
AIR FROM HEATED SPACE
THIS FURNACE AND ANY OTHER
FUEL-BURNING APPLIANCE MUST
BE PROVIDED WITH ENOUGH
FRESH AIR FOR PROPER
COMBUSTION AND VENTILATION
OF THE FLUE GASES. MOST
HOMES WILL REQUIRE THAT
OUTSIDE AIR BE SUPPLIED INTO
THE FURNACE AREA. FAILURE TO
DO SO CAN CAUSE DEATH FROM
CARBON MONOXIDE POISONING.
Adequate facilities for providing air for
combustion and ventilation must be
provided in accordance with section
5.3, Air for Combustion and Ventilation,
of the National Fuel Gas Code, ANSI,
Z223.1 latest edition or CAN/CGA
B149.1 and .2 or, applicable provisions
for the local building codes, and not
obstructed so as to prevent the flow of
air to the furnace.
IMPORTANT: Air for combustion and
ventilation must not come from a
corrosive atmosphere. Any failure due
to corrosive elements in the
atmosphere is excluded from warranty
coverage.
The following types of installation may
require OUTDOOR AIR for
combustion, due to chemical
exposures:
• Commercial buildings
• Buildings with indoor pools
• Furnaces installed in laundry rooms
• Furnaces in hobby or craft rooms
• Furnaces installed near chemical
storage areas.
Exposure to the following substances
in the combustion air supply may also
require OUTDOOR AIR for
combustion:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine-based swimming pool
chemicals
• Water softening chemicals
COMBUSTION AND VENTILATION AIR
WARNING
!
FOUR ANGLE BRACKETS ARE SHIPPED WITH EACH
UNIT THAT CAN BE INSTALLED HORIZONTALLY. THESE
BRACKETS MAY BE USED TO SECURE THE RETURN
AIR DUCT TO A HORIZONTAL UNIT.
• De-icing salts or chemicals
• Carbon tetrachloride
• Halogen type refrigerants
• Cleaning solvents (such as
perchloroethylene)
• Printing inks, paint removers,
varnishes, etc.
• Hydrochloric acid
• Cements and glues
• Antistatic fabric softeners for clothes
dryers
• Masonry acid washing materials

Combustion air must be free of acid
forming chemicals; such as sulphur,
fluorine and chlorine. These elements
are found in aerosol sprays,
detergents, bleaches, cleaning
solvents, air fresheners, paint and
varnish removers, refrigerants and
many other commercial and household
products. Vapors from these products
when burned in a gas flame form acid
compounds. The acid compounds
increase the dew point temperature of
the flue products and are highly
corrosive after they condense.
ALL FURNACE INSTALLATIONS
MUST COMPLY WITH THE
NATIONAL FUEL GAS CODE AND
LOCAL CODES TO PROVIDE
ADEQUATE COMBUSTION AND
VENTILATION AIR FOR THE
FURNACE. FAILURE TO DO SO CAN
CREATE HAZARDOUS CONDITIONS
RESULTING IN PROPERTY
DAMAGE, BODILY INJURY OR
DEATH FROM SMOKE, FIRE OR
CARBON MONOXIDE.
Combustion air requirements are
determined by whether the furnace is
in an open (unconfined) area or in a
confined space such as a closet or
small room.
EXAMPLE 1.
FURNACE LOCATED IN AN
UNCONFINED SPACE
Using indoor air for combustion.
An unconfined space must have at
least 50 cubic feet for each 1,000 Btuh
of the total input for all appliances in
the space. Here are a few examples of
the room sizes required for different
inputs. The sizes are based on 8 foot
ceilings.
Btuh Minimum Sq. Feet Typical Room Size
Input With 8' Ceiling With 8' Ceiling
45,000 281 12*x24*or 16*x18*
50,000 312 14*x24*or 18*x18*
67,500 421 15*x28*or 20*x21*
75,000 469 15*x31*or 20*x24*
100,000 625 20*x31*or 25*x25*
125,000 833 23*x34*or 26*x30*
150,000 938 25*x38*or 30*x31*
If the open space containing the
furnace is in a building with tight
construction (contemporary
construction), outside air may still be
required for the furnace to operate and
vent properly. Outside air openings
should be sized the same as for a
confined space.
10
WARNING
!
FIGURE 7
AIR FROM ATTIC/CRAWL SPACE
➤EXAMPLE 2.
FURNACE LOCATED IN A
CONFINED SPACE
A confined space (any space smaller
than shown above as “unconfined”)
must have openings into the space
which are located in accordance with
the requirements set forth in the
following subsections A and B. Size the
openings by how they are connected to
the heated area or to the outside, and
by the input of all appliances in the
space.
If confined space is within a building
with tight construction, combustion air
must be taken from outdoors or area
freely communicating with the
outdoors.
A. USING INDOOR AIR FOR
COMBUSTION
IMPORTANT: Air should not be taken
from a heated space with a fireplace,
exhaust fan or other device that may
produce a negative pressure.
If combustion air is taken from the
heated area, the openings must
each have at least 100 square
inches of free area. Each opening
must have at least one square inch
of free area for each 1,000 Btuh of
total input in the space. Here are
some examples of typical openings
required.
Btuh Free Area
Input Each Opening
45,000 100 Square Inches
100,000 100 Square Inches
150,000 150 Square Inches
B. USING OUTDOOR AIR FOR
COMBUSTION
IMPORTANT: NEVER TAKE
COMBUSTION AIR FROM AN
ATTIC SPACE THAT IS
EQUIPPED WITH POWER
VENTILATION.
The confined space must
communicate with the outdoors
according to Methods 1 and 2. The
minimum air opening dimension
shall not be less than 3 inches.
When using ducts, they shall be of
the same cross-sectional area as
the free area of the openings to
which they connect.
Method 1
Provide two permanent openings,
one located within 12 inches of the
top and one located within 12 inches
of the bottom of the enclosure. Each
opening shall communicate directly,
or by ducts, with the outdoors or
spaces (crawl or attic) that freely
communicate with the outdoors.
a. Where directly communicating
with the outdoors or where
communicating to the outdoors
through VERTICAL DUCTS, each
opening shall have a minimum
free area of 1 square inch for
each 4000 BTUH of total
appliance input rating in the
enclosure. Here are typical duct
sizes.

a. One square inch for each 3000
BTUH of the total input rating of all
equipment located in the enclosure,
AND
b. Not less than the sum of the areas
of all vent connectors in the confined
space.
IMPORTANT: IF THE FURNACE IS IN
A LOCATION WITH AN EXHAUST
FAN, THERE MUST BE SUFFICIENT
VENTILATION TO PREVENT THE
EXHAUST FAN FROM CREATING A
NEGATIVE PRESSURE IN THE
ROOM.
Combustion air openings must NOT
BE RESTRICTED in any manner.
CONSULT LOCAL CODES FOR
SPECIAL REQUIREMENTS.
Air opening in the furnace casing front,
return air grilles, and warm air registers
must not be obstructed.
b. Where communicating with
outdoors through HORIZONTAL
DUCTS, each opening shall have
a minimum free area of 1 square
inch for each 2000 BTUH of
total input rating for all equipment
in the enclosure. Here are typical
duct sizes.
11
FIGURE 8
OUTSIDE AIR USING A HORIZONTAL INLET & OUTLET
Method 2
One permanent opening, located within
12 inches of the top of the enclosure,
shall be permitted where the
equipment has clearances of at least 1
inch from the sides and back and 6
inches from the front of the appliance.
The opening shall directly
communicate with the outdoors or
communicate through a vertical or
horizontal duct to the outdoors or
spaces (crawl or attic) that freely
communicate with the outdoors and
have a minimum free area of:
VERTICAL OUTDOOR AIR
OPENING DIMENSIONS
BTUH Free Area Round
Input Each Opening Pipe Size
45,000 11.25 sq. inches 4(
50,000 12.50 sq. inches 4(
67,500 16.90 sq. inches 5(
75,000 18.75 sq. inches 5(
100,000 25.00 sq. inches 6(
125,000 31.25 sq. inches 7(
150,000 37.50 sq. inches 7(
HORIZONTAL OUTDOOR AIR
OPENING DIMENSIONS
BTUH Free Area Round
Input Each Opening Pipe Size
45,000 22.50 sq. inches 6(
50,000 25.00 sq. inches 6(
67,500 33.75 sq. inches 7(
75,000 37.50 sq. inches 7(
100,000 50.00 sq. inches 8(
125,000 62.50 sq. inches 9(
150,000 75.00 sq. inches 10(

GENERAL INFORMATION
Vent the furnace in accordance with
these instructions, National Fuel Gas
Code, ANSI Z223.1 and/or the Natural
Gas Installation Code, CAN/CGA-
B149.1 & .2 and requirements or codes
of the local utility or other authority
having jurisdiction.
IMPORTANT: THIS FURNACE IS
NOT CERTIFIED FOR USE WITH A
POWER VENTER OR ANY OTHER
TYPE OF HORIZONTAL VENTING.
DEVICES ATTACHED TO THE FLUE
OR VENT FOR THE PURPOSE OF
REDUCING HEAT LOSS UP THE
CHIMNEY HAVE NOT BEEN TESTED
AND HAVE NOT BEEN INCLUDED IN
THE DESIGN CERTIFICATION OF
THIS FURNACE. WE, THE
MANUFACTURER, CANNOT AND
WILL NOT BE RESPONSIBLE FOR
INJURY OR DAMAGE CAUSED BY
THE USE OF SUCH UNTESTED
AND/OR UNCERTIFIED DEVICES,
ACCESSORIES OR COMPONENTS.
DRAFT INDUCER
VENT PIPE ATTACHING HOLES
MUST BE PREDRILLED IN THE
DRAFT INDUCER COLLAR TO
PREVENT PLASTIC MATERIAL
FROM CRACKING. DRILL 1/8(
DIAMETER HOLES THROUGH THE
VENT PIPE AND COLLAR AND USE
#8 SCREWS TO ATTACH. SEE
FIGURE 9. FAILURE TO FOLLOW
THIS WARNING CAN CAUSE
RECIRCULATION OF FLUE
PRODUCTS CAUSING CARBON
MONOXIDE POISONING
RESULTING IN PERSONAL INJURY
OR DEATH.
NOTE: On downflow units, be certain
that the vent pipe is positioned over
the induced draft motor outlet. Attach
the vent pipe to the induced draft
motor collar as noted above.
IMPORTANT APPLICATION
NOTES
When the furnace is used as a
replacement, the existing vent system
should be inspected to assure that
there are no obstructions, blockage, or
any signs of corrosion.
IMPORTANT: WHEN THE VENT
TABLE PERMITS MORE THAN ONE
DIAMETER OF PIPE FOR A
CONNECTOR OR VENT, THE
SMALLEST PERMITTED DIAMETER
MUST BE USED,
VENT PIPE MAY BE TYPE “B-1,”
EITHER RIGID OR SUITABLE
FLEXIBLE CONSTRUCTION THAT
CARRIES A U.L. LISTING.
COMMON VENTING IS ALLOWED
WITH VERTICAL B-1 VENT SYSTEMS,
AND LINED MASONRY CHIMNEYS.
FOLLOW THE NATIONAL FUEL GAS
CODE, ANSI Z223.1 AND/OR THE
NATURAL GAS INSTALLATION
CODE, CAN/CGA-B149.1 & .2 FOR
PROPER INSTALLATION PRACTICES.
IMPORTANT: WHEN COMMON
VENTING, USE B-1 VENT
CONNECTORS.
SINGLE WALL VENT CONNECTORS
TO “B-1 VENT OR MASONRY
CHIMNEYS” MAY BE USED UNDER
THE GUIDELINES OF THE
NATIONAL FUEL GAS CODE, ANSI
Z223.1 AND/OR THE NATURAL GAS
INSTALLATION CODE, CAN/CGA-
B149.1 & .2.
12
WARNING
!
WARNING
!
FURNACE CATEGORY
INFORMATION
This furnace is shipped as a Category I
type induced draft furnace. A Category
Ifurnace operates with a nonpositive
vent pressure and has a vent gas
temperature at least 140°F above the
dew point of the vent gases. A
Category Itype may be a draft hood
equipped furnace or have a fan
assisted combustion system (induced
draft). The inducer is used to pull flue
products through the combustion
chamber and as they leave the
furnace, most of the energy has been
dissipated. The buoyant effect of the
flue gases provides venting to the
outdoors.
During the off cycle, the inducer is off
and there is very little flow through the
vent, cooling the vent. During the on
cycle there is no dilution airflow, as
with a draft hood type furnace.
Although the vent heats up rapidly
without dilution air, the flue products
contain more water vapor, which
results in a higher dew point
temperature. It is most important that
you follow the guidelines in these
instructions to prevent the possible
formation of condensation in the
venting system.
As a Category Ifurnace it may be
vented vertically with type B-1 vent
pipe and also may be common vented,
as described in these instructions.
FIGURE 9
ATTACHING TO DRAFT INDUCER COLLAR
VENTING
STA-0765-01

13
The entire length of the vent
connector shall be readily
accessible for inspection, cleaning
and replacement.
“B-1” VERTICAL VENTING
Install type “B-1” vents in accordance
with the terms of their listings and the
vent manufacturer’s instructions.
Support and space “B-1” vents in
accordance with their listings and the
manufacturer’s instructions. All vents
must be supported to maintain their
minimum clearances from combustible
material.
VERTICAL VENTING
Categorized
Furnace Vent
Input Size Required
50K 3(
75K *4(
100K *4(
125K *4(
150K *5(
*NOTE: All furnaces have a 3(vent
connection as shipped from the factory. A 3(
to 4(or 3(to 5(vent transition is required on
all but the 50,000 BTUH models when
vertically vented or common vented with
metal vent pipes. THE VENT TRANSITION
CONNECTION MUST BE MADE AT THE
FURNACE VENT EXIT. It must originate
with an adapter if required, at the furnace
flue collar and terminate either in a listed
cap or roof assembly. When common
venting, the vent connector size may differ
from the above diameters depending on
application. See ANSI Z21.47-
1993/CAN/CGA-2.3-M93 or latest edition
tables.
VERTICAL VENT SYSTEMS:
1. Terminate a gas vent above the roof
surface with a listed cap or listed
roof assembly. Gas vents 12 inches
in size or smaller with listed caps
shall be permitted to be terminated
in accordance with Figure 10,
provided they are at least 8 feet from
a vertical wall or similar obstruction.
Terminate all other gas vents not
less than 2 feet above the highest
point where they pass through the
roof and at least 2 feet higher than
any portion of a building within 10
feet.
2. Terminate a type B gas vent at least
5 feet in vertical height above the
highest connected equipment draft
hood or flue collar.
DO NOT CONNECT THIS FURNACE
TO A CHIMNEY USED TO VENT A
SOLID FUEL APPLIANCE (WOOD
OR COAL). VENTING WITH A SOLID
FUEL APPLIANCE CAN LEAD TO
IMPROPER FUNCTIONING OF THE
UNIT, AND DUE TO SOOTING, THE
POSSIBILITY OF FIRE RESULTING
IN PROPERTY DAMAGE,
PERSONAL INJURY OR DEATH.
3. Must rise 1⁄4(per foot away from the
furnace on horizontal runs and be
supported with straps or hangers so
it has no sags or dips. Supports at 4
foot intervals and at all elbows are
recommended.
4. Mechanically fasten the vent
connector to the outlet collar of the
furnace with at least (2) sheet metal
screws except vent connectors that
are B-1 material. Assemble these
assembled in accordance with the
manufacturer’s instructions. See
Figure 9.
NOTE: Refer to the National Fuel Gas
Code, ANSI Z223.1 and/or the Natural
Gas Installation Code, CAN/CGA-
B149.1 & .2.
Single appliance venting of a fan
assisted furnace into a tile-lined
masonry chimney is prohibited. Line
the chimney with either Type B vent or
with a listed, single wall, metal lining
system. Reference National Fuel Gas
Code, ANSI Z223.1 and/or the Natural
Gas Installation Code, CAN/CGA-
B149.1 & .2. See Figure 11 for typical
B-1 vent chase.
FIGURE 10
TYPICAL VENTING WITH “B-1” VENT
WARNING
!

3. Insofar as is practical, close all
building doors, windows and all
doors between the space where the
appliances remaining connected to
the common venting system are
located. Turn on clothes dryers and
any appliance not connected to the
common venting system. Turn on
any exhaust fans, such as range
hoods and bathroom exhausts, so
they will operate at maximum speed.
Do not operate a summer exhaust
fan. Close fireplace dampers.
4. Follow the lighting instructions.
Place the appliance being inspected
into operation. Adjust the thermostat
so the appliance will operate
continuously.
5. Test for spillage at the draft hood
relief opening after 5 minutes of
main burner operation. Use the
flame of a match or candle, or
smoke from a cigarette, cigar, or
pipe.
EXISTING VENT SYSTEMS
IMPORTANT RETROFIT
VENTING INSTRUCTIONS
If this furnace is a replacement
installation, ALWAYS INSPECT the
existing vent system to be sure there
are no obstructions, blockages, or
signs of corrosion.
When the existing furnace is removed
from a venting system serving other
appliances, the venting is likely to be
too large to properly vent the
remaining attached appliances.
The following steps shall be followed
with each appliance that remains
connected to the common venting
system, while the other appliances that
remain connected to the common
venting systems are not in operation.
NOTE: WHEN THE VENT TABLE
PERMITS MORE THAN ONE
DIAMETER OF PIPE FOR A
CONNECTOR OR VENT, THE
SMALLEST PERMITTED DIAMETER
MUST BE USED.
1. Seal any unused openings in the
common venting system.
2. Visually inspect the venting system
for proper size and horizontal pitch
and determine that there is no
blockage, restriction, leakage,
corrosion or other deficiencies which
could cause an unsafe condition.
14
FIGURE 11
DEDICATED VENTING THROUGH
CHIMNEY WITH “B-1” VENT
6. After it has been determined that
each appliance that remains
connected to the common venting
system properly vents (when tested
as outlined above) return doors,
windows, exhaust fans, fireplace
dampers and any other gas-burning
appliance to their previous
conditions of use.
7. If improper venting is observed
during any of the above tests, resize
the common venting system. Refer
to National Fuel Gas Code, ANSI
Z223.1 and/or the Natural Gas
Installation Code, CAN/CGA-B149.1
& .2.

FIGURE 12
GAS PIPING INSTALLATION
UPFLOW & DOWNFLOW
15
GAS SUPPLY AND PIPING
GAS SUPPLY
THIS FURNACE IS EQUIPPED AT
THE FACTORY FOR USE ON
NATURAL GAS ONLY. CONVER-
SION TO LP GAS REQUIRES A
SPECIAL KIT SUPPLIED BY THE
DISTRIBUTOR OR MANU-
FACTURER. MAILING ADDRESSES
ARE LISTED ON THE FURNACE
RATING PLATE, PARTS LIST AND
WARRANTY. FAILURE TO USE
THE PROPER CONVERSION KIT
CAN CAUSE FIRE, CARBON
MONOXIDE POISONING,
EXPLOSION, PROPERTY
DAMAGE, PERSONAL INJURY OR
DEATH.
See the conversion kit index
supplied with the furnace. This
index identifies the proper LP Gas
Conversion Kit required for each
particular furnace.
IMPORTANT: Any additions,
changes or conversions required for
the furnace to satisfactorily meet the
application should be made by a
qualified installer, service agency or
the gas supplier, using factory-
specified or approved parts.
IMPORTANT: Connect this furnace
only to gas supplied by a commercial
utility.
IMPORTANT: A U.L. recognized
fuel gas and CO detector(s) are
recommended in all applications,
and their installation should be in
accordance with the detector
manufacturer’s recommendations
and/or local laws, rules, regulations or
customs.
GAS PIPING
Install the gas piping according to all
local codes and regulations of the
utility company.
If possible, run a separate gas supply
line directly from the meter to the
furnace. Consult the local gas
company for the location of the
manual main shut-off valve. The gas
line and manual gas valve must be
adequate in size to prevent undue
pressure drop and never smaller
than the pipe size to the com-
bination gas valve on the furnace.
Refer to Table 2 for the recom-
mended pipe size for natural gas and
Table 3 for LP gas pipe sizes.
!WARNING
HORIZONTAL
IMPORTANT: It is permissible to run
flexible gas connector inside the unit to
a piece of black pipe.
Install a ground joint union outside
the cabinet to easily remove the
control valve assembly. Install a
manual shut-off valve in the gas line
outside the furnace casing. The valve
should be readily accessible to turn the
gas supply on or off. Install a drip leg in
the gas supply line as close to the
furnace as possible. Always use a pipe
compound resistant to the action of
liquefied petroleum gases on all
threaded connections.
IMPORTANT: When making gas pipe
connections, use a back-up wrench to
prevent any twisting of the control
assembly and gas valve.
Any strains on the gas valve can
change the position of the gas orifices
in the burners. This can cause erratic
furnace operation.
IMPORTANT: ENSURE that the
furnace gas control valve not be
subjected to high gas line supply
pressures.
DISCONNECT the furnace and its
individual shut-off valve from the gas
supply piping during any pressure
testing that exceeds 1/2 p.s.i.g. (3.48
kPa).
MANUAL GAS
VALVE UNION
4 TO 5 FEET
ABOVE FLOOR
REQ’D BY SOME
UTILITIES
DRIP LEG
DIRECT SPARK IGNITOR
GAS VALVE
MANIFOLD
FLAME
SENSOR
BURNERS
MANUAL GAS VALVE
4 TO 5 FEET
ABOVE FLOOR
REQ’D BY SOME
UTILITIES.
DRIP LEG UNION
DUCT
DIRECT SPARK IGNITOR
BURNERS
FLAME SENSOR
MANIFOLD GAS VALVE
STA-0764-01
ST-A0763-01

16
TABLE 2
NATURAL GAS PIPE CAPACITY TABLE (CU. FT./HR.)
Capacity of gas pipe of different diameters and lengths in cu. ft. per hr. with pressure drop of 0.3 in. and specific
gravity of 0.60 (natural gas).
Nominal Length of Pipe, Feet
Iron Pipe
Size, Inches 10 20 30 40 50 60 70 80
1/2 132 92 73 63 56 50 46 43
3/4 278 190 152 130 115 105 96 90
1520 350 285 245 215 195 180 170
1-1/4 1,050 730 590 500 440 400 370 350
1-1/2 1,600 1,100 890 760 670 610 560 530
After the length of pipe has been determined, select the pipe size which will provide the minimum cubic feet per hour
required for the gas input rating of the furnace. By formula: Gas Input of Furnace (BTU/HR)
Cu. Ft. Per Hr. Required = Heating Value of Gas (BTU/FT3)
The gas input of the furnace is marked on the furnace rating plate. The heating value of the gas (BTU/FT3) may be
determined by consulting the local natural gas utility or the LP gas supplier.
TABLE 3
LP GAS PIPE CAPACITY TABLE (CU. FT./HR.)
Maximum capacity of pipe in thousands of BTU per hour of undiluted liquefied petroleum gases (at 11 inches
water column inlet pressure).
(Based on a Pressure Drop of 0.5 Inch Water Column)
Nominal Length of Pipe, Feet
Iron Pipe
Size, Inches 10 20 30 40 50 60 70 80 90 100 125 150
1/2 275 189 152 129 114 103 96 89 83 78 69 63
3/4 567 393 315 267 237 217 196 182 173 162 146 132
1 1,071 732 590 504 448 409 378 346 322 307 275 252
1-1/4 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511
1-1/2 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787
2 6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496
Example (LP): Input BTU requirement of unit, 150,000
Equivalent length of pipe, 60 ft. = 3/4" IPS required.
SETTING GAS PRESSURE
The maximum gas supply pressure
to the furnace should be 10.5(w.c.
natural gas, or 13(w.c. LP gas. The
minimum supply gas pressure to the
gas valve should be 5" w.c. natural gas
or 11" w.c. LP gas. A properly
calibrated U-Tube manometer is
required for accurate gas pressure
measurements.
Supply Gas Pressure Measurement.
A line pressure tap is on the input side
of the gas valve.
1. With gas shut off to the furnace at
the manual gas valve outside the
unit, remove the input pressure tap
plug.
2. Connect a U-Tube manometer to
the pressure tap.
3. Turn on the gas supply and
operate the furnace and all other
gas-fired units on the same gas
line as the furnace.
4. Note or adjust the line gas
pressure to give:
A. 5(- 10.5(w.c. for natural gas.
B. 11(- 13(w.c. for LP gas.
5. Shut off the gas at the manual gas
valve and remove the
U-Tube manometer.
6. Replace the pressure tap plug
before turning on the gas.
If the supply gas line pressure is above
these ranges, install an in-line gas
regulator to the furnace for natural gas
units. With LP gas, have the LP
supplier reduce the line pressure at the
regulator.
If supply gas line pressure is below
these ranges, either remove any
restrictions in the gas supply piping or
enlarge the gas pipe. See Tables 2 and
3. With LP gas, have the LP supplier
adjust the line pressure at the regulator.
NEVER PURGE A GAS LINE INTO
THE COMBUSTION CHAMBER.
NEVER USE MATCHES, FLAME OR
ANY IGNITION SOURCE FOR
CHECKING LEAKAGE. FAILURE TO
FOLLOW THIS WARNING CAN
CAUSE AN EXPLOSION OR FIRE
RESULTING IN PROPERTY
DAMAGE, PERSONAL INJURY OR
DEATH.
To check for gas leakage, use an
approved chloride-free soap and water
solution, an electronic combustible gas
detector (see Figure 13), or other
approved method.
!WARNING
FIGURE 13
ELECTRONIC COMBUSTIBLE
GAS DETECTOR

LP CONVERSION
The gas valve is not field convertible for
use with LP gas. LP conversion kit no.
RXGJ-FP09 is required. The kit
includes a LP gas valve, burner orifices
and the Installation Instructions. Follow
the kit instructions for installing and
adjusting the orifices and valve.
NOTE: Order the correct LP conversion
kit from the furnace manufacturer.
Furnace conversion to LP gas must
be performed by a qualified
technician.
To change orifice spuds for either
conversion to LP or for elevation:
1. Shut off the manual main gas
valve and remove the gas supply
piping from the gas valve.
2. Remove the four (4) screws
securing the manifold assembly
and remove the assembly.
3. Replace the orifice spuds.
4. Reassemble in reverse order.
Consult the tables at right if there is any
question concerning orifice sizing.
5. Turn the gas supply back on and
check for proper operation and
manifold pressure.
6. Attach the notice label alerting the
next service technician that the
furnace has been converted to LP
gas.
17
RATING PLATE ELEVATION
INPUT
BTU/HR 0 TO 7,999 FT. 8,000 FT. AND ABOVE
NATURAL GAS HEATING VALUE @ 1,000 BTU/FT3, SPECIFIC GRAVITY 0.62
MANIFOLD PRESSURE @ 3.5(W.C.
50,000 42 43
75,000 42 43
100,000 42 43
125,000 42 43
150,000 42 43
L.P. GAS HEATING VALUE @ 2,475 BTU/FT3, SPECIFIC GRAVITY 1.52/
MANIFOLD PRESSURE @ 10(W.C.
50,000 54 55
75,000 54 55
100,000 54 55
125,000 54 55
150,000 54 55
ORIFICE SIZING CHART
RATING PLATE ELEVATION
INPUT
BTU/HR 0 TO 1,999 FT. 2,000 FT. TO 4,500 FT.
NATURAL GAS HEATING VALUE @ 1,000 BTU/FT3, SPECIFIC GRAVITY 0.62
MANIFOLD PRESSURE @ 3.5(W.C.
50,000 42 42
75,000 42 42
100,000 42 42
125,000 42 42
150,000 42 42
L.P. GAS HEATING VALUE @ 2,475 BTU/FT3, SPECIFIC GRAVITY 1.52/
MANIFOLD PRESSURE @ 10(W.C.
50,000 54 54
75,000 54 54
100,000 54 54
125,000 54 54
150,000 54 54
ORIFICE SIZING CHART (CANADA)

TURN OFF ELECTRIC POWER AT
THE FUSE BOX OR SERVICE PANEL
BEFORE MAKING ANY
ELECTRICAL CONNECTIONS.
ALSO, THE GROUND CONNECTION
MUST BE COMPLETED BEFORE
MAKING LINE VOLTAGE
CONNECTIONS. FAILURE TO DO
SO CAN RESULT IN ELECTRICAL
SHOCK, SEVERE PERSONAL
INJURY OR DEATH.
IMPORTANT: THE FURNACE MUST
BE INSTALLED SO THAT THE
ELECTRICAL COMPONENTS ARE
PROTECTED FROM WATER
(FURNACE CONDENSATE).
ELECTRICAL CONNECTIONS
THE CABINET MUST BE
PERMANENTLY GROUNDED. A
GROUND SCREW IS PROVIDED IN
THE JUNCTION BOX FOR THIS
PURPOSE. FAILURE TO DO SO CAN
RESULT IN FIRE, ELECTRICAL
SHOCK, PERSONAL INJURY OR
DEATH.
The electrical supply requirements are
listed on the furnace rating plate.
Use a separate fused branch electrical
circuit containing a properly sized fuse
or circuit breaker. Run this circuit
directly from the main switch box to an
electrical disconnect which must be
readily accessible and located within
sight of the furnace. Connect from the
disconnect to the junction box on the
left side of the furnace, inside the
control compartment. See appropriate
wiring diagram.
NOTE: The electrical junction box
inside the furnace control compartment
may be relocated to the right side if
necessary. A knockout is provided.
IMPORTANT: L1 (hot) and L2 (neutral)
polarity must be observed when
making field connections to the
furnace. The ignition control on electric
ignition models will not sense flame if
L1 and L2 are reversed.
Installation of the electric supply line
should be in accordance with the
National Electric Code ANSI/NFPA No.
70, latest edition, or Canadian
Electrical Code Part 1 - CSA Standard
C22.1 and local building codes.
This can be obtained from:
National Fire Protection Association
Batterymarch Park
Quincy, MA 02269
Canadian Standards Association
178 Roxdale Boulevard
Roxdale, Ontario, Canada M92 1R3
WARNING
!
WARNING
!
ELECTRICAL WIRING
ELECTRONIC NIGHT SETBACK
THERMOSTATS ARE COMPATIBLE
WITH THE FURNACE CONTROL
SYSTEM. SOME MAY REQUIRE AN
ISOLATION RELAY.
If an isolation relay is needed, install it
as close to the control board as
possible. Use a single-pole, single-
throw relay with a 24-volt operating
coil. The relay contacts should be
designed for 24-volt loads.
Connect one end of the operating coil
to the thermostat “W” terminal.
Connect the other end of the coil to the
“C” terminal on the control board. See
Figure 14.
Connect one side of the normally open
contacts to the control board “W”
terminal.
When the thermostat calls for heat, it
powers the 24-volt operating coil. This
closes the relay contacts and conducts
power from terminal 3 and 4 to terminal
“W” on the control board and starts the
furnace ignition sequence.
A single or two stage thermostat may
be used, however a two-stage
thermostat is recommended for
optimum performance.
The room thermostat must be
compatible with the integrated furnace
control on the furnace. All thermostats
available from the furnace
manufacturer’s Parts Department are
acceptable. Generally, all thermostats
that are not of the “current robbing”
type are compatible with the integrated
furnace control we use.
HEAT ANTICIPATOR SETTINGS
If a current reading taken at the
thermostat is not performed, an initial
setting of .15 amps is recommended.
Adjust as needed to improve comfort
level.
ISOLATION RELAY
IMPORTANT: USE OF AN
ISOLATION RELAY WITH THE TWO
STAGE FURNACE SHOULD NOT BE
REQUIRED, BUT NOT ALL
THERMOSTAT
FIELD WIRE SIZE FOR 24 VOLT THERMOSTAT CIRCUITS
SOLID COPPER WIRE - AWG.
3.0
2.5
2.0
16
16
18
14
14
16
12
12
14
10
12
12
10
12
12
10
10
10
50 100 150 200 250 300
Length of Run – Feet (1)
Thermostat Load - Amps
①The total wire length is the distance from the furnace to the
thermostat and back to the furnace.
NOTE: Do not use 24 volt control wiring smaller than No. 18.
18
FIGURE 14
ISOLATION RELAY
ST-A0804-01

19
FIELD INSTALLED OPTION
ACCESSORIES
ELECTRONIC AIR CLEANER
1. Electronic air cleaner line voltage
power can be supplied from the
screw terminal “EAC” and a line
voltage neutral screw terminal on
the control board. See Figure 15.
This will power the electronic air
cleaner whenever the circulating air
blower is in operation.
HUMIDIFIER
2. Humidifier line voltage power can be
supplied from screw terminal “HUM”
to a line voltage neutral screw
terminal on the control board. See
Figure 15. This will power the
humidifier whenever the burner is on
and the circulating air blower is
operating in the heating mode.
NOTE: Maximum current –1.0 amps
for each option.
FURNACE TWINNING
INSTALLATIONS
Twinning operation of two furnaces,
installed side-by-side, connected by a
common duct system with main power
supplied by the same source, and
controlled by a common thermostat can
be done with the UTEC 1095-101
integrated control boards.
The Status LED will flash 5 times if the
twinning is not set up properly.
Single Stage Thermostat
(See Figure 16)
a. Control board “ONE” is on furnace
connected to the thermostat.
b. The 24 VAC supply to both control
boards must be in phase with each
other.
c. Connect the “W2”, “C” and “TWIN”
terminals to counterparts on each
control.
d. Both control boards must have
switch #3 in “ON” position.
e. Adjust the heat anticipator current to
0.15 amps.
Two Stage Thermostat
(See Figure 17)
a. The 24 VAC supply to both control
boards must be in phase with each
other.
b. Control board “ONE” is on the
furnace connected to the thermostat.
c. Connect the “W”, “W2”, “C” and
“TWIN” terminals from one control to
the “W”, “W2”, “C” and “TWIN”
terminals of the second control
respectively.
d. Both control boards must have
“Twin” switch #3 in “ON” position.
e. Adjust the heat anticipator current to
0.15 amps.
NOTE: Leave Switch #4 in the “OFF”
position. It does not affect the
twinning operation.
HIGH ALTITUDE KIT
Models with inputs over 50,000 btu/hr
installed at altitudes of 5,000 feet and
above require a low fire pressure switch
change. These may be ordered under
Option Code No. 278. Models with this
option code will have the additional
pressure switch, Kit no. RXGY-13,
packed with the furnace. This kit
includes pressure switch no. 42-23648-
07, which has a set point of -0.10(W.C.
and burner orifices which should be
changed for altitudes of 8,000 feet and
above for U.S. models. The low fire
pressure switch is installed in the lower
position on the furnace. Orifice size
information is shown on the table
below:
U.S. 0-7,999 Ft. 8,000 Ft. & Above
Natural gas #42 #43
LP gas #54 #55
CANADA 0-1,999 Ft. 2,000 Ft. to 4,500 Ft.
Natural gas #42 #42
LP gas #54 #54
NOTICE: DO NOT make any attempt
to rerate the furnace by changing
orifices or the gas pressure. Allow the
natural derate of the gas to occur. The
natural derate will range from
approximately 1.8% to 2.8% per 1,000
feet.
FIGURE 15
LINE VOLTAGE CONNECTIONS
UTEC 1095-101 CONTROL BOARD
ST-A0761-01
Install the room thermostat in
accordance with the instruction sheet
in the box with the thermostat. Run the
thermostat lead wires inside the control
compartment. Connect the thermostat
as shown on the wiring diagram. Never
install the thermostat on an outside
wall or where it will be influenced by
drafts, concealed hot or cold water
pipes, lighting fixtures, radiation from
fireplace, rays of sun, lamps,
television, radios or air streams from
registers. Refer to the instructions
packed with the thermostat for best
anticipator adjustment or selection or
see below.

20
FIGURE 16
UTEC NO. 1095-100 CONTROL BOARD
TWINNING CONNECTION SINGLE STAGE OPERATION
I685