York GM9S-DH, GF9S-DH, GY9S-DH User Manual

INSTALLATION MANUAL

HIGH EFFICIENCY
TUBULAR HEAT EXCHANGER SERIES

MODELS: GY9S*DH / GM9S*DH / GF9S*DH
(Single Stage Downflow/Horizontal)

40 - 120 MBH INPUT
(11.72 - 35.17 KW) INPUT

LIST OF SECTIONS

SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

DUCTWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

FILTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

GAS PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

ELECTRICAL POWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Transition Kit Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Return Filter Grill and Return Duct Installation . . . . . . . . . . . . . . . . . . . 8

Typical Attic Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Typical Suspended Furnace / Crawl Space Installation . . . . . . . . . . . . 9

Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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

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

Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Thermostat Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Accessory Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Typical Twinned Furnace Application . . . . . . . . . . . . . . . . . . . . . . . .13

Single Stage Twinning Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . 14

Two-Stage Twinning Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 14

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Home Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Downflow/Horizontal Vent Assembly . . . . . . . . . . . . . . . . . . . . . . . . .18

Termination Configuration - 1 Pipe . . . . . . . . . . . . . . . . . . . . . . . . . .18

Termination Configuration - 2 Pipe . . . . . . . . . . . . . . . . . . . . . . . . . .18

Termination Configuration - 2 Pipe Horizontal . . . . . . . . . . . . . . . . . . 18

Crawl Space Termination Configuration - 2Pipe . . . . . . . . . . . . . . . .19

Double Horizontal Sealed Combustion Air and Vent Termination . . . 19

Double Vertical Sealed Combustion Air and Vent Termination . . . . . 19

Unit Clearances to Combustibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Minimum Duct Sizing For Proper Airflow . . . . . . . . . . . . . . . . . . . . . . .5

Round Duct Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Cabinet and Duct Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Recommended Filter Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Nominal Manifold Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Electrical and Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Maximum Equivalent Pipe Length . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Equivalent Length of Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Elbow Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

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.
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 m inor or moderate injury.
alert against unsafe practices and hazards involving only property dam­age.

.

.

LIST OF FIGURES

LIST OF TABLES

It is also used to

EFFICIENCY
RATING
CERTIFIED

ISO 9001

Certified Quality

Management System

TWINNING AND STAGING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

COMBUSTION AIR AND VENT SYSTEM . . . . . . . . . . . . . . . . . . . . .14

CONDENSATE PIPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

SAFETY CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

START-UP AND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .31

WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Sealed Combustion Air Intake Connection and Vent Connection . . .19
Combustion Airflow Path Through The Furnace Casing to the Burner

Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Outside and Ambient Combustion Air . . . . . . . . . . . . . . . . . . . . . . . . .21

Attic Combustion Air Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Condensate Drain Internal Hose Routing . . . . . . . . . . . . . . . . . . . . . .22

Downflow Condensate Drain Hose Configuration . . . . . . . . . . . . . . .23

Horizontal Left Condensate Drain Hose Configuration . . . . . . . . . . . .24

Horizontal Left Condensate Drain Hose Configuration . . . . . . . . . . . .25

Horizontal Right Condensate Drain Hose Configuration

(Option 1 - Front of Casing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Horizontal Right Condensate Drain Hose Configuration

(Option 1 - Front of Casing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Horizontal Right Condensate Drain Hose Configuration

(Option 2 - Back of Casing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Horizontal Right Condensate Drain Hose Configuration

(Option 2 - Back of Casing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Pressure Switch Tubing Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Gas Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Reading Gas Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Furnace Control Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Combustion Air Intake and Vent Connection Size at Furnace

(All Models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Estimated Free Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Free Area - Outdoor Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Unconfined Space Minimum Area in Square Inches . . . . . . . . . . . . .20

Condensate Drain Hose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Inlet Gas Pressure Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Nominal Manifold Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Blower Performance CFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Filter Performance - Pressure Drop Inches W.C. and (kPa) . . . . . . . .37

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 mainte­nance can cause injury or property damage. Refer to this manual
for assistance or for additional information, consult a qualified con­tractor, installer or service agency.

This product must be installed in strict compliance with the installa­tion instructions and any applicable local, state, and national codes
including, but not limited to building, electrical, and mechanical
codes.

268890-UIM-B-0607

268890-UIM-B-0607

SPECIFIC SAFETY RULES AND PRECAUTIONS

1. Only Natural gas or Propane (LP) gas are approved for use with
this furnace. Refer to the furnace rating plate or Section IV of
these instructions.

2. Install this furnace only in a location and position as specified in
SECTION I of these instructions.

3. A gas-fired furnace for installation in a residential garage must be
installed as specified in SECTION I of these instructions.

4. Provide adequate combustion and ventilation air to the furnace
space as specified in SECTION VI of these instructions.

5. Combustion products must be discharged outdoors. Connect this
furnace to an approved vent system only, as specified in SEC­TION VII of these instructions.

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 detection of leaks to
check all connections. A fire or explosion may result causing prop­erty damage, personal injury or loss of life.

6. Tests for gas leaks as specified in SECTION X of these instruc­tions.

7. Always install the furnace to operate within the furnace’s intended
temperature rise range. Only connect the furnace to a duct system
which has an external static pressure within the allowable range,
as specified on the furnace rating plate.

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

9. It is permitted to use the furnace for heating of buildings or struc­tures under construction. Installation must comply with all manu­facturer’s installation instructions including:

• Proper vent installation;

• Furnace operating under thermostatic control;

• Return air duct sealed to the furnace;

• Air filters in place;

• Set furnace input rate and temperature rise per rating plate

marking;

• Means for providing outdoor air required for combustion;

• Return air temperature maintained between 55ºF (13ºC) and

80ºF (27ºC);

• The air filter must be replaced upon substantial completion of

the construction process;

• Clean furnace, duct work and components upon substantial

completion of the construction process, and verify furnace­operating conditions including ignition, input rate, temperature
rise and venting, according to the manufacturer’s instructions.

10. When installed in a Non-HUD-Approved Modular Home or building
constructed on-site, combustion air shall not be supplied from
occupied spaces.

11. The size of the unit should be based on an acceptable heat loss
calculation for the structure. ACCA, Manual J or other approved
methods may be used.

SAFETY REQUIREMENTS

• This furnace should be installed in accordance with all national
and local building/safety codes and requirements, local plumbing
or wastewater codes, and other applicable codes. In the absence
of local codes, install in accordance with the National Fuel Gas
Code ANSI Z223.1/NFPA 54, National Fuel Gas Code, and/or
CAN/CGA B149.1 Natural Gas and Propane Installation Code
(latest editions). Furnaces have been certified to the latest edition
of standard ANSI Z21-47 • CSA 2.3.

• Refer to the unit rating plate for the furnace model number, and
then see the dimensions page of this instruction for return air ple­num dimensions in Figure 3. The plenum must be installed
according to the instructions.

• Provide clearances from combustible materials as listed under
Clearances to Combustibles in Table 1.

• Provide clearances for servicing ensuring that service access is
allowed for both the burners and blower.

• These models ARE NOT
into a HUD Approved Modular Home
(Mobile) Home.

• This furnace is not approved for installation in trailers or recre­ational vehicles.

• Failure to carefully read and follow all instructions in this
manual can result in furnace malfunction, death, personal
injury and/or property damage.

• Furnaces for installation on combustible flooring shall not be
installed directly on carpeting, tile or other combustible material
other than wood flooring.

• Check the rating plate and power supply to be sure that the elec­trical characteristics match. All models use nominal 115 VAC, 1
Phase, 60-Hertz power supply. DO NOT CONNECT THIS APPLI­ANCE TO A 50 HZ POWER SUPPLY OR A VOLTAGE ABOVE
130 VOLTS.

• Furnace shall be installed so the electrical components are pro­tected from water.

• Installing and servicing heating equipment can be hazardous due
to the electrical components and the gas fired components. Only
trained and qualified personnel should install, repair, or service
gas heating equipment. Untrained service personnel can perform
basic maintenance functions such as cleaning and replacing the
air filters. When working on heating equipment, observe precau­tions in the manuals and on the labels attached to the unit and
other safety precautions that may apply.

• These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances
these instructions exceed certain local codes and ordinances,
especially those 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.

CSA listed or approved for installation

or a Manufactured

COMBUSTION AIR QUALITY
(LIST OF CONTAMINANTS)

The furnace will require OUTDOOR AIR for combustion when the fur­nace is located in any of the following environments.

• Restricted Environments

• Commercial buildings

• Buildings with indoor pools

• Furnaces installed in laundry rooms

• Furnaces installed in hobby or craft rooms

• Furnaces installed near chemical storage areas

• Chemical exposure

The furnace will require OUTDOOR AIR for combustion when the fur­nace is located in an area where the furnace is being exposed to the fol­lowing substances and / or chemicals.

• Permanent wave solutions

• Chlorinated waxes and cleaners

• Chlorine based swimming pool chemicals

• Water softening chemicals

• 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

When outdoor air is used for combustion, the combustion air intake pipe
termination must be located external to the building and in an area
where there will be no exposure to the substances listed above.

2 Unitary Products Group

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 fur­nace.

1. Spray or aerosol cans, rags, brooms, dust mops, vacuum
cleaners or other cleaning tools.

2. Soap powders, bleaches, waxes or other cleaning com­pounds; plastic items or containers; gasoline, kerosene, ciga­rette lighter fluid, dry cleaning fluids or other volatile fluid.

3. Paint thinners and other painting compounds.

4. Paper bags, boxes or other paper products

Never operate the furnace with the blower door removed. To
do so could result in serious personal injury and/or equipment
damage.

FOR FURNACES INSTALLED IN THE COMMON­WEALTH OF MASSACHUSETTS ONLY

For all side wall horizontally vented gas fueled equipment installed in
every dwelling, building or structure used in whole or in part for resi­dential purposes, including those owned or operated by the Com­monwealth 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 require­ments shall be satisfied:

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 th e
services of qualified licensed professionals for the installation of
hard wired carbon monoxide detectors

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.

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 mon­oxide detector with an alarm shall be installed.

2. APPROVED CARBON MONOXIDE DETECTORS. Each car­bon monoxide detector as required in accordance with the
above provisions shall comply with NFPA 720 and be ANSI/UL
2034 listed and IAS certified.

3. SIGNAGE. A metal or plastic identification plate shall be perma­nently 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 OBSTRUC­TIONS".

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 car­bon monoxide detectors and signage installed in accordance
with the provisions of 248 CMR 5.08(2)(a)1 through 4.

268890-UIM-B-0607

INSPECTION

As soon as a unit is received, it should be inspected for possib le dam­age 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.

FURNACE LOCATION AND CLEARANCES

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.

5. Where the outdoor combustion air/vent terminal will not be blocked
or restricted. Refer to “COMBUSTION AIR / VENT CLEAR­ANCES” located in SECTION VII of these instructions. These min­imum clearances must be maintained in the installation.

6. Where the unit will be installed in a level position with no more
than 1/4” (0.6 cm) slope side-to-side and front-to-back to provide
proper condensate drainage.

Installation in freezing temperatures:

1. Furnace shall be installed in an area where ventilation facilities
provide for safe limits of ambient temperature under normal oper­ating conditions. Ambient temperatures must not fall below 32°F
(0°C) unless the condensate system is protected from freezing.

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.

Improper installation in an ambient below 32ºF (0.0° C) could create
a hazard, resulting in damage, injury or death.

3. If this furnace is installed in any area where the ambient tempera­ture may drop below 32° F (0° C), a UL listed self-regulated heat
tape must be installed on any condensate drain lines. It is required
that self regulating heat tape rated at 3 watts per foot be used.
This must be installed around the condensate drain lines in the
unconditioned space. Always install the heat tape per the manu­facturer's instructions. Cover the self-regulating heat tape with
fiberglass, Armaflex or other heat resistant insulating material.

4. If this unit is installed in an unconditioned space and an extended
power failure occurs, there will be potential damage to the conden­sate trap, drain lines and internal unit components. Following a
power failure situation, do not operate the unit until inspection and
repairs are performed.

Clearances for access:

Ample clearances should be provided to permit easy access to the unit.
The following minimum clearances are recommended:

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.

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 clear­ances for combustible materials where accessibility clearances are
greater.

Unitary Products Group 3

268890-UIM-B-0607

Downflow/Horizontal furnaces for installation on combustible floor­ing only when installed on the accessory combustible floor base on
wood flooring only and shall not be installed directly on carpeting,
tile or other combustible material.

Check the rating plate and power supply to be sure that the electri­cal characteristics match. All models use nominal 115 VAC, 1
Phase 60Hz power supply.

Furnace shall be installed so the electrical components are pro­tected from water.

Installation in a residential garage:

1. 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:

Application Downflow Horizontal

Top In. (cm) 1 (2.5) 0 (0)
Front In. (cm) 3 (7.6) 3 (7.6)
Rear In. (cm) 0 (0) 0 (0)
Left Side In. (cm) 0 (0) 1 (2.5)
Right Side In. (cm) 0 (0) 1 (2.5)
Flue In. (cm) 0 (0) 0 (0)

Floor / Bottom In. (cm)
Closet Yes Yes

Alcove Yes Yes
Attic Yes Yes

Line Contact NA

1. Combustible floor base or air conditioning coil required for use on combusti-

2. Line contact only permitted between lines formed by the intersection of the

Unit Clearances to Combustibles

1

1 (2.5)

ble floor.
rear panel (top in horizontal position) of the furnace jacket and building

joists, studs or framing.

0 (0)

Yes

2

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.

2. Be installed in accordance with standards of NFPA (National Fire
Protection Association) as outlined in NFPA pamphlets 90A and
90B (latest editions) or applicable national, provincial, or state, and
local fire and safety codes.

3. Create a closed duct system. For residential and Non-HUD Modu­lar Home installations, when a furnace is installed so that the sup­ply ducts carry air circulated by the furnace to areas outside the
space containing the furnace, the return air shall also be handled
by a duct(s) sealed to the furnace casing and terminating outside
the space containing the furnace.

4. Complete a path for heated or cooled air to circulate through the
air conditioning and heating equipment and to and from the condi­tioned space.

The cooling coil must be installed in the supply air duct, down­stream of the furnace. Cooled air may not be passed over the heat
exchanger.

When the furnace is used in conjunction with a cooling coil, the coil
must be installed parallel with, or in the supply air side of the furnace to
avoid condensation in the primary heat exchanger. When a parallel flow
arrangement is used, dampers or other means used to contro l airflow
must be adequate to prevent chilled air from entering the furnace. If
manually operated, 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.

The duct system must be properly sized to obtain the correct airflow
for the furnace size that is being installed.

Refer to Table 7 and the furnace rating plate for the correct rise
range and static pressures

If the ducts are undersized, the result will be high duct static pres­sures 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.

FLOOR BASE AND DUCTWORK INSTALLATION

Downflow Combustible Floor Base

Installations on combustible materials require the use a com­bustible floor base shown in Figure 1.

The floor base must be secured to the floor. A supply air duct
plenum with 1" (2.54 cm) flange is installed through the
opening provided. The supply air duct is then secured to the

duct system with screws and sealed to prevent leaks. Do not
shoot screws through the flanges of the supply air duct into the top of
the combustible floor base. Install the furnace on the combustible floor
base so that the corners of the furnace are parallel with the corner
brackets of the floor base. 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 connec­tor. Refer to the installation instructions for additional information.

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.

Ductwork Installation

NOTE: When attaching duct flange, do not shoot the screw down into

the casing. Use the formed flange intended for duct flange attachment.
A proper Heat Loss/Gain Calculation should be done on all installations

for proper application of equipment. From this the ductwork sizing can
be calculated, ACCA Manual J and D and industry standards are help­ful.

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 plenum should be if sufficient size so that the fur­nace operates at the specified external static pressure and within the air
temperature rise specified on the nameplate.

Table 2 is a guide for determining whether the rectangular duct system
that the furnace is being connected to be of sufficient size for proper fur­nace operation.

4 Unitary Products Group

268890-UIM-B-0607

Use the Example below to help you in calculating the duct area to deter­mine whether the ducts have sufficient area so that the furnace oper­ates at the specified external static pressure and within the air
temperature rise specified on the nameplate.

The following are general duct sizing guidelines that may not serve to
requirements of every application.

Example: The furnace input is 80,000 BTUH, 1,200 CFM blower
requirement. The recommended duct area is 216 sq.in, there are two 8
x 12 rectangular ducts attached to the plenum and there are two 7 inch
round ducts attached to the furnace.

2. The square inch area for 7 inch round ducts, 38.4 square inch x 2
= 76.8 square inches,

3. Then take the 192 square inch from the rectangular duct and add it
to the 76.8 square inch of round duct. The total square inch of duct
attached to the furnace supply plenum is 268.8 square inches.
This exceeds the recommended 216 square inch of duct.

In this example, the duct system attached to the plenum has a sufficient
area so that the furnace operates at the specified external static pres­sure and within the air temperature rise specified on the nameplate.
Providing the return duct is properly sized as well.

1. Take 8 x 12, which equals 96 square inch x 2 = 192 square inches
then go to round duct size located in Table 3.

TABLE 2:

Minimum Duct Sizing For Proper Airflow

Input Nominal Airflow

Return

1

Rectangular

2

Round

2

Supply

3

Rectangular

2

Round

BTU/H(kW) CFM(m³/min) In² (cm²) in. x in.(cm x cm) in. (cm)dia. In²(cm²) in. x in.(cm x cm) in. (cm)dia.

40,000 (11.7) 1,200 (34.0) 280 (1806) 14 x 20 (35.6 x 90.8) 18 (45.7) 216 (1394) 12 x 18 (30.5 x 45.7) 16 (40.6)
60,000 (17.6) 1,200 (34.0) 280 (1806) 14 x 20 (35.6 x 50.8) 18 (45.7) 216 (1394) 12 x 18 (30.5 x 45.7) 16 (40.6)
80,000 (23.4) 1,200 (34.0) 280 (1806) 14 x 20 (35.6 x 50.8) 18 (45.7) 216 (1394) 12 x 18 (30.5 x 45.7) 16 (40.6)
80,000 (23.4) 1,600 (45.3) 360 (2322) 18 x 20 (45.7 x 50.8) 22 (55.8) 280 (1806) 14 x 20 (35.6 x 50.8) 18 (45.7)

100,000 (29.3) 1,600 (45.3) 360 (2322) 18 x 20 (45.7 x 50.8) 22 (55.8) 280 (1806) 14 x 20 (35.6 x 50.8) 18 (45.7)
100,000 (29.3) 2,000 (56.6) 440 (2839) 20 x 22 (50.8 x 55.8) 24 (60.9) 390 (2516) 16 x 22 (40.6 x 55.8) 22 (55.8)
120,000 (35.2) 2,000 (56.6) 440 (2839) 20 x 22 (50.8 x 55.8) 24 (60.9) 390 (2516) 16 x 22 (40.6 x 55.8) 22 (55.8)

NOTE: This chart does not replace proper duct sizing calculat ions or t a ke into accou nt st atic pressure drop f or run lengt h and fitt i ngs. Maint ai n prope r te mperatur e rise

and static pressures.

1. Maximum return air velocity in rigid duct @ 700 feet per minute (213 m/min).

2. Example return main trunk duct minimum dimensions.

3. Maximum supply air velocity in rigid duct @ 900 feet per minute (274m/min).

TABLE 3:

Round Duct Size

The transition duct must be the same dimensional size as the rectangu­lar opening in the base of the furnace.

Round Duct Size Calculated Area For Each Round Duct Size

Inches (cm)

Sq.in (cm

5 (13) 19.6 (126)
6 (15) 28.2 (182)
7 (18) 38.4 (248)
8 (20) 50.2 (324)
9 (23) 63.6 (410)

10 (25) 78.5 (506)

2

)

DOWNFLOW
FURNACE

WARM AIR PLENUM
WITH 1” FLANGES

FIBERGLASS
INSULATION

11 (28) 95 (613)
12 (30) 113.1 (730)
13 (33) 132.7 (856)
14 (36) 153.9 (993)

1. The Air Temperature Rise is determined by subtracting the Return
Air Temperature Reading from the Supply Air Temperature Read­ing.

FIBERGLASS TAPE
UNDER FLANGE

COMBUSTIBLE FLOOR
BASE ACCESSORY

2. The External Static Pressure is determined by adding the Supply
Duct Static Pressure reading to the Return Duct Static Pressure
reading.

FIGURE 1 : Combustible Floor Base Accessory

TABLES 2 AND 3 are to be used as a guide only to help the installer
determine if the duct sizes are large enough to obtain the proper air flow
(CFM) through the furnace. TABLES 2 and 3 ARE NOT to be used to
design ductwork for the building where the furnace is being installed.
There are several variables associated with proper duct sizing that are
not included in the tables. To properly design the ductwork for the build­ing, Refer to the ASHRAE Fundamentals Handbook, Chapter on
“DUCT DESIGN” or a company that specializes in Residential and Mod­ular Home duct designs.

IMPORTANT: If the supply air duct is being connected to the furnace
without the use of an accessory duct connector, then a transition duct

The supply air temperature MUST NEVER exceed the Maximum
Supply Air Temperature, specified on the nameplate.

Operating the furnace above the maximum supply air temperature
will cause the heat exchanger to overheat, causing premature heat
exchanger failure. Improper duct sizing, dirty air filters, incorrect
manifold pressure, incorrect gas orifice and/or a faulty limit switch
can cause the furnace to operate above the maximum supply air
temperature. Refer to sections II, III, IX & X for additional informa­tion on correcting the problem.

must be installed with flanges or tabs that are securely attach and
sealed to the supply air duct and to the base of the furnace. The transi­tion duct must have insulation between the transition duct and any com­bustible material.

2

Unitary Products Group 5

268890-UIM-B-0607

Downflow Air Conditioning Coil Cabinet

The Cooling Coil Cabinet can be used in place of the combustible floor
base for downflow installations on combustible materials. The furnace
should be installed with the cooling coil cabinet specifically intended for
downflow applications. The cooling coil cabinet must be secured to the
floor. A supply air duct plenum is installed through the opening pro­vided. The supply air duct is then secured to the duct system with
screws and sealed to prevent leaks. If a matching cooling coil is used, it
may be placed directly on the furnace outlet using the accessory transi­tion kit and sealed to prevent leakage. The transition kit must be used to
secure the cooling coil cabinet to the furnace casing when installed in a
downflow configuration.

These kits are required in downflow application when using G*F* series
coils. These kits are not required with MC/FC series coils, but please
ensurethat the coil and furnace are sucured and that there are noair
leaks.

This transition kit may be installed in one of two ways. The transition kit
may be installed and secured to either the furnace or the cooling coil
cabinet by the use of screws and then it must be sealed to prevent
leaks.

• If the transition kit has been installed on the cooling coil cabinet it
must be secured to the cooling coil cabinet with screws. The sup­ply air side of the furnace is then placed on the cooling coil cabi­net and then sealed for leaks.

• If the transition kit has been installed on the supply air side of the
furnace it must be secured to the furnace with screws. The fur­nace and the transition kit are then placed on the cooling coil cab­inet and then sealed for leaks.

NOTE: Refer to instructions packed out with coil cabinet, for securing
and sealing to the furnace.

IMPORTANT: The furnace, transition kit, and the cooling coil cabinet
MUST BE SEALED as needed to prevent leaks, AND SECURED. Refer
to the assembly drawing in Figure 2.

IMPORTANT: On all installations without a coil, a removable access
panel is recommended 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.

AIRFLOW

TRANSITION

DOWNFLOW
FURNACE

AIRFLOW

TRANSITION
KIT

FIGURE 2: Transition Kit Assembly

KIT

AIRFLOW

COOLING
COIL
CABINET

AIRFLOW

REFRIGERANT
LINES

DRAIN
CONNECTIONS

Horizontal Models

IMPORTANT: This furnace may be installed in a horizontal position on
either side as shown above. It must not be installed on its back.

Horizontal Installations With a Cooling Coil Cabinet

The furnace should be installed with the cooling coil cabinet specifically
intended for horizontal applications. If a matching cooling coil is used, it
may be placed directly on the supply air side of the furnace and sealed
to prevent leakage. A warm air duct plenum with 1" (2.54 cm) is
installed through the opening provided. The supply air duct system is
connected to the warm air plenum and sealed to prevent leaks.

IMPORTANT: The furnace, the cooling coil cabinet, and all duct work
MUST BE SEALED as needed to prevent leaks, AND SECURED. Refer
to the assembly drawing in Figure 2.

Attach the supply plenum to the air conditioning coil cabinet outlet duct
flanges through the use of S cleat material when a metal plenum is
used. The use of an approved flexible duct connector is recommended
on all installations. The connection to the furnace, air conditioning coil
cabinet and the supply plenum should be sealed to prevent air leakage.

The sheet metal plenum should be crosshatched to eliminate any pop­ping of the sheet metal when the indoor fan is energized. The minimum
plenum height is 12" (30.5 cm). 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 controls may not operate at all. Also the plastic
drain pan in the under the air conditioning coil can overheat and melt
Refer to the installation instructions supplied with the air conditioning
coil for additional information.

Horizontal Installations Without a Cooling Coil Cabinet

When installing this appliance, the furnace must be installed so as to
create a closed duct system, the supply duct system must be con­nected to the furnace outlet and the supply duct system must terminate
outside the space containing the furnace. 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.

Attach the supply plenum to the furnace outlet duct flanges through the
use of S cleat material when a metal plenum is used. 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. On all installations without a
coil, a removable access panel is recommended 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.

6 Unitary Products Group

T-STAT WIRING 7/8” K.O.

HORIZONTAL CONDENSATE
DRAIN OPENING 1-3/4”

HORIZONTAL CONDENSATE
DRAIN OPENING 2”

JUNCTION BOX
HOLE 7/8”

GAS PIPE ENTRY 1-1/2”

CONDENSATE DRAIN
HOLE 7/8”

SIDE PIPING HOLE 3-3/8”

28-1/2

LEFT SIDE

1-1/4

19-1/4

268890-UIM-B-0607

A

T-STAT WIRING 7/8” K.O.

HORIZONTAL CONDENSATE
DRAIN OPENING 1-3/4”

HORIZONTAL
CONDENSATE
DRAIN OPENING 1-3/4”

JUNCTION BOX
HOLE 7/8”

GAS PIPE
ENTRY 1-1/2”

CONDENSATE DRAIN
HOLE 7/8”

RIGHT SIDE

5/8

40

FRONT

1-1/4

D

C

23-5/8

5/8

B

20

BOTTOM IMAGE

SUPPLY END

2-1/4

23-1/4

TOP IMAGE

RETURN END

FIGURE 3: Dimensions
TABLE 4:

Cabinet and Duct Dimensions

BTUH (kW)

Input/Output

CFM

Cabinet

Size

Cabinet Dimension

A (in.) A (cm) B (in.) B (cm) C (in.) C (cm) D (in.) D (cm)

40/37 (11.7/10.8) 1200 (34.0) A 14-1/2 36.8 13-1/4 33.7 12 30.5 1-3/4 4.44
60/56 (17.6/16.4) 1200 (34.0) B 17-1/2 44.4 16-1/4 41.3 15 38.1 1-3/4 4.44
80/75 (23.4/22.0) 1200 (34.0) B 17-1/2 44.4 16-1/4 41.3 15 38.1 1-3/4 4.44

80/75 (23.4/22.0) 1600 (45.3) C 21 53.3 19-3/4 50.2 18-1/2 47.0 2-1/8 5.40
100/95 (29.3/27.8) 1600 (45.3) C 21 53.3 19-3/4 50.2 18-1/2 47.0 2-1/8 5.40
100/95 (29.3/27.8) 2000 (56.6) C 21 53.3 19-3/4 50.2 18-1/2 47.0 2-1/8 5.40

120/112 (35.1/32.8) 2000 (56.6) D 24-1/2 62.2 23-1/4 59.1 22 55.9 2-1/2 6.35

RESIDENTIAL AND NON HUD MODULAR HOME
DOWNFLOW AND HORIZONTAL RETURN PLENUM

IMPORTANT: If an external mounted filter rack is being used see the
instructions provided with that accessory for proper hole cut size.

CONNECTION

The return duct system must be connected to the furnace inlet and the
return duct system must terminate outside the space containing the fur­nace. 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.

Attach the return plenum to the furnace inlet duct flanges. This is typi­cally through the use of S cleat material when a metal plenum is used.
The use of an approved flexible duct connector is recommended on all
installations. The connection of the plenum to the furnace and all the
ducts connecting to the plenum must 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.

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 must 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.

Attic installations must meet all minimum clearances to combustibles
and have floor support with required service accessibility.

SECTION III: FILTERS

FILTER INSTALLATION

All applications require the use of a filter. Replacement filter size is
shown in Table 5.

TABLE 5:

NOTES:

Recommended Filter Sizes

Input / Output

BTU/H (kW)

(m

CFM

3

/min)

Cabinet

Size

Top Return

Filter in(cm)

40 (11.7) 1200 (34) A (2) 14 x 20 (36 x 51)
60 (17.8) 1200 (34) B (2) 14 x 20 (36 x 51)
80 (23.4) 1200 (34) B (2) 14 x 20 (36 x 51)

80 (23.4) 1600 (45) C (2) 14 x 20 (36 x 51)
100 (29.3) 1600 (45) C (2) 14 x 20 (36 x 51)
100 (29.3) 2000 (57) C (2) 14 x 20 (36 x 51)
120 (35.1) 2000 (57) D (2) 14 x 20 (36 x 51)

1. Air velocity through throwaway type filters may not exceed 300 feet
per minute. All velocities over this require the use of high velocity fil­ters.

Unitary Products Group 7

268890-UIM-B-0607

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.

Filters(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.

If the accessory electronic air cleaner is installed, be sure the air
cleaner is designed to accommodate the furnace CFM (cm/m) and the
air cleaner is installed so it does not obstruct the return airflow. Consid­eration should be given when locating the air cleaner for maintenance
and temperatures should the indoor fan motor fail to operate. The use
of straps and / or supports is required to support the weight of the elec­tronic air cleaner. It is recommended that the air cleaner not be located
within 12 inches (30.5 cm) from the top of the return air opening on the
furnace. Refer to the instructions supplied with the electronic air
cleaner.

All loose accessories shipped with the furnace must be removed
from the blower compartment, prior to installation.

If pleated media air filters or any filter that has a large pressure drop is
installed in the return air duct system be sure that the pressure drop
caused by the air filter will not prevent the furnace from operating within
the rise range specified on the rating plate. If the furnace does not oper­ate within the specified rise range then a larger air filter or an air filter
that has a lower pressure drop must be installed.

IMPORTANT: For easier filter access in a downflow configuration, a
removable access panel is recommended in the vertical run of the
return air plenum immediately above the furnace.

CLOSET

COMBUSTION
AIR

VENT
PIPE

RETURN
AIR

AIR
FILTERS

HORIZONTAL APPLICATION

Horizontal Filters

All filters and mounting provision must be field supplied. Filters(s) may
be located in the duct system external to the furnace or in a return filter
grille(s). Filters(s) may be located in the duct system using an external
duct filter box attached to the furnace plenum. Any branch duct (rectan­gular or round duct) attached to the plenum must attach to the vertical
plenum above the filter height. The use of straps and / or supports is
required to support the weight of the external filter box.

An accessory filter rack is available.

ATTIC INSTALLATION

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

GAS
PIPING

SUPPLY
AIR

12” CLEARANCE
FOR SERVICE

FIGURE 5: Typical Attic Installation

This appliance is design certified for line contact when the furnace is
installed in the horizontal left or right position. The line contact is only
permissible between lines 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.

IMPORTANT: In either a horizontal left or right installation, a minimum
of 8" (20.3 cm) clearance is required beneath the furnace to allow for
the installation of the condensate trap and drain pipe. Refer to "CON­DENSATE PIPING" section of this manual for more information.

COMBUSTION
AIR

30” MIN.
WORK AREA

FILTER RACK

VENT PIPE
(maintain required
clearances to
combustible)

RETURN
AIR

When a furnace is installed in an attic or other insulated space,

ELECTRICAL
SUPPLY

GAS SUPPLY
(EITHER SIDE)

keep all insulating materials at least 12 inches (30.5 cm) away from
furnace and burner combustion air openings.

If this furnace is installed over a finished space, a condensate

FIGURE 4: Return Filter Grill and Return Duct Installation
IMPORTANT: Air velocity through throwaway type filters must not

exceed 300 feet per minute (91 m/min). All velocities over this require
the use of high velocity filters. Refer to Table 19.

safety pan must be installed.

SUSPENDED FURNACE / CRAWL SPACE
INSTALLATION

The furnace can be hung from floor hoists or installed on suitable blocks
or pad. Blocks or pad installations shall provide adequate height to
ensure the unit will not be subject to water damage. Units may also be
suspended from rafters or floor joists using rods, pipe angle supports or

All installations must have a filter installed.

straps. Angle supports should be placed at the supply air end and near
the blower deck. Do not support at return air end of unit. All four sus­pension points must be level to ensure quite furnace operation. When
suspending the furnace use a secure a platform constructed of plywood
or other building material secured to the floor joists. Refer to Figure 6
for typical crawl space installation.

8 Unitary Products Group

EXTERNAL MANUAL
SHUTOFF VALVE

268890-UIM-B-0607

ANGLE IRON
BRACKET

1” MAX. BETWEEN
ROD & FURNACE

6” MIN. BETWEEN
ROD & FURNACE

1” MAX. BETWEEN
ROD & FURNACE

SUPPORT
BRACKET

FIGURE 6: Typical Suspended Furnace / Crawl Space Installation

In any application where temperatures below freezing are possible,
see “BELOW FREEZING LOCATIONS”.

SECTION IV: GAS PIPING

GAS SAFETY

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.

OUTLET
PRESSURE
PORT

INLET

WRENCH
BOSS

INLET
PRESSURE
PORT

ON/OFF SWITCH
(Shown in ON position)

OFF

ON

FIGURE 7: Gas Valve
IMPORTANT: 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.

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 con­nector. Do not use a connector that has previously serviced another gas
appliance.

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 instal­lation of a drip leg and ground union is required. Refer to Figure 8.

VENT PORT

OUTLET

MAIN REGULATOR
ADJUSTMENT

TO GAS
SUPPLY

DRIP
LEG

TO GAS
SUPPLY

GROUNDED JOINT UNION
MAY BE INSTALLED
INSIDE OR OUTSIDE UNIT.

FIGURE 8: Downflow Gas Piping

MANUAL
SHUT-OFF

GAS
PIPE

VALV E

DRIP
LEG

GAS
PIPE

MANUAL
SHUT-OFF VALVE

DRIP
LEG

GAS BURNERS

GAS VALVE

FIGURE 9: Horizontal Gas Piping
IMPORTANT: 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).

Never apply a pipe wrench to the body of the gas valve when
installing piping. A wrench must be placed on the octagonal 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.

Gas piping may be connected from either side of the furnace using any
of the gas pipe entry knockouts on both sides of the furnace. Refer to
Figure 3 dimensions.

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 fac­tory-supplied LP conversion kit. Follow the instructions supplied with
the LP kit. Refer to Table 6 or the instructions in the propane (LP) con­version kit for the proper gas orifice size.

HIGH ALTITUDE GAS ORIFICE CONVERSION

This furnace is constructed at the factory for natural gas-fired operation
at 0 – 8,000 feet (0-m – 2,438 m) above sea level.

The manifold pressure must be changed in order to manitain proper
and safe operation when the furnace is installed in a location where the
altitude is greater than 8,000 feet (2,438 m) above sea level. Refer to to
Table 6 for proper manifold pressure settings.

HIGH ALTITUDE PRESSURE SWITCH CONVERSION

For installation where the altitude is less than 8,000 feet (2,438 m), it is
not required that the pressure switch be changed. For altitudes above
8,000 feet (2,438 m), see Field Installed Accessories - High Altitude
pressure Switch.

Unitary Products Group 9

268890-UIM-B-0607

TABLE 6:

Nominal Manifold Pressure

Manifold Pressures (in wc) Manifold Pressures (kpa)

Altitude (feet) Altitude (m)

0-7999 8000-8999 9000-9999 0-2437 2438-2742 2743-3048

800 3.5 3.5 3.5

29.8 0.87 0.87 0.87
850 3.5 3.5 3.5 31.7 0.87 0.87 0.87
900 3.5 3.5 3.5 33.5 0.87 0.87 0.87
950 3.5 3.5 3.3 35.4 0.87 0.87 0.81

1000 3.5 3.2 2.9 37.3 0.87 0.80 0.73

(MJ/cu m)

Gas Heating Value

Gas Heating Value

(BTU/cu ft.)

1050 3.5 2.9 2.7 39.1 0.87 0.73 0.67
1100 3.2 2.7 2.4 41.0 0.80 0.66 0.61

2500 (LP) 9.8 8.2 7.5 93.2 (LP) 2.44 2.03 1.86

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 pro­pane (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.

SECTION V: ELECTRICAL POWER

ELECTRICAL POWER CONNECTIONS

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 7 in
these instructions for specific furnace electrical data.

TABLE 7:

Electrical and Performance Data

Input/Cabinet Output Nominal Airflow Cabinet Width Total Unit AFUE Air Temp. Rise

MBH kW MBH kW CFM

3

m

/min

In. mm Amps % °F °C

40/A 12 37 10.8 1200 34 14-1/2 368 9 94 35 - 65 19 - 36
60/B 18 55 16.1 1200 34.0 17-1/2 444 9 92 35 - 65 19 - 36
80/B 23 74 21.7 1200 34.0 17-1/2 444 9 92 35 - 65 19 - 36

80/C 23 74 21.7 1600 45.3 21 533 12 92 35 - 65 19 - 36
100/C 29 93 27.3 1600 45.3 21 533 12 92 35 - 65 19 - 36
100/C 29 93 27.3 2000 56.6 21 533 14 92 35 - 65 19 - 36
120/D 35 112 32.8 2000 56.6 24-1/2 622 14 92 35 - 65 19 - 36

Input/Cabinet

Max. Outlet

Air Temp.

Blower Blower Size

MBH kW °F °C HP Amps In. cm Lbs. Kg.

40/A 12 165 73.9 1/2 7.0 11 x 8 27.9 x 20.3 20 14 120 54.5
60/B 18 165 73.9 1/2 7.0 11 x 8 27.9 x 20.3 20 14 130 59.0
80/B 23 165 73.9 1/2 7.0 11 x 8 27.9 x 20.3 20 14 145 65.9

80/C 23 165 73.9 3/4 10.2 11 x 10 27.9 x 25.4 20 14 155 70.5
100/C 29 165 73.9 3/4 10.2 11 x 10 25.4 x 25.4 20 14 170 77.3
100/C 29 165 73.9 1 12.7 11 x 11 27.9 x 27.9 20 12 175 79.5
120/D 35 165 73.9 1 12.7 11 x 11 27.9 x 27.9 20 12 180 81.8

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.

NOTES:

1. For altitudes above 2000 ft. (609 m) reduce capacity 4% for each 1000 ft. above sea level.

2. Wire size based on copper conductors, 140° F (60°C), 3% voltage drop.

3. Continuous return air temperature must not be below 55°F (12.8° C).

Use copper conductors only.

Max.

Over-current

Protect

Min. Wire Size
(awg) @ 75 ft.

One Way

Operation

Weight

10 Unitary Products Group

SUPPLY VOLTAGE CONNECTIONS

IMPORTANT: 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.

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 conve­nience 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 shown in Figure 41.

2. Remove the screws retaining the junction 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 junc­tion box there will be three wires, a Black Wire, a White Wire and a
Green Wire. Connect the power supply as shown on the unit-wir­ing label on the inside of the blower compartment door or Figure

10. The black furnace lead must be connected to the L1 (hot) wire
from the power supply. The white furnace lead must be connected
to neutral. Connect the green furnace lead (equipment ground) to
the power supply ground. An alternate wiring method is to use a
field provided 2” (5.08 cm) x 4” (10.2 cm) box and cover on the
outside 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.

3. The furnace's control system requires correct polarity of the power
supply and a proper ground connection. If the power supply polar­ity is reversed, the control board will flash 9 times. The furnace will
not operate until the polarity is corrected. Refer to “Furnace Diag­nostics” section of the “User’s Information, Maintenance, & Ser­vice Manual” provided with this furnace.

268890-UIM-B-0607

COMBUSTION
AIR

CLASS 2 SYSTEM
CONTROL WIRING
TO THERMOSTAT

(BLK) LI (HOT)

(WHT) N

(GRN)GND

FIGURE 10: Electrical Wiring

JUNCTION
BOX

BLOWER
COMPARTMENT

VENT PIPE

IGNITION
MODULE

TRANSFORMER

LOW VOLTAGE CONTROL WIRING CONNECTIONS

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 Figure 11. Electronic thermo­stats may require the common wire to be connected as shown with the
dashed line in Figure 11. Apply strain relief to thermostat wires passing
through cabinet. If air conditioning equipment is installed, use thermo­stat wiring to connect the Y and C terminals on the furnace control
board to the yellow and brown wires on the condensing unit (unit out­side). Refer to Figure 11.

IMPORTANT: Set the heat anticipator in the room thermostat to 0.45
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 anticipators. They may have other
type cycle rate adjustments. Follow the thermostat 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.

For additional connection diagrams for all UPG equipment refer to “Low
Voltage System Wiring” document available online at www.upgnet.com
in the Product Catalog Section.

Unitary Products Group 11

268890-UIM-B-0607

SINGLE STAGE

AIR CONDITIONING

Y

C

24-Volt Common

Single Stage Cool

24V HUMIDIFIER

HEAT PUMP

SINGLE STAGE

Y

C

24-Volt Common

Single Stage Heat/Cool

R

24-Volt Hot

O

W

W1/66

First Stage Heat

First Stage Heat Out

X/L

Malfunction Light

Reversing Valve–Energized in Cool

PSC

C

FURNACE CONTROL

Optional w/Batteries

C

*BN11C01124

*DP11C40124

*DN11C00124

R

Y/Y2

24-Volt Common

24-Volt Hot

Single/Second Stage Cool

Y

RH

First Stage Cool

24-Volt Hot (Heat XFMR)

Y

RH

First Stage Cool

24-Volt Common

24-Volt Hot (Heat XFMR)

G

W

Fan

Single Stage Heat

RC

Fan

G

W

First Stage Heat

24-Volt Hot (Cool XFMR)

RC

Fan

G

W

First Stage Heat

24-Volt Hot (Cool XFMR)

HM1

Humidistat

on thermostat not necessary

Selection of GAS/ELEC switch

PSC

FURNACE CONTROL

C

C

R

Y/Y2

24-Volt Common

24-Volt Common

24-Volt Hot

Single/Second Stage Cool

Y

R

24-Volt Hot

First Stage Heat/Cool

G

W

Single Stage Heat

E

W1

G

Emergency Heat

Second Stage Heat

Fan

L

O

Fan

Malfunction Light

must be set to Heat Pump 1

Reversing Valve–Energized in Cool

Step 1 of Thermostat User Configuration Menu

must be set to Pump OFF

Step 9 of Thermostat User Configuration Menu

*BN21H00124

*DP21H40124

*DN21H00124

Y

R

RC

First Stage Cool

24-Volt Hot (Cool XFMR)

24-Volt Hot (Heat XFMR)

G

W

Fan

First Stage Heat

*DN22U00124 *BP21H50124 *PP32H70124

System Type - must be set to 0

Thermostat Installer Setup Number 1 -

Thermostat Installer Setup Number 15 -

Compressor Protection - must be set to 5

THERMOSTAT THERMOSTAT THERMOSTAT

Single Stage H/P - E*RD, E*BD, ERHS, HPX13 - w/Single Stage Furnace, 1 Stage Cooling Ready - (G,L)*8/9S, XYF80-U, XYF80-U*L, XYF90-U

N/A N/A

*BN11C00124 *BP11C50124 *PP11C70224

THERMOSTAT THERMOSTAT THERMOSTAT

C

24-Volt Common

W/031-01975- Series Demand Control

HP1

AC1 Single Stage A/C w/Single Stage Furnace, 1 Stage Cooling Ready - (G,L)*8/9S, XYF80-U, XYF80-U*L, XYF90-U

FIGURE 11: Thermostat Chart

12 Unitary Products Group

268890-UIM-B-0607

ACCESSORY CONNECTIONS

The furnace control will allow power-switching control of vario us acces­sories. Refer to Figure 12, for connection details.

HUM. HOT

BLK

WHT

BLK

WHT

EAC
HUM

SWITCHED
CIRCUITS

NEUTRALS

115 VOLT
HUMIDIFER

EAC HOT

115 VOLT
ELECTRONIC
AIR CLEANER

FIGURE 12: Accessory Connections

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 opera­tion.

HUMIDIFIER CONNECTION

Two 1/4” (0.64 cm) spade terminals (HUM and NEUTRAL) for humidi­fier connections are located on the control board. The terminals provide
115 VAC (1.0 amp maximum) during heating system operation.

SECTION VI: TWINNING AND STAGING

NOTE: Y ou can twin two furnaces that have the same integrated control
module. Check the part number on the integrated control module. You

cannot twin

part numbers. If the part numbers of the two integrated control modules
are different they may not communicate with each other so they will not
work in a twinning application.

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 cir­culating 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 simulta­neously.

Before installing the relay and wiring, disconnect electrical power to
both furnaces. Failure to cut power could result in electrical shock
or equipment damage.

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.

two furnaces that have different integrated control module

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 sin­gle return air plenum, common to both furnaces must be used.

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 13.

If furnace staging is desired with two single stage furnaces on a com­mon 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 fur­naces 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.

VENT PIPE

ELECTRICAL
SUPPLY

COMMON

SUPPLY

PLENUM

GAS SUPPLY
(BOTH SIDES)

SUPPLY
AIR

1 COIL FOR
EACH FURNACE

FIGURE 13: Typical Twinned Furnace Application
IMPORTANT: When two furnaces are twinned, typical system total air-

flow will be approximately 85% of additive individual furnaces, i.e., two
2000 CFM (56.6 m

3

/m) units will yield a total 3400 CFM (96.3 m3/m).

GAS PIPING

Furnace gas supplies must be provided as specified with these instruc­tions. 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.

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.

Unitary Products Group 13

268890-UIM-B-0607

Single-Wire Twinning Instructions

Connect the control wiring as shown in the Figure 14.

1. Connect the low voltage wiring from the wall thermostat to the ter­minal 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.

Single-Wire Twinning 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 fur­naces 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.

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 2 CONTROL BOARD

RELAY

Y

W

G

C

R

TWIN

Y

TO A/C

FURNACE 1 CONTROL BOARD

W

G

C

R

TWIN

Y

WG

WALL THERMOSTAT

ISOLATION

R

Single-Wire St ag in g Instructi on s

Connect the control wiring as shown in the Figure 15.

1. Connect the low voltage wiring from the wall thermostat to the ter­minal strip on the control board of Furnace #1. For staging applica­tions, 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.

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.

Single-Wire St ag ing Operation

Heating - On a call for first-stage heat (W1 signal) from the wall thermo­stat, 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 satis­fied, 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.

FURNACE 1 CONTROL BOARD

W

G

C

R

TWIN

Y

ISOLATION

FURNACE 2 CONTROL BOARD

RELAY

W

G

C

TWIN

R

Y

FIGURE 14: Single Stage Twinning Wiring Diagram

STAGING

TO A/C

W1 G

WALL THERMOSTAT

W2

R

Y

In applications where more heating capacity or more airflow capacity is
needed than what one furnace can deliver, twinning can be used to

FIGURE 15: Two-Stage Twinning Wiring Diagram

make two furnaces operate in tandem, using one duct system and one
room thermostat. 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 necessary 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.

Single-Wire Staging

The single-wire twinning feature of this board can also be used for stag­ing 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 communica­tion makes the second furnace blower come on at the same time, and
on the same speed, as the first furnace blower.

SECTION VII: COMBUSTION AIR AND
VENT SYSTEM

COMBUSTION AIR AND VENT SAFETY

This Category IV, dual certified direct vent furnace is designed for resi­dential application. It may be installed without modification to the con­densate system in a basement, garage, equipment room, alcove, attic
or any other indoor location provided the space temperature is 32 °F
(0°C) or higher and where all required clearance to combustibles and
other restrictions are met. The combustion air and 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.

IMPORTANT: The “VENT SYSTEM” must be installed as specified in
these instructions for Residential and Non HUD Modular Homes. The
sealed combustion air / vent system is the only configuration that can
be installed in a Non HUD Modular Home.

14 Unitary Products Group

268890-UIM-B-0607

This furnace may not be common vented with any other appliance,
since it requires separate, properly sized air intake and vent lines.
The furnace shall not be connected to any type of B, BW or L vent
or vent connector, and not connected to any portion of a factory­built or masonry chimney

The furnace shall not be connected to a chimney flue serving a sep­arate appliance designed to burn solid fuel.

When combustion air pipe is installed above a suspended ceiling or
when it passes through a warm and humid space, the pipe must be
insulated with 1/2” Armaflex or other heat resistant type insulation.

Vent piping must be insulated with 1/2” insulation if it will be sub­jected to freezing temperatures such as routing through unheated
areas or through an unused chimney.

COMBUSTION AIR/VENT PIPE SIZING

The size of pipe required will be determined by the furnace model, the
total length of pipe required and the number of elbows required.

Table 8 lists the maximum equivalent length of pipe allowed for each
model of furnace. The equivalent length of elbows is shown in Table 9.
The equivalent length of the vent system is the total length of straight
pipe PLUS the equivalent length of all of the elbows.

The following rules must also be followed:

1. Long radius (sweep) elbows are recommended. Standard elbows
may be used, but since they have a longer equivalent length, they
will reduce the total length of pipe that will be allowed. Short radius
(plumbing vent) elbows are not allowed. The standard dimensions
of the acceptable elbows are shown below.

2. The maximum equivalent length listed in Table 8 is for the vent pip­ing and the air intake piping separately. For example, if the table
allows 65 equivalent feet for a particular model, then the vent can
have 65 equivalent feet of pipe, AND the combustion air intake can
have another 65 equivalent feet of pipe.

3. Three vent terminal elbows (two for the vent and one for the com­bustion air intake) are already accounted for and need not be
included in the equivalent length calculation.

4. All combustion air and vent pipe must conform to American
National Standards Institute (ANSI) and American Society for Test­ing and Materials (ASTM) standards D1785 (Schedule 40 PVC),
D2665 (PVC-DWV), F891 (PVC-DWV Cellular Core), D2261
(ABS-DWV) or F628 (Schedule 40 ABS). Pipe cement and primer
must conform to ASTM Standard D2546 (PVC) or D2235 (ABS). If
ABS pipe is to be used, any joint where ABS pipe is joined to PVC
pipe must be glued with cement that is approved for use with
BOTH materials. Metallic materials must not be used for venting or
air intake.

5. If a flexible connector is used in the vent system, it must be made
of a material that is resistant to acidic exposure and to at least
225° F temperature. Flexible connectors are also allowed in the
combustion air pipe.

6. All models are supplied with 2" vent connections. When the pipe
must be increased to 3" diameter, the transition from 2" to 3" must
be done as close to the furnace as possible. For upflow models,
the transition from 2" to 3" should be done immediately above the
furnace. For downflow or horizontal models, the transition from 2"
to 3" pipe should be done immediately after the drain tee or drain
elbow.

7. In Canada, vents shall be certified to ULC S636, Standard for T ype
BH Gas Venting Systems. IPEX System 636 PVC is certified to
this standard.

8. In Canada, the first three feet (900 mm) of the vent must be readily
accessible for inspection.

TABLE 8:

TABLE 9:

Example:
An 80,000 BTUH furnace requires 32 feet of pipe and four 90º elbows.

Using 2" pipe and standard elbows, the total equivalent length will be:

This exceeds the 65 foot maximum equivalent length of 2" pipe allowed
for that model and is thus not

By using sweep elbows, the total equivalent length will be:

This is less than the 65 foot maximum equivalent length of 2" pipe
allowed for that model and is thus acceptable.

Alternatively, using 3" pipe and standard elbows, the total equivalent
length will be:

This is less than the 90 foot maximum equivalent length of 3" pipe
allowed for that model and is thus acceptable.

Maximum Equivalent Pipe Length

Model Input

BTUH (kW)

40,000 (11.7) 2 (5.1) 65 (19.8)
40,000 (11.7) 3 (7.6) 90 (27.4)
60,000 (17.6) 2 (5.1) 65 (19.8)
60,000 (17.6) 3 (7.6) 90 (27.4)
80,000 (23.4) 2 (5.1) 65 (19.8)

80,000 (23.4) 3 (7.6) 90 (27.4)
100,000 (29.3) 2 (5.1) 30 (9.2)
100,000 (29.3) 3 (7.6) 85 (25.9)
120,000 (29.3) 3 (7.6) 60 (18.3)

Equivalent Length of Fittings

Fitting Equivalent Length

2" 90º sweep elbow 5 feet of 2" pipe

2" 45º sweep elbow 2-1/2 feet of 2" pipe
2" 90º standard elbow 10 feet of 2" pipe
2" 45º standard elbow 5 feet of 2" pipe

3" 90º sweep elbow 5 feet of 3" pipe

3" 45º sweep elbow 2-1/2 feet of 3" pipe
3" 90º standard elbow 10 feet of 3" pipe
3" 45º standard elbow 5 feet of 3" pipe

2" corrugated connector 10 feet of 2" pipe
3" corrugated connector 10 feet of 3" pipe

32 feet of 2" pipe = 32 equivalent feet
4 - 90º standard 2" elbows = (4x10) = 40 equivalent feet
Total = 72 equivalent feet of 2" pipe

32 feet of 2" pipe = 32 equivalent feet
4 - 90º standard 2" elbows = (4x5) = 20 equivalent feet
Total = 52 equivalent feet of 2" pipe

32 feet of 3" pipe = 32 equivalent feet
4 - 90º standard 2" elbows = (4x5) = 40 equivalent feet
Total = 72 equivalent feet of 3" pipe

Pipe Size

Inches (cm)

acceptable.

Maximum

Equivalent

length feet (m)

Unitary Products Group 15

268890-UIM-B-0607

A

A

STANDARD ELBOW

FIGURE 16:

Dimensions

TABLE 10: Elbow

A

A

LONG (SWEEP) ELBOW

Dimensions

Elbow "A" Dimension

2" Standard 2-5/16"
3" Standard 3-1/16"
2" Sweep 3-1/4"
3" Sweep 4-1/16"

Dimensions are those required in Standard ASTM D-3311.

NOTE: Sidewall vent terminal may be used for sidewall vent termina­tions. Refer to part list in the back of the USERS INFORMATION AND
SERVICE AND MAINTENANCE MANUAL for the terminal part number.

TABLE 11:

Combustion Air Intake and Vent Connection Size at Furnace

(All Models)

FURNACE VENT CONNECTION SIZES

Furnace Input

40 - 100 MBH

(17.5 - 29.3 kW)

120 MBH

(35.2 kW)

Intake Pipe Size 2” (5.1 cm) 3” (7.6 cm)

Vent Pipe Size 2” (5.1 cm) 2” (5.1 cm)

*. Vent pipe size must be increased to 3” diameter after connection to furnace

on this model.

IMPORTANT: Accessory concentric vent / intake termination kits
1CT0302 and 1CT0303 are available and approved for use with these
furnaces. Horizontal sidewall vent terminations kits 1HT0901 &
1HT0902 are also approved for use with these furnaces.

IMPORTANT: Furnace vent pipe connections are sized for 2” (5.1 cm).
pipe. Any pipe size change must be made outside the furnace casing in
a vertical pipe section to allow proper drainage of condensate. An offset
using two 45º (degree) elbows will be required for plenum clearance
when the vent is increased to 3” (7.6 cm).

COMBUSTION AIR AND VENT PIPING ASSEMBLY

The final assembly procedure for the combustion air and vent piping is
as follows:

1. Cut piping to the proper length beginning at the furnace.

2. Deburr the piping inside and outside.

3. Chamfer (bevel) the outer edges of the piping.

4. Dry-fit the vent piping assembly from the furnace to the outside ter­mination checking for proper fit support and slope.

5. Dry-fit the combustion air piping assembly checking for proper fit,
support and slope on the following systems:

A. Sealed combustion air systems from the furnace to the out-

side termination.

B. Ventilated combustion air systems from the furnace to the

attic or crawl space termination.

Solvent cements are flammable and must be used in well-ventilated
areas only. Keep them away from heat, sparks and open flames.
Do not breathe vapors and avoid contact with skin and eyes.

6. Disassemble the combustion air and vent piping, apply cement
primer and the cement per the manufactures instructions. Primer
and cement must conform to ASTM D2564 for PVC, or ASTM
D2235 for ABS piping.

7. All joints must provide a permanent airtight and watertight seal.

8. Support the combustion air and vent piping such that it is angled a
minimum of 1/4” per foot (0.635 cm/m) so that condensate will flow
back towards the furnace. Piping should be supported with pipe
hangers to prevent sagging.

9. Seal around the openings where the combustion air and / or vent
piping pass through the roof or sidewalls.

COMBUSTION AIR / VENT CLEARANCES

IMPORTANT: The vent must be installed with the minimum clearances
as shown in Figure 17, and must comply with local codes and require­ments.

16 Unitary Products Group

VENT CLEARANCES

D

E

V

B

V

L

FIGURE 17: Home Layout

FIXED
CLOSED

C

V
V

F

B

A

B

V

B

G

V

B

B

I

V

X

V

J

OPERABLE

H

M

X

V

K

FIXED
CLOSED

V

VENT TERMINAL

X

AIR SUPPLY

AREA WHERE TERMINAL IS NOT PERMITTED

268890-UIM-B-0607

Direct Vent Terminal Clearances

A. Clearance above grade, veranda, porch, deck, or

balcony

B. Clearance to window or door that may be opened

Canadian Installations

1,3

US Installation

12 inches (30 cm) 12 inches (30 cm)

12 inches (30 cm) for models ≤100,000 BTUH (30 kW),
36 inches (91 cm) for models >100,000 BTUH (30 kW)

Two-pipe (direct vent) applic ations: 9 inches (23 cm)
for models ≤50,000 BTUH (15 kW), 12 inches (30 cm)
for models >50,000 BTUH (15 kW). ††

2,3

C. Clearance to permanently closed window 12 inches (30 cm) 12 inches (30 cm)
D. Vertical clearance to ventilated soffit located

above the terminal within a horizontal distance
of 2 feet (61 cm) from the center line of the terminal

E. Clearance to unventilated soffit

F. Clearance to outside corner

12 inches (30 cm) or in accordance with local
installation codes and the requirements of the gas
supplier.

12 inches (30 cm) or in accordance with local
installation codes and the requirements of the gas
supplier

12 inches (30 cm) or in accordance with local
installation codes and the requirements of the gas
supplier

12 inches (30 cm) or in accordance with local
installation codes and the requirements of th e gas sup­plier

12 inches (30 cm) or in accordance with local
installation codes and the requirements of the gas
supplier

12 inches (30 cm) or in accordance with local
installation codes and the requirements of the gas
supplier

G. Clearance to inside corner 3 feet (91 cm) 3 feet (91 cm)

H. Clearance to each side of center line

extended above meter/regulator assembly

Above a meter/regulator assembly within 3 feet (91 cm)
horizontally of the vertical center-line of the regulator
vent outlet to a maximum vertical distance of 15 feet

(4.5 cm) above the meter/regulator assembly.
I. Clearance to service regulator vent outlet 3 feet (91 cm)
J. Clearance to nonmechanical air supply inlet to

building or the combustion air inlet to any other
appliance

12 inches (30 cm) for models ≤100,000 BTUH (30 kW),

36 inches (91 cm) for models >100,000 BTUH (30 kW)

K. Clearance to a mechanical supply inlet 6 feet (1.83 m)
L. Clearance above paved sidewalk or paved

driveway located on public property

7 feet (2.13 m)†

M. Clearance under veranda, porch, deck, or balcony 12 inches (30 cm)‡

1. In accordance with the current CSA B149.1-00, Natural Gas and Propane Installation Code.

2. In accordance with the current ANSI Z223.1 / NFPA 54, National Gas Code.

3. In accordance with the current ANSI Z21.47 * CSA 2.3 American National Standard.

Above a meter/regulator assembly within 3 feet (91
cm) horizontally of the vertical center-line of the regula­tor vent outlet to a maximum vertical distance of 15
feet (4.5 cm) above the meter/regulator assembly.

3 feet (91 cm) or in accordance with local installation
codes and the requirements of the gas supplier.

Two-pipe (direct vent) applic ations: 9 inches (23 cm)
for models ≤50,000 BTUH (15 kW), 12 inches (30 cm)
for models >50,000 BTUH (15 kW).

3 feet (91 cm) above if within 10 feet (3 cm)
horizontally

7 feet (2.13 m) or in accordance with local installation
codes and the requirements of the gas supplier.

12 inches (30 cm) or in accordance with local installa­tion codes and the requirements of the gas supplier

.

† A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings and serves both dwellings.
†† 12 inches (30 cm) up from the bottom edge of the structure for Two-pipe (direct vent) applications per ANSI Z223. 1 / NFPA 54, National Gas Code.
‡ Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor and the distance between the top of the vent termina­tion and the underside of the veranda, porch, or deck is greater tha n 1 foot (30 cm) as specified in CSA B149.1-00.
A vent shall not terminate less than 1 foot (30 cm) above a grade level.
Any fresh air or make up inlet for dryer or furnace area is considered to be forced air inlet.
Avoid areas where condensate drippage may cause problems such as above planters, patios, or adjacent to windows where steam may cause fogging.
A terminus of a vent shall be fitted with a cap in accordance with the vent manufacturer’s installation instructions, or in accordance with the installation instructions for a
special venting system.
IMPORTANT: Consideration must be given for degradation of building materials by flue gases. Sidewall termination may require sealing or shielding of building surfaces
with a corrosion resistant material to protect against combu stion product co rrosion. Con sidera tion must be g iven t o wind dire ction in order to preven t flue product s and /or
condensate from being blown against the building surfaces. If a metal shield is used it must be a stainless steel material at a minimum dimension of 20 inches. It is rec­ommended that a retaining type collar be used that is attached to the building surface to prevent movement of the vent pipe.
Responsibility for the provision of proper adequate venting and air supply for application shall rest with the installer.
Vent shall extend high enough above building, or a neighboring obstruction, so that wind from any direction will not create a positive pressure in the vicinity of the vent.

Unitary Products Group 17

268890-UIM-B-0607

VENT SYSTEM

This furnace is certified to be installed with one of two possible vent
configurations.

1. Horizontal vent system. This vent system can be installed com­pletely horizontal or combinations of horizontal, vertical, or offset
using elbows.

2. Vertical vent system. This vent system can be installed completely
vertical or a combination of horizontal, vertical, or offset using
elbows.

HORIZONTAL VENT APPLICATIONS AND
TERMINATION

When selecting the location for a horizontal combustion air / vent termi­nation, the following should be considered:

1. Observe all clearances listed in vent clearances in these instruc­tions.

2. Termination should be positioned where vent vapors will not dam­age plants or shrubs or air conditioning equipment.

3. Termination should be located where it will not be affected by wind
gusts, light snow, airborne leaves or allow recirculation of flue
gases.

4. Termination should be located where it will not be damaged or
exposed to flying stones, balls, etc.

5. Termination should be positioned where vent vapors are not objec­tionable.

6. Horizontal portions of the vent system must slope upwards and be
supported to prevent sagging. The vent system may be supported
by the use of clamps or hangers secured to a permanent part of
the structure every 4 ft. (1.22 m).

7. Sealed combustion air systems must be installed so the vent and
the combustion air pipes terminate in the same atmospheric zone.
Refer to Figures 19, 20, & 21.

DOWNFLOW VENT ASSEMBLY

1. Place the 2” (5.08 cm) 45° PVC street elbow on the vent connec­tion shown in Figure 18.

2. Place the 2” (5.08 cm) PVC WYE (“Y”) assembly on the 2” (5.08
cm) 45° PVC street elbow as shown in Figure 18.

3. Locate the rubber condensate hose in front of the blower access
panel.

4. Slide the hose through the hole in the top cover, and insert the
hose on to the barbed fitting on the bottom of the 2” (5.08 cm) PVC
WYE (“Y”) assembly as shown in Figure 18.

RETURN
AIR

2” PVC
45°
STELL

DOWNFLOW

2” (5.08 cm)
VENT PIPE

2” PVC
WYE

FURNACE
VENT PIPE

RETURN
AIR

BARBED
FITTING

HORIZONTAL LEFT

HORIZONTAL RIGHT

RETURN
AIR

HORIZONTAL VENT ASSEMBLY

Horizontal Left Vent Assembly

1. Place the 2” (5.08 cm) 45° PVC street elbow on the vent connec­tion shown in Figure 18.

2. Place the 2” (5.08 cm) PVC WYE (“Y”) assembly on the 2” (5.08
cm) 45° PVC street elbow as shown in Figure 18.

3. Refer to the “DOWNFLOW/HORIZONTAL CONDENSATE INTER­NAL DRAIN CONFIGURATIONS” for futher details.

Horizontal Right Vent Assembly

1. Place the 2” (5.08 cm) 45° PVC street elbow on the vent connec­tion shown in Figure 18.

2. Place the 2” (5.08 cm) PVC WYE (“Y”) assembly on the 2” (5.08
cm) 45° PVC street elbow as shown in Figure 18.

3. Refer to the “DOWNFLOW/HORIZONTAL CONDENSATE INTER­NAL DRAIN CONFIGURATIONS” for futher details.

MAINTAIN 12” MINIMUM CLEARANCE
ABOVE HIGHEST ANTICIPATED SNOW
LEVEL. MAXIMUM 24” ABOVE ROOF.

12” MIN.

12” MIN.

FIGURE 19: Termination Configuration - 1 Pipe

12” VERTICAL SEPARATION
BETWEEN COMBUSTION AIR

MAINTAIN 12”
MINIMUM
CLEARANCE
ABOVE HIGHEST
ANTICIPATED
SNOW LEVEL.

AND VENT

FIGURE 20: Termination Configuration - 2 Pipe

MINIMUM

12” SEPARATION BETWEEN BOTTOMOF
COMBUSTION AIR PIPE AND TOP OF VENT.
MAINTAIN 12” MIN. CLEARANCE ABOVE

12” MIN.

HIGHEST ANTICIPATED SNOW LEVEL.

12” MIN.

12” MINIMUM
BELOW
OVERHANG

12” MINIMUM
SEPARATION
BETWEEN BOTTOM
OF COMBUSTION
AIR PIPE AND
BOTTOM OF VENT

MAINTAIN 12”
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
HIGHER

FIGURE 18: Downflow/Horizontal Vent Assembly

FIGURE 21: Termination Configuration - 2 Pipe Horizontal

18 Unitary Products Group

268890-UIM-B-0607

12” MINIMUM
BELOW

VENT DRAIN

OVERHANG

12”

MINIMUM

SEPARATION
BETWEEN BOTTOM
OF COMBUSTION
AIR PIPE AND
BOTTOM OF VENT

MAINTAIN 12”
MINIMUM CLEARANCE
ABOVE HIGHEST
ANTICIPATED SNOW
LEVEL OR GRADE,
WHICHEVER IS
HIGHER

FIGURE 22: Crawl Space Termination Configuration - 2Pipe

VERTICAL VENT APPLICATIONS AND
TERMINATION

Roof mounted vertical terminals may be field fabricated. Standard PVC/
SRD fittings may be used. If installing a vertical venting system through
any unconditioned space such as an attic or crawl space it must be
insulated.

1. Observe all clearances listed in vent clearances in these instruc­tions.

2. Termination should be positioned where vent vapors are not objec­tionable.

3. Termination should be located where it will not be affected by wind
gusts, light snow, or allow recirculation of flue gases.

4. Termination should be located where it cannot be damaged,
plugged or restricted by tree limbs, leaves and branches.

5. Horizontal portions of the vent system must slope upwards and be
supported to prevent sagging. The vent system may be supported
by the use of clamps or hangers secured to a permanent part of
the structure every 4 ft. (1.22 m).

VENTING MULTIPLE UNITS

Only the sealed combustion system can be used for installations requir­ing more than one furnace in a structure. A separate sealed combustion
air pipe and a separate vent pipe must be installed for each furnace. Do
not connect more than one furnace to a combustion air pipe or a vent
pipe. The combustion air and vent termination must be located as
shown in Figures 23 or 24.

VENT

MIN.
6”

FIGURE 24: Double Vertical Sealed Combustion Air and Vent

Termination

COMBUSTION AIR SUPPLY

All installations must comply with Section 5.3, Air for Combustion and
Ventilation of the National Fuel Gas Code, ANSI Z223.1 or Sections

7.2, 7.3 or 7.4 of CAN/CGA B149.1 or .2 Installation Code - latest edi­tions.

This furnace is certified to be installed with one of three possible com­bustion air intake configurations.

1. OUTDOOR COMBUSTION AIR:

This is a sealed combustion air
configuration where the combustion air is supplied through a PVC
or ABS pipe that is connected to the PVC coupling attached to the
burner box and is terminated in the same atmospheric zone as the
vent. This type of installation is approved on all models. Refer to
Figures 25 & 27.

2. AMBIENT COMBUSTION AIR:

Combustion air is supplied from
the area surrounding the furnace through the combustion air pipe
in the furnace casing. The combustion air and the vent pipes are
not terminated in the same atmospheric zone. Refer to Figures 19
& 26 for vent terminations. Refer to “AMBIENT COMBUSTION
AIR SUPPLY” and “VENT AND SUPPLY OUTSIDE AIR SAFETY
CHECK PROCEDURE” for proper installation.

3. VENTILATED COMBUSTION AIR:

Combustion air is supplied
through a PVC or ABS pipe that is connected to the PVC coupling
attached to the burner box and is terminated in a ventilated attic or
crawl space. The combustion air and the vent pipes are not termi­nated in the same atmospheric zone. Refer to Figure 28 for crawl
space and attic termination. Only the combustion air intake may
terminate in the attic. The vent must terminate outside.

Outdoor Combustion Air

Combustion Air Intake/Vent Connections

This installation requires combustion air to be brought in from outdoors.
This requires a properly sized pipe (shown in Figures 31, 33, or 35) that
will bring air in from the outdoors to the furnace combustion air intake
collar on the burner box. The second pipe (shown in Figures 31, 33 or

35) is the furnace vent pipe.

2” (5.08 cm)
VENT
CONNECTION

COMBUSTION AIR

2”
MIN.

FIGURE 23: Double Horizontal Sealed Combustion Air and Vent

Termination

AIR INTAKE

FIGURE 25: Sealed Combustion Air Intake Connection and Vent

Connection

Unitary Products Group 19

268890-UIM-B-0607

The combustion air intake pipe should be located either through the
wall (horizontal or side vent) or through the roof (vertical vent). Care
should be taken to locate side vented systems where trees or shrubs
will not block or restrict supply air from entering the terminal.

Also, the terminal assembly should be located as far as possible from a
swimming pool or a location where swimming pool chemicals might be
stored. Be sure the terminal assembly follows the outdoor clearances
listed in Section #1 “COMBUSTION AIR QUALITY (LIST OF CONTAM­INANTS).”

Fresh air pipe can either be routed through the furnace or routed ou t­side the furnace.

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. It is
not piped directly into the burner box. A single, properly sized pipe from
the furnace vent connector to the outdoors must be provided. For down­flow models combustion air is brought into the furnace through the unit
top panel opening. Do not install a pipe into the combustion air pipe at
the top of the furnace. Refer to Figures 19 & 26.

This type of installation requires that the supply air to the appli­ance(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 cre­ate 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 appli­ance to soot and generate dangerous levels of CARBON MONOX­IDE, which can lead to serious injury, property damage and / or
death.

3

An unconfined space is not less than 50 cu.ft (1.42 m
hr. (0.2928 kW) input rating for all of the appliances installed in that
area.

Rooms communicating directly with the space containing the appli­ances are considered part of the unconfined space, if openings are not
furnished with doors.

A confined space is an area with less than 50 cu.ft (1.42 m
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 combus­tion and ventilation in confined spaces.

VENT PIPE PASSES

COMBUSTION
AIRFLOW

THROUGH TOP PANEL

) per 1,000 Btu/

3

) per 1,000

Combustion Air Source From Outdoors

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 12, to estimate free area.

TABLE 12:

* Do not use less than 1/4” (0.635 cm) mesh
+ Free area or louvers and grilles varies widely; the installer should follow lou-

Estimated Free Area

Wood or Metal

Louvers or Grilles

Screens+

ver or grilles
manufacturer’s instructions.

Wood 20-25%*
Metal 60-70% *
1/4” (0.635 cm)

mesh or larger 100%

Dampers, Louvers and Grilles (Canada Only)

1. The free area of a supply air opening shall be calculated by sub­tracting the blockage area of all fixed louvers grilles or screens
from the gross area of the opening.

2. Apertures in a fixed louver, a grilles, or screen shall have no
dimension smaller than 0.25” (0.64 cm).

3. A manually operated damper or manually adjustable louvers are
not permitted for use.

4. A automatically operated damper or automatically adjustable lou­vers shall be interlocked so that the main burner cannot operate
unless either the damper or the louver is in the fully open position.

TABLE 13:

BTUH Input

40,000
60,000

80,000
100,000
120,000

EXAMPLE: Determining Free Area.
Appliance 1Appliance 2Total Input
100,000 + 30,000 = (130,000 ÷ 4,000) = 32.5 Sq. In. Vertical
Appliance 1Appliance 2Total Input
100,000 + 30,000 = (130,000 ÷ 2,000) = 65 Sq. In. Horizontal

TABLE 14:

BTUH Input Rating Minimum Free Area Required for Each Opening

Free Area - Outdoor Air

Minimum Free Area Required for Each Opening

Rating

Horizontal Duct

(2,000 BTUH)

20 sq. in. (129 cm
30 sq. in. (194 cm
40 sq. in. (258 cm
50 sq. in. (323 cm
60 sq. in. (387 cm

Vertical Duct or

Opening to Outside

(4,000 BTUH)

2

) 10 sq. in. (65 cm2)

2

) 15 sq. in. (97 cm2)

2

) 20 sq. in. (129 cm2)

2

) 25 sq. in. (161 cm2)

2

) 30 sq. in. (194 cm2)

Unconfined Sp ace Minimum Area in Square Inches

40,000
60,000

80,000
100,000
120,000

40 (258 cm
60 (387 cm

80 (516 cm
100 (645 cm
120 (774 cm

2

)

2

)

2

)

2

)

2

)

Round Duct

(4,000

BTUH)

4” (10 cm)
5” (13 cm)
5” (13 cm)
6” (15 cm)
7” (18 cm)

COMBUSTION AIRFLOW
3-WAY TRANSITION

FIGURE 26: Combustion Airflow Path Through The Furnace Casing to

the Burner Box

20 Unitary Products Group

268890-UIM-B-0607

GABLE
VENT

VENTILATED

OPTIONAL
INLET (a)

SOFFIT
VENT

5. A square or rectangular shaped duct shall only be used
when the required free area of the supply opening is

22

9 in (58.06 cm ) or larger. When a square or rectangular
duct is used, its small dimensionshall not be less than
3 in (7.6 cm).

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.

ATTIC

TOP ABOVE
INSULATION

OUTLET
AIR (a)

GAS
WATER
HEATER

VENTILATED

CRAWL SPACE

GAS
VENT

FURNACE

AIR SUPPLY OPENINGS AND DUCTS

An opening may be used in lieu of a duct to provide to provide the outside air

1.

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 “AIR SOURCE FROM OUTDOORS
AND VENT AND SUPPLY AIR SAFETY CHECK” in these instructions for
additional information and safety check procedure.

The duct shall be either metal, or a material meeting the class 1

2.

requirements of CAN4-S110 Standard for Air Ducts.

The duct shall be least the same cross-sectional area as the free

3.

area of the air supply inlet opening to which it connects.

The duct shall terminate within 12 in (30.5 cm) above, and

4.

within 24 in (61 cm) horizontally from, the burner level of
the appliance having the largest input.

GABLE

SOFFIT
VENT

INLET
AIR (b)

VENT

VENTILATED

ATTIC
TOP ABOVE
INSULATION

GAS
WATER
HEATER

FIGURE 27: Outside and Ambient Combustion Air

Vent and Supply (Outside) Air Safety Check Procedure

Follow the procedure in ANSI Z223.1 National Fuel Gas Code. Refer to
the section on the “Recommended Procedure for Safety Inspection of
an Existing Appliance” or in Canada B149.1-00 Natural Gas and Pro­pane Installation Code section on “Venting Systems and Air Supply for
Appliances” and all local codes. In addition to the procedure specified in
ANSI Z223.1, 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.

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 and all doors.

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 continuously.

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, fireplace 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.

GAS
VENT

FURNACE

OUTLET
AIR (a)

INLET
AIR (a)

Two

GAS
VENT

FURNACE

OUTLET
AIR (b)

INLET
AIR (b)

COMBUSTION AIR SOURCE FROM OUTDOORS

Two permanent openings, one within 12 in (30.5 mm) of the top and

1.

INLET
AIR (a)

one within 12 in (30.5 mm) of bottom of the confined space,
permanent openings,
with the outdoors, crawl spaces or attic spaces.

One permanent openings, commencing within 12 in (30.5 mm)of the

2.
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 minimum
free area of:
a.

1 square in per 3000 Btu per hour (6.45 cm 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.

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 blocking effects of louvers, grilles and screens must be given
consideration in calculating free area. If the free area of a specific
louver aor grille is not known.

shall communicate directly or by means of ducts

GAS
WATER
HEATER

2

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 B149.1-00 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, refer to Table 8 of these instructions.

Ventilated Combustion Air

The ventilated attic space or a crawl space from which the combustion
air is taken must comply with the requirements specified in “COMBUS­TION 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. Refer to Table 8 for intake pipe sizing, allowable length and elbow
usage. Follow all notes, procedures and required materials in the
SEALED COMBUSTION AIR SUPPLY section in these instructions
when installing the combustion air pipe from the unit and into a venti­lated attic space or crawl space. DO NOT terminate vent pipe in an Attic
or Crawl Space.

Ventilated Combustion Air Termination

Refer to Figure 28 for required attic termination for the combustion air
intake pipe. For attic termination, use two 90 elbows with the open end
in a downward position. Be sure to maintain 12” (30.5 cm) clearance
above any insulation, flooring or other material.

A crawl space combustion air installation consists of a straight pipe from
the PVC coupling on the burner box that extends into the crawl space
and terminates with a 1/4” (0.63 cm) mesh screen and no elbows.

Unitary Products Group 21

268890-UIM-B-0607

12” MINIMUM BETWEEN
BOTTOM OF BELOW AND
ANY MATERIAL

12”
MIN.

FIGURE 28: Attic Combustion Air Termination
Specially Engineered Installations

The above requirements shall be permitted to be waived where special
engineering, approved by the authority having jurisdiction, provides an
adequate supply of air for combustion, ventilation and dilution of flue
gases.

Be sure to instruct the owner not to block this intake pipe.

SECTION VIII: CONDENSATE PIPING

CONDENSATE DRAIN TUBE 5/8” (1.59 cm)

FIGURE 29: Condensate Drain Internal Hose Routing

CONDENSATE DRAIN

The condensate drain connection is provided in the furnace for field
installation. It consists of the hoses shown below, a NPT male connec­tion, and a 1/2” (1.27 cm) female x 3/4” (1.9 cm) PVC slip coupling.
Some of the drain hoses will be needed to convert the condensate drain
system when the furnace is installed in a horizontal left or right configu­ration. Refer to Figures 30 - 36 for the condensate hose sizes for con­densate drain connections.

IMPORTANT: The condensate drain from the furnace may be con­nected in common with the drain from an air conditioning coil if allowed
by local code.

IMPORTANT: Condensate must be disposed of properly. Follow local
plumbing or wastewater codes. The drain line must maintain a 1/4" per
foot (0.635 cm per meter) slope to the drain.

CONDENSATE DRAIN TRAP AND DRAIN FREEZE
PROTECTION

Special precautions MUST be made if installing furnace in an area,
which may drop below freezing. This can cause improper operation or
damage to the equipment. If the furnace is installed in an area that has
the potential of freezing, the drain line and the drain trap must be pro­tected. Use a 3 to 6 watt per foot at 115 vac, 40º F (4.4° C) self-regulat­ing, shielded and waterproof heat tape. Wrap the drain trap and the
drain line with the heat tape and secure with ties. Follow the heat tape
manufacturer's recommendations.

CONDENSATE DRAIN HOSE PART NUMBERS

TABLE 15:

Part
Number

028-15156-000 #1 Drain tube - Condensate pan (Down flow)
028-15176-000 #2 Drain tube - Inducer (Horizontal RT.)

028-15168-000 #3 Drain tube - Inducer (Down flow)
028-15176-000 #4 Drain tube - Rain gutter (Down flow & Horizontal RT.)
028-15176-000 #5 Drain tube - After Tee (Down flow)
028-15196-000 #6 Drain tube – Upper rain gutter (Horizontal LT.)
028-15169-001 #7 Drain tube - After Tee (Horizontal RT.)
028-13309-004 #8 Drain tube - P-trap (All models)
028-15158-000 #9 Drain tube - Vent system (Horizontal LT.)

028-15197-000 #10
Hoses #2, #4, #5, along with a barbed nipple, and a barbed tee are part of

condensate hose assembly 028-15176-000.

Condensate Drain Hose

Hose

Numb

er

-Vent system Down flow)

- Before Tee (Horizonta l RT.)

Drain tube – Condensate pan (Horizontal –
drain closer to the front of the furnace, both LT & RT)

Description

DOWNFLOW/HORIZONTAL CONDENSATE
INTERNAL DRAIN CONFIGURATIONS

Downflow - Refer to Figure 30

Furnace is shipped with one end of condensate hose #2 left open in the
furnace. If the provided Wye's drain is aligned with the opening in the
top of the furnace, hose #2 can be used. If it is desired that the Wye and
street elbow assembly point away from the opening in the casing top,
then the #2 hose will have to be replaced with provided #9 hose. The
dogleg end of hose #9 hose should be installed on the drain of the Wye.

22 Unitary Products Group

268890-UIM-B-0607

HOSE #5

3/4”

HOSE #2 (if drain aligned
above the hole in
furnace top)

HOSE #4 (with 3/8”
barbed nipple)

3/8” Barbed Tee

HOSE #5

HOSE #1

HOSE #3

3/4”

SPRING CLAMP

9”

HOSE #4

2”

SPRING CLAMP

3/4”

1-1/8”

3/4”

DOG

LEG

* USED AFTER
CONDENSATE
TRAP

DOGLEG

5/8”

1”

2-3/4”

-

SPRING CLAMP

HOSE #8

1”

SPRING CLAMP

CUT
4-1/2”
PIECE

HOSE #3

3-3/8”

17-1/2”

SPRING CLAMP

SPRING CLAMP

22-1/8”

8-1/8”

HOSE #2

1”

HOSE #1

3/8”

2-3/4”

DOG
LEG

FIGURE 30: Downflow Condensate Drain Hose Configuration

Horizontal Left Air Flow (Inducer Low) ­Refer to Figures 31 & 32

1. Remove all the condensate hoses inside the furnace, leaving the
3/8" barbed nipple and hose # 4, both factory installed, in the rain
gutter.

2. Remove the condensate trap and its bracket from inside the fur­nace, saving the screws for use later.

3. Remove the yellow cap from the top drain of the rain gutter and
install loosely packed 3/8" barbed nipple in it.

4. Remove the large condensate cap from the side of the condensate
pan and install it on the middle drain of the condensate pan, from
where #1 hose was removed.

5. Install longer dogleg end of hose #10 through the casing hole on to
the side drain of the condensate pan, where cap was removed in
step #4. Some lubricant may have to be used to facilitate this
installation as the hose is designed as a tight fit over the conden­sate drain. The other, shorter, dogleg end of hose #10 should be
installed into the large recessed drain in the condensate trap.

6. Install the condensate trap bracket, with the condensate trap, on to
the front side of the furnace, using the screws removed in step #1.

1/2”

HOSE #9

3/4”

33”

3/4”

7. Switch the blocked condensate hose to the condensate tap on the
bottom of the condensate pan (close to the inducer).

8. Install hose #9 between the external drain on the Wye and the
condensate trap; with the dogleg end installed on the protruded
(stub) drain of the condensate trap. The length of hose #9 may
have to be trimmed to ensure proper condensate drainage.

9. Remove all condensate hoses off the 3/8" barbed tee.

10. Cut 1-1/2" length of straight 3/8" hose off of hose #5 and install it
on the 3/8" barbed tee. The other end of the 1-1/2" hose should be
installed on the welled opening on the condensate trap.

11. Install one end of the 3/8" barbed tee on hose #4 as shown.
Ensure that hose #4 follows a gradual downward slope all the way
to the barbed tee.

12. Install hose #6 between the top drain of the rain gutter of the
inducer and the remaining open end of 3/8" barbed tee.

13. Ensure that all hoses are properly installed, have no kinks, and are
draining properly. All hoses on the condensate trap should be
pushed all the way down to ensure against leakage.

1-5/8”

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THIS TUBE FOR THE

BLOCKED CONDENSATE

SWITCH MUST BE

RELOCATED FROM ITS

ORIGINAL FACTORY

INSTALLED LOCATION

BEHIND THE COMBUSTION

AIR PIPE TO THE TAP BEHIND

THE DRAFT INDUCER. A SMALL

HOSE IS INSTALLED ON THE TAP

TO FACILITATE THIS.

(STEP 7)

HOSE #9

HOSE #4

3-WAY TRANSITION (Shown)

(Provided with some furnaces)

BLOCKED

CONDENSATE

TAP

AIR

COMBUSTION

PIPE

HOSE #6

CUT FROM

HOSE #5 (1-1/2” long)

FIGURE 31: Horizontal Left Condensate Drain Hose Configuration

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268890-UIM-B-0607

1-5/8”

*USED AFTER

2-3/4”

1”

HOSE #8*

CONDENSATE

TRAP

SPRING CLAMP

1”

DOG

LEG

22-1/8”

HOSE #4

2”

3/4”

HOSE #5

SPRING CLAMP

3/4”

SPRING CLAMP

3/4”

1/2”

9”

HOSE #10

1/2”

5-1/4”

HOSE #6

2-3/4”

90°

90°

3-13/16”

13-16”

25/32”

HOSE #6

60°

1-3/8”

3/8”

BARBED

70°

TEE

HOSE #4

1-5/16”

1-1/2” LONG

3/8” HOSE

3/4”

33”

HOSE #9

3/4”

HOSE #10

1-1/2” PIECE

OF 3/8” HOSE

3/8” BARBED

NIPPLES

3/8” BARBED

NIPPLES

HOSE #6

3/8”

BARBED

HOSE #4

TEE

RECOMMENDED

CONDENSATE

TRAP ORIENTATION

FIGURE 32: Horizontal Left Condensate Drain Hose Configuration

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268890-UIM-B-0607

Horizontal Right Air Flow (Inducer High)
Refer to Figures 33-36

Installation with condensate trap bracket (Front of casing):
Refer to Figure 33 & 34

1. Remove the 2" knockout on the casing side, away from the
inducer motor.

2. Remove all the condensate hoses inside the furnace, including the
3/8" barbed nipple, factory installed, in the rain gutter.

3. Remove the drain cap from the bottom rain gutter drain and insert
the 3/8” barbed nipple removed above in the bottom rain gutter
drain. Place the cap, just removed, to the other side of the rain gut­ter on the inducer.

4. Remove the condensate trap and its bracket from inside the fur­nace, saving the screws for later use.

5. Remove the large condensate cap from the side of the condensate
pan and install it on the middle drain of the condensate pan, from
where #1 hose was removed.

6. Install longer dogleg end of hose #10 through the casing hole on to
the side drain of the condensate pan, where cap was removed in
step #3. Some lubricant may have to be used to facilitate this
installation as the hose is designed to be a tight fit over the con­densate drain. The other, smaller, dogleg end of hose #10 should
be installed into the large recessed drain in the condensate trap.

7. Install the condensate trap bracket, with the condensate trap, on to
the front side of the furnace, using the screws removed in step #1.

8. Install the dogleg end of hose #9 on the Wye drain and route the
hose through the opening on top of the furnace, as shown. Install
the other end of the #9 hose to the barbed tee, inside the furnace.

9. Install the dogleg end of hose #4 to the rain gutter on the inducer.
The other end of hose #4 should be installed on the 3/8" barbed
tee.

10. Install one end of hose #7 on the 3/8" barbed tee inside the fur­nace. Guide the other end of hose #7 towards the condensate
trap, and install it on the tap on the condensate trap.

11. Install the dogleg end of hose #2 on the bottom drain of the
inducer. Guide the other end of hose #2 towards the condensate
trap, and install it on the small recessed drain in the condensate
trap.

12. Ensure that all hoses are properly installed, have no kinks, and are
draining properly. All hoses on the condensate trap and conden­sate pan should be pushed all the way down to ensure against
leakage and performance. Some hoses may have to be trimmed
for proper fit.

NOTE: The condensate trap can also be installed on the 2" knockout
opening, in this configuration, using the provided condensate trap
bracket. Some modifications may, however, have to be made to the
condensate hoses.

Ensure all condensate hoses are pushed all the way down on the
condensate trap, barbed fittings, and condensate pan drains.

Plug all unused condensate trap, condensate pan and inducer drain
connection points using plugs provided.

Installation with condensate trap bracket (Back of casing):
Refer to Figure 35 & 36

1. Remove the 2" knockout on the casing side, away from the
inducer motor.

2. Remove all the condensate hoses inside the furnace, including the
3/8" barbed nipple, factory installed, in the rain gutter.

3. Remove the drain cap from the bottom rain gutter drain and insert
the 3/8” barbed nipple removed above in the bottom rain gutter
drain. Place the cap, just removed, to the other side of the rain gut­ter on the inducer.

4. Remove the condensate trap and it's bracket from inside the fur­nace, saving the screws for later, use.

5. Remove the large condensate cap from the side of the condensate
pan and install it on the middle drain of the condensate pan, from
where #1 hose was removed.

6. Do not remove condensate trap from the condensate trap bracket.

7. Cut 2-1/2" straight piece from hose #1 and install it through the
knockout opening in the casing on the side of the condensate pan,
from where the cap was previously removed. Insert the other end
of the hose into the large recessed drain on the condensate trap.

8. Install the condensate trap bracket to the 2” inch hole on the side
of casing, using existing holes, lining up the condensate pan open­ing with the larger opening on the condensate trap.

9. Install the dogleg end of hose #9 on the Wye drain and route the
hose through the opening on top of the furnace. Install the other
end of the #9 hose to the barbed tee, inside the furnace.

10. Install the dogleg end of hose #4 on 3/8" barbed nipple, in the rain
gutter. The other end of hose #4 should be installed on the 3/8"
barbed tee.

11. Install one end of hose #7 on the 3/8" barbed tee inside the fur­nace. Guide the other end of hose #7 towards the condensate
trap, and install it on the tap on the condensate trap

12. Install the dogleg end of hose #2 on the bottom drain of the
inducer. Guide the other end of hose #2 towards the condensate
trap, and install it on the small recessed drain in the condensate
trap.

13. Ensure that all hoses are properly installed, have no kinks, and are
draining properly. All hoses on the condensate trap should be
pushed all the way down to ensure against leakage. All hoses on
the condensate pan should be pulled all the way up to ensure
proper operation.

26 Unitary Products Group

3/8” BARBED TEE

HOSE #2

268890-UIM-B-0607

THIS TUBE FOR THE

BLOCKED CONDENSATE

SWITCH HAS BEEN

FACTORY INSTALLED

FOR THIS POSITION.

HOSE #9

HOSE #4

HOSE #7

FIGURE 33: Horizontal Right Condensate Drain Hose Configuration (Option 1 - Front of Casing)

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1-5/8”

3/4”

HOSE #9

3/4”

33”

3/8”

HOSE #2

17-1/2”

HOSE #4

SPRING CLAMP

3/4”

SPRING CLAMP

DOG-LEG

1/2”

* USED AFTER

CONDENSATE

2-3/4”

1”

HOSE #8*

TRAP

SPRING CLAMP

1”

DOG-LEG

22-1/8”

3/4”

3/4”

HOSE #7

HOSE #4

21”

HOSE #10

1/2”

5-1/4”

2-3/4”

90°

90°

3-13/16”

13-16”

HOSE #1

CUT

SPRING CLAMP

1”

2-3/4”

4-1/2”

PIECE

8-1/8”

-

DOGLEG

HOSE #2

HOSE #7

2”

3/4”

3/8” BARBED

NIPPLE

HOSE #7

3/8”

BARBED

HOSE #9

RECOMMENDED

CONDENSATE

TRAP ORIENTATION

TEE

HOSE #10

FIGURE 34: Horizontal Right Condensate Drain Hose Configuration (Option 1 - Front of Casing)

28 Unitary Products Group

HOSE #2

268890-UIM-B-0607

3-WAY TRANSITION (Shown)

(Provided with some furnaces)

3/8” BARBED TEE

HOSE #9

HOSE #4

CUT FROM

HOSE #1

HOSE #7

(2-1/2” long)

THIS TUBE FOR THE

BLOCKED CONDENSATE

SWITCH HAS BEEN

FACTORY INSTALLED

FOR THIS POSITION.

FIGURE 35: Horizontal Right Condensate Drain Hose Configuration (Option 2 - Back of Casing)

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3/8”

HOSE #2

17-1/2”

HOSE #4

SPRING CLAMP

3/4”

SPRING CLAMP

DOG-LEG

1/2”

1-5/8”

3/4”

HOSE #9

3/4”

33”

* USED AFTER

CONDENSATE

TRAP

2-3/4”

1”

HOSE #8*

SPRING CLAMP

1”

DOG-LEG

22-1/8”

HOSE #1

CUT

SPRING CLAMP

1”

2-3/4”

4-1/2”

PIECE

8-1/8”

-

DOGLEG

HOSE #4

3/4”

3/4”

HOSE #7

21”

HOSE #10

1/2”

5-1/4”

2-3/4”

90°

90°

3-13/16”

13-16”

2”

3/4”

HOSE #2

3/8” BARBED

NIPPLE

HOSE #1

HOSE #7

3/8”

BARBED

TEE

RECOMMENDED

CONDENSATE

TRAP ORIENTATION

HOSE #9

HOSE #7

FIGURE 36: Horizontal Right Condensate Drain Hose Configuration (Option 2 - Back of Casing)

30 Unitary Products Group

CONDENSATE DRAIN TERMINATION

DO NOT terminate condensate drain in a chimney, or where the drain
line may freeze. The line must terminate at an inside drain to prevent
freezing of the condensate and possible property damage. DO NOT
trap the drain line at any other location than at the condensate drain
trap supplied with the furnace. A condensate sump pump MUST be
used if required by local codes, or if no indoor floor drain is available.
The condensate sump pump must be approved for use with acidic con­densate.

268890-UIM-B-0607

CONDENSATE DRAIN PRE-START UP PROCEDURE

The condensate trap must be filled with water before putting the furnace
into operation. Perform the following procedures only after the conden­sate trap has been properly piped to a drain connection using the pro­cedure in this instruction. The recommended procedure is as follows:

1. Disconnect the condensate drain hose from the induced draft
blower discharge.

2. Elevate this hose and fill with water using a funnel.

3. Replace the condensate drain hose and clamps. If this procedure
is not followed, the unit may not properly drain on initial start up.

SECTION IX: SAFETY CONTROLS

CONTROL CIRCUIT FUSE

A 3-amp fuse is provided on the control circuit board to pr otect the 24­volt 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

This unit is equipped with an electrical interlock switch mounted in the
blower 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.

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 dis­connect.

Blower and burner must never be operated without the blower
panel in place.

ROLLOUT SWITCH CONTROLS

These controls are mounted on the burner box assembly. If the temper­ature in the burner box exceeds its set point, the ignition control and the
gas valve are de-energized. The operation of this control indicates a
malfunction in the combustion air blower, heat exchanger or a blocked
vent pipe connection. Corrective action is required. These are manual
reset controls that must be reset before operation can continue.

PRESSURE SWITCHES

This furnace is supplied with a pressure switch which monitors the flow
through the combustion air/vent piping system. This switch de-ener­gizes the ignition control module and the gas valve if any of the follow­ing conditions are present. Refer to Figure 37 for tubing connections.

1. Blockage of combustion air piping or terminal.

2. Blockage of vent piping or terminal.

3. Failure of combustion air blower motor.

4. Blockage of condensate drain piping.

DOWNFLOW/HORIZONTAL

FIGURE 37: Pressure Switch Tubing Routing

LIMIT CONTROLS

There is high temperature limit control located on the furnace vestibule
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

1. Dirty filter,

2. If the indoor fan motor should fail, or

3. Too many supply or return registers closed or blocked off.
The control module will lockout if the limit trips 5 consecutive times

within a single call for heat. Control will reset and try ignition again after
1 hour.

SECTION X: START-UP AND
ADJUSTMENTS

The initial start-up of the furnace requires the following additional
procedures:

IMPORTANT: All electrical connections made in the field and in the fac-

tory should be checked for proper tightness.
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.

Perform the following procedures only after the condensate trap
has been properly piped to a drain connection using the procedure
in this instruction. Be sure proper ventilation is available to dilute
and carry away any vented gas.

TOOLS AND INFORMATION THAT WILL BE
REQUIRED IN ORDER TO PROPERL Y PERFORM THE
FURNACE STARTUP PROCEDURE.

1. Call the local gas supplier to obtain heating value of the natural
gas. If you cannot obtain the heating valve of the gas from the gas
supplier, you may use a default value of 1030 BTU/SCF (38.4 MJ /
m³).

2. You will need a thermometer or portable digital thermometer to
read the supply and return air temperatures.

3. You will need a U-tube manometer or digital equipment that has
the ability to read pressures between 0 – 15” in.w.c (0 - 3.73 kPa)
in order to measure the gas line and the manifold pressures.

4. You will need a 3/32” Allen wrench for the pressure port plugs in
the gas valve.

5. You will need 2 pieces of 1/8” (0.3 cm) ID flexible tubing that is 12”
(30 cm) in length, 2 – pieces of 1/8” (0.3 cm) tubing that are 4”
(10.1 cm) in length, a 1/8” (0.3 cm) tee and a 1/8” (0.3 cm) adapter
to connect the U-tube manometer or the digital pressure measur­ing equipment to the gas valve pressure ports.

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There is an accessory kit (1PK0601) available from Source 1, which
has the following items:

• 1 - 12” (30 cm) length x 1/8” (0.3 cm) diameter tubing

• 2 – pieces of 4” (10 cm) length x 1/8” (0.3 cm) diameter tubing

• 1 - 5/16” (0.8 cm) tee

• 1 – 5/16” (0.8 cm) x 1/8” (3.175 mm) reducing coupling

• 1 – 1/8” (0.3 cm) adapter

There is a accessory kit (1PK0602) available from Source 1, which has
the following items:

• 12” (30 cm) length x 1/8” (0.3 cm) diameter tubing

• 2 – pieces of 4” (10 cm) length x 1/8” (0.3 cm) diameter tubing

• 1 - 5/16” (0.8 cm) tee

• 1 – 5/16” (0.8 cm) x 1/8” (0.3 cm) reducing coupling

• 1 – 1/8” (0.3 cm) adapter

• 1 - Dwyer – Manometer

These items are required in order to properly perform the required star­tup procedure.

IGNITION SYSTEM SEQUENCE

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:
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.

b. After this warm up, the ignition module will energize (open)

the main gas valve.

c. After flame is established, the supply air blower will start in

about 30 seconds.

IMPORTANT: Burner ignition may not be satisfactory on first startup
due to residual air in the gas line or until gas manifold pressure is
adjusted. The ignition control will make 3 attempts to light before lock­ing out.

With furnace in operation, check all of the pipe joints, gas valve connec­tions 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.

The furnace and its equipment shutoff valve must be disconnected from
the gas supply piping system during any pressure testing of that system
at test pressures in excess of 1/2 PSI (3.45 kPa).

The furnace must be isolated from the gas supply piping system by
closing the equipment shutoff valve during any pressure testing of the
gas supply piping system.

CALCULATING THE FURNACE INPUT
(NATURAL GAS)

NOTE: Burner orifices are sized to provide proper input rate using natu­ral gas with a heating value of 1030 BTU/Ft
ing value of your gas is significantly different, it may be necessary to
replace the orifices.

NOTE: Front door of burner box must be secured when checking gas
input.

1. Turn off all other gas appliances connected to the gas meter.

2. At the gas meter, measure the time (with a stop watch) it takes to
use 2 cubic ft. (0.0566 m

3. Calculate the furnace input by using one of the following equa­tions.

3

.) of gas.

3

(38.4 MJ/m3). If the heat-

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.

32 Unitary Products Group

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In the USA use the following formula to calculate the furnace input.

For natural gas multiply the heat content of the gas BTU/SCF or Default 1030 BTU/SCF (38.4 MJ/m
the gas meter, times a barometric pressure and temperature correction factor of 0.960; times 3600, then divided by the time (In seconds) it took to
measure 2 cubic ft. (0.056 m) of gas from the gas meter.

For propane (LP) gas multiply the heat content of the gas BTU/SCF or Default 2500 BTU/SCF (93.15 MJ/m
sured at the gas meter, times a barometric pressure and temperature correction factor of 0.960; times 3600, then divided by the time (In seconds) it
took to measure 1 cubic ft. (0.028 m) of gas from the gas meter.

The formula for US input calculation using a cubic foot gas meter:

BTU/ft3 x 2 cu.ft. x 0.960 x 3600

Seconds it took to measure the 2 cu.ft. of gas Seconds it took to measure the 1 cu.ft. of ga s

NATURAL GAS INPUT CALCULATION PROPANE (LP) GAS INPUT CALCULATION

EXAMPLE: EXAMPLE:

1030 x 2 x 0.960 x 3600

90.5 108

Natural Gas Propane Gas

1030 BTU/SCF 2500 BTU/SCF

=BTU/H

= 78,666.90

BTU/ft3 x 1 cu.ft. x 0.960 x 3600

2500 x 1 x 0.960 x 3600

In Canada you will use the following formula to calculate the furnace input if you are using a cubic foot gas meter.

For Natural Gas multiply the Heat content of the gas MJ/m

3

(or Default 38.4), times 2 cubic ft. of gas x 0.028 to convert from cubic feet to cubic
meters measured at the gas meter, times a barometric pressure and temperature correction factor of 0.960; times 3600, then divided by the time it
took to measure 2 cubic ft. (0.056 m) of gas from the gas meter.

3

For Propane (LP) Gas multiply the Heat content of the gas MJ/m

(or Default 93.15), times 1 cu. ft. of gas x 0.028 to convert from cubic feet to cubic
meters measured at the gas meter, times a barometric pressure and temperature correction factor of 0.960; times 3600, then divided by the time it
took to measure 1 cubic ft. (0.028 m) of gas from the gas meter.

The formula for metric input calculation using a cubic foot gas meter:

3

x 2 cu.ft. x 0.028 x 0.960 x 3600

MJ/m

Seconds it took to measure the 2 cu.ft . of gas

NATURAL GAS INPUT CALCULATION

EXAMPLE:

38.4 x 2 x 0.028 x 0.960 x 3600

Natural Gas

1030 BTU/SCF = 38.4 MJ/m

PROPANE (LP) GAS INPUT CALCULATION

EXAMPLE:

93.15 x 1 x 0.028 x 0.960 x 3600

Propane Gas

2500 BTU/SCF = 93.15 MJ/m

90.5

3

108

3

= MJ/H x 0.2777 = kW x 3412.14 = BTU/H

= 82.12 x 0.2777 = 22.80 x 3412.14 = 77,796.80

= 83.46 x 0.2777 = 23.18 x 3412.14 = 79,093.4

In Canada use the following formula to calculate the furnace input if you are using a gas meter that measures cubic meters.

3

For Natural Gas multiply the Heat content of the gas MJ/m

(or Default 38.4), times 0.10 m3 of gas measured at the gas meter, times a barometric

pressure and temperature correction factor of 0.960; times 3600, then divided by the time it took to measure 0.10 m

3

For Propane (LP) Gas multiply the Heat content of the gas MJ/m

(or Default 93.15), times 0.10 m3 of gas measured at the gas meter, times a baro­metric pressure and temperature correction factor of 0.960; times 3600, then divided by the time it took to measure 0.10 m
meter.

The formula for metric input calculation using a cubic meter gas meter:

MJ/m3 x m3 x 0.960 x 3600

Seconds it took to measure the 0.10

NATURAL GAS INPUT CALCULATION

EXAMPLE:

38.4 x 0.1 x 0.960 x 3600
160

Natural Gas

1030 BTU/SCF = 38.4 MJ/m

PROPANE (LP) GAS INPUT CALCULATION

EXAMPLE:

93.15 x 0.1 x 0.960 x 3600
387

Propane Gas

2500 BTU/SCF = 93.15 MJ/m

m

3

3

of gas

3

= MJ/H x 0.2777 = kW x 3412.14 = BTU/H

= 82.94 x 0.2777 = 23.03 x 3412.14 = 78,581.60

= 83.19 x 0.2777 = 23.10 x 3412.14 = 78,826.3

3

), times 2 cubic ft. (0.056 m) of gas measured at

3

), times 1 cubic ft. (0.028 m) of gas mea-

=BTU/H

= 80,000.00

3

of gas from the gas meter.

3

of gas from the gas

DO NOT ADJUST the manifold pressure regulator if the actual input is equal to or within 8% less than the furnace input specified on the rating plate
or if the furnace rise is above the specified rise range on the rating plate.

If the actual input is significantly higher than the furnace input specified on the rating plate then replace the gas orifices with the gas orifices
of the proper size for the type of gas you are using.

Unitary Products Group 33

268890-UIM-B-0607

Be sure to relight any gas appliances that were turned off at the
start of this input check.

TABLE 16:

IMPORTANT: The inlet gas pressure operating range table specifies

what the minimum and maximum gas line presures must be for the fur­nace to operate safely. The gas line pressure MUST BE

• 7” W.C. (1.74 kPA) for Natural Gas

• 11” W.C. (2.74 kPA) for Propane (LP) Gas

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.

Inlet Gas Pressure Range

INLET GAS PRESSURE RANGE

Natural Gas Propane (LP)

Minimum 4.5” W. C. (1.12 kPa) 8.0” W.C. (1.99 kPa)

Maximum 10.5” W.C. (2.61 kPa) 13.0” (3.24 kPa) W.C.

Reading the gas pressure with the burner box cover removed -

Remove the screws securing the burner box front cover plate. Remove
the cover. The gasket and may stick in place. Connect the positive side
of the manometer to the gas valve as described in E above. There will
be no second connection to the manometer, as it will reference atmo­spheric pressure. Refer to Figure 39 for connection details.

IMPORTANT: The cap for the pressure regulator must be removed
entirely to gain access to the adjustment screw. Loosening or tightening
the cap does not adjust the flow of gas.

1. Refer to Figure 38 for location of pressure regulator adjustment
cap and adjustment screw on main gas valve.

2. Turn gas and electrical supplies on and follow the operating
instructions to place the unit back in operation.

3. Adjust manifold pressure by adjusting gas valve regulator screw
for the appropriate gas per the following:

TABLE 17:

Nominal Manifold Pressure

NOMINAL MANIFOLD PRESSURE

Natural Gas 3.5" w.c. (0.87 kPa)

Propane (LP) Gas 10.0" w.c. (2.488 kPa)

ADJUSTMENT OF MANIFOLD GAS PRESSURE

Manifold gas pressure may be measured by two different procedures. It
may be measured with the burner box cover in place or it may be mea­sured with the burner box cover removed. Follow th e appropriate sec­tion in the instructions below. Refer to Figure 38 for a drawing of the
locations of the pressure ports on the gas valve.

T urn 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.

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 setscrew by turn­ing it 1 turn counter clockwise. DO NOT REMOVE THE SET
SCREW FROM THE PRESSURE PORT.

Read the inlet gas pressure using either of the two meth­ods below.

Reading the gas pressure with the burner box cover in place:

A. Disconnect the pressure reference hose from the right side of

the burner box. Using a tee fitting and a short piece of hose,
connect the negative side of the manometer to the burner
box as described in below.

B. Remove one end the 5/16” (0.8 cm) ID flexible tubing over

the pressure port on the burner box.

C. Insert the end of the 5/16” (0.8 cm) tubing, that has the 1/8”

(0.3 cm) adapter at the end of the tube, in to the 1/8” (0.3 cm)
tee.

D. Connect the 1/8” (0.3 cm) tee to the burner box adapter and

to the negative side of a U-tube manometer or digital pres­sure measuring equipment with 2 – 1/8” (0.3 cm) tubes.

E. Use the 5/16” (0.8 cm x 1/8” (0.3 cm) reducing coupling and a

4” (10.2 cm) piece of 1/8” (0.3 cm) tubing to connect the posi­tive side of the manometer to the gas valve pressure refer­ence port. Refer to Figure 39 for connection details.

OUTLET
PRESSURE
PORT

INLET

WRENCH
BOSS

INLET
PRESSURE
PORT

OFF

ON

ON/OFF SWITCH
(Shown in ON position)

VENT PORT

OUTLET

MAIN REGULATOR
ADJUSTMENT

FIGURE 38: Gas Valve
IMPORTANT: If gas valve regulator is turned in (clockwise), manifold

pressure is increased. If screw is turned out (counterclockwise), mani­fold pressure will decrease.

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)”.

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 and fittings from the gas valve pressure
tap and the pressure reference hose from the right side of the
burner box and tighten the pressure tap plug using the 3/32”
Allen wrench. Replace the burner box front cover (if it was
removed) and place the pressure reference hose back on the gas
valve.

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 gas detector, a non-corrosive
leak detection fluid, or other leak detection methods.

The manifold pressure must be checked with the screw-off cap for
the gas valve pressure regulator in place. If not, the manifold pres­sure setting could result in an over-fire condition. A high manifold
pressure will cause an over-fire condition, which could cause pre­mature heat exchanger failure. If the manifold pressure is too low,
sooting and eventual clogging of the heat exchanger could occur.
Be sure that gas valve regulator cap is in place and burner box to
gas valve pressure reference hose is connected.

34 Unitary Products Group

6
5
4
3
2
1
0
1
2
3
4
5
6

BURNER BOX

6
5
4
3
2
1
0
1
2
3
4
5
6

PRESSURE
REFERENCE
HOSE

268890-UIM-B-0607

WITH BURNER BOX COVER IN PLACE WITH BURNER BOX COVER REMOVED

TEE
FITTING

GAS
VALV E

BURNER BOX
PRESSURE
REFERENCE
HOSE

GAS VALVE

6
5
4

U-TUBE
MANOMETER

3
2
1
0
1
2
3
4
5
6

3.5 IN
WATER COLUMN
GAS PRESSURE
SHOWN

FIGURE 39: Reading Gas Pressure

ADJUSTMENT OF TEMPERATURE RISE

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 Table 7 “ELECTRICAL AND PERFORMANCE
DATA”.

The supply air temperature cannot exceed the “Maximum Supply
Air Temperature” specified in these instructions and on the fur­nace 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.

The temperature rise, or temperature difference between the return air
and the heated supply air from the furnace, must be within the range
shown on the furnace rating plate and within the application limitations
as shown in Table 7.

After about 20 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.

6
5
4

U-TUBE
MANOMETER

3
2
1
0
1
2
3
4
5
6

3.5 IN
WATER COLUMN
GAS PRESSURE
SHOWN

All direct-drive blowers have multi-speed motors. The blower motor
speed taps are located in the control box in the blower compartment.
Refer to Figure 40, 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 are provided.

Do not energize more than one motor speed at a time or damage to
the motor will result.

ADJUSTMENT OF FAN CONTROL SETTINGS

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 sec­onds. 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 40.

The blower speed connections shown in Figure 40 are typical. How­ever, these connections may vary from model to model and may be
changed as needed to give proper heating and cooling airflow.

TWIN

FAN OFF
ADJUSTMENT
JUMPER

FIGURE 40: Furnace Control Board

Unitary Products Group 35

Y/Y2

W

R

G

C

120

180

90

60

BLOWER

OFF

DELAY

HUM

PAR K

PARK

HI COOL

HEAT

EAC-H

L1

XFMR

NEUTRALS

YELLOW-MED. LOW

RED-LOW
BLACK-HI

BLUE-MED. HI

268890-UIM-B-0607

FURNACE CONTROL DIAGNOSTICS

The furnace has built-in, self-diagnostic capability. If a system problem
occurs, a blinking LED shows a fault code. The LED can flash red,
green or amber to indicate various conditions. It is located behind a
clear view port in the blower compartment door.

The control continuously monitors its own operation and the operation
of the system. If a failure occurs, the LED will indicate the failure code. If
the failure is internal to the control, the light will stay on continuously. In
this case, the entire control should be replaced, as the control is not
field repairable.

Flash sequence codes 1 through 10 are as follows: LED will turn “on”
for 1/4 second and “off” for 1/4 second. This pattern will be repeated the
number of times equal to the code. For example, six “on” flashes equals
a number 6 fault code. All flash code sequences are broken by a 2 sec­ond “off” period.

SLOW GREEN FLASH: Normal operation.
SLOW AMBER FLASH: Normal operation with call for heat.
RAPID RED FLASH: Twinning error, incorrect 24V phasing. Check

twinning wiring.
RAPID AMBER FLASH: Flame sense current is below 1.5 microamps.

Check and clean flame sensor. Check for proper gas flow.
4 AMBER FLASHES: The control board is recieving a “Y” signal fr om

the thermostat without a “G” signal, indicating improper thermostat wir­ing.

1 RED FLASH: This indicates that flame was sensed when there was
not a call for heat. With this fault code the control will turn on both the
inducer motor and supply air blower. A gas valve that leaks through or
is slow closing would typically cause this fault.

2 RED FLASHES: This indicates that the normally open pressure
switch contacts are stuck in the closed position. The control confirms
these contacts are open at the beginning of each heat cycle. This would
indicate a faulty pressure switch or miswiring.

3 RED FLASHES: This indicates the normally open pressure switch
contact did not close after the inducer was energized. This could be
caused by a number of problems: faulty inducer, blocked vent pipe, bro­ken pressure switch hose or faulty pressure switch.

4 RED FLASHES: This indicates that a primary or auxiliary limit switch
has opened its normally closed contacts. With this fault code the control
will operate the supply air blower and inducer. This condition may be
caused by: dirty filter, improperly sized duct system, incorrect blower
speed setting, incorrect firing rate or faulty blower motor.

5 RED FLASHES: This fault is indicated if the normally closed contacts
in the rollout switch opens. The rollout control is manually reset. If it has
opened, check for proper combustion air, proper inducer operation, and
primary heat exchanger failure or burner problem. Be sure to reset the
switch after correcting the failure condition.

6 RED FLASHES: This indicates that after the unit was operating, the
pressure switch opened 4 times during the call for heat. If the main
blower is in a “Delay on” mode it will complete it, and any subsequent
delay off period. The furnace will lock out for one hour and then restart.

7 RED FLASHES: This fault code indicates that the flame could not be
established. This no-light condition occurred 3 times (2 retries) during
the call for heat before locking out. Low gas pressure, faulty gas valve,
faulty hot surface ignitor or burner problem may cause this. The furnace
will lock out for one hour and then restart.

8 RED FLASHES: This fault is indicated if the flame is lost 5 times (4
recycles) during the heating cycle. This could be caused by low gas
pressure or faulty gas valve. The furnace will lock out for one hour and
then restart.

9 RED F

problem. 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.

10 RED FLASHES: Gas valve energized with no call for heat. Check
gas valve and gas valve wiring.

11 RED FLA SHES: This indicates that a primary or auxiliary 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.

12 RED FLASHES: This code indicates an open igniter circuit, which
could be caused by a disconnected or loose wire or by a cracked or bro­ken igniter.

STEADY ON RED: Control failure. Replace control board.
60-MINUTE AUTOMATIC RESET FROM LOCKOUT: This control

includes a “watchdog” type circuit that will reset from a lockout condition
after 60 minutes. Operational faults 6,7,8 will be reset. This provides
protection to an unoccupied structure if a temporary condition exists
causing a furnace malfunction. An example would be a low incoming
gas supply pressure preventing unit operation. When the gas pressure
is restored, at some point the “watchdog” would restart the unit and pro­vide heat for the house.

NOTE: If a flame is detected the control flashes the LED for 1/8 of a

LASHES: Indicates reversed line voltage polarity or grounding

second and then enters a flame stabilization period.

IGNITION CONTROL

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)

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.

The control stores up to five separate error codes. 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 button, 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.

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.

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.

36 Unitary Products Group

268890-UIM-B-0607

TABLE 18:

MODELS

Input/
Airflow/
Cabinet

40/1200/A

60/1200/B

80/1200/B

80/1600/C

100/1600/C

100/2000/C

120/2000/D

NOTES:

Blower Performance CFM

Airflow with Top Return - without Filters (CFM)

Speed

Tap

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0.025 0.050 0.075 0.099 0.124 0.149 0.174 0.199 0.224 0.249

High 1635 1590 1535 1480 1415 1340 1280 1185 NR NR 46 45 43 42 40 38 36 34 NR NR

Med-High 1179 1170 1160 1140 1135 1098 1048 1026 NR NR 33 33 33 32 32 31 30 29 NR NR

Med-Low969967967959938905860802NRNR2727272727262423NRNR

Low 774 753 745 726 698 674 652 612 NR NR 22 21 21 21 20 19 18 17 NR NR

High 1687 1652 1631 1595 1557 1511 1456 1382 1313 1211 48 47 46 45 44 43 41 39 37 34

Med-High 1193 1183 1173 1162 1142 1115 1076 1036 982 950 34 33 33 33 32 32 30 29 28 27

Med-Low93393392191190287282579377171226262626262523222220

Low 752 745 731 718 698 652 602 580 536 496 21 21 21 20 20 18 17 16 15 14

High 1686 1658 1623 1572 1534 1465 1391 1305 1202 1091 48 47 46 44 43 41 39 37 34 31

Med-High 1257 1223 1218 1203 1177 1142 1094 1026 939 874 36 35 34 34 33 32 31 29 27 25

Med-Low97798297695593489984379173868628282827262524222119

Low 775 777 757 733 698 663 627 584 549 490 22 22 21 21 20 19 18 17 16 14

High 2071 2026 1981 1935 1864 1796 1713 1625 1532 1401 59 57 56 55 53 51 48 46 43 40

Med-High 1583 1590 1569 1554 1532 1502 1457 1409 1327 1221 45 45 44 44 43 43 41 40 38 35

Med-Low 1256 1275 1275 1288 1275 1265 1232 1187 1126 1023 36 36 36 36 36 36 35 34 32 29

Low 937 939 936 945 942 936 912 874 810 726 27 27 26 27 27 26 26 25 23 21

High 1996 1961 1938 1896 1836 1779 1707 1625 1531 1399 56 56 55 54 52 50 48 46 43 40

Med-High 1449 1480 1495 1488 1488 1449 1417 1368 1299 1208 41 42 42 42 42 41 40 39 37 34

Med-Low 1167 1192 1192 1187 1202 1192 1182 1140 1097 1018 33 34 34 34 34 34 33 32 31 29

Low 932 900 871 840 805 761 710 663 641 623 26 25 25 24 23 22 20 19 18 18

High 2404 2320 2225 2138 2034 1924 1816 1692 1559 1422 68 66 63 61 58 54 51 48 44 40

Med-High 2018 1955 1883 1815 1750 1670 1586 1497 1394 1246 57 55 53 51 50 47 45 42 39 35

Med-Low 1626 1581 1531 1488 1418 1363 1291 1225 1123 964 46 45 43 42 40 39 37 35 32 27

Low 1336 1291 1249 1205 1155 1091 1018 951 884 759 38 37 35 34 33 31 29 27 25 21

High 2520 2432 2353 2251 2152 2042 1947 1815 1701 1525 71 69 67 64 61 58 55 51 48 43

Med-High 2018 1979 1945 1911 1863 1779 1705 1599 1493 1353 57 56 55 54 53 50 48 45 42 38

Med-Low 1586 1545 1501 1457 1407 1351 1287 1216 1081 926 45 44 42 41 40 38 36 34 31 26

Low 1321 1266 1213 1163 1111 1071 987 864 763 700 37 36 34 33 31 30 28 24 22 20

1. Airflow expressed in standard cubic feet per minute (CFM) and in cubic meters per minute (m

2. Motor voltage at 115 V.

3. NR = Operation at this static pressure is not recommended.

External Static Pressure, Inches W.C.

Airflow with Top Return - without Filters (m

External Static Pressure, Inches (kPa)

3

/min).

3

min)

FILTER PERFORMANCE

The airflow capacity data published in Table 18 represents blower per­formance WITHOUT filters. To determine the approximate blower per­formance of the system, apply the filter drop value for the filter being

NOTE: The filter pressure drop values in Table 19 are typical values for
the type of filter listed and should only be used as a guideline. Actual
pressure drop ratings for each filter type vary between filter manufactur­ers.

used or select an appropriate value from the Table 19.

TABLE 19:

Filter Performance - Pressure Drop Inches W.C. and (kPa)

Airflow Range

CFM

3

m

/min in2 cm

Minimum

Opening Size

Filter Type

Disposable Washable Fiber Pleated

2

In W.C. kPA In W.C. kPA In W.C. kPA

0 - 750 0 - 21.4 230 1484 0.01 0.00249 0.01 0.00249 0.15 0.03736

751 - 1000 21.25 - 28.32 330 2129 0.05 0.01245 0.05 0.01245 0.20 0.04982
1001 - 1250 28.33 - 35.40 330 2129 0.10 0.02491 0.10 0.02491 0.20 0.04982
1251 - 1500 35.41 - 42.48 330 2129 0.10 0.02491 0.10 0.02491 0.25 0.06227
1501 - 1750 42.49 - 49.55 380 2452 0.15 0.03736 0.14 0.03487 0.30 0.07473
1751 - 2000 49.56 - 56.63 380 2542 0.19 0.04733 0.18 0.04484 0.30 0.07473

2001 & Above 56.64 - Above 463 2987 0.19 0.04733 0.18 0.04484 0.30 0.07473

Unitary Products Group 37

268890-UIM-B-0607

APPLYING FILTER PRESSURE DROP TO
DETERMINE SYSTEM AIRFLOW

To determine the approximate airflow of the unit with a filter in place, fol­low the steps below:

1. Select the filter type.

2. Determine the External System Static Pressure (ESP) without the
filter.

3. Select a filter pressure drop from the table based upon the number
of return air openings or return air opening size and add to the
ESP from Step 2 to determine the total system static.

4. If total system static matches a ESP value in the airflow table (i.e.

0.20, 0.60, etc,) the system airflow corresponds to the intersection
of the ESP column and Model/Blower Speed row.

5. If the total system static falls between ESP values in the table (i.e.

0.58, 0.75, etc.), the static pressure may be rounded to the nearest
value in the table determining the airflow using Step 4 or calculate
the airflow by using the following example.

FIELD INST ALLED ACCESSORIES - NON-ELECTRICAL

MODEL NO. DESCRIPTION USED WITH

1NP0347 PROPANE (LP) CONVERSION KIT ALL MODELS
1CT0302 CONCENTRIC INTAKE/VENT 2” ALL MODELS EXCEPT 120 MBH
1CT0303 CONCENTRIC INTAKE/VENT 3” ALL MODELS
1PS0904
1PS0901 60/100/120
1PS0902 80/1200
1PS0903 80/1600
1NK0301 CONDENSATE NEUTRALIZER KIT ALL MODELS
1HT0901 SIDEWALL VENT TERMINATION KIT 3” ALL MODELS
1HT0902 SIDEWALL VENT TERMINATION KIT 2” ALL MODELS
1CB0314 COMBUSTIBLE FLOOR BASE
1CB0317 17-1/2” CABINET
1CB0321 21” CABINET

1CB0324 24 1/2” CABINET
1TK0914

1TK0917 17-1/2” CABINET
1TK0921 21” CABINET
1TK0924 24 1/2” CABINET
1VK0901 3-WAY TRANSITION KIT All MODELS

These kits are required in downflow application when using G*F*

series coils. These kits are not required with MC/FC series coils,
but please ensure that the coil and furnace are secured and that

HIGH ALTITUDE PRESSURE SWITCH KIT

(Does Not Include Orifices)

there are noair leaks.

COIL TRANSITION KIT

Example: For a 120,000 Btuh furnace operating on high speed blower,
it is found that total system static is 0.58" w.c. To determine the system
airflow, complete the following steps:

1. Obtain the airflow values at 0.50" & 0.60" ESP.
Airflow @ 0.50": 2152 CFM

Airflow @ 0.60": 2042 CFM

2. Subtract the airflow @ 0.50" from the airflow @ 0.60" to obtain air­flow difference.

2042 - 2152 = -110 CFM

3. Subtract the total system static from 0.50" and divide this differ­ence by the difference in ESP values in the table, 0.60" - 0.50", to
obtain a percentage.

(0.58 - 0.50) / (0.60 - 0.50) = 0.8

4. Multiply percentage by airflow difference to obtain airflow reduc­tion.

(0.8) x (-110) = -88

5. Subract airflow reduction value to airflow @ 0.50" to obtain actual
airflow @ 0.58" ESP.

2152 - 88 = 2064

40

14-1/2” CABINET

14-1/2” CABINET

38 Unitary Products Group

SECTION XI: WIRING DIAGRAM

268890-UIM-B-0607

FIGURE 41: Wiring Diagram

Unitary Products Group 39

NOTES

Subject to change without notice. Printed in U.S.A. 268890-UIM-B-0607
Copyright © by York International Corp. 2007. All rights reserved. Supersedes: 268890-UIM-A-0407

Unitary 5005 Norman
Product York OK
Group Drive 73069