Whirlpool WFCU User manual

90+ GAS FURNACE INSTALLATION INSTRUCTIONS
GAS FURNACE SAFETY
Table of Contents
GAS FURNACE SAFETY................................................................1
INSTALLATION REQUIREMENTS................................................3
Tools and Parts ............................................................................3
Location Requirements................................................................3
Installation Configurations ...........................................................4
Duct Work Requirements.............................................................5
Electrical Requirements ...............................................................5
Gas Supply Requirements...........................................................5
Venting Requirements..................................................................5
INSTALLATION INSTRUCTIONS..................................................6
Inspect Shipment .........................................................................6
Plan Vent System.........................................................................7
Determine Vent Pipe Direction.....................................................9
Connect Venting.........................................................................14
Install Condensate Disposal.......................................................14
Install Duct Work ........................................................................15
Filter Specifications....................................................................15
Make Electrical Connections .....................................................16
Make Gas Connections..............................................................17
Check the Furnace Input Rate ...................................................17
Adjust the Furnace Input Rate ...................................................18
Complete Installation..................................................................19
Sequence of Operation ..............................................................20
Controls ......................................................................................20
TROUBLESHOOTING ..................................................................21
ASSISTANCE OR SERVICE.........................................................24
Accessories ................................................................................24
46948D003
Whirlpool®Home Cooling and Heating
7901 S.W. 6th Court
Plantation, Florida 33324
Models WFCU, WFCC, WGFDC, WGFDU
You can be killed or seriously injured if you don't
immediately follow instructions.
You can be killed or seriously injured if you don't
follow instructions.
All safety messages will tell you what the potential hazard is, tell you how to reduce the chance of injury, and tell you
what can happen if the instructions are not followed.
Your safety and the safety of others are very important.
We have provided many important safety messages in this manual and on your appliance. Always read and obey all
safety messages.
This is the safety alert symbol.
This symbol alerts you to potential hazards that can kill or hurt you and others.
All safety messages will follow the safety alert symbol and either the word “DANGER” or
“WARNING.” These words mean:

2
ADDITIONAL SAFETY INFORMATION
SAVE THESE INSTRUCTIONS
■
Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.
■
Install this furnace only in a location and position
as specified in the Location Requirements section
of these instructions.
■
Provide adequate combustion and ventilation air to
the furnace space as specified in the “Venting
Requirements” section of these instructions.
■
Adequate clearance must be provided around the
vent-air intake terminals.
Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system
only, as specified in the “Venting Requirements”
section of these instructions.
■
■
Never test for gas leaks with an open flame. Use a
commercially available soap solution made specif-
ically for the detection of leaks to check all connec-
tions, as specified in the “Make Gas Connections”
section of these instructions.
Always install furnace to operate within the furnace’s
intended temperature-rise range with a duct system
which has an external static pressure within the
allowable range, as specified in the “Complete
Installation” section of these instructions. See
furnace rating plate.
■
IMPORTANT SAFETY INSTRUCTIONS
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.
■
■
A gas-fired furnace for installation in a residential
garage must be installed as specified in the
“Location Requirements” section of these
instructions.
The furnace is not to be used for temporary heating
of buildings or structures under construction.
■
■
The furnace shall be installed so the electrical
components are protected from water.
■ Furnaces for indoor installation on combustible
flooring shall not be installed directly on carpeting,
tile or other combustible material other than wood
flooring.
The California Safe Drinking Water and Toxic Enforcement Act requires the Governor of California to publish a list
of substances known to the State of California to cause cancer, birth defects, or other reproductive harm, and
requires businesses to warn of potential exposure to such substances.
WARNING: This product contains a chemical known to the State of California to cause cancer, birth defects, or
other reproductive harm.
This appliance can cause low-level exposure to some of the substances listed, including benzene, formaldehyde,
carbon monoxide, toluene, and soot.
In the State of Massachusetts, the following installation instructions apply:
■ Installations and repairs must be performed by a qualified or licensed contractor, plumber, or gasfitter qualified or
licensed by the State of Massachusetts.
■ If using a ball valve, it shall be a T-handle type.
■ A flexible gas connector, when used, must not exceed 3 feet.

3
INSTALLATION
REQUIREMENTS
These instructions are intended as a general guide only for use by
qualified persons and do not supersede any national or local
codes in any way. Compliance with all local, state, or national
codes pertaining to this type of equipment should be determined
prior to installation.
Read this entire instruction manual, as well as the instructions
supplied in separate equipment, before starting the installation.
The installation of the furnace, wiring, warm air ducts, venting,
etc. must conform to the requirements of the National Fire
Protection Association; the National Fuel Gas Code, ANSI
Z223.1/NFPA No. 54 (latest edition) and the National Electrical
Code, ANSI/NFPA No. 70 (latest edition) in the United States, and
any state laws, local ordinances (including plumbing or
wastewater codes), or local gas utility requirements. Local
authorities having jurisdiction should be consulted before
installation is made. Such applicable regulations or requirements
take precedence over the general instructions in this manual.
This furnace design is certified by CSA International as a
Category IV furnace in compliance with the latest edition of
American National Standard Z21.47/CSA Standard 2.3 for Gas-
Fired Central Furnaces, for operation with natural gas or propane.
Consult the rating plate on the furnace for gas type before
installing.
Tools and Parts
Assemble the required tools before starting installation. Read and
follow the instructions provided with any tools listed here.
Tools Needed:
Parts Needed:
Check local codes and with gas supplier. Check existing gas
supply, electrical supply, and venting, and read “Duct Work
Requirements,” “Electrical Requirements,” “Gas Supply
Requirements” and “Venting Requirements” before purchasing
parts.
Parts Supplied
■Inlet air restrictor plate
■Flue pipe screen
Location Requirements
IMPORTANT: Do not use the furnace as a heater in a building
under construction. The furnace can be severely damaged due to
the abnormal environment caused by construction. Chlorides
from sources such as paint, stain, or varnish; tile and counter
cements; adhesives; and foam insulation are abundant in a
structure under construction and can be highly corrosive. Low
return air temperature can cause condensation in the furnace and
other damage that can shorten the life of the furnace.
■The condensate drain on this furnace is incorporated within
the furnace and must be primed before start-up. The
condensate system must not be exposed to temperatures
under 32°F.
■The furnace is suitable for installation in buildings
constructed on site. The furnace should be centralized in
respect to the heat distribution system as much as
practicable.
■Pipe wrench
■Screwdriver
■Tape measure
■Thread sealant
■Non-corrosive leak check solution
■Test gauge with ¹⁄₈ in. NPT
connection
(for measuring gas supply pressure)
Explosion Hazard
Keep flammable materials and vapors, such as
gasoline, away from furnace.
Place furnace so that burners are at least 18 inches
(46 cm) above the floor for a garage installation.
Failure to follow these instructions can result in death,
explosion, or fire.
Explosion Hazard
Do not install this furnace in a mobile home.
Doing so can result in death, explosion, fire, or
carbon monoxide poisoning.

4
■All models are suitable for closet or utility room installation.
Utility room installation requires:
A door opening large enough for the widest part of the
furnace.
A door opening large enough to remove/replace any other
appliance located in the utility room, such as a water heater.
Any other appliances arranged so that each appliance can be
removed/replaced without disturbing the furnace.
■In a residential garage, a gas-fired furnace must be installed
so the burner(s) and the ignition source are located not less
than 18 in. above the floor. The furnace is to be located or
protected to avoid physical damage by vehicles.
■If the furnace is to be installed in an attic or other insulated
space, it must be kept free and clear of insulating materials.
Installation Clearances
■A 2 in. minimum clearance is required in front for air openings
into the combustion chamber.
■All servicing and cleaning of the furnace can be performed
from the front. If installed in a closet or utility room, provide 24
in. clearance in front for service if the door to the room is not
in line with the front of the furnace. Where servicing
clearances are greater than clearances to combustibles,
servicing clearances take precedence.
Minimum Clearance to Combustibles Chart
High Altitude Installations
■This furnace is approved for operation at altitudes from 0 to
4,500 feet above sea level without any required modifications.
■From 4,500 to 7,500 ft, the gas manifold pressure needs to be
adjusted according to the information shown in the Manifold
Pressure vs. Altitude charts.
IMPORTANT:
For installations above 7,500 ft, the furnace input rate is to be
reduced per the requirements of the National Fuel Gas Code
(ANSI Z223.1/NFPA 54, latest edition), at the rate of 4 percent for
each 1,000 feet above sea level.
The furnace is not recommended for installation above 10,000 ft.
Installation Configurations
WGFDU and WFCU models must be installed only as upflow
furnaces.
WGFDC and WFCC models must be installed only as
counterflow (downflow) furnaces.
IMPORTANT: To ensure access to parts for servicing, install
upflow and counterflow furnaces so that the burner and blower
access panels are readily accessible.
Installation for Counterflow (Downflow) Models
IMPORTANT:
■The furnace may be installed directly on the supply plenum or
coil cabinet if the furnace is installed on a non-combustible
floor.
■For installations on combustible flooring, a special base must
be ordered and used. See the “Accessories”section.
1. Cut, size and frame opening in floor to fit the Combustible
floor base and provide a minimum 1 in. clearance between
the Supply Duct and combustible materials. The four legs on
the base assembly should recess into the floor and the base
should rest on all four outside flanges.
2. Construct duct connections with 1 in. to 1³⁄₄ in. right angle
flanges, and long enough to extend below the floor joists.
3. Drop the duct connections through the top of the base
assembly with the right angle flanges in good contact with
the glass tape on top of the base assembly.
4. Carefully position the furnace over the right angle duct
flanges.
Unit Sides 0"
Rear of Unit 0"
Front of Unit 2"
Flue Pipe 0"
Plenum Top (upflow) 1"
Supply Duct (counterflow) 1"
WARNING
Fire Hazard
Before installing counterflow (downflow) furnace on
combustible surface, such as wood, install one of the
following kits:
WABASE 511 (14.5" cabinets)
WABASE 512 (17.5" cabinets)
WABASE 568 (21" cabinets)
WABASE 569 (24.5" cabinets)
Contact your local dealer.
Failure to do so can result in death or fire.

5
Combustible Floor Installation (Counterflow Models only)
Duct Work Requirements
Install the conditioned air plenum, ducts and air filters (if not
provided on the furnace) in accordance with NFPA 90B Standard
for the Installation of Warm Air Heating and Air-Conditioning
Systems (latest edition).
The furnace is provided with flanges for the connection of the
plenum and ducts.
All air filters must be listed as Class 2 furnace air filters.
Electrical Requirements
■The furnace must be grounded and wired in accordance with
local codes or, in the absence of local codes, with the
National Electrical Code ANSI/NFPA No. 70 (latest edition).
■In all instances, other than wiring for the thermostat, the
wiring to be done and any replacement of wire shall conform
with the temperature limitation for Type T wire –63°F (35°C)
rise.
■The line voltage supply should be routed through a readily
accessible disconnect located within sight of the furnace. A
junction box on the furnace side panel is provided for line
voltage connections. See the furnace wiring diagram for
specific connection information.
■Proper polarity of the supply connections (“HOT”and
“NEUTRAL”) must be observed to ensure that safety controls
provide the protection intended.
Gas Supply Requirements
This furnace is equipped for use with natural gas. A conversion
kit is required for use with propane. To order the correct
conversion kit, see “Accessories.”
■Gas supply piping should be installed in accordance with
local codes and the regulations of the utility. Piping must be
of adequate size to prevent undue pressure drop. Consult the
local utility or gas supplier for complete details on special
requirements for sizing gas piping.
■If local codes allow the use of a flexible gas appliance
connector, always use a new listed connector. Do not use a
connector which has previously serviced another gas
appliance.
Venting Requirements
Adequate provisions for combustion air and ventilation of furnace
must be made. Refer to Section 5.3, “Air for Combustion and
Ventilation,”of the National Fuel Gas Code, ANSI Z223.1/NFPA54
(latest edition), or applicable provisions of the local building
codes.
Unconfined Space
An unconfined space is defined as “a space whose volume is
more than 50 cubic feet per 1000 BTU per hour of the combined
input rating of all appliances installed in that space.”
When a furnace is installed in an unconfined space in a building,
it can be assumed that the infiltration will be sufficient to supply
the required air.
If the furnace is installed in a ventilated attic or crawl space, it is
assumed that the air infiltration is sufficient to supply the required
combustion air. However, in a building of unusually tight
construction, additional outdoor air should be provided.
Confined Space
A confined space is defined as “a space whose volume is less
than 50 cubic feet per 1000 BTU per hour of the combined input
rating of all appliances installed in that space.”Use Direct Vent
method. See “Plan Ventilation System.”
1. Furnace
2. Woven glass tape (between
flanges of outlet duct and
base assembly)
3. Base assembly
4. Combustible flooring
5. Leg
6. Supply plenum or coil cabinet
(not provided - accessory)
3
5
6
2
1
4
WARNING
Electrical Shock Hazard
Electrically ground furnace.
Connect ground wire to green ground screw.
Failure to do so can result in death or electrical shock.

6
Contaminated Combustion Air
Excessive exposure to contaminated combustion air will result in
performance related problems. The recommended source of
combustion air is outdoor air.
Outdoor air as the source of combustion air
If the furnace is installed in a confined space, it is recommended
that the necessary combustion air come from the outdoors by
way of an attic, crawl space, air duct, or direct opening.
Outdoor air is required as the source of combustion air when the
indoor air is contaminated with chemical substances and in the
following types of installations:
■Furnaces installed in commercial buildings
■Furnaces installed in buildings with indoor pools
■Furnaces installed in hobby or craft rooms
■Furnaces installed near chemical storage areas
■Furnaces installed in laundry rooms
■Furnaces installed in hair salons
Indoor air as the source of combustion air
Indoor air as the source of combustion air is acceptable in most
applications if the following guidelines are met:
■All provisions for indoor combustion air must meet the
requirements for combustion air indicated in the National Fuel
Gas Code, ANSI Z223.1/NFPA 54 (latest edition), and/or any
applicable local codes.
■If indoor combustion air is used, the air supply to the furnace
should not be exposed to the following substances:
Permanent wave solutions
Chlorinated waxes and cleaners
Chlorine-based swimming pool chemicals
Water softening chemicals
Deicing salts or chemicals
Carbon tetrachloride
Halogen-type refrigerants
Cleaning solvents (such as perchloroethylene)
Printing inks, paint removers, varnishes, etc.
Cements and glues
Antistatic fabric softeners for clothes dryers
Masonry acid washing materials
Chlorinated laundry products
Hydrochloric acid
INSTALLATION
INSTRUCTIONS
Inspect Shipment
This furnace is shipped in one package, completely assembled
and wired. The thermostat is shipped in a separate carton when
ordered.
■Check the unit rating plate to confirm specifications are as
ordered.
■Upon receipt of equipment, carefully inspect it for possible
shipping damage. Take special care to examine the unit
inside the carton if the carton is damaged.
■If damage is found, it should be noted on the carrier’s freight
bill. Damage claims should be filed with the carrier
immediately. Claims of shortages should be filed with the
seller within 5 days.
NOTE: If any damages are discovered and reported to the
carrier, do not install the unit, as your claim may be denied.
Explosion Hazard
Furnace must be installed and serviced by a
qualified person.
Examples of a qualified person include:
licensed heating personnel,
authorized gas company personnel.
Read and follow all instructions provided for
installation, adjustment, service, alteration, or
maintenance.
Failure to follow these instructions can result in death,
explosion, fire, or carbon monoxide poisoning.
Excessive Weight Hazard
Use two or more people to move and install furnace.
WARNING
Failure to do so can result in back or other injury.

7
Plan Vent System
The high efficiency of this furnace is accomplished by the
removal of both sensible and latent heat from the flue gases. The
removal of latent heat results in the condensation of moisture in
the flue gases. This condensation occurs in the secondary heat
exchanger and in the vent system. Therefore, this furnace
requires special venting considerations and the instructions must
be followed to ensure proper operation. All venting must be in
accordance with the codes having jurisdiction in the area and
these instructions.
IMPORTANT:
■The venting system must be supported with mounting straps
to prevent any weight load from being applied to the vent
blower. Horizontal vent pipe must be supported every 5 ft and
vertical pipe should be supported every 10 ft to prevent
sagging and provide rigid support.
■This furnace must not be connected to any Type B, BW, or L
vent or vent connector and must not be connected to any
portion of a factory-built or masonry chimney.
■This furnace is not to be common vented with any other
appliance. The vent pipe must not be connected to a
chimney flue serving a separate appliance designed to burn
solid fuel.
Venting Options
WFCU, WFCC, WGFDC and WGFDU models can be installed as
either direct vent or non-direct vent units.
For either type of installation, special venting considerations
must be followed. See “Determine Vent Pipe Direction”section
for the type of furnace and venting being installed.
Direct Vent
A direct vent (two pipe) installation requires that all the air
necessary for combustion be supplied from outside the dwelling
through an air intake pipe.
■All vents passing through floors, ceilings, and walls must be
installed in accordance with National Fuel Gas Code, ANSI
Z223.1/NFPA 54 (latest edition). In all applications where the
flue pipe is run through an unconditioned space, ¹⁄₂ in.
insulation must be used over the pipe. In extremely cold
climates, ³⁄₄ in. insulation is recommended.
Non-Direct Vent
A non-direct vent (one pipe) installation uses air from inside the
dwelling for combustion.
■The furnace is shipped with the air inlet pipe terminated to the
top panel for either inside or outside combustion air. An inlet
air restrictor plate is supplied with this furnace and can be
found in the plastic bag containing these Installation
Instructions and the User’s Information Manual.
■For installations using inside air for combustion (non-direct
vent), attach a 90°elbow (not supplied) to the inlet coupler
and install the restrictor plate inside the elbow (see “Non-
Direct Vent Installation”).
Inlet Air Restrictor Plate
Flue Pipe Screen
A flue pipe screen designed to keep objects out of the flue pipe is
included in the plastic bag.
In all installations, this screen should be installed at the
termination of the flue pipe.
Flue Pipe Screen
The inlet air restrictor plate
must be installed in all
installations using inside air
for combustion (non-direct
vent).
The flue pipe screen
should be installed at the
termination of the flue pipe
in all installations.

8
Materials
■All pipe, fittings, primer, and solvent cement must conform
with American National Standard Institute and the American
Society for Testing and Materials (ANSI/ASTM) standards.
The solvent shall be free flowing and contain no lumps,
undissolved particles, or any foreign matter that adversely
affects the joint strength or chemical resistance of the
cement. The cement shall show no gelatinization,
stratification, or separation that cannot be removed by
stirring. See “Piping and Fitting Specifications”for approved
piping and fitting materials.
Piping and Fitting Specifications
■The primers and solvents used must also meet ASTM
specifications. PVC primer is specified in ASTM F656. Use
PVC solvent as specified in ASTM D2564 and ABS solvent
cement as specified ASTM D2235. Low temperature solvent
cement is recommended. Metal or plastic strapping may be
used for vent pipe hangers.
■When making ABS joints, pieces can be prepared with a
cleaner. When joining ABS to PVC materials, use PVC solvent
cement as specified in ASTM D3138.
■Preferred fittings are DWV style or long sweep. Seal all joints
gas tight with appropriate cement. In areas where vent and air
intake pipes are exposed to abnormal stress or are subject to
damage, schedule 80 pipe should be used.
■Use high temperature RTV silicone sealant to attach the air
intake pipe into the connector on the burner box so the air
intake pipe can be removed if service is required.
NOTE: Do not use cement.
Vent Pipe Size and Length
The vent pipe and air intake pipe (in direct vent installations)
should be sized in accordance with the information found in the
“Vent Tables.”One 90°elbow is equivalent to 5 ft of pipe.Two 45°
elbows are equivalent to one 90°elbow.The minimum length
certified for use with this furnace is 5 ft and one elbow, not
including the vent and air intake terminals.
Vent Table - 40,000 - 80,000 BTU/HR Models
Vent Table- 90,000 - 100,000 BTU/HR Models
Piping and Fitting Material ASTM Specification
Schedule 40 PVC (Pipe) D1785
Schedule 40 PVC (Cellular Core Pipe) F891
Schedule 40 PVC (Fittings) D2466
SDR-26 (Pipe) D2241
Schedule 40 ABS (Pipe) D1527
Schedule 40 ABS (Fittings) D2468
Schedule 40 & 80 CPVC (Pipe) F441
ABS-DWV Drain Waste & Vent
(Pipe & Fittings)
D2661
PVC-DWV Drain Waste & Vent
(Pipe & Fittings)
D2665
Vent Pipe
Length (ft) Minimum Pipe Diameter (in.)
5 1.51.522222222
10 1.5222222222
20 2222222222.5
30 22222222.52.52.5
40 2 2 2 2 2 2.5 2.5 2.5 2.5 2.5
50 2 2 2.5 2.5 2.5 2.5 2.5 2.5 2.5 NR
60 2 2.5 2.5 2.5 2.5 2.5 2.5 NR NR NR
70 2.5 2.5 2.5 2.5 2.5 NR NR NR NR NR
80 2.52.52.5NRNRNRNRNRNRNR
90 2.5 2.5 NR NR NR NR NR NR NR NR
Number of 90°
Elbows 0123456789
NR = Not Recommended
Vent Pipe
Length (ft) Minimum Pipe Diameter (in.)
5 NR2222222.52.52.5
10 2222222.52.52.52.5
20 2 2 2 2 2 2.5 2.5 2.5 2.5 3
30 2 2 2 2.5 2.5 2.5 2.5 3 3 3
40 2 2 2.5 2.5 2.5 3 3 3 3 3
50 2.52.52.5333333NR
60 2.5333333NRNRNR
70 3 3 3 3 3 NRNRNRNRNR
80 3 3 3 NRNRNRNRNRNRNR
90 3 3 NR NR NR NR NR NR NR NR
Number of 90°
Elbows 0123456789
NR = Not Recommended

9
Vent Table - 112,000 - 125,000 BTU/HR Models In the event that the pipe length is in between the lengths listed in
the Vent Table, use the next larger length listed. For example, if a
length of pipe needed to install the furnace is 27 ft, use the
diameter values for the 30 ft row in the tables.
For direct vent installations, if the vent and air intake pipe are not
equal in length and number of elbows, then determine the
minimum pipe diameter for both the vent and air intake. If the
results indicate different diameters, use the larger of the two for
both the vent and air intake.
NOTE: Under no circumstances should the vent and air intake
pipe size be different in diameter. See “Install Vent System”for
the unit model and type of installation.
Determine Vent Pipe Direction
The vent system of the furnace must be self-supporting and must not apply any weight load to the combustion blower.
Combustion Air Sources
There are 2 sources for combustion air:
1. From outside the building (Direct Vent)
2. From inside the building (Non-Direct Vent)
Please read the information provided here about Vertical and
Horizontal Venting, then find and follow the instructions for your
venting configuration.
Vertical Venting
A vertical vent should extend through the roof a minimum of 2 ft
and not be obstructed a minimum of 10 ft in any direction.
Horizontal Venting
The vent terminal location shall comply with Section 7.8 of the
National Fuel Gas Code (ANSI Z223.1) or local requirement,
whichever takes precedence. For informational purposes, the
applicable sections of Section 7.8 are reprinted here:
The venting system shall terminate at least 3 feet (0.9 m)
above any forced air inlet located within 10 feet (3.1 m).This
provision shall not apply to the combustion air inlet of a direct
vent appliance or to the separation of the circulating air inlet
and vent discharge of a listed outdoor appliance.
For non-direct vent installation, the vent system shall
terminate at least 4 feet (1.2 m) below, 4 feet (1.2 m)
horizontally from, or 12 inches (30 cm) above any door,
window, or gravity inlet into any building.The bottom of the
vent terminal shall be located at least 12 inches (30 cm)
above grade or maximum expected snow depth.
For direct vent installation of models with an input rating of
50,000 BTUH or less, the vent system shall terminate at least
9 inches (23 cm) from any opening through which flue gases
could enter a building. For direct vent installation of models
with an input greater than 50,000 BTUH, the vent system
shall terminate at least 12 inches (30 cm) from any opening
through which flue gases could enter a building.
Regardless of input, the vent terminal and air intake shall
terminate at least 12 inches (30 cm) above grade or maximum
expected snow depth.
The vent system, regardless of installation type, shall
terminate a minimum horizontal clearance of 4 ft from electric
meters, gas meters, regulators, and relief equipment.
Vent Pipe
Length (ft) Minimum Pipe Diameter (in.)
5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
10 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 3
20 2.5 2.5 2.5 2.5 2.5 2.5 2.5 3 3 NR
30 2.5 2.5 2.5 2.5 2.5 3 3 NR NR NR
40 2.5 2.5 2.5 2.5 3 NR NR NR NR NR
50 2.5 3 3 NRNRNRNRNRNRNR
60 3 3 NR NR NR NR NR NR NR NR
Number of 90°
Elbows 0123456789
NR = Not Recommended

10
Direct Vent Installation Upflow Models
■Refer to the appropriate vent table for proper pipe size, vent
length and the number of elbows allowed, and air intake
length and the number of elbows allowed.
■Refer to the “Materials”section for the proper venting
material.
■Do not install the inlet air restrictor plate in any direct vent
installation. The inlet air restrictor plate (see “Inlet Air
Restrictor Plate”section) supplied with this furnace is to be
used only in non-direct vent applications.
■The flue pipe screen, designed to keep objects out of the flue
pipe (see “Flue Pipe Screen”section), should be installed at
the termination of the flue pipe.
NOTE: Do not place an additional flue pipe screen in the
intake termination because the air intake may freeze shut.
■For proper operation, the vent and air intake pipe must be
installed in the same pressure zone. Therefore, in horizontal
venting applications they must be on the same side of the
house within the parameters as shown.
NOTE: The 18 in. dimension shown below is the minimum
recommended height for extremely cold areas. In these
areas, moisture in the flue gases may condense and freeze on
the air intake if this height is reduced. In milder climates, this
may be reduced to a minimum of 6 in. Height may be
increased as needed provided total length of pipe to furnace
is not exceeded.
Direct Vent-Upflow (Horizontal Venting)
Direct Vent - Upflow (Vertical Venting)
1. Air intake pipe
2. Condensate collar
3. Optional piece
4. Flue pipe screen (inside flue pipe)
5. Flue pipe
6. Air intake pipe
7. Wall
(CLOSED) DRAIN HOLE
THRU.
59.69/56.64
18"
Run Ptich = 1/4"
Per Foot Min.
Height to Provide
12" Clearance to
Max. Snow Level.
6"
1
2
3
5
4
6
7
3" Min. - 48" Max.
Overhead View
3
7
5
6
1. Flue pipe
2. Condensate collar
3. Flue pipe screen (inside flue pipe)
4. Storm collars
5. Flashing
6. Air intake pipe
6.5" Min. - 24" Max.
10 Ft.
Min.
2 Ft.
Min.
Run Pitch = 1/4"
Per Foot Min.
1
2
4
3
5
6