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
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.
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
Rear of Unit
Front of Unit
Plenum Top (upflow)
Supply Duct (counterflow)
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.
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.
WGFDU and WFCU models must be installed only as upflow
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
Before installing counterflow (downflow) furnace on
combustible surface, such as wood, install one of the
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.
The furnace may be installed directly on the supply plenum or
coil cabinet if the furnace is installed on a non-combustible
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