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.
Do not install this furnace in a mobile home.
Doing so can result in death, explosion, fire, or
carbon monoxide poisoning.
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 (0ºC).
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
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" (45.7 cm) 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" (5.1 cm) 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 the furnace is installed in a closet or utility
room, provide 24" (61 cm) 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 ft (0 to 1,371.6 m) above sea level without any required
From 4,500 to 7,500 ft (1,371.6 m to 2,286 m), the gas
manifold pressure needs to be adjusted according to the
information shown in the Manifold Pressure vs. Altitude Chart
in the "Adjust the Furnace Input Rate" section.
For installations above 7,500 ft (2,286 m), 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 ft (304.8 m) above sea level.
The furnace is not recommended for installation above 10,000 ft
2" (5.1 cm)
1" (2.5 cm)