507962-01
Page 10 of 53
Issue 2149
Installation
Setting Equipment
Do not install the furnace on its front, back or in the
horizontal position. See Figure 13. Do no connect the
return air ducts to the back of the furnace. Doing so
will adversely affect the operation of the safety control
devices, which could result in personal injury or death.
WARNING
Select a location that allows for the required clearances
that are listed on the unit nameplate. Also consider gas
supply connections, electrical supply, vent connection,
condensate trap and drain connections, and installation
and service clearances [24 inches (610 mm) at unit front].
The unit must be level from side to side. Tilt the unit slightly
(maximum 1/2 in. from level) from back to front to aid in the
draining of the heat exchanger. See Figure 12.
Shipping Bolt Removal
NOTE:
Units with a 1/2 hp blower motors are equipped
with three flexible legs and one rigid leg. The rigid leg
is equipped with a shipping bolt and a flat white plastic
washer (rather than the rubber mounting grommet used
with a flexible mounting leg). See Figure 11. The bolt and
washer must be removed before the furnace is placed into
operation. After the bolt and washer have been removed,
the rigid leg will not touch the blower housing.
Allow for clearances to combustible materials as indicated
on the unit nameplate. Minimum clearances for closet or
alcove installations are shown in Figure 14.
Figure 11.
Units with 1/2 HP Blower Motor
Blower access panel must be securely in place when
blower and burners are operating. Gas fumes, which
could contain carbon monoxide, can be drawn into
living space resulting in personal injury or death.
WARNING
Figure 12. Setting Equipment
Figure 13.
Improper installation of the furnace can result in
personal injury or death. Combustion and flue products
must never be allowed to enter the return air system or
air in the living space. Use sheet metal screws and joint
tape to seal return air system to furnace.
In platform installations with furnace return, the furnace
should be sealed airtight to the return air plenum. A door
must never be used as a portion of the return air duct
system. The base must provide a stable support and an
airtight seal to the furnace. Allow absolutely no sagging,
cracks, gaps, etc.
For no reason should return and supply air duct systems
ever be connected to or from other heating devices
such as a fireplace or stove, etc. Fire, explosion, carbon
monoxide poisoning, personal injury and/or property
damage could result.
WARNING
The unit may be installed three ways in downflow
applications: on non-combustible flooring, on combustible
flooring using an additive base, or on a reverse-flow
cooling coil cabinet. Do not drag the unit across the floor
in the downflow position. Floor and furnace flange damage
will result.
Refer to Figure 14 for clearances in downflow applications.