506843-01
Page 10 of 39
Issue 1132
Installation on Non-Combustible Flooring (Figure 11)
1. Cut floor opening keeping in mind clearances listed on
unit rating plate. Also keep in mind gas supply
connections, electrical supply, flue and air intake
connections and sufficient installation and servicing
clearances. See Table 1 for correct floor opening size.
2. Flange warm air plenum and lower the plenum into the
opening.
3. Set the unit over the plenum and seal the plenum to the
unit.
4. Ensure that the seal is adequate.
Installation on Combustible Flooring (Figure 12)
1. When unit is installed on a combustible floor, a downflow
combustible flooring base must be installed between the
furnace and the floor. The base must be ordered
separately. See Table 2 for opening size to cut in floor.
Installation Clearances
Figure 10
* Front
0
Back
0
Sides
0†
Vent
Floor
0
NC‡
* Front clearance in alcove installation must be 24 in. (610 mm).
Maintain a minimum of 24 in. (610 mm) for front service access.
† Allow proper clearances to accommodate condensate trap and vent
pipe installation.
‡ The furnace may be installed on a combustible wood floor if an
optional additive base is installed between the furnace and the
combustivle floor.
WARNING
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.
Table 1
NON-COMBUSTIBLE FLOOR OPENING SIZE
NOTE:
Floor opening dimensions listed are 1/4 inch (6 mm) larger
than the unit opening. See dimension drawing on page 2.
CAUTION
The furnace and combustible flooring base shall not be
installed directly on carpeting, tile, or other combustible
material other than wood flooring.
Figure 11
