8
GAS FIRED VENTED
FLOOR FURNACES
CUTTING THE FLOOR OPENING
Consult the specification chart on page 5 for the correct
floor opening size for the floor furnace to be installed.
Lay out the opening size on the floor by using masking
tape or cutting a piece of cardboard to the opening size.
The opening must be cut square. If you have determined
that there is nothing under the floor to interfere with the
installation, you are now ready to cut the opening. Start
by drilling 1/2 inch holes inside the lines of each comer.
Use a keyhole saw or a properly grounded saber saw to
cut along the lines making sure to keep the lines straight
and the comers square. If the opening dimensions are not
correct, it may be difficult to fit the floor furnace into the
opening. Forcing the floor furnace through the opening
may create stresses that cause the floor furnace to be
excessively noisy.
FIGURE 4
Most installations will require cutting a floor joist
Cut the floor joist so that double headers of the same size
lumber can be used to frame around the floor furnace.
Double headers are necessary to maintain the strength of
the floor.
FIGURE 5
IF THE CLEARANCE BETWEEN THE BOTTOM OF THE
FLOOR FURNACE AND THE GROUND IS NOT ADEQUATE:
Dig a pit that will provide clearances of at least 6 inches
under the floor furnace, 18 inches on the end where the gas
valve is located and 12 inches on the other three sides. Slope
the sides of the pit to prevent dirt from caving into the pit.
If there is any possibility that water may accumulate in
the pit, a drain must be provided.
If a drain cannot be
FLOOR
FURNACE
OPENING
JOIST
DOUBLE
HEADER
provided, fabricate a waterproof pan of at least 16 ounce
per square foot sheet copper or a suitable substitute. Size
the pan to provide 6 inches clearance to the bottom of the
floor furnace, 18 inches on the side where the gas valve is
located and 6 inches on the other three sides. The sides of
the pan must extend at least 4 inches above the ground.
Anchor the pan to prevent it from floating up against
the bottom of the floor furnace when water is present.
Failure to do so may result in the pan rising to seal off
air for combustion and venting. If this occurs, carbon
monoxide (C.O.) a colorless, odorless gas may be
formed which can cause serious injury or death.
SETTING THE FLOOR FURNACE
Lay aside the grill and package containing the
thermostat, wires, etc., grasp two opposite sides of
the outer casing and lower the floor furnace gently
through the opening. Support the furnace evenly by
the flange at the top of the outer casing. Trim back
carpet, padding, and other types of floor covering so
that the entire flange rests directly on the floor. If not
evenly supported on all four sides, stresses may be
created that cause excessive expansion and
contraction noises as the floor furnace heats and
cools. Anchor the floor furnace in place by driving
two galvanized roofing nails through each side
of the outer casing into the double headers
approximately 1 inch below the flange. Place the grill
into position making sure it lays flat against the outer
casing flange. Leave the grill in place until time to
light the furnace to keep occupants from falling into
the furnace.
INSTALLING THE DRAFT HOOD
The draft hood must be installed in the same
atmospheric pressure zone as the combustion air
inlet. The draft hood is packed in its own carton
within the master pack. Make sure the draft hood
received is the correct one for the floor furnace being
installed. Included in the carton are two rope-like
gaskets and 7 sheet metal screws. Begin by pressing
the rope-like gasket material into the groove
provided around the two male vent outlets on the
floor furnace.
Figure 6
Slip the two female couplings in the draft hood over
the male outlets extending through the outer casing,
making sure the gaskets remain in place. Press the
draft hood tight against the casing and use the 7
sheet metal screws to secure it tightly. All 7 screws
must be used to prevent leakage of vent gases.
Never install or operate a floor furnace without a
draft hood. To do so could result in serious injury,
property damage or death.
CONNECTING THE VENT
Refer to the specifications on
page 5
for the correct
vent pipe size. Familiarize yourself with local codes
or contact authorities to determine the approved
material and method of installing the vent.
NOTE:
An
FLOOR
FURNACE
FLOOR
6" Minimum
JOIST
JOIST
GROUND
LEVEL
DRAFT
HOOD
VENT PIPE
6" Minimum
12"
Min.
18"
Minimum
PIT
PIT
