7
Damper Installation
An automatic shut-off damper is available (see
replacement parts list). An automated shut off
damper is required when the home is air con-
ditioned by a self-contained unit. This damper
is designed to fit in the feeder duct cavity,
directly under the furnace. A damper is required
to prevent chilled air from flowing over the
furnace heat exchanger. For proper installa-
tion, refer to the instructions provided with the
damper.
Installation of Furnace onto the MA-200
Base
Lift the furnace over the base so that the flange
at the back comes to rest on the inside rails of
the base.
Raise the front of the furnace to clear the gasket
on the bottom of the furnace and slide the back
until the rear flange drops into the channel at the
rear of the base. Be careful not to damage the
combustion air adapter, if present, while posi-
tioning the unit.
Be sure that the furnace is all the way back so
as to engage the tabs on the rear flange on the
base.
Open the access door. Fasten the front of the
furnace and the base to the floor with #8 x 1/2"
long sheet metal screws.
Using the provided hose clamp, secure the
flexible combustion air tubing from the burner to
the combustion air adapter.
Installation of Furnace onto the MA-100
Base
Tilt the furnace forward and carefully work the
furnace back over the MA-100 Universal base.
Lift the furnace as necessary when positioning
the unit over the base assembly to prevent any
damage to the feeder duct assembly and com-
bustion air adapter, if present.
Be sure the furnace is positioned all the way to
the back of the base assembly.
Open the furnace door and fasten the furnace
to the base using #8 x 1/2" long sheet metal
screws.
Install the feeder duct by bending the tabs inside
the heat duct and using the metal tape to insure
an airtight connection.
Set the bottom base panel over the feeder duct.
Slit the corners of the feeder duct down to the
top of the base. While the top of the distribution
duct is pulled up with one hand, bend down each
side of the feeder duct tightly to the base with the
other hand. Trim the metal to allow one inch
flange over the top of the base and seal that
flange with the metal tape.
Secure the top panel to the floor with two (2)
screws through the front flange.
If a “V” or “U”-box crossover system is to be
used, see the instructions provided with the
crossover system.
Combustion Air Duct/Pipe Installation
The CMF furnace must draw the combustion air
from outside, except for special installations
(See Table 1). This can be accomplished either
by using the 2”X7” rectangular combustion air
duct provided in the MA series base kits or using
the direct vent kit.
When the rectangular combustion air duct is to
be used, install the combustion air duct through
the selected knockout in the base. For direct
vent applications, the rear knock-out in the
furnace base cannot be used. After the
combustion air duct has been positioned, install
the combustion air adapter. This adapter will
transition the 2”X7” opening of the combustion
air duct to the 2” diameter of the burner flexible
tubing. This adapter is included in the MA series
base kits. For retrofit applications in which the
MA series base is already installed, the
combustion air adapter can be ordered as a kit.
Refer to the Replacement Parts List for more
details on ordering this kit.
Secure the adapter with either wood or metal
fasteners (field provided), depending upon the
particular installation. Ensure that the gasket
for the adapter is positioned properly before
installing the adapter. Attach the flexible hose
from the burner to the combustion air adapter
using the provided metal hose clamp.
When the direct vent kit is used, follow the
instructions provided with the kit. Note: The
direct vent kit should be installed before
positioning the furnace on the base.
Summary of Contents for CMF 100-PG
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