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Reassemble Appliance:
1. Reassemble the burner assembly into the furnace.
2. Reconnect the gas piping and electrical wires to the gas
valve.
3. Open the manual shut-off valve and follow the “Operating
Instructions” as outlined previously in this manual to put
the furnace into operation.
Centrifugal Switch
The electric motor for the blower which supplies combustion
air to the burner is equipped with a centrifugal switch wired
in series with the burner controls. This switch is normally
open until the speed of the blower motor closes it thereby
powering the burner controls. The burner controls will not
function until the blower motor is operating at full speed.
Firing Rate Conversion
The rated firing rates of the CMF80 convertible furnaces
(PO & PG) can be adjusted from the factory setting of
75,000 BTU/hr.
The firing rate can be changed to either 65,000 BTU/hr. or to
90,000 BTU/hr. using the appropriate certified NORDYNE
conversion kit installed by a NORDYNE distributor or Ser-
vice PRO. See the Replacement Parts Listing for the appro-
priate kit number to order.
Air Supply for Sealed Combustion
1. Close and latch burner access door to complete the
outdoor combustion air passage.
2. If the space below the home is enclosed, be sure a vent
or duct of at least 18 square inches of free area is
provided from the outside to provide sufficient air for
combustion. Make sure the combustion air duct extends
through the floor and is unobstructed.
Gas Burner Controls (Direct Ignition Series)
Combination Electric Gas Valve and
Pressure Regulator
The combination electric gas valve and pressure regulator
performs several functions. The gas valve control lever has
two positions. The OFF position completely shuts off the gas
supply. The ON position allows gas flow through the
redundant gas valve when it is energized electrically.
Gas to LP Conversion
This gas fired heating appliance was shipped from the
factory for use with natural gas. However, the appliance can
be converted to be used with LP gas. Use the following
procedure for gas conversion of the burner.
Remove the Burner Assembly:
1. Follow instructions “To Turn Off Gas To Appliance.”
2. Shut off gas supply at meter.
3. Disconnect gas burner electric cord, gas piping to burner,
and thermostat leads.
4. Remove three (3) hexagon nuts holding burner in place.
Change the Main Burner Orifice:
1. Disconnect inlet pipe union at burner. Disconnect
burner power cord.
2. Disconnect the two wires leading to gas control valve.
3. Remove three (3) bolts from U-shaped manifold plate
and orifice assembly.
4. Remove the main orifice and replace it with the alternate
fuel orifice supplied in the plastic bag with this burner.
Change the Pressure Regulator:
1. Remove the regulator converter and its black cover
located on top of the gas valve and invert. (See Figure
16 — For LP, the red ring will be located at the bottom
and the “LP” stamping on the converter will appear right
side up.)
2. Screw converter back into the regulator, hand tight plus
1/8 turn, and replace the black cover onto the converter
top to protect the threads.
Figure 7. Natural Gas Configuration
