19
at 10.0 in WC. This pressure can be checked
at the port located on the gas outlet end of the
gas valve using a pressure gauge or U-tube
manometer, which must be installed according
to the manufacturer’s supplied instructions. If
the manifold pressure is not equal to the valves
above, then it must be adjusted. To adjust the
manifold pressure, remove the regulator
converter from the gas valve, as shown in
Figure 16. Then turn the adjusting screw
clockwise to increase the pressure or
counterclockwise to reduce the pressure. Once
the manifold pressure is correctly set, replace
the regulator converter in the same manner as
it was removed earlier.
To install a pressure gauge or U-tube manometer
in the gas valve:
1.
Determine which pressure, the inlet gas or
manifold pressure, you want to measure.
2.
With a 3/16” Allen wrench, remove the
appropriate tap plug located on the gas
valve. When measuring the inlet gas
pressure, remove the tap plug on the inlet
side of the gas valve. When measuring the
manifold pressure, remove the tap plug on
the outlet side of the gas valve.
3.
Install a fitting, which has a 1/8” NPT pipe
thread that is compatible with the pressure
gauge or U-tube manometer.
4.
Install the pressure gauge or U-tube ma-
nometer according to the manufacturer’s
supplied instructions.
5.
After measuring the pressure, be sure to
remove the pressure gauge or U-tube
manometer from the gas valve and replace
the tap plug. Ensure that the tap plug is tight
and not cross-threaded.
Gas Burner Controls
The gas valve lever can be set to ON or OFF,
as shown in Figure 16. When in the ON position,
gas flow through the gas valve is allowed when
the valve is energized electrically. When in the
OFF position, gas flow is completely shut off.
Combustion Blower Centrifugal Switch
Figure 16. Natural Gas Configuration
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.
Natural Gas to LP Conversion
This gas fired heating appliance was shipped
from the factory for use with natural gas. How-
ever, the appliance can be converted to be used
with LP gas. Use the following procedure for
gas conversion of the burner.
1. Follow instructions “To Turn Off Gas To
Appliance” earlier in these instructions.
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.
5. Disconnect inlet pipe union at burner.
Table 5. Air Shutter Setting
for Different Fuels
Input
Natural
LP Gas
Oil
(BTU/H)
Gas Setting
Setting
Setting
65,000
3.0
3.0
3.0
75,000
3.5
3.5
4.0
90,000
4.0
4.0
3.5
Regulator
Converter
Summary of Contents for CMF 100-PG
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