GC9C80 Service Manual
SERVICING
32
B
The length of Dimension “A” determines the angle of Gas
Stream “B”.
B
A dent or burr will cause a severe deection of the gas stream.
The line pressure supplied to the gas valve must be within the
range specied below. The supply pressure can be measured
at the gas valve inlet pressure tap or at a hose tting installed
in the gas piping drip leg. The supply pressure must be
measured with the burners operating. To measure the gas
supply pressure, use the following procedure.
INLET OUTLET
Gas Valve On/Off
Selector Switch
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High Fire Regulator
Adjust
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Common
Terminal(C)
White-Rodgers Model 36J54 Connected to Manometer
3.5
1. Turn OFF gas to furnace at the manual gas shuto
valve external to the furnace.
2. Connect a calibrated manometer (or appropriate gas
pressure gauge) at either the gas valve inlet pressure
tap or the gas piping drip leg. See White-Rodgers
36J54 gas valve gure for location of inlet pressure tap.
Natural Gas Minimum: 4.5" w.c.
Maximum: 10.0" w.c.
Propane Gas
Minimum: 11.0" w.c.
Maximum: 13.0" w.c.
If measuring gas pressure at the drip leg, a
eld-supplied hose barb tting must be installed prior
to making the hose connection. If using the inlet pres-
sure tap on the White-Rodgers 36J54 gas valve, then
use the 36G/J Valve Pressure Check Kit, Part No.
0151K00000S.
3. Turn ON the gas supply and operate the furnace and
all other gas consuming appliances on the same gas
supply line.
4. Measure furnace gas supply pressure with burners
ring. Supply pressure must be within the range speci-
ed in the Inlet Gas Supply Pressure table.
If supply pressure diers from table, make the necessary
adjustments to pressure regulator, gas piping size, etc., and/
or consult with local gas utility.
5. Turn OFF gas to furnace at the manual shuto valve
and disconnect manometer. Reinstall plug before turn-
ing on gas to furnace.
6. Turn OFF any unnecessary gas appliances stated in
step 3.
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Only small variations in gas pressure should be made by adjusting
the gas valve pressure regulator. The manifold pressure must be
measured with the burners operating. To measure and adjust the
manifold pressure, use the following procedure.