Checking Gas Pressure; Gas Supply Pressure Measurement; Gas Pressure Test; Gas Manifold Pressure Measurement And Adjustment - Goodman GMEC96 Series Service And Troubleshooting

SERVICING
D ALL G
ISCONNECT AS AND
1. Check orifice visually for distortion and/or burrs.
2. Check orifice size with orifice sizing drills.
The length of Dimension "A" determines the angle of Gas
Stream "B".
A dent or burr will cause a severe deflection of the gas stream.

CHECKING GAS PRESSURE

Gas Supply Pressure Measurement

Gas Pressure Test

The line pressure supplied to the gas valve must be within the
range specified below. The supply pressure can be measured
at the gas valve inlet pressure tap or at a hose fitting 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
Gas Valve On/Off
Selector Switch
White-Rodgers Model 36J54 (Two-Stage)
WARNING
E P S
LECTRICAL OWER UPPLY.
A
GAS
STREAM B
DENT OR
BURR
GAS
STREAM B
OUTLET
3.5
White-Rodgers Model 36J54 Connected to Manometer
White-Rodgers Model 36J54 Connected to Manometer
1. Turn OFF gas to furnace at the manual gas shutoff
valve external to the furnace.
2. Connect a calibrated water manometer (or appropriate
gas pressure gauge) at either the gas valve inlet pres-
sure tap or the gas piping drip leg. See White-Rodgers
36J54 gas valve figure for location of inlet pressure tap.
INLET GAS SUPPLY PRESSURE
Natural Gas Minimum: 4.5" w.c.
Propane Gas Minimum: 11.0" w.c.
NOTE: If measuring gas pressure at the drip leg, a
field-supplied hose barb fitting 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
firing. Supply pressure must be within the range speci-
fied in the Inlet Gas Supply Pressure table.
If supply pressure differs 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 shutoff valve
and disconnect manometer. Reinstall plug before turn-
ing on gas to furnace.
6. Turn OFF any unnecessary gas appliances stated in
step 3.
Gas Manifold Pressure Measurement and Ad-
justment
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.
High Fire Regulator
Adjust
Regulator
Vent
Common
Terminal(C)
Maximum: 10.0" w.c.
Maximum: 13.0" w.c.
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