Service Manual

SYSTEM OPERATION
73
WARNING
D
ISCONNECT ELECTRICAL POWER AND SHUT OFF GAS SUPPLY.
1. After turning off gas to furnace at the manual gas shutoff
valve external to the furnace, remove burner compart-
ment door to gain access to the gas valve.
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 as shown in the follow-
ing figures.
NOTE: At either location, a hose fitting must be installed
prior to making the hose connection.
NOTE: Use adapter kit #0151K00000S to measure gas pres-
sure on White-Rodgers 36J54 gas valves.
GAS LINE
GAS SHUTOFF VALVE
GAS LINE
TO FURNACE
DRIP LEG CAP
WITH FITTING
MANOMETER HOSE
MANOMETER
OPEN TO
ATMOSPHERE
Measuring Inlet Gas Pressure
(Alternate Method)
3. Turn ON the gas and electrical power supply and oper-
ate the furnace and all other gas consuming appliances
on the same gas supply line.
4. Measure furnace gas supply pressure with burners fir-
ing. Supply pressure must be within the range specified
in the following table.
Natural Gas Minimum: 4.5" w.c. Maximum: 10.0" w.c.
Propane Gas Minimum: 11.0" w.c. Maximum: 13.0" w.c.
INLET GAS SUPPLY PRESSURE
If supply pressure differs from above, make necessary ad-
justments to pressure regulator, gas piping size, etc., and/
or consult with local gas utility.
WARNING
HIGH VOLTAGE
D
ISCONNECT ALL ELECTRICAL POWER AND SHUT OFF GAS
SUPPLY BEFORE SERVICING OR INSTALLING THIS UNIT.
MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO
DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
5. Disconnect manometer after turning off gas at manual
shutoff valve. Reinstall plug before turning on gas to fur-
nace.
6. Turn OFF any unnecessary gas appliances started in
step 3.
7. Turn on gas to furnace and check for leaks. If leaks are
found, repair and then reinstall burner compartment door.
8. Turn on electrical power and verify proper unit operation.
WARNING
HIGH VOLTAGE
D
ISCONNECT ALL ELECTRICAL POWER AND SHUT OFF GAS
SUPPLY BEFORE SERVICING OR INSTALLING THIS UNIT.
MULTIPLE POWER SOURCES MAY BE PRESENT. FAILURE TO
DO SO MAY CAUSE PROPERTY DAMAGE, PERSONAL INJURY OR DEATH.
Gas Manifold Pressure Measurement and Adjust-
ment
Natural Gas Adjustments
WARNING
HIGH VOLTAGE
D
ISCONNECT
ALL
ELECTRICAL POWER AND SHUT OFF GAS SUPPLY
BEFORE SERVICING OR INSTALLING.
NOTE: Use apapter kit #0151K00000S to measure gas pres-
sure on White-Rodgers 36J54 gas valves.
Only small variations in gas pressure should be made by
adjusting the gas valve pressure regulator. The manifold pres-
sure must be measured with the burners operating. To mea-
sure and adjust the manifold pressure, use the following pro-
cedure.
1. After turning off gas to furnace at the manual gas shutoff
valve external to the furnace, remove burner compart-
ment door to gain access to the gas valve.
2. Connect a calibrated water manometer (or appropriate
gas pressure gauge) at the gas valve outlet pressure
tap. Refer to Measuring Gas Pressure: Two-Stage Valves
figure for two-stage gas valve outlet pressure tap con-
nections.