32
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 mea
-
sured 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.
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
pressure tap or the gas piping drip leg. See White-
Rodgers 36J54 gas valve figure for location of inlet
pressure tap.
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 pressure 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
specified 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
turning on gas to furnace.
6. Turn OFF any unnecessary gas appliances stated in
step 3.
Gas Manifold Pressure Measurement and
Adjustment
T
O
PREVENT
UNRELIABLE
OPERATION
OR
EQUIPMENT
DAMAGE
,
THE
GAS
MANIFOLD
PRESSURE
MUST
BE
AS
SPECIFIED
ON
THE
UNIT
RATING
PLATE
. O
NLY
MINOR
ADJUSTMENTS
SHOULD
BE
MADE
BY
ADJUSTING
THE
GAS
VALVE
PRESSURE
REGULATOR
.
CAUTION
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.
1. Turn OFF gas to furnace at the manual gas shutoff
valve external to the furnace.
2. Turn off all electrical power to the system.
3. Outlet pressure tap connections:
White-Rodgers 36J54 valve: Back outlet pressure
test screw (inlet/outlet pressure tap) out one turn
(counterclockwise, not more than one turn).
4. Attach a hose and manometer to the outlet pressure
tap (White-Rodgers valve).
5. Turn ON the gas supply.
6. Turn on power and close thermostat “R” and “W1”
contacts to provide a call for low stage heat.
7. Measure the gas manifold pressure with burners firing.
Adjust manifold pressure using the
Manifold Gas
Pressure
table shown below.
Range
Nominal
Natural
Low Stage 1.6 - 2.2" w .c.
1.9" w .c.
High Stage 3.2 - 3.8" w .c.
3.5" w .c.
Propane
Low Stage 5.7 - 6.3" w .c.
6.0" w .c.
High Stage 9.7 - 10.3" w .c. 10.0" w .c.
Manifold Gas Pressure
Gas
8. Remove regulator cover screw from the low (LO)
outlet pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclockwise to
decrease pressure. Replace regulator cover screw.
9. Close thermostat “R”, “W1” and “W2” contacts to
provide a call for high stage heat.
10. Remove regulator cover screw from the high (HI)
outlet pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclockwise to
decrease pressure. Replace regulator cover screw.
11. Turn off all electrical power and gas supply to the
system.
12. Remove the manometer hose from the hose barb fitting
or outlet pressure tap.
13. Replace outlet pressure tap:
White-Rodgers 36J54 valve: Turn outlet pressure
test screw in to seal pressure port (clockwise, 7 in-lb
minimum).
14. Turn on electrical power and gas supply to the system.
15. Close thermostat contacts “R” and “W1/W2” to
energize the valve.
Using a leak detection solution or soap suds, check for
leaks at outlet pressure tap plug (Honeywell valve) or screw
(White-Rodgers valve). Bubbles forming indicate a leak.
SHUT OFF GAS AND REPAIR ALL LEAKS IMMEDIATELY!
NOTE:
For gas to gas conversion, consult your dealer for
appropriate conversion.
INLET
OUTLET
Gas Valve On/Off
Selector Switch
White-Rodgers Model 36J54 (Two-Stage)
