37
Furnace Shutdown
1. Set the thermostat to the lowest setting. The
integrated control will close the gas valve and
extinguish flame. Following a 15 second delay, the
induced draft blower will be de-energized. After
the blower off delay time expires, the blower de-
energizes.
2. Remove the burner compartment door and move
the furnace gas valve manual control to the OFF
position.
3.
Close the manual gas shutoff valve external to the
furnace.
4. Replace the burner compartment door.
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.
1.
Turn OFF gas to furnace at the manual gas shutoff
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
36J22 gas valve figure for location of inlet pressure
tap.
OUTLET
INLET
Gas Valve ON/OFF Selector Switch
Outlet Pressure
Inlet Pressure
Regulator
Cover Screw
White-Rodgers Model 36J22
Figure 48
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 36J22 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.
Gas
Range
Nominal
Natural
3.2 - 3.8" w.c.
3.5" w.c.
Propane
9.7 - 10.3" w.c.
10.0" w.c.
Manifold Gas Pressure
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.
Measuring Inlet Gas Pressure (Alt. Method)
Figure 49
Gas Manifold Pressure Measurement and
Adjustment
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 36J22 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 “W”
contacts to provide a call for heat.
7. Measure the gas manifold pressure with burners
firing. Adjust manifold pressure using the
Manifold
Gas Pressure
table shown on this page.
