SERVICING
37
e. Measure the gas manifold pressure with burn-
ers firing. Adjust manifold pressure using the
Manifold Gas Pressure
table shown below.
f.
Remove regulator cover screw from the outlet
pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclock-
wise to decrease pressure. Replace regulator
cover screw.
g.
Turn off all electrical power and gas supply to
the system.
h. Remove the manometer hose from the hose
barb fitting or outlet pressure boss.
i.
Turn outlet pressure test screw in to seal pres-
sure port (clockwise, 7 in-lb minimum).
6. Honeywell VR8215 Valve
a. Remove the outlet pressure boss plug. Install
an 1/8” NPT hose barb fitting into the outlet
pressure tap.
b. Attach a hose and manometer to the outlet
pressure barb fitting.
c. Turn ON the gas supply.
d.
Turn on power and close thermostat “R” and
“W1” contacts to provide a call for low stage heat.
e. Measure the gas manifold pressure with burn-
ers firing. Adjust manifold pressure using the
Manifold Gas Pressure
table shown below.
f.
Remove regulator cover screw from the outlet
pressure regulator adjust tower and turn screw
clockwise to increase pressure or counterclock-
wise to decrease pressure. Replace regulator
cover screw.
g.
Turn off all electrical power and gas supply to
the system.
h. Remove the manometer hose from the hose
barb fitting or outlet pressure boss.
i.
Remove the 1/8” NPT hose barb fitting from the
outlet pressure tap. Replace the outlet pressure
boss plug and seal with a high quality thread
sealer.
WARNING
HIGH VOLTAGE
Disconnect 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.
7. Turn on gas to furnace and check for leaks. If leaks
are found, repair and then reinstall burner compart-
ment door.
8. Turn on electrical power and verify proper unit operation.
Gas Manifold Pressure Measurement
and Adjustment
CAUTION
To prevent unreliable operation or equipment damage, the gas
manifold pressure must be as specified on the unit rating plate.
Only minor adjustments should be made by adjusting the gas
valve pressure regulator.
NOTE:
Use adapter kit #0151K00000S to measure gas
pressure on White-Rodgers 36J22 gas valves.
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.
WARNING
HIGH VOLTAGE
Disconnect ALL electrical power and shut off gas supply
before servicing or installing.
1.
After turning off gas to furnace at the manual gas shut
-
off valve external to the furnace, remove burner com
-
partment door to gain access to the gas valve.
2. Connect a calibrated manometer (or appropriate gas
pressure gauge) at the gas valve outlet pressure
tap. Refer to
Measuring Gas Pressure: Single Stage
Valves
figure for single stage valve outlet pressure tap
connections.
WARNING
Line Voltage now present.
3. Turn ON the gas and electrical power supply and op-
erate the furnace.
4.
Measure gas manifold pressure with burners firing.
Adjust manifold pressure using the table below.
3.5" w.c.
10.0" w.c.
Manifold Gas Pressure
Natural Gas
Propane Gas
The final manifold pressure must not vary more than ± 0.3”
w.c. from the above specified pressures. Any necessary ma
-
jor changes in gas flow rate should be made by changing the
size of the burner orifice.
5. White-Rodgers 36G22 Valves:
a. Back outlet pressure test screw (inlet/outlet
pressure boss) out one turn (counterclockwise,
not more than one turn).
b. Attach a hose and manometer to the outlet
pressure outlet pressure boss.
c. Turn ON the gas supply.
d.
Turn on power and close thermostat “R” and
“W1” contacts to provide a call for low stage
heat.
