14. Repeat the adjustment procedure for the sec ond
gas valve on the 500,000 Btu/hr model.
15. Turn the gas valve control knob(s) to “ON”
position.
16. Turn the power “ON” at the main dis con nect
switch. The appliance is now ready to op er ate.
If manifold pressure can not be properly adjusted, use
the following procedure to check gas supply pressure
with a manometer connected to the inlet pressure tap on
the gas control.
FIG. 19 Gas Supply Pressure
1. Turn the power “OFF” at the main dis con nect
switch.
2. Turn gas valve control knob(s) to the “OFF”
position.
3. The 500,000 Btu/hr model will have two gas
valves. Turn the gas valve control knob on each
valve to the “OFF” position.
4. Shut off gas supply at the manual valve in the gas
piping to the appliance. If fuel supply is L.P. gas,
shut off gas supply at the tank.
5. Remove the 1/8" hex plug, located on the “inlet”
side of the gas valve and install a fitting suitable to
connect to a manometer or magnahelic gauge. On
two gas valve models, remove the hex plug from
the gas valve closest to the gas sup ply connection.
Range of scale should be 14" w.c. or greater to
check inlet pressure. See Figures 18 and 19 for
location.
6. Turn on gas supply at the manual valve, turn on
L.P. gas at tank if required.
7. Turn the power “ON” at the main dis con nect
switch.
8. Turn gas valve control knob to “PILOT”
po si tion on standing pilot models. Follow the
“Lighting Instructions” for standing pilot models
to light the pilot. Turn gas valve control knob to
the “ON” po si tion when the pilot is established.
Turn gas valve control knob(s) to the “ON”
position on spark ig ni tion models.
9. Set the thermostat(s) to call for heat.
10. Observe the gas supply pressure with all burn ers
firing. Ensure inlet pressure is within
specified range. Check gas supply pressure with all
other gas fired appliances in operation to en sure
prop er gas volume during periods of peak gas
usage.
11. If gas pressure is out of range, contact gas utility,
gas supplier, qualified installer or service agen cy
to determine necessary steps to provide prop er gas
pressure to the control.
12. If the gas supply pressure is within the spec i fied
range, proceed with the following steps to return
the appliance to service.
13. Turn the power “OFF” at the main dis con nect
switch.
14. Turn gas valve control knob to “PILOT” po si tion on
standing pilot models. Turn gas valve control
knob(s) to “OFF” position on spark ig ni tion mod els.
15. Shut off gas supply at the manual valve in the gas
piping to the appliance. If fuel supply is
L.P. Gas, shut off gas supply at the tank.
16. Remove the manometer and related fittings from
the “inlet” side of the gas valve, replace 1/8" hex
plug in gas valve.
17. Turn on gas supply at the manual valve, turn on
L.P. Gas at tank if required.
18. Turn the power “ON” at the main dis con nect
switch.
19. Turn the gas valve control knob(s) to the “ON”
position. If the pilot is not burning, follow the
“Light ing Instructions” for standing pilot models to
light the pilot. Spark ignition models will au to mat -
i cal ly light the pilot on a call for heat.
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