GPGM3 Installation Manual
15
Rollout Protection
Secondary Limit Control
The secondary limit control is located on the top of the
blower scroll assembly. This control opens when elevated
temperatures are sensed. Elevated temperatures at the
control are normally caused by blower failure. The reason
for the opening should be determined and repaired prior to
resetting.
If the power to the unit is interrupted during the heating
cycle, it may cause the secondary limit to trip. Once the
blower compartment temperature drops below the limit
reset temperature, the limit will automatically reset.
Secondary
Control Limit
Back of Unit
Pre-Operation Checks
1. Close the manual gas valve external to the unit.
2.
3. Set the room thermostat to its lowest possible setting.
4. Remove the heat exchanger door on the side of the
unit by removing screws.
5. This unit is equipped with an ignition device which au-
tomatically lights the main burner. DO NOT try to light
burner by any other method.
6. Move the gas control valve switch to the OFF position.
Do not force.
7.
8. Smell for gas, including near the ground. This is im-
portant because some types of gas are heavier than
gas, immediately follow the warnings on page 3 of this
smell is noted, move the gas control valve switch to
the ON position.
9. Replace the heat exchanger door on the side of the
unit.
10. Open the manual gas valve external to the unit.
11. Turn on the electrical power supply to the unit.
12. Set the thermostat to desired setting.
Gas Supply And Manifold Check
Gas supply pressure and manifold pressure with the burn-
On/Off
Selector
Switch
INLET
OUTLET
Inlet
Pressure Boss
Low Fire
Regulator Adjust
High Fire Regulator
Adjust
Regulator
Vent
Outlet
Pressure Boss
CAUTION
WARNING
HIGH VOLTAGE