GPG16M Installation Instructions
13
INSTALLATION - COMBUSTION AIR INTAKE HOOD
1. Locate the second hood.
2. Using the three screws provided, attach the hood (with the
opening facing down) to the heat exchanger access door.
CONDENSATE DRAIN
CONDENSATE DRAIN CONNECTION
A 3/4” NPT drain connection is supplied for condensate piping. An external
trap must be installed for proper condensate drainage.
NORMAL SEQUENCES OF OPERATION
HEATING
This unit is equipped with an ignition control that automatically lights
the main burner. DO NOT attempt to light the main burners by any
other method.
1. Thermostat calls for low or high stage heating.
2. Induced draft blower energizes for 15-second pre-purge.
3. The spark igniter and low and high stage gas valve are energized
for 7 seconds. NOTE: The igniter produces a very intense electrical
spark that ignites the gas.
4. Main burners light and control detects presence of flame.
5. If the call is for low stage heat, the induced draft blower switches to low speed and the high stage gas valve closes 5 seconds
after the main burners light. If call is for high stage heat, induced draft blower remains at high speed and high stage gas valve
remains open.
NOTE: If a single stage thermostat is used, the control will step to low stage after the main burners light and remain at low
stage for 5 or 10 minutes, depending on jumper position. If the call for HEAT remains after the transition delay time expires,
the control will transition from low stage to high stage.
6. The 30-second HEAT FAN ON delay time begins after the main burners light.
7. The unit delivers heat to the conditioned space until the thermostat is satisfied.
8. Gas valve(s) de-energizes. The induced draft blower continues operation for a 30-second post-purge.
9. Induced draft blower remains at low speed (or switches from high to low if operating at high stage heat) for the 30-second post
purge.
10.Ignition control begins timing the HEAT FAN OFF delay. There is an adjustable HEAT FAN OFF delay of approximately 90/120/
150/180 seconds (factory set at 150). If the unit is operating at high stage when the call for heat is removed, the blower will
operate for 30 seconds at high heat speed then switch to low heat speed for the remainder of the selected HEAT FAN OFF delay.
NOTE: After the HEAT FAN OFF delay time has elapsed, the blower will de-energize. This allows any additional heat in the heat
exchanger to be transferred to the conditioned space.
COOLING
1. Thermostat calls for low or high stage cooling.
2. If the thermostat call is for low stage cooling, the compressor and outdoor fan are energized at low stage. If the thermostat
call is for high stage cooling, the compressor and outdoor fan are energized at high stage.
3. The indoor blower will energize approximately 6 seconds later.
4. The unit delivers cooling to the conditioned space until the thermostat is satisfied.
5. The compressor and outdoor fan will be de-energized when the thermostat opens.
6. The indoor blower continues to run at low cool speed for approximately 60 seconds after the thermostat is satisfied. This allows
additional cooling from the indoor coil to be transferred to the conditioned space. Then, the indoor blower is de-energized.
NOTE: A 180-second anti-short cycle is integral to the control and prevents recycling of the compressor.
DRAIN
CONNECTION
UNIT 2" MINIMUM
FLEXIBLE
TUBING-HOSE
OR PIPE
3" MINIMUM
A POSITIVE LIQUID
SEAL IS REQUIRED
Drain Connection










