GPG16M Installation Instructions

17
Unit Shutdown
1. Set the thermostat to lowest setting.
2. Turn off the electrical power supply to the unit.
3. Remove the heat exchanger door on the side of the unit by removing screws.
4. Move the gas control valve switch to the OFF position. Do not force.
5. Close manual gas shutoff valve external to the unit.
6. Replace the heat exchanger door on the unit.
7. If cooling and/or air circulation will be desired, turn ON the electrical power.
COOLING STARTUP
NOTE: Check all manual reset limit controls in heating circuit if cooling mode does not
operate.
Compressor Protection Devices
The compressor includes components which are designed to protect the compressor
against abnormal operating conditions.
Cooling Refrigerant Charging (Models with TXV)
Check unit charge before putting the cooling section into full
operation. The unit has a thermostatic expansion valve metering
device. To ensure the unit is properly charged for the intended
application, check the unit refrigerant sub-cooling at the condenser.
The refrigerant sub-cooling is a function of outdoor ambient
temperature and return air temperature of the conditioned space.
It is the installing contractors responsibility to ensure the proper
refrigerant sub-cooling at the condenser is adjusted for each
application. As the outdoor ambient temperature rises the sub-
cooling decreases and as the outdoor ambient temperature lowers, the sub-cooling increases. NOTE: Proper sub-cooling adjustment
optimizes cooling performance. Models equipped with thermostatic expansion valve, charge the system to sub-cooling, range shown on
chart, when necessary, adjust expansion valve stem for superheat
setting.
NOTE: The expansion valve will not need adjustment for most
applications. Ensure system superheat is set within range listed on
chart.
Superheat Adjustment
To adjust superheat, remove the control box cover and locate the
expansion valve on the liquid line of the evaporator. Unscrew the
cover from the expansion valve, locate the adjustment screw, and turn it
clockwise (in) to increase superheat or counterclockwise (out) to decrease
superheat. Replace adjustment cap. Wait a minimum of 10 minutes between
adjustments to allow time for the TXV and pressures to stabilize.
Cooling Operation
NOTE: Mechanical cooling cannot be reliably provided at ambient temperatures
below 50° F.
1. Turn on the electrical power supply to the unit.
2. Place the room thermostat selector switch in the COOL position (or
AUTO if available, and if automatic changeover from cooling to heating
is desired).
3. Set the room thermostat to the desired temperature.
TROUBLESHOOTING
IGNITION CONTROL ERROR CODES
The following presents probable causes of questionable unit operation. Refer to Diagnostic Indicator Chart for an interpretation of the
signal and to this section for an explanation.
Remove the control box access panel and note the number of diagnostic LED flashes. Refer to Diagnostic Indicator Chart for an
interpretation of the signal and to this section for an explanation.
LO COOL
HI COOL
LO HEAT
HI HEAT
U6
U7
U4
U5
U3
K2
K1
P1
ECON
STAGE
DEL A Y
SPEEDUP
SW1
FAULT
RECA L L
BL OWER
OFF DEL A Y
F1
RCW1W2
GY1Y2
Control Board (Top)
Models # Superheat °F Subcooling °F
GPG1624060M41 9 - 13 9 - 13
GPG1630080M41 8 - 12 10 - 14
GPG1636080M41 10 - 14 8 - 12
GPG1642100M41 10 - 14 6 - 10
GPG1648100M41 8 - 12 8 - 12
Design superheat & subcooling
@ 95 °F outdoor ambient temperature