GPCH3 Installation Manual

8

9. Check the cooling mode for the heat pump in the
same manner as above. The reversing valve is
energized when the thermostat is placed in the
cooling position. A clicking sound should be noticeable

setting to call for cooling, the contractor is energized.
The compressor, blower and fan should then be
running. After the cooling mode is checked out, turn
the thermostat system switch to “OFF”.
10. Turn the thermostat system switch to “HEAT” and fan
switch to “AUTO”.
11. Slowly raise the heating temperature setting. When

the temperature setting. The compressor, blower and
fan should now be running with the reversing valve in

unit time to settle out, make sure the unit is supplying
heated air.
12. If the out door ambient is above 80°F, the unit may
trip on its high pressure cut out when on heating. The
compressor should stop. The heating cycle must be
thoroughly checked, so postpone the test to another
day when conditions are more suitable but-DO NOT
FAIL TO TEST.
13. If the out door ambient is low and the unit operates
properly on the heating cycle, you may check the
󰀨
return air until the unit trips. If unit operates properly
in the heating cycle, raise the temperature setting
until the heating second stage makes contact.
Supplemental resistance heat, if installed should now
come on. Make sure it operates properly.






14. For thermostats with emergency heat switch, return
to step 11. The emergency heat switch is located
at the bottom of the thermostat. Move the switch to
emergency heat. The heat pump will stop, the blower
will continue to run, all heaters will come on and the
thermostat emergency heat light will come on.
15. If checking the unit in the wintertime, when the
outdoor coil is cold enough to actuate the defrost
control, observe at least one defrost cycle to make
sure the unit defrosts completely.
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EVAPORATOR

SERVICE VALVE
SERVICE PORT
REVERSING VALVE
CONDENSER
SERVICE PORT
COMPRESSOR
SERVICE PORT
ACCUMULATOR
EXPANSION DEVICE
CHECK VALVE
ORIFIC E
SERVICE
VALVE
CHECK VALVE
ORIFIC E
INDOOR
CO IL

OUTDOOR
CO IL
EVAPORATOR

SERVICE VALVE
SERVICE PORT
REVERSING VALVE
CONDENSER
COMPRESSOR
SERVICE PORT
ACCUMULATOR
CHECK VALVE
ORIFIC E
SERVICE
VALVE
CHECK VALVE
ORIFIC E
INDOOR
CO IL

OUTDOOR
CO IL
