Compressor Is Not
Operating
Check that thermostat is on.
Head Pressure Too High
Check that the condenser air inlet and outlet are not blocked.
Check that the condensing coil is not restricted.
Check that the condenser filter is not restricted.
Check that condenser fan motor is working and the condenser fan is not damaged.
Check that refrigerant is not overcharged.
Check the sub-cooling.
Check that the service valves are fully open.
Head Pressure Too
Low
Check unit for refrigerant leaks.
Perform pump-down procedure to verify the valves are pumping.
If equipped, check
if sight glass is flashing or showing low charge.
Low Suction Pressure
Check unit for refrigerant leaks.
Check that evaporator fan motors are working.
Check that the air flow is being directed through the evaporator coil.
(All interior panels and must be in place as well as the evaporator fan shroud.)
Check that the Evaporator Coil is clear of ice and debris.
If equipped, check the sight glass for flashing
.
High Suction Pressure
Check for refrigerant being overcharged.
Check for refrigeration restrictions.
Perform pump-down procedure to verity the valves are pumping.
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