Cause
Check Item
Action
(Turn OFF Main Switch)
Phenomenon
Excessively
High
Discharge
Pressure
Insufficient
Cooling
Operation
Check expansion valve
opening.
Correctly charge
refrigerant.
Excessively
Charged
Refrigerant
Excessively
High Air
Temp. to
Outdoor Unit
Heat
Exchanger
Check each temp.
and pressure.
Charge refrigerant
after vacuum pumping.
Non-
Condensed
Gas in Cycle
Check for clogging.
Remove clogging.
Clogging of
Discharge
Piping
Check Clogging of
Outdoor Unit
Heat Exchanger.
Remove clogging.
Obstacles at inlet or
outlet of outdoor unit
heat exchanger?
Remove obstacles.
Short-Circuited Air
to Outdoor Unit?
Remove cause of
short-circuited air.
Any Other Heat Load
near Outdoor Unit?
Remove heat source.
Is service space for
outdoor unit sufficient?
Secure service space.
Correct Fan Speed?
Replace fan motor.
Insufficient
Air Flow to
Outdoor Unit
Heat
Exchanger
Check for clogging.
Remove clogging.
Check for connecting
cord and connector.
Replace connector.
Is there operation
sound from coil?
Replace coil.
Is thermistor on
compressor normal?
Replace thermistor.
Is thermistor installed
correctly on
compressor?
Correctly install it.
Failure or
Malfunction
of Expansion
Valve
Check temp. difference
between inlet and
outlet of reversing valve.
Check for leakage of
solenoid valve.
Excessively
Low Suction
Pressure
Failure of
Bypass
Solenoid
Valve
Replace solenoid valve.
Replace failed
expansion valve of
indoor unit.
Replace reversing valve.
Malfunction
or Internal
Leakage of
Reversing
Valve
Check temp. difference
at inlet and outlet of
reversing valve.
Replace reversing valve.
Malfunction or Internal
Leakage of Reversing Valve
Check for expansion
valve of indoor unit in
the same system.
Discharge Temp. of
Indoor Unit is Unstable.
(
●
Abnormalities of Devices)
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