8-4. Trouble Diagnosis of Each Part
8-4-1. Problems of Each Part and Inspection Points
For details about the inspection points, refer to the Inspection Points for Each Part.
Problems
Inspection
points
Indoor unit
Indoor unit does not operate.
Self-Diagnostics check
Indoor controller
(control unit)
Indoor fan motor
Room temperature
sensor
Heat exchanger
temperature sensor
Inter-unit cable
Switch circuit board
Outdoor control circuit
board
Diode module
HIC
Electrolytic capacitor
Fuse
Compressor
Compressor protective
sensor
Outdoor fan motor
4-way valve
Coil thermistor
Electric expansion valve
Branch tubing
temperature sensor
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Operation lamp blinking.
Operation lamp does not illuminate.
Indoor fan dose not turn.
Outdoor unit does not operate.
Outdoor fan dose not turn.
4-way valve does not operate.
The compressor (only) does not
operate.
The compressor stops on occasion.
The compressor speed does not
increase.
The outdoor air temperature is high,
however defrost operation occurs.
Defrost operation does not occur.
The electric expansion valve does
not operate.
Does not cool or cooling
performance is inadequate.
Does not heat or heating
performance is inadequate.
Outdoor unit
Others
No. of
Inspection
Points for
Each part
Indoor unit
Outdoor unit
56
