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9-4. Unit Problems and Inspection Points
• For details about the inspection points, refer to Inspection points for each part.
Indoor unit
Indoor unit
Outdoor unit
Others
The outdoor air temperature is high,
however defrost operation occurs.
Indoor unit does not operate.
Self-Diagnostics check
1
Indoor controller
(control unit)
2
Indoor fan motor
3
Room temperature
sensor
4
Heat exchanger
temperature sensor
5
Inter-unit cable
6
Switch circuit board
7
Outdoor control
circuit board
8
Diode module
9
HIC
!
Electrolytic capacitor
#
Compressor
$
Compressor
protective thermistor
%
Outdoor fan motor
&
4-way valve
(
Coil thermistor
)
Electric expansion
valve
~
Branch tubing
temperature sensor
+
Breaker
,
Refrigerant gas
pressure
Measure during
a test run.
Operation lamp flashes.
Indoor fan does not turn.
Operation lamp does not illuminate.
The compressor (only) does not
operate.
The compressor stops on occasion.
The compressor speed does not
increase.
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 does not operate.
Outdoor fan does not turn.
4-way valve does not operate.
Problems
Inspection
points
Others
Note
Outdoor unit
"
Fuse
