Troubleshooting
SiBE04-101
90
Service Diagnosis
4.4
Operation Shutdown Due to High-Pressure Control or Freeze-Up Protection
(Thermistor Activation)
Remote Controller
Display
A5
Indoor unit LED
Display
Method of
Malfunction
Detection
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger thermistor is used
for the high pressure control (operation stop)
The freeze protection control (operation halt) is activated during cooling operation according to the
temperature detected by the indoor unit heat exchanger thermistor.
Malfunction
Decision
Conditions
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger thermistor is above
67˚C
Freeze-Up protection
When the indoor unit heat exchanger temperature is below 0˚C during cooling operation.
Supposed Causes
Operation halt due to clogged air filter of the indoor unit.
Operation halt due to dust accumulation on the indoor unit heat exchanger.
Operation halt due to short-circuit.
Detection error due to faulty indoor unit heat exchanger thermistor.
Detection error due to faulty indoor unit PCB.
Troubleshooting
Check No.1
Refer to P.119
NO
NO
NO
Check No. 1
Indoor unit heat exchanger
thermistor check
Check the intake air filter.
Check the air passage.
YES
YES
Check the dust accumulation on
the indoor unit heat exchanger.
YES
YES
Is there any short-circuit?
Is it very dirty?
Is it very dirty?
Does it conform to the
thermistor characteristic
chart?
NO
Provide sufficient air passage.
Clean the air filter.
Clean the heat exchanger.
Replace the indoor unit PCB(1).
Replace the thermistor.
(R1170)
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
SiBE04-101.book Page 90 Monday, October 15, 2001 3:08 PM
