Specifications

SiENBE04-507A Troubleshooting
Service Diagnosis 117
4.5 Thermistor or Related Abnormality (Indoor Unit)
Remote
Controller
Display
C4, C9
Method of
Malfunction
Detection
The temperatures detected by the thermistors are used to determine thermistor errors.
Malfunction
Decision
Conditions
When the thermistor input is more than 4.96 V or less than 0.04 V during compressor
operation∗.
∗ (reference)
When above about 212°C (less than 120 ohms) or below about -50°C (more than 1,860 kohms).
Note: The values vary slightly in some models.
Supposed
Causes
 Faulty connector connection
 Faulty thermistor
 Faulty PCB
Troubleshooting
Check No.6
Refer to P.146
C4 : Heat exchanger thermistor
C9 : Room temperature thermistor
Check the connector connection.
Correct the connection.
Replace the thermistor.
(Replace the indoor unit PCB.)
Replace the indoor unit PCB.
Is it normal?
Is it normal?
(R1403)
Check No. 6
Thermistor resistance check
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Caution
NO
NO
YES
YES