SiUS30-1301
Troubleshooting by Indication on the Remote Controller
Service Diagnosis
173
3.11 Thermistor Abnormality
Error Code
C4
,
C5
,
C9
Applicable
Models
All indoor models
Method of Error
Detection
The error is detected by temperature detected by thermistor.
Error Decision
Conditions
When the thermistor becomes disconnected or shorted while the unit is running.
Supposed
Causes
Defective thermistor
Defective indoor unit PCB
Defective connector connection
Broken or disconnected wire
Troubleshooting
Note:
1. Error code and thermistor
Refer to P.250.
Is the
thermistor normal?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
5 k
Ω
to 90 k
Ω
Remove the thermistor from
the indoor unit PCB, and then
insert it again.
Remove the thermistor from
the indoor unit PCB, and then
make resistance measurement
of the thermistor using a
multiple meter.
Normal (The error is caused by
defective contact.)
YES
NO
Replace the indoor unit PCB.
YES
Replace the thermistor (
∗
1).
NO
CHECK 11
Error Code
Thermistor
Except FXTQ
FXTQ
C4
Heat exchanger liquid pipe thermistor
R2T
R1T
C5
Heat exchanger gas pipe thermistor
R3T
R2T
C9
Suction air thermistor
R1T
—
CHECK 11