Troubleshooting for Wall Mounted and LSP Duct Type Indoor Unit
SiSG121917E
123
Part 6 Service Diagnosis
Reference
5.4 Thermistor or Related Abnormality (Indoor Unit)
Error Code
C4
,
C9
Method of Error
Detection
The temperatures detected by the thermistors determine thermistor errors.
Error Decision
Conditions
The voltage between the both ends of the thermistor is either 4.96 V or more, or 0.04 V or less
with the power on.
Supposed
Causes
Disconnection of connector
Defective thermistor(s)
Defective indoor unit PCB
Troubleshooting
C4
: Indoor heat exchanger thermistor
C9
: Room temperature thermistor
Check No.01
Refer to P.169
YES
(R21
8
70)
N
O
Check No. 01
Check the thermistor resistance
v
al
u
e.
YES
N
O
Caution
Correct the connection.
Replace the defecti
v
e
thermistor.
Replace the indoor
u
nit PCB
(control PCB).
N
ormal?
N
ormal?
Check the connection of
connectors.
Be s
u
re to t
u
rn off the po
w
er s
w
itch
b
efore connecting or disconnecting
connectors, or parts may
b
e damaged.