SiAU18-715 Troubleshooting for Outdoor Unit
Troubleshooting 371
7.12 Malfunction of Thermistor (R4T) for Outdoor Unit Heat
Exchanger
Remote
Controller
Display
J6
Applicable
Models
AII outdoor unit models
Method of
Malfunction
Detection
Malfunction is detected from the temperature detected by the heat exchanger thermistor.
Malfunction
Decision
Conditions
When a short circuit or an open circuit in the heat exchange thermistor is detected.
Supposed
Causes
Defect of thermistor (R4T) for outdoor unit heat exchanger
Defect of outdoor unit PCB (A1P)
Troubleshooting
∗
Refer to thermistor resistance / temperature characteristics table on P405.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Connector is
connected to outdoor unit
PC board (A1P).
Resistance
is normal when
measured after
disconnecting the thermistor
(R7T) from the outdoor
unit PC board.
(3.5kΩ~
360kΩ)
Replace outdoor unit PC
board (A1P).
(Q0561)
Connect the thermistor
and turn on again.
NO
Replace the thermistor
(R7T).
NO
YES
YES