Check code
Abnormal points and detection methods Causes and check points
Abnormal if TH3 detects to be open/short.
(The open/short detection is disabled during 10 sec. to 10 min. after
compressor starts, during defrosting operation, or for 10 min. after
returning from the defrosting operation.)
Open: -40 [-40°F] or less
Short: 90 [194°F] or more TH3: Piping temperature thermistor
Disconnection or contact failure of connectors
Characteristic defect of thermistor
Defective outdoor controller board
●Diagnosis of defectives
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Diagnosis Remedy
5105
Piping temperature thermistor (TH3) open/short
The black square (■) indicates a switch position.
No
Yes
Yes
Yes
No
No
Is there any abnormality such
as a disconnection, looseness or
breakage?
Is the detected resistance normal?
Is the detected temperature normal?
Connect the wiring/connector properly
Replace it in case of a breakage.
Replace the thermistor.
Replace the controller board
(Malfunction of thermistor circuit).
No abnormality
( A connector contact failure is suspected).
Check the wiring and connector connection of TH3.
Disconnect the connector to check the
resistance of TH3 using a tester.
Check a temperature of TH3.
ON
OFF
12345678
SW1 Setting
Display on LED1,2
Unit
-99.9 999.9 °F
The detected temperature of TH3 can be displayed by an
operation of SW1 on the outdoor controller board
60
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