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9-4. TROUBLESHOOTING CHECK TABLE
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the
power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp blinks.
OPERATION INDICATOR
Lit
Blinking
Not lit
No. Abnormal
point
Operation indicator lamp
Symptom
Condition
Remedy
1 Miswiring or
serial signal
Left lamp blinks.
0.5-second ON
0.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
The serial signal from the outdoor unit is not
received for a maximum of 6 minutes.
• Refer to 9-6. "How to check miswiring
and serial signal error".
2
Indoor coil
thermistor
Left lamp blinks.
2-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
The indoor coil or the room temperature
thermistor is short or open circuit.
• Refer to 9-7.the characteristics of
indoor coil thermistor, and the room
temperature thermistor.
Room
temperature
thermistor
3 Indoor fan
motor
Left lamp blinks.
3-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
The rotational frequency feedback signal is not
emitted during the indoor fan operation.
• Refer to 9-6. "Check of indoor fan
motor".
4
Indoor
control
system
Left lamp blinks.
4-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
• Replace the indoor electronic control
P.C. board.
5
Outdoor
power
system
Left lamp blinks.
5-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
It consecutively occurs 3 times that the
compressor stops for overcurrent protection or
start-up failure protection within 1 minute after
start-up.
• Refer to "How to check of inverter/
compressor".
Refer to outdoor unit service manual.
• Check the stop valve.
6 Outdoor
thermistors
Left lamp blinks.
6-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
The outdoor thermistors short or open circuit
during the compressor operation.
• Refer to "Check of outdoor thermistor".
Refer to outdoor unit service manual.
7
Outdoor
control
system
Left lamp blinks.
7-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the
outdoor electronic control P.C. board.
• Replace the inverter P.C. board or the
outdoor electronic control P.C. board.
Refer to outdoor unit service manual.
8 Other
abnormality
Left lamp blinks.
14-time blink
2.5-second OFF
Indoor unit
and outdoor
unit do not
operate.
An abnormality other than above mentioned is
detected.
•
Confirm the abnormality in detail using
the failure mode recall function for
outdoor unit.
OBH501D