27
No. Abnormal
point
Operation indicator lamp
Symptom
Condition
Remedy
1
Miswiring
or serial
signal
Upper 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 6 minutes.
• Refer to 10-6.
"How to
check miswiring and serial
signal error".
2
Indoor coil
thermistor
Upper lamp blinks
.
2-time blink
2.5-second OFF
The indoor coil or the room tem-
perature thermistor is short or
open circuit.
• Refer to the characteristics
of indoor coil thermistor, and
the room temperature ther-
mistor (10-7.).
Room tem-
perature
thermistor
3 Indoor fan
motor
Upper lamp blinks
.
3-time blink
2.5-second OFF
The rotational frequency feedback
signal is not emitted during the
indoor fan operation.
• Refer to 10-6. "Check of
indoor fan motor".
4
Indoor con-
trol system
Upper lamp blinks
.
4-time blink
2.5-second OFF
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 sys-
tem
Upper lamp blinks
.
5-time blink
2.5-second OFF
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
Upper lamp blinks
.
6-time blink
2.5-second OFF
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 sys-
tem
Upper lamp blinks
.
7-time blink
2.5-second OFF
It cannot properly read data in the
nonvolatile memory of the inverter
P.C. board or the outdoor elec-
tronic control P.C. board.
• Replace the inverter P.C.
board or the outdoor elec-
tronic control P.C. board.
Refer to outdoor unit service
manual.
8 Other ab-
normality
Upper lamp blinks
.
14-time blink or more
2.5-second OFF
An abnormality other than above
mentioned is detected.
• Check the stop valve.
•
Check the 4-way valve.
•
Confirm the abnormality in
detail using the failure mode
recall function for outdoor
unit.
9
Outdoor
control sys-
tem
Upper lamp lights up.
Outdoor unit
does not oper-
ate
It cannot properly read data in the
nonvolatile memory of the inverter
P.C. board.
• Check the blinking pattern of
the LED on the inverter P.C.
board.
10-4. 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
OBH864
