36
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
(POWER)
(AIR PURIFYING)
Lit
Blinking
Not lit
No. Abnormal
point
Operation indicator lamp
Symptom
Condition
Remedy
1
Miswiring
or serial
signal
POWER 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.
The indoor unit is connected to a low-stand-
by-power model after once connected to a
non-low-standby-power model.
• Refer to 10-6. "How to check
miswiring and serial signal er-
ror".
• Refer to
NOTE
.
2
Indoor coil
thermistor
POWER lamp blinks.
2-time blink
2.5-second OFF
The indoor coil or the room temperature ther-
mistor is short or open circuit.
• Refer to the characteristics of
indoor coil thermistor, and the
room temperature thermistor
(10-7.).
Room tem-
perature
thermistor
3 Indoor fan
motor
POWER 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 in-
door fan motor".
4 Indoor con-
trol system
POWER 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
POWER lamp blinks.
5-time blink
2.5-second OFF
It consecutively occurs 3 times that the com-
pressor stops for overcurrent protection or
startup failure protection within 1 minute after
startup.
• Refer to "How to check of in-
verter/compressor".
Refer to outdoor unit service
manual
• Check the stop valve.
6 Outdoor
thermistors
POWER 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
POWER 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 out-
door 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 ab-
normality
*2 on 10-3
POWER lamp blinks.
14-time blink or more
2.5-second OFF
An abnormality other than the above is de-
tected.
An abnormality of the indoor thermistors, the
defrost thermistor or ambient temperature
thermistor is detected.
• Check the stop valve.
• Check the 4-way valve.
• Check the abnormality in detail
using the failure mode recall
function for outdoor unit.
• Refer to TEST POINT DIA-
GRAM AND VOLTAGE" on the
service manual of indoor and
outdoor unit for the characteris-
tics of the thermistors. (Do not
start the operation again with-
out repair to prevent hazards.)
9
Outdoor
control sys-
tem
POWER lamp lights up.
Outdoor unit
does not oper-
ate
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the out-
door electronic control P.C. board.
• Check the blinking pattern of
the LED on the inverter P.C.
board or the outdoor electronic
control P.C. board.
• The following indicator applies regardless of shape of the indication.
NOTE
: The indoor unit may have been connected to a non-low-standby-power model outdoor unit. To use a low-standby-
power model, clear the error history by referring to “Deleting the memorized abnormal condition” described in 10-2.1. When
the error history is being cleared, the connection information also will be initialized. The indoor unit will be compatible with a
low-standby-power model after initialization. If the operation indicator lamp continues to blink as shown in No.1 after the pro-
cedure, refer to 10-6.
“How to check miswiring and serial error”.
OBH902A
