18
2. Indoor unit failure mode table
Upper lamp of OP-
ERATION INDICA-
TOR lamp
Abnormal point
(Failure mode)
Condition Remedy
Not lighted
Normal
—
—
1-time
fl
ash every
0.5-second
Room temperature
thermistor
The room temperature thermistor short or
open circuit is detected every 8 seconds dur-
ing operation.
Refer to the characteristics of the room temperature
thermistor (9-7.).
2-time
fl
ash
2.5-second OFF
Indoor coil
thermistor
The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.
Refer to the characteristics of the main indoor coil ther-
mistor, the sub indoor coil thermistor (9-7.).
3-time
fl
ash
2.5-second OFF
Serial signal
The serial signal from outdoor unit is not re-
ceived for a maximum of 6 minutes.
Refer to 9-6. "How to check miswiring and serial
signal error".
11-time
fl
ash
2.5-second OFF
Indoor fan motor
The rotational frequency feedback signal is
not emitted for 12 seconds after the indoor fan
motor is operated.
Refer to 9-6. "Check of indoor fan motor".
12-time
fl
ash
2.5-second OFF
Indoor control
system
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.
NOTE
: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (9-4.).
OBH685
