Mitsubishi Electric MSZ-HR25VFK-ER1 Service Manual page 25

2. Table of indoor unit failure mode recall function
Left/Upper lamp of
Abnormal point
OPERATION
(Failure mode)
INDICATOR lamp *1
Not lit Normal
1-time blink every Room tempera-
0.5-second ture thermistor
Indoor coil
2-time blink
2.5-second OFF
thermistor
3-time blink
Serial signal
2.5-second OFF
11-time blink
Indoor fan motor
2.5-second OFF
12-time blink Indoor control
2.5-second OFF system
*1 Left lamp: HR25/35/42/50VF
Upper lamp: HR60/71VF
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
OBH822F
Condition
—
The room temperature thermistor short or
open circuit is detected every 8 seconds dur-
ing operation.
The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.
The serial signal from outdoor unit is not
received for a maximum of 6 minutes.
The rotational frequency feedback signal is not
emitted for the 12 seconds after the indoor fan
is operated.
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
25
Remedy
—
Refer to the characteristics of the room temperature
thermistor (10-7.).
Refer to the characteristics of the main indoor coil
thermistor, the sub indoor coil thermistor (10-7.).
Refer to 10-6. "How to check miswiring and serial
signal error".
Refer to 10-6. "Check of indoor fan motor".
Replace the indoor electronic control P.C. board.