No.
1
2
4
6
7
SymptomOperation indicator lamp Condition
Remedy
0.5-second ON
0.5-second OFF
Mis-Wiring
Outdoor
thermistor
Outdoor
control
system
Indoor coil
thermistor
3 minutes after power supply turns ON, when
serial signal is not received.
<Thermistor short>
Thermistors are abnormal when they short
after compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open
after compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more
than 10 minutes after compressor start-up.
It cannot properly read data in the nonvolatile
memory of the deicer P.C. board.
Outdoor unit stops [and restarts 3 minutes
later (MUH-GA60VB).]
• Shortage of refrigerant
• Check the deicer P.C.
board.
Refer to "Check of outdoor
thermistor". Refer to outdoor
service manual.
• Check the deicer P.C. board.
Refer to outdoor service
manual.
• Refer to 9-5. D "How to check
mis-wiring ".
3
Indoor fan
motor
MUH-GA80VB
Low
discharge
temperature
protection
MUH-GA80VB
Discharge temperature has been 50: or less
on cool operation, or has been 49: or less on
heat operation for 20 minutes.
Abnormal
point
Outdoor unit
does not
operate.
Room
temperature
thermistor
2-time flash
2.5-second OFF
Detect Indoor coil/room temperature
thermistor short or open circuit every 8
seconds during operation.
• Refer to the characteristics
of indoor coil thermistor, and
room temperature thermistor
(9-6.).
3-time flash
2.5-second OFF
Indoor fan repeats
12 seconds ON
and 3minutes OFF.
When the indoor
fan breaks, the fan
keeps stopping.
Rotational frequency feedback signal is not
emitted for 12-second after indoor fan motor is
operated.
• Refer to 9-5. A "Check of
indoor fan motor".
4-time flash
2.5-second OFF
Indoor
control
system
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
• Check the indoor electronic
control P.C. board.
6-time flash
2.5-second OFF
MUH-GA80VB
• Refer to "Check of LEV".
• Check refrigerant circuit and
refrigerant amount.
Refer to outdoor unit service
manual.
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
Outdoor unit
does not
operate.
5
7-time flash
2.5-second OFF
10-time flash
2.5-second OFF