Instruction Of Troubleshooting - Mitsubishi Electric MLZ-KP25VF Service Manual

11-3. INSTRUCTION OF TROUBLESHOOTING

Start
Indoor unit
Indoor unit operates.
operates.
Outdoor unit does not
Outdoor unit
operate normally.
does not
operate.
Outdoor unit
Outdoor unit
operates only
does not
in Test Run
operate
operation.
even in
1
Test Run
operation.
1
Refer to
Check room
"How to check
temperature
inverter/
thermistor.
compressor".
Refer to 11-7.
"TEST POINT
DIAGRAM AND
VOLTAGE".
Left lamp
Left lamp
Left lamp
2-time flash
Flash on and off
3-time flash
Cause:
at 0.5-second
Cause:
Indoor unit
intervals
Indoor unit
Cause:
room temp-
Indoor/
indoor fan
erature/
Outdoor unit
motor
indoor coil
thermistor
or trouble
of serial signal
Refer to 11-6.
Check room
Refer to 11-6.
temperature
"How to
indoor fan
thermistor
check
motor".
and indoor
miswiring
coil thermis-
and serial
tor.
signal error
Refer to 11-7.
(when
"Test point
outdoor unit
diagram and
does not work)".
voltage".
OBH801
Indoor unit
does not receive
the signal from
remote controller.
Indoor unit
Unit does not
operates, when
operate
EMERGENCY
normal
OPERATION
operation in
switch is pressed.
COOL or
HEAT mode.
Refer to 11-6.
Refer to
"Check of
"Check of
remote controller,
R.V. coil".
receiver P.C.
board and
indoor electronic
control P.C.
board".
Left lamp
Left lamp
4-time flash
5-time flash
Cause:
Cause:
Indoor unit
Outdoor unit
indoor unit
power
control
system
system
abnormality
Refer to
Replace the
"How to check
"Check of indoor
the inverter/
electronic
compressor".
control
P.C. board.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
If blinking of OPERATION
Indoor unit
INDICATOR lamp cannot be
does not operate,
checked, it can be checked with
when
failure mode recall function.
EMERGENCY
OPERATION
switch is pressed.
1
"Test Run operation" means the
operation within 30 minutes after
EMERGENCY OPERATION switch
is pressed.
1. Check indoor/outdoor
connecting wire.
(Check if the power
is supplied to the
Refer to outdoor unit service manual.
indoor unit.)
2. Refer to 11-6.
"Check of indoor
electronic control
P.C. board and indoor
fan motor".
Left lamp
Left lamp
7-time flash
6-time flash
Cause:
Cause:
Outdoor unit
Outdoor unit
outdoor
thermistor
control
in outdoor
system
unit
Refer to Replace the
"Check of inverter P.C.
outdoor board or
thermistors". the outdoor
electronic
control P.C.
board.
28
Left lamp Left lamp
9-time flash 14-time flash
Cause: or more
Indoor unit Cause:
Outdoor unit
float sensor
or drain abnormality
pump
stop valve.
Refer to 11-6. Check the Check
"Check of drain pump. "Flow chart of
float sensor". the detailed
outdoor unit
failure mode
recall function."