Mitsubishi Electric MCFH-A12WV Service Manual page 12

9-2. Instruction of troubleshooting
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Outdoor unit
doesn't
Outdoor unit
operate
operates in
even in
only Test Run
Test Run
operation.
operation.
Check room
temperature
Refer to
thermistor.
Refer to "Check of
"Test point
outdoor unit".
diagram and
voltage" on
page 18.
Flash on and
2-time flash
off at 0.5-
Cause:
second Indoor unit
interval
• Trouble of
Cause:
room
Indoor/
temperature/
Outdoor unit
indoor coil
• Mis-wiring thermistor
or trouble of
serial signal
Check room
Refer to E
temperature
"How to
thermistor
check mis-
and indoor
wiring and
coil
serial signal
thermistor.
error (When
Refer to
outdoor unit
"Test point
doesn't
diagram and
work)" on
voltage"
page 17.
on page 18.
As for outdoor unit MUCFH type, refer to the service manual OB337.
As for outdoor unit MUH type, refer to the service manual OB331.
As for outdoor unit MXZ type, refer to the service manual OB319.
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
Unit doesn't
Outdoor unit
operate
doesn't
normal
stop even
operation in
if indoor unit
COOL or
stops.
HEAT mode.
Refer to Refer to
"Check of "Check of
outdoor unit".
R.V. coil".
4-time flash
MXZ type
Cause: 5-time flash
Cause:
Indoor unit
Outdoor unit
• Trouble of
• Outdoor
indoor
power
electric
system
P.C. board
abnormality
Refer to D
Refer to
"Check of
"Check of
indoor
inverter/
electric
compressor"
control P.C.
and "Check
board" on
of power
page 16.
supply".
Indoor unit
doesn't receive
the signal from
remote controller.
Indoor unit
operates, when
the EMERGENCY
OPERATION
switch is pressed.
Refer to B
"Check of
remote controller
and receiver
P.C. board"
on page 15.
6-time flash MXZ type
MUCFH-A24WV
Cause:
7-time flash
Outdoor unit
Cause:
• Trouble of
Outdoor unit
thermistor
• Trouble of
in outdoor
outdoor
unit
control
system
Refer to MUCFH-A24WV
"Check of Replace the
outdoor deicer
thermistor". P.C. board.
MXZ type
Replace the
outdoor
electronic
control
P.C. board.
12
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is pressed.
1. Check indoor /
outdoor
connecting wire.
2. Refer to C
"Check of indoor
electronic control
P.C. board"
on page 16.