Mitsubishi MSH-A18WV Service Manual page 21

10-2. 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
thermistor.
Refer to
Refer to
"Check of
"Test point
diagram and outdoor unit".
voltage" on
page 27.
Flash on and
2-time flash
off at 0.5- Cause:
second
Indoor unit
intervals
• Trouble of
Cause: room temp-
Indoor/
erature/
Outdoor unit
indoor coil
• Mis-wiring thermistor
Check room
Refer to D
temperature
"How to
thermistor
check
and indoor
mis-wiring
coil thermis-
(When
tor.
outdoor unit
Refer to
doesn't work)"
"Test point
on page 26.
diagram and
voltage"
on page 27.
As for outdoor unit MUH type, refer to service manual OB322.
As for outdoor unit MXZ type, refer to 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".
3-time flash
4-time flash
Cause: Cause:
Indoor unit
Indoor unit
• Trouble of
• Trouble of
indoor unit
indoor fan
control
motor
system
Refer to A
Replace the
"Check of indoor
indoor fan electronic
motor"
control
on page 24.
P.C. board.
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 24.
MXZ type
6-time flash
5-time flash
Cause:
Cause:
Outdoor unit
Outdoor unit
• Trouble of
• Outdoor
thermistor
power
in outdoor
system
unit
abnormality
Refer to
Refer to
"Check of
"Check of
inverter/
outdoor
compressor"
thermistor".
and "Check
of power
supply".
21
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 25.
10-time flash
7-time flash
Cause:
Cause:
Outdoor unit
Outdoor unit
MUH-A30WV
• Trouble of
• Trouble of
outdoor
low discharge
control
temperature
system
protection
MXZ type
• Outdoor
refrigerant
system
MUH type
abnormality
Replace the
deicer
P.C. board.
MUH-A30WV
Refer to
MXZ type
"Check of
Replace the
LEV".
outdoor
MXZ type
electronic Refer to
outdoor
control
refrigerant
P.C. board.
system
related items.