31
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
Indoor unit
doesn't receive
the signal from
remote controller.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Outdoor unit
operates in
only Test Run
operation.
Outdoor unit
doesn't
operate
even in
Test Run
operation.
Indoor unit
operates, when
the EMERGENCY
OPERATION
switch is pressed.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is pressed.
Check room
temperature
thermistor.
Refer to
"Test point
diagram and
voltage".
Refer to
E
"Check of
inverter/
compressor"
on page 38.
Refer to
"Check of
remote controller
and receiver
P.C. board".
1. Check indoor/ outdoor
connecting wire.
(Check if the power
is supplied to the
indoor unit.)
2. Refer to
"Check of indoor
electronic control
P.C. board".
Unit doesn't
operate
normal
operation in
COOL or
HEAT mode.
Refer to
C
"Check of
R.V. coil"
on page 37.
Flash on and
off at
0.5-second
intervals
Cause:
Indoor/
Outdoor unit
• Mis-wiring
or trouble of
serial signal
2-time flash
Cause:
Indoor unit
• Trouble of
room temp-
erature/
indoor coil
thermistor
MSZ type
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
5-time flash
Cause:
Outdoor unit
• Outdoor
power
system
abnormality
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor
control
system
Refer to
B
"How to
check
mis-wiring
and serial
signal error
(When
outdoor unit
doesn't
work)".
Check room
temperature
thermistor
and indoor
coil thermis-
tor.
Refer to
"Test point
diagram and
voltage".
Refer to
"Check of
indoor fan
motor".
Refer to
E
"Check of
inverter/
compressor"
on page 38.
Refer to
F
"Check of
outdoor
thermistors"
on page 39.
Replace the
outdoor
electronic
control P.C.
board.
4-time flash
Cause:
Indoor unit
• Trouble of
indoor unit
control
system
Replace the
indoor
electronic
control
P.C. board.
As for indoor unit MSZ type, refer to service manual OB345.
As for indoor unit MCFZ type, refer to service manual OB344 REVISED EDITION - A.
Indoor unit operates.
Outdoor unit doesn't
operate normally.
10-2. Instruction of troubleshooting
OB346A --2qxp 04.6.14 1:20 PM Page 31
Summary of Contents for MUZ-A18YV
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