18
10-3. INSTRUCTION OF TROUBLESHOOTING
Indoor unit operates.
Outdoor unit does
not operate.
If blinking of OPERATION INDI-
CATOR lamp cannot be checked,
it can be checked with failure
mode recall function.
Indoor unit operates.
Outdoor unit does
not operate normally.
Indoor unit does
not receive the
signal from remote
controller.
OPERATION INDICATOR
lamp on the indoor unit is
blinking on and off.
Outdoor unit
operates only
in Test Run
operation.
*1
Outdoor unit
does not
operate even
in Test Run
operation.
*1
Unit does not
operate nor-
mal operation
in COOL or
HEAT mode.
Indoor unit
operates, when
the emergency
operation switch
is pressed.
Indoor unit does
not operate, when
the emergency
operation switch
is pressed.
Check room
temperature
thermistor.
Refer to 10-7.
"Test point
diagram and
voltage".
Refer to "How
to check
inverter/com-
pressor".
Refer to
"Check of R.V.
coil".
Refer to 10-6.
"Check of remote
controller and
indoor electronic
control P.C.
board".
1. Check indoor/out-
door connecting wire.
(Check if the power is
supplied to the indoor
unit.)
2. Refer to 10-6. "Check
of indoor P.C. board
and indoor fan motor".
Start
*1 "Test Run operation" means
the operation within 30 minutes
after the emergency operation
switch is pressed.
Refer to outdoor unit service manual.
Upper lamp
Blink on and
off at 0.5-sec
-
ond intervals
Cause:
Indoor/Outdoor
unit
• Miswiring or
trouble of
serial signal
Upper lamp
2-time blink
Cause:
Indoor unit
• Trouble
of room
temperature
/ indoor coil
thermistor
Upper lamp
3-time blink
Cause:
Indoor unit
• Trouble of
indoor fan
motor
Upper lamp
4-time blink
Cause:
Indoor unit
• Trouble
of indoor
unit control
system
Upper lamp
5-time blink
Cause:
Outdoor unit
• Outdoor
power sys-
tem abnor-
mality
Upper lamp
6-time blink
Cause:
Outdoor unit
• Trouble of
thermistor in
outdoor unit
Upper lamp
7-time blink
Cause:
Outdoor unit
• Trouble of
outdoor con-
trol system
Upper lamp
14-time blink
or more
Cause:
Outdoor unit
• Other ab-
normality
Indoor/Out-
door unit
• Trouble of
thermistors
Refer to 10-
6. "How to
check mis-
wiring and
serial signal
error".
Check room
temperature
thermistor
and indoor
coil thermis-
tor. Refer to
10-7."Test
point diagram
and voltage".
Refer to 10-
6. "Check
of indoor fan
motor".
Replace the
indoor elec-
tronic control
P.C. board.
Refer to
"How to
check
inverter/com-
pressor".
Refer to
"Check of
outdoor ther-
mistors".
Replace the
inverter P.C.
board or
the outdoor
electronic
control P.C.
board.
• Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall func-
tion."
• Check
thermistors.
Refer to
"Test point
diagram and
voltage" in
the service
manual of
indoor and
outdoor unit.
*2
*2 There is possibility that diesel explosion may occur due to the air mixed in the refrigerant circuit.
First, ensure that there are no leakage points on the valves, flare connections, etc. that allow the
air to flow into the refrigerant circuit, or no blockage points (e.g. clogged or closed valves) in the
refrigerant circuit that cause an increase in pressure.
If there is no abnormal point like above and the system operates cooling and heating modes nor-
mally, the indoor thermistor might have a problem, resulting in false detection.
Check both the indoor coil thermistor and the room temperature thermistor, and replace faulty
thermistor(s), if any.
NOTE:
Do not start the operation again without repair to prevent hazards.
OBH905
