15
Yes
No
Yes
No
No
Yes
Yes
No
Measure the resistance
of the pipe temperature
thermistor / liquid.
Indoor controller board is defective.
Check the pipe temperature
thermistor / liquid.
Turn off the power supply and turn it on again to operate the unit in
cooling mode.
Connection is defective.
Is the connector CN21 on the
indoor controller board connected?
Pipe temperature
thermistor / liquid
is defective.
Is the resistance 0 (short circuit) or
∞
(open circuit)?
No
Yes
Yes
No
Measure the resistance of
condenser/evaporator
temperature thermistor.
Check the condenser/evaporator
temperature thermistor.
Is the connector CN29 on the
indoor controller board connected?
Refer to the TECHNICAL &
SERVICE MANUAL of
outdoor unit.
Is the error of indoor unit?
Connection is defective.
Condenser/evaporator
temperature thermistor
is defective.
Is the resistance 0 (short circuit) or
∞
(open circuit)?
Normal
Operation lamp blinks twice in a
fixed period.
Check code : 5102
Yes
No
Yes
No
Indoor fan motor does not rotate.
Measure the resistance of connectors FAN1
and 2 on the indoor controller board.
Connection is defective.
Turn off the power supply and check the connectors
FAN1 and 2 on the indoor controller board visually.
Indoor fan motor is defective.
Are the connectors FAN1 and 2
connected?
Indoor controller board is defective.
Is the resistance 0 (short circuit) or
∞
(open circuit)?
OC303-A-1.qxp 04.9.21 4:08 PM Page 15
