Fujitsu AO G12KBTB Series Service Instructions Manual page 55

Trouble shooting 16
INDOOR UNIT Error Method:
Drain Pump Error
Detective Actuators:
Indoor unit Controller PCB Circuit
Float switch
Forecast of Cause :
1. Float switch failure
4. Drain pump failure
Check Point 1 : Check Float switch
Check operation of float switch. (any blocking by dust, etc.)
Remove Float switch and check ON/OFF switching operation
by using a meter.
>>If Float switch is abnormal, replace it.
OK
Check Point 2 : Check Connector and Wire
Check loose contact of CN9 /shorted wire (pinched wire).
>>Replace Float switch if the wire is abnormal
OK
Check Point 3 : Check Drain hose
Check Drain hose .
>>If there is Hose clogging. Please clear the clog.
OK
Check Point 4 : Check Controller PCB and Drain Pump
Check Drain Pump.
If drain pump is not run on the working condition,
check the voltage of the CN71 on the controller PCB.
DC12V
RED
CN71-1
CN71
CN71-2
WHITE
CN71-3
CN71-4
B
Measurement result
12V : Replace the Drain Pump
Other than 12V : Replace the controller PCB
Indicate or Display:
Error code : 53
Detective details:
When Float switch is ON for more than 3 minutes.
2. Shorted connector/wire
5. Hose clogging
DC DRAIN PUMP MOTOR
M
02-17
Outdoor unit : No indication
3. Controller PCB failure
ON OFF