Fujitsu ASU18RMLQ Service Instruction page 39

Trouble shooting 6
INDOOR UNIT Error Method:
Water Drain Abnormal
Detective Actuators:
Indoor Unit Main PCB Circuit
Float Switch
Forecast of Cause :
1. Float Switch 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 detective, replace it.
OK OK
Check Point 2 : Check Connector (CN9) / Wire
Check Point 2 :
Check loose contact of CN9 /shorted wire (pinched wire).
>>Replace Float switch if the wire is abnormal
OK OK
Check Point 3 : Replace Main PCB
If Check Point 1 & 2 do not improve the symptom, change Controller PCB.
Indicate or Display:
Refer to error code table.
Detective details:
When Float Switch is ON for more than 3 minutes.
2. Shorted connector/ wire
02-13
3. Main PCB failure
ON ON OFF OFF