Fujitsu ASU18RLF Service Instructions Manual page 55

Trouble shooting 11
INDOOR UNIT Error Method:
Drain Pump Error
Detective Actuators:
Indoor unit controller PCB circuit
Float switch
Forecast of Cause:
1. Float switch failure 2. Shorted connector/wire 3. Controller PCB failure
Test 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
Test 2 : Check Connector (CN 9) / Wire
Check loose contact of CN9 /shorted wire (pinched wire).
>> Replace Float switch if the wire is abnormal.
OK
Test 3 : Check Drain Hose
Check Drain Hose .
>> If there is Hose clogging. Please clear the clog.
OK
Test 4 : Check Controller PCB
If Test 1 - 3 do not improve the symptom, change
Controller PCB and execute the check operation again.
Indicate of Display:
Indoor Unit
Operation lamp : 5 time Flash
Timer lamp : 3 time Flash
ERROR CODE : [E : 53]
Detective details:
When Float switch is ON for more than 3 minutes.
ON
Attention!!
Wall mount / Compact wall mount type
does not have a float switch.
In this case, replace
and set up the original address.
Please refer to.
02-15
Outdoor Unit
Monitor
A B C D
: Light ON : Light OFF n : n time blinking
4. Drain pump failure 5. Hose clogging
OFF
PCB
Controller
E F