Fujitsu AO G18LBCA Series Service Instruction page 35

Trouble shooting 5
INDOOR UNIT Error Method:
Combination error
Detective Actuators:
Indoor unit
Forecast of Cause:
1. The selection of indoor units is incorrect
Check Point 1 : Check the type of indoor unit
Check the type of the connected indoor unit.
>> If abnormal condition is found, correct it.
OK
Check Point 2 : Replace Main PCB
If Check Point 1 do not improve the symptom, replace Main PCB of Outdoor unit.
Indicate or Display:
Error code : 23
Detective details:
1. The outdoor unit receives the serial signal of applied refrigerant information
from Indoor unit. When the refrigerant is R410a.
2. When the outdoor unit type is multi.
02-06
Outdoor unit : No indication