Fujitsu

General indoor unit malfunction. Check indoor unit operation and connections.

Indoor control board malfunction. Professional PCB inspection and replacement required.

Room temperature sensor fault. Replace indoor temperature sensor.

Evaporator coil sensor malfunction. Professional sensor replacement needed.

Indoor fan motor malfunction or speed detection error. Check motor operation.

Indoor/outdoor communication failure. Check control wiring and connections.

General outdoor unit malfunction. Inspect outdoor unit operation.

Outdoor ambient temperature sensor fault. Replace outdoor sensor.

Condenser coil temperature sensor malfunction. Professional sensor replacement required.

High pressure protection activated. Check refrigerant system and ventilation.

Low pressure protection activated. Check for refrigerant leaks and insufficient charge.

Compressor discharge temperature sensor fault. Professional replacement required.

Compressor suction temperature sensor malfunction. Check sensor and connections.

Current sensor malfunction. Professional sensor replacement required.

Voltage sensor fault. Check electrical connections and sensor.

Outdoor unit control board malfunction. Professional PCB replacement required.

Air filter severely clogged. Clean or replace air filters immediately.

Indoor coil freeze protection activated. Check airflow and refrigerant levels.

Reversing valve malfunction. Professional valve inspection and replacement needed.

Fan speed control fault. Check fan motor and control electronics.

Refrigerant flow control malfunction. Check expansion valve operation.

Condensate overflow protection activated. Check drain system.

Defrost cycle malfunction. Check defrost sensors and control.

Fresh air damper control fault. Check damper motor and position.

Insufficient refrigerant detected. Check for leaks and recharge system professionally.

Electronic expansion valve malfunction. Professional valve replacement required.

Compressor overheating protection. Check refrigerant levels and electrical supply.

Inverter circuit overheating. Check ventilation and component condition.

Supply voltage too high. Check electrical supply and voltage regulation.

Electrical current too high. Check wiring and electrical connections.

System temperature too high. Check system operation and ventilation.

Power module heat sink overheating. Check cooling fan and clean heat sink.

Motor protection circuit activated. Check motor condition and electrical connections.

Compressor discharge pressure too high. Check condenser coil and refrigerant charge.

Superheat too high. Check expansion valve and refrigerant charge.

Subcooling too high. Check refrigerant overcharge and condenser operation.

Supply voltage too low. Check electrical connections and utility supply.

Electrical current too low. Check motor and electrical connections.

System temperature too low. Check system operation and settings.

Superheat too low. Check expansion valve and refrigerant flow.

Subcooling too low. Check refrigerant charge and condenser performance.