| E1 | Communication fault between indoor and outdoor units | Wiring fault, damaged communication cable, or PCB issue | Professional inspection of inter-unit wiring and control boards |
| E2 | Indoor unit room temperature sensor fault | Damaged, disconnected, or out-of-range thermistor | Sensor resistance test and replacement by a certified technician |
| E6 | Outdoor ambient temperature sensor fault | Corroded or physically damaged outdoor sensor | Outdoor sensor replacement and heating mode retest |
| C4 | Indoor unit pipe temperature sensor fault | Faulty pipe thermistor affecting heat mode refrigerant monitoring | Thermistor replacement and refrigerant pressure verification |
| F1 | Refrigerant leak detection alert | Low refrigerant pressure detected by the system pressure sensor | Leak location, repair, and refrigerant recharge to specification |
| P1 | High pressure protection fault on outdoor unit | Blocked condenser coil, refrigerant overcharge, or outdoor fan failure | Condenser inspection, pressure measurement, and fan motor test |
| P2 | Low pressure protection fault | Refrigerant undercharge or expansion valve restriction | Refrigerant level verification and pressure restoration to rated values |
| E4 | Drain pump or condensate fault | Blocked drain, pump motor fault, or float switch activation | Drain system clearance and pump or float switch inspection |
| H6 | Outdoor fan motor protection fault | Fan motor overload, bearing failure, or obstruction in the outdoor unit | Outdoor fan motor inspection, amperage test, and replacement if required |