Carrier air conditioner error codes
Displayed on the indoor unit or remote when a fault is detected. Always isolate power before inspecting a unit — repairs belong to a qualified technician.
| Code | Meaning | Applies to | |
|---|---|---|---|
| E0 | Indoor unit EEPROM parameter error (QHC inverter hi-wall series). | All models | Details |
| E1 | Meaning depends on series — QHC inverter hi-wall: indoor / outdoor units communication error; QED fixed-speed: EEPROM error. | All models | Details |
| E2 | Zero-crossing signal detection error (QED fixed-speed series). | All models | Details |
| E3 | Indoor fan speed out of control (QHC inverter hi-wall, QED fixed-speed series). | All models | Details |
| E4 | Meaning depends on series — QHC inverter hi-wall: indoor room temperature sensor T1 open or short circuit; QED fixed-speed: compressor over-current (4 successive events). | All models | Details |
| E5 | Meaning depends on series — QHC inverter hi-wall: evaporator coil temperature sensor T2 open or short circuit; QED fixed-speed: indoor room temperature sensor T1 open or short circuit. | All models | Details |
| E6 | Evaporator coil temperature sensor T2 open or short circuit (QED fixed-speed series). | All models | Details |
| E9 | Indoor and outdoor unit communication error (QED fixed-speed series). | All models | Details |
| EC | Meaning depends on series — QHC inverter hi-wall: refrigerant leakage detection; QED fixed-speed: refrigerant leak detection. | All models | Details |
| F0 | Low refrigerant protection. | All models | Details |
| F1 | Outdoor ambient temperature sensor T4 open or short circuit (QHC inverter hi-wall series). | All models | Details |
| F2 | Condenser coil temperature sensor T3 open or short circuit (QHC inverter hi-wall series). | All models | Details |
| F3 | Compressor discharge temperature sensor T5 open or short circuit (QHC inverter hi-wall series). | All models | Details |
| F4 | Outdoor unit EEPROM parameter error (QHC inverter hi-wall series). | All models | Details |
| F5 | Outdoor fan speed out of control (QHC inverter hi-wall series). | All models | Details |
| P0 | IPM malfunction or IGBT over-current protection (QHC inverter hi-wall series). | All models | Details |
| P1 | Over-voltage or under-voltage protection (QHC inverter hi-wall series). | All models | Details |
| P2 | High temperature protection of compressor top (QHC inverter hi-wall series). | All models | Details |
| P4 | Inverter compressor drive error (QHC inverter hi-wall series). | All models | Details |