Fault Codes / Airwell

30 codes

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• D3 — High pressure protection via pressure switch (outdoor)
• E0 — Communication error outdoor/indoor
• P5 — P5 = protective shutdown due to excessive outdoor condenser outlet temperature (T3). (IPM / compressor-driver protection is P6, not P5.)

VRF Engineering Manual

• A1 — Mode conflict (e.g. cooling/heating requested simultaneously in the same system).
• A2 — Water overflow (indoor unit float switch triggered).
• A3 — Indoor unit EEPROM fault 2.
• b1 — Room air temperature (RAT) sensor is faulty.
• b5 — Indoor coil outlet temperature (ICOT) sensor is faulty.
• b7 — Indoor coil middle temperature (ICMT) sensor is disconnected.
• b8 — Indoor unit EEPROM fault 1.
• b9 — Indoor unit hot-keep protection active.
• bb — Overheating protection triggered (indoor unit).
• bC — Refrigerant leakage detection triggered.
• bF — Condenser temperature sensor 1 (CDT) is faulty (outdoor unit).
• d1 — Compressor discharge 1 protection.
• d2 — High pressure protection (via pressure sensor).
• d3 — High pressure protection (via switch 1).
• d4 — Low pressure protection (via sensor).
• d5 — Low pressure protection (via switch).
• d8 — Compressor discharge 2 protection.
• d9 — High pressure sensor fault.

YHD

• E2 — Indoor temperature sensor open/short.
• E6 — Communication error.
• P0 — High pressure protection (outdoor).
• P1 — Low pressure protection.
• P2 — Compressor overcurrent.
• P4 — IPM protection / inverter fault.
• P6 — Compressor startup failure.
• P7 — Incorrect phase sequence / phase loss.
• P9 — Indoor coil freeze protection.