Fault Codes / Vaillant

Vaillant — Fault Codes

37 codes

flexoTHERM/aroTHERM

F.022 — Water pressure too low.
F.037 — Fan fault.
F.042 — Coding resistor fault.
F.073 — Water pressure sensor fault.
F.086 — Contact (limit) thermostat opened.
F.103 — Spare-part detection fault.
F.1117 — Compressor: phase failure.
F.1118 — Compressor: wrong phase sequence.
F.1288 — DHW tank temperature sensor SP1 fault.
F.514 — Sensor fault: compressor inlet temperature.
F.517 — Sensor fault: compressor outlet temperature.
F.519 — Sensor fault: return flow temperature sensor — faulty or incorrectly connected to the main PCB. NOT the high-pressure sensor (that's F.546).
F.520 — Sensor fault: flow temperature.
F.523 — Sensor fault: VF1.
F.526 — Sensor fault: EEV evaporator-side temperature.
F.532 — Building circuit: flow too low.
F.536 — Compressor discharge temperature too high.
F.537 — High pressure switch opened.
F.539 — Refrigerant pressure too low.
F.546 — High pressure sensor fault.
F.554 — Refrigerant pressure out of operating range.
F.582 — EEV fault (electronic expansion valve).
F.585 — Sensor fault: EEV condenser-side temperature.
F.685 — Comm fault: system controller not detected (eBUS lost).
F.714 — Source circuit: pressure too low.
F.718 — Fan unit: fan blocked – rotation signal missing.
F.723 — Building circuit: pressure too low.
F.731 — High-pressure switch open – refrigerant pressure too high (46 bar(g)).
F.732 — Compressor discharge temperature too high (over 130 °C).
F.733 — Evaporation temperature too low.
F.750 — Connection fault: compressor.
F.751 — Compressor: overcurrent fault.
F.752 — Inverter fault.
F.753 — Connection fault: inverter not detected.
F.754 — Fan unit fault.
F.755 — 4-way valve position incorrect.
F.774 — Sensor fault: air inlet temperature.