Heat pump error codes and fault guides
Browse 26 published, evidence-gated Heat pump guides. Each page states the supported model and region, official source, safe checks, and the point to stop.
Heat pump fault guides
1–24 of 26
a spare-part or software identification fault
F.103 is identified by Vaillant support as a spare-part or software identification fault. Follow the official, model-scoped checks and service boundary below.
compressor inrush-current limiter fault
F.1119 is identified by Vaillant support as compressor inrush-current limiter fault. Follow the official, model-scoped checks and service boundary below.
immersion-heater phase failure
F.1120 is identified by Vaillant support as immersion-heater phase failure. Follow the official, model-scoped checks and service boundary below.
low water pressure in the heating system
F.22 is identified by Vaillant support as low water pressure in the heating system. Follow the official, model-scoped checks and service boundary below.
coding-resistor fault
F.42 is identified by Vaillant support as coding-resistor fault. Follow the official, model-scoped checks and service boundary below.
compressor inlet-temperature sensor fault
F.514 is identified by Vaillant support as compressor inlet-temperature sensor fault. Follow the official, model-scoped checks and service boundary below.
building-circuit flow-temperature sensor fault
F.520 is identified by Vaillant support as building-circuit flow-temperature sensor fault. Follow the official, model-scoped checks and service boundary below.
building-circuit flow rate too low
F.532 is identified by Vaillant support as building-circuit flow rate too low. Follow the official, model-scoped checks and service boundary below.
compressor outlet temperature range too high
F.536 is identified by Vaillant support as compressor outlet temperature range too high. Follow the official, model-scoped checks and service boundary below.
compressor outlet pressure too high
F.537 is identified by Vaillant support as compressor outlet pressure too high. Follow the official, model-scoped checks and service boundary below.
refrigerant pressure too low
F.539 is identified by Vaillant support as refrigerant pressure too low. Follow the official, model-scoped checks and service boundary below.
refrigerant pressure outside the operating range
F.554 is identified by Vaillant support as refrigerant pressure outside the operating range. Follow the official, model-scoped checks and service boundary below.
building-circuit flow temperature too low
F.583 is identified by Vaillant support as building-circuit flow temperature too low. Follow the official, model-scoped checks and service boundary below.
low refrigerant-pressure sensor fault
F.703 is identified by Vaillant support as low refrigerant-pressure sensor fault. Follow the official, model-scoped checks and service boundary below.
blocked fan unit
F.718 is identified by Vaillant support as blocked fan unit. Follow the official, model-scoped checks and service boundary below.
compressor outlet temperature too low
F.729 is identified by Vaillant support as compressor outlet temperature too low. Follow the official, model-scoped checks and service boundary below.
refrigerant high-pressure switch open
F.731 is identified by Vaillant support as refrigerant high-pressure switch open. Follow the official, model-scoped checks and service boundary below.
compressor outlet temperature too high
F.732 is identified by Vaillant support as compressor outlet temperature too high. Follow the official, model-scoped checks and service boundary below.
evaporation temperature too low
F.733 is identified by Vaillant support as evaporation temperature too low. Follow the official, model-scoped checks and service boundary below.
condensation temperature too high
F.737 is identified by Vaillant support as condensation temperature too high. Follow the official, model-scoped checks and service boundary below.
frequency-converter or inverter-board fault
F.752 is identified by Vaillant support as frequency-converter or inverter-board fault. Follow the official, model-scoped checks and service boundary below.
frequency-converter recognition or connection fault
F.753 is identified by Vaillant support as frequency-converter recognition or connection fault. Follow the official, model-scoped checks and service boundary below.
air-inlet temperature sensor fault
F.774 is identified by Vaillant support as air-inlet temperature sensor fault. Follow the official, model-scoped checks and service boundary below.
building-circuit pump fault
F.788 is identified by Vaillant support as building-circuit pump fault. Follow the official, model-scoped checks and service boundary below.