BoilerFaultCodes F.436 High
Boiler Fault Code F.436
Also written as F436 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.436 appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has detected an electrical fault with the sensor that measures how fast water is moving through the system, causing the unit to stop working to protect itself. (As reported on Viessmann Vitodens 100-W WB1A)
Pick your boiler brand for the F.436 fix
Source
Information for the F.436 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026