BoilerFaultCodes 80:0 High
Boiler Fault Code 80:0
Also written as 800 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 80:0 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is experiencing a communication error between its control system and the temperature sensors, meaning it cannot accurately monitor the water temperature. (As reported on Viessmann Vitodens 200-W)
Pick your boiler brand for the 80:0 fix
Source
Information for the 80:0 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