BoilerFaultCodes 106 High
Boiler Fault Code 106
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 106 appears across 2 boiler brands 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 has stopped working because the water returning from your radiators is significantly hotter than the water leaving the boiler, suggesting the water isn't flowing correctly. (As reported on Ariston Clas ONE System)
Pick your boiler brand for the 106 fix
Source
Information for the 106 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