BoilerFaultCodes 2 01 High
Boiler Fault Code 2 01
Also written as 201 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2 01 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's hot water sensor has failed or has a wiring issue, meaning it cannot accurately measure the temperature of the water coming out of your taps. (As reported on Ariston Genus HE)
Pick your boiler brand for the 2 01 fix
Source
Information for the 2 01 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