2 0 5 Medium
Boiler Fault Code 2 0 5
Also written as 205 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 2 0 5 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is having difficulty communicating with an optional bolt-on solar heating component and is reporting a connection error for that sensor. (As reported on Ariston HS Premium)
Pick your boiler brand for the 2 0 5 fix
Source
Information for the 2 0 5 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 27 April 2026