302 High
Boiler Fault Code 302
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 302 appears across 2 boiler brands and 8 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has lost its connection between the main control board and the display panel, meaning they can no longer talk to each other. (As reported on Ariston Alteas One)
Pick your boiler brand for the 302 fix
Source
Information for the 302 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