BoilerFaultCodes 3Y High
Boiler Fault Code 3Y
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 3Y 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 has detected that the internal fan is spinning at the wrong speed, which prevents the unit from safely starting the combustion process. (As reported on Buderus 600-28C)
Pick your boiler brand for the 3Y fix
Source
Information for the 3Y 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