BoilerFaultCodes 349 High
Boiler Fault Code 349
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 349 appears across 3 boiler brands and 6 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 water inside is heating up far too quickly compared to the amount of gas being used, which suggests there may be a blockage in your heating system preventing water from flowing correctly. (As reported on Worcester Bosch 24/28/35 CDi MkII)
Pick your boiler brand for the 349 fix
Source
Information for the 349 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