BoilerFaultCodes 342 High
Boiler Fault Code 342
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 342 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 has detected that the water is heating up much faster than it should, suggesting a potential restriction in the internal flow. (As reported on Worcester Bosch Greenstar 12i System)
Pick your boiler brand for the 342 fix
Source
Information for the 342 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 31 August 2026