How much does it cost to fix boiler error code 34?

Typical repair cost for the boiler 34 fault is £180-450 including labour.

34 Emergency

Boiler Fault Code 34

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 34 appears across 8 boiler brands and 32 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 gas is potentially still flowing or a flame signal is present when it should be turned off, which is a safety concern. (As reported on Ideal Maximiser SE)

Pick your boiler brand for the 34 fix

Alpha 34 5 models Atag 34 1 model Ferroli 34 3 models Grant 34 1 model Halstead 34 8 models Ideal 34 1 model Johnson Starley 34 10 models Vokera 34 3 models

Source

Information for the 34 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