E34 High

Boiler Fault Code E34

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code E34 appears across 6 boiler brands and 26 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 an issue with the electrical power supply coming from the grid or your home's wiring, meaning the electricity frequency is incorrect for it to operate safely. (As reported on Vokera Condexa Pro)

Pick your boiler brand for the E34 fix

Ariston E34 3 models Ferroli E34 1 model Johnson Starley E34 7 models Keston E34 9 models Remeha E34 5 models Vokera E34 1 model

Source

Information for the E34 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