é1 High

Boiler Fault Code é1

Also written as 1 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code é1 appears across 9 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 that the water inside is getting too hot too quickly, usually because there isn't enough water pressure or the water isn't moving through the pipes properly. (As reported on Remeha Avanta Plus)

Pick your boiler brand for the é1 fix

Atmos é1 4 models Biasi é1 2 models Daikin é1 3 models Dimplex é1 3 models Halstead é1 1 model Heatline é1 1 model Maxol é1 1 model Remeha é1 9 models Worcester Bosch é1 2 models

Source

Information for the é1 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