BoilerFaultCodes 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 16 boiler brands and 39 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
Ariston é1 1 model Atmos é1 4 models Biasi é1 2 models Daikin é1 2 models Dimplex é1 1 model ECA é1 2 models Grant é1 1 model Halstead é1 2 models Heatline é1 1 model Ideal é1 1 model Intergas é1 1 model Potterton é1 5 models Remeha é1 11 models Unical é1 2 models Vaillant é1 2 models Worcester Bosch é1 1 model
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 31 August 2026