E18 High

Boiler Fault Code E18

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code E18 appears across 12 boiler brands and 37 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has shut itself down for safety because a internal limit was exceeded, likely due to overheating or a lack of water circulation. (As reported on Vokera Condexa Pro)

Pick your boiler brand for the E18 fix

Ariston E18 2 models Atag E18 1 model Baxi E18 1 model Biasi E18 3 models Halstead E18 6 models Ideal E18 1 model Johnson Starley E18 2 models Keston E18 7 models Navien E18 6 models Potterton E18 3 models Remeha E18 3 models Vokera E18 2 models

Source

Information for the E18 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