E20 High

Boiler Fault Code E20

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code E20 appears across 8 boiler brands and 41 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler thinks a flame is present even though it hasn't turned the gas on, usually caused by a blocked drain or a faulty sensor. (As reported on Potterton Powermax HE)

Pick your boiler brand for the E20 fix

Alpha E20 1 model Ariston E20 5 models Baxi E20 9 models Biasi E20 4 models Keston E20 1 model Main E20 7 models Potterton E20 13 models Vokera E20 1 model

Source

Information for the E20 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