BoilerFaultCodes E12 High
Boiler Fault Code E12
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E12 appears across 14 boiler brands and 83 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is struggling to pump water around the system, often because the water pressure is too low or there is a blockage or air bubble preventing flow. (As reported on Potterton Assure Combi / System)
Pick your boiler brand for the E12 fix
Alpha E12 3 models Ariston E12 2 models Baxi E12 25 models Biasi E12 6 models Halstead E12 6 models Heatline E12 2 models Intergas E12 6 models Johnson Starley E12 8 models Navien E12 6 models Potterton E12 3 models Remeha E12 9 models Saunier Duval E12 4 models Viessmann E12 1 model Vokera E12 2 models
Source
Information for the E12 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