BoilerFaultCodes E03 High
Boiler Fault Code E03
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E03 appears across 20 boiler brands and 150 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 down because its internal temperature sensors have detected that the exhaust gases are getting too hot, which could damage the system. (As reported on Intergas Combi Compact Eco RF)
Pick your boiler brand for the E03 fix
Alpha E03 29 models Ariston E03 3 models Atag E03 2 models Baxi E03 9 models Biasi E03 11 models Ferroli E03 9 models Halstead E03 6 models Heatline E03 7 models Ideal E03 6 models Intergas E03 6 models Johnson Starley E03 12 models Keston E03 9 models Navien E03 6 models Potterton E03 5 models Ravenheat E03 9 models Remeha E03 7 models Saunier Duval E03 6 models Viessmann E03 1 model Vokera E03 6 models Warmhaus E03 1 model
Source
Information for the E03 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