BoilerFaultCodes E5218 High
Boiler Fault Code E5218
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E5218 appears across 1 boiler brand and 2 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 the internal water temperature has become too hot, likely due to a lack of water flow or a circulation problem. (As reported on Worcester Bosch Greenstar Si Combi / i System)
Pick your boiler brand for the E5218 fix
Source
Information for the E5218 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