Boiler Fault Code ER 11

Also written as ER11 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code ER 11 appears across 3 boiler brands and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected that the water pressure inside the heating system is too high and has shut itself down to prevent damage. (As reported on Ferroli Xignal)