How much does it cost to fix boiler error code EE6666?

Typical repair cost for the boiler EE6666 fault is £120-200 including labour.

EE6666 High

Boiler Fault Code EE6666

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code EE6666 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because a sensor that measures the water temperature is sending an incorrect electrical signal, causing the system to shut down to prevent overheating. (As reported on Ariston Genus 24 MFFI)

Pick your boiler brand for the EE6666 fix

Ariston EE6666 3 models

Source

Information for the EE6666 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