How much does it cost to fix boiler error code 3!?

Typical repair cost for the boiler 3! fault is £120-210 including labour.

3! High

Boiler Fault Code 3!

Also written as 3 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 3! appears across 3 boiler brands and 21 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 it thinks the main internal thermometer has developed an electrical fault and can no longer accurately measure water temperature. (As reported on Remeha Quinta 115)

Pick your boiler brand for the 3! fix

Biasi 3! 2 models Chaffoteaux 3! 2 models Remeha 3! 17 models

Source

Information for the 3! 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