How much does it cost to fix boiler error code Err.1?

Typical repair cost for the boiler Err.1 fault is £150-300 including labour.

Err.1 High

Boiler Fault Code Err.1

Also written as ERR1 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Err.1 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 detected an internal logic error and has locked itself out to prevent potential damage, meaning you currently have no heating or hot water. (As reported on Atag E22c)

Pick your boiler brand for the Err.1 fix

Atag Err.1 2 models

Source

Information for the Err.1 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