How much does it cost to fix boiler error code A6?

Typical repair cost for the boiler A6 fault is £150-£300 including labour.

A6 High

Boiler Fault Code A6

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code A6 appears across 3 boiler brands and 7 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 communication failure between its main electronic circuit boards, meaning it has temporarily stopped working for safety reasons. (As reported on Worcester Bosch Greenstar Highflow)

Pick your boiler brand for the A6 fix

Atag A6 5 models Sime A6 1 model Worcester Bosch A6 1 model

Source

Information for the A6 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 31 August 2026