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 Medium

Boiler Fault Code A6

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code A6 appears across 2 boiler brands 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 recorded a fault in its history that indicates the fan or flue system failed to operate correctly during a previous cycle. (As reported on Sime Metropolis DGT 25 BF)

Pick your boiler brand for the A6 fix

Atag A6 1 model Sime 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 7 July 2026