How much does it cost to fix boiler error code 5S?

Typical repair cost for the boiler 5S fault is £120-280 including labour.

5S High

Boiler Fault Code 5S

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 5S appears across 1 boiler brand and 1 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 cannot confirm that the fan is blowing air through the flue correctly and safely. (As reported on Worcester Bosch Greenstar i Junior)

Pick your boiler brand for the 5S fix

Worcester Bosch 5S 1 model

Source

Information for the 5S 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