How much does it cost to fix boiler error code 4 flashes?

Typical repair cost for the boiler 4 flashes fault is £120-280 including labour.

4 flashes High

Boiler Fault Code 4 flashes

Also written as 4FLASHES — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 31 August 2026

Fault code 4 flashes appears across 2 boiler brands and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has lost its memory chip, which tells it exactly how to operate safely, and it has stopped working as a safety precaution. (As reported on Worcester Bosch Greenstar 35 CDi range)

Pick your boiler brand for the 4 flashes fix

Baxi 4 flashes 1 model Worcester Bosch 4 flashes 2 models

Source

Information for the 4 flashes 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