How much does it cost to fix boiler error code 30 40 50?

Typical repair cost for the boiler 30 40 50 fault is £120-250 including labour.

30 40 50 High

Boiler Fault Code 30 40 50

Also written as 304050 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code 30 40 50 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 that hot water isn't moving through your heating system properly, so it has shut down to prevent itself from overheating. (As reported on Chaffoteaux Serelia 24 MFFI)

Pick your boiler brand for the 30 40 50 fix

Chaffoteaux 30 40 50 2 models

Source

Information for the 30 40 50 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