How much does it cost to fix boiler error code Fault led (B) illuminated?

Typical repair cost for the boiler Fault led (B) illuminated fault is £150-300 including labour.

Fault led (B) illuminated High

Boiler Fault Code Fault led (B) illuminated

Also written as FAULTLEDBILLUMINATED — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Fault led (B) illuminated 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 is failing to ignite the flame it needs to heat your water or radiators due to a persistent ignition issue. (As reported on Ideal Boxer)

Pick your boiler brand for the Fault led (B) illuminated fix

Ideal Fault led (B) illuminated 1 model

Source

Information for the Fault led (B) illuminated 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