BoilerFaultCodes BURNER indicator Slow flash High
Boiler Fault Code BURNER indicator Slow flash
Also written as BURNERINDICATORSLOWFLASH — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code BURNER indicator Slow flash appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's electronic brain is malfunctioning and needs to be replaced by a professional to get your heating system running again. (As reported on Grant Vortex Eco)
Pick your boiler brand for the BURNER indicator Slow flash fix
Source
Information for the BURNER indicator Slow flash 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