1 red flash High

Boiler Fault Code 1 red flash

Also written as 1REDFLASH — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 1 red flash appears across 1 boiler brand and 27 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 it is getting too hot or that water isn't moving through the system correctly, causing it to shut down for safety. (As reported on Baxi EcoBlue)

Pick your boiler brand for the 1 red flash fix

Baxi 1 red flash 27 models

Source

Information for the 1 red 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