Burner reset light red/green inverted flash (2.5s on, 0.5s off) High

Boiler Fault Code Burner reset light red/green inverted flash (2.5s on, 0.5s off)

Also written as BURNERRESETLIGHTREDGREENINVERTEDFLASH25SON05SOFF — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Burner reset light red/green inverted flash (2.5s on, 0.5s off) appears across 2 boiler brands 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's internal computer has detected an electrical fault with the valve that controls the fuel supply, causing the system to shut down for safety. (As reported on Grant Vortex Blue)

Pick your boiler brand for the Burner reset light red/green inverted flash (2.5s on, 0.5s off) fix

Grant Burner reset light red/green inverted flash (2.5s on, 0.5s off) 1 model Worcester Bosch Burner reset light red/green inverted flash (2.5s on, 0.5s off) 1 model

Source

Information for the Burner reset light red/green inverted flash (2.5s on, 0.5s off) 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 7 July 2026