How much does it cost to fix boiler error code Flashes red/green?

Typical repair cost for the boiler Flashes red/green fault is £150-300 including labour.

Flashes red/green High

Boiler Fault Code Flashes red/green

Also written as FLASHESREDGREEN — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Flashes red/green 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 is struggling because the internal water pump is stuck or not receiving power, which prevents heat from circulating through your home. (As reported on Grant Vortex Eco)

Pick your boiler brand for the Flashes red/green fix

Grant Flashes red/green 5 models

Source

Information for the Flashes red/green 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