How much does it cost to fix boiler error code Faulty modulation gas valve?

Typical repair cost for the boiler Faulty modulation gas valve fault is £180-320 including labour.

Faulty modulation gas valve High

Boiler Fault Code Faulty modulation gas valve

Also written as FAULTYMODULATIONGASVALVE — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 27 April 2026

Fault code Faulty modulation gas valve 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 unable to control the flow of gas correctly, which means it cannot fire up to provide heating or hot water. (As reported on Biasi Riva Compact HE M96a)

Pick your boiler brand for the Faulty modulation gas valve fix

Biasi Faulty modulation gas valve 1 model

Source

Information for the Faulty modulation gas valve 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