Faulty modulation gas valve High

Biasi Faulty modulation gas valve Fault Code

Also written as FAULTYMODULATIONGASVALVE — same fault.

The Biasi Faulty modulation gas valve fault code means: your boiler is unable to control the flow of gas correctly, which means it cannot fire up to provide heating or hot water.. It appears on 1 Biasi model in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Faulty on-off operators or not electrically supplied.
Typical repair cost £180-320 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Biasi models that show the Faulty modulation gas valve fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Biasi Faulty modulation gas valve fault code information on this page is sourced and cross-checked against the official Biasi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026