How much does it cost to fix Biasi error code 65 +?

Typical repair cost for the Biasi 65 + fault is £120-350 including labour.

65 + High

Biasi 65 + Fault Code

Q: What does the Biasi 65 + fault code mean?

Your boiler is struggling to manage the flame correctly and has shut down as a safety precaution because it cannot maintain a stable burn.

Also written as 65 — same fault.

The Biasi 65 + fault code means: your boiler is struggling to manage the flame correctly and has shut down as a safety precaution because it cannot maintain a stable burn.. It appears on 4 Biasi models in our database.

Technical description: System fails to control combustion and exits modulator control parameters.

Typical repair cost £120-350 (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 65 + fault code

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

Source

Biasi 65 + 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