How much does it cost to fix Biasi error code E25?

Typical repair cost for the Biasi E25 fault is £120-380 including labour.

E25 High

Biasi E25 Fault Code

Q: What does the Biasi E25 fault code mean?

Your boiler has detected a conflict where it is getting too hot internally, likely because water is stuck or the sensors are sending conflicting information to the brains of the unit.

The Biasi E25 fault code means: your boiler has detected a conflict where it is getting too hot internally, likely because water is stuck or the sensors are sending conflicting information to the brains of the unit.. It appears on 6 Biasi models in our database.

Technical description: Main electronic p.c.b. / D.H.W. flow switch / Diverter valve

Typical repair cost £120-380 (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 E25 fault code

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

Source

Biasi E25 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