How much does it cost to fix Biasi error code E12?

Typical repair cost for the Biasi E12 fault is £90-£160 including labour.

E12 High

Biasi E12 Fault Code

Q: What does the Biasi E12 fault code mean?

Your boiler has detected that a sensor responsible for monitoring the temperature of the water returning from your radiators has developed a fault, preventing the system from operating correctly.

The Biasi E12 fault code means: your boiler has detected that a sensor responsible for monitoring the temperature of the water returning from your radiators has developed a fault, preventing the system from operating correctly.. It appears on 6 Biasi models in our database.

Technical description: Faulty central heating temp. probe NTC (return)

Typical repair cost £90-£160 (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 E12 fault code

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

Source

Biasi E12 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