E89 High

Biasi E89 Fault Code

The Biasi E89 fault code means: your boiler's electronic brain is struggling to process the incoming electrical power properly or has developed an internal hardware fault.. It appears on 2 Biasi models 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: Internal error (usually hardware) or problems with the mains electrical supply (excessive distortion of waveform).
Typical repair cost £280-550 (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 E89 fault code

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

Source

Biasi E89 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 31 August 2026