E89 High

Biasi E89 Fault Code

The Biasi E89 fault code means: your boiler has detected an issue with its internal computer board or the electrical power being supplied to it.. 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: Internal error (usually hardware) or problems with the mains electrical supply (excessive distortion of waveform).
Typical repair cost £250-450 (including labour)

DIY fix possible

Turn the boiler power off at the fused spur switchWait for 60 secondsTurn the power back on and press the Reset button

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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 7 July 2026