Er 05 High

Biasi Er 05 Fault Code

Also written as ER05 — same fault.

The Biasi Er 05 fault code means: your boiler has detected an issue with the internal fan that pushes exhaust gases out of your home, so it has safely shut itself down to prevent operation.. It appears on 3 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: Faulty fan control system
Typical repair cost £180-350 (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 Er 05 fault code

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

Source

Biasi Er 05 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