Er99 High

Biasi Er99 Fault Code

Also written as ER99 — same fault.

The Biasi Er99 fault code means: your boiler has lost its configuration settings or isn't receiving power correctly, meaning it doesn't know which specific model it is supposed to be.. 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: No power / Boiler type not correctly set in Pr01
Typical repair cost £100-£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 Er99 fault code

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

Source

Biasi Er99 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