How much does it cost to fix Biasi error code Er 03?

Typical repair cost for the Biasi Er 03 fault is £280-450 including labour.

Er 03 High

Biasi Er 03 Fault Code

Q: What does the Biasi Er 03 fault code mean?

Your boiler's main control board has encountered an internal electronic failure and is unable to manage the heating process.

Also written as ER03 — same fault.

The Biasi Er 03 fault code means: your boiler's main control board has encountered an internal electronic failure and is unable to manage the heating process.. It appears on 1 Biasi model in our database.

Technical description: Main circuit electronic p.b.c. fault

Typical repair cost £280-450 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Biasi models that show the Er 03 fault code

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

Advance 25C Repair: £280-450

Source

Biasi Er 03 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