78 High

Biasi 78 Fault Code

The Biasi 78 fault code means: your boiler is struggling to get enough gas to stay lit, which has caused it to stop working for safety reasons.. It appears on 4 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: Probable low gas pressure.
Typical repair cost £100-280 (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 78 fault code

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

Source

Biasi 78 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