E09 High

Biasi E09 Fault Code

The Biasi E09 fault code means: your boiler has detected that the exhaust gases are either too hot or are not flowing correctly through the flue pipe, causing the system to shut down for safety.. It appears on 6 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: Flue gas NTC probe / Flue pipes fault
Typical repair cost £120-250 (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 E09 fault code

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

Source

Biasi E09 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