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.
Technical description: Flue gas NTC probe / Flue pipes fault
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