BoilerFaultCodesFerroli A07 Fault Code
The Ferroli A07 fault code means: your boiler has shut down because the exhaust fumes have become dangerously hot, which could indicate a blockage or a heat exchanger problem.. It appears on 3 Ferroli models in our database.
Technical description: High flue gas temperature
What causes the Ferroli A07 fault?
This fault occurs when the internal sensors detect that the exhaust gases are reaching dangerously high temperatures, triggering an automatic shutdown to prevent heat damage. The most common cause is a build-up of debris or limescale inside the main heat exchanger, which prevents heat from being transferred to your water and pushes it out through the flue instead. It can also be caused by a faulty sensor giving an incorrect reading or a physical blockage in the chimney-like flue pipe.
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 →Ferroli models that show the A07 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli A07 fault code information on this page is sourced and cross-checked against the official Ferroli service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026