BoilerFaultCodesFerroli A13 Fault Code
The Ferroli A13 fault code means: your boiler has detected an issue with the sensor that monitors exhaust gases, causing the system to lock down for safety.. It appears on 3 Ferroli models in our database.
Technical description: Flue probe fault
What causes the Ferroli A13 fault?
This fault occurs when the sensor responsible for measuring the temperature of the exhaust gases sends an incorrect or missing signal to the boiler's control board. The most common reason is that the probe itself has failed due to constant exposure to high temperatures, or the electrical wiring connecting the sensor has become loose or damaged.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ferroli models that show the A13 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli A13 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