BoilerFaultCodesFerroli 12 Fault Code
The Ferroli 12 fault code means: your boiler has failed to ignite, which means it cannot heat your water or your home because it isn't getting a flame started.. It appears on 3 Ferroli models in our database.
Technical description: Boiler failed to light. Make sure that the gas isolation valve on the boiler and on the gas meter are open. Press the RESET button (2 Fig. 1).
DIY fix possible
Check that your gas emergency control valve and any boiler isolation valves are turned to the 'on' positionCheck if other gas appliances in your home, such as a hob, are working to confirm your gas supply is activePress the Reset button on the control panel to see if the boiler restarts
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Gas Safe Register →Ferroli models that show the 12 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli 12 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