BoilerFaultCodesFerroli 20 Fault Code
The Ferroli 20 fault code means: your boiler is not firing up because it cannot detect a flame, which means it currently cannot provide heating or hot water.. It appears on 4 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 supply is turned on at the meterEnsure the gas isolation valve near the boiler is set to the open positionPress the reset button once to try and restart the boiler
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like 20: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Ferroli models that show the 20 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli 20 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 7 July 2026