Ferroli 20 Fault Code
The Ferroli 20 fault code means: your boiler is trying to start but the flame is not catching, likely because it is not receiving a gas supply.. 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).
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 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 27 April 2026