Ferroli LED1 on Fault Code
Also written as LED1ON — same fault.
The Ferroli LED1 on fault code means: your boiler has detected a failure with the safety system that handles smoke and fumes, preventing it from firing up for your safety.. It appears on 3 Ferroli models in our database.
Technical description: N/C contact of air pressure switch should be closed between 67-66 of P.C.B.
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 LED1 on fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ferroli LED1 on 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