BoilerFaultCodesAriston S 01 Fault Code
Also written as S01 — same fault.
The Ariston S 01 fault code means: your boiler tried to light the burner but couldn't detect a flame, so it is currently not providing heating or hot water.. It appears on 6 Ariston models in our database.
Technical description: Flame not detected on first attempt
DIY fix possible
Check if other gas appliances, like a hob, are working to ensure gas supply is activeCheck for any credit on your prepaid gas meterTurn the boiler off and on again to trigger a reset
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 S 01: no call-out fees, no surprise bills.
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Ariston models that show the S 01 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston S 01 fault code information on this page is sourced and cross-checked against the official Ariston service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026