Ariston 40-60-80 (ll-ll-ll) Fault Code
Also written as 406080LLLLLL — same fault.
The Ariston 40-60-80 (ll-ll-ll) fault code means: your boiler is struggling because it cannot detect that it is successfully pulling fresh air in and pushing exhaust fumes out, so it has stopped running to keep you safe.. It appears on 4 Ariston models in our database.
Technical description: Fan on but does not activate air pressure switch
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ariston models that show the 40-60-80 (ll-ll-ll) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston 40-60-80 (ll-ll-ll) 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 27 April 2026