BoilerFaultCodesAriston 1 08 Fault Code
Also written as 108 — same fault.
The Ariston 1 08 fault code means: your boiler has lost water pressure, which means there isn't enough water inside the system for it to operate safely and effectively.. It appears on 5 Ariston models in our database.
Technical description: Water missing on primary circuit (P<Pmin)
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the small valve(s) until you hear water flowing and watch the pressure gauge.Close the valves tightly once the pressure gauge reaches between 1.0 and 1.5 bar.
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Ariston models that show the 1 08 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston 1 08 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