BoilerFaultCodesAriston Err / 108 Fault Code
Also written as ERR108 — same fault.
The Ariston Err / 108 fault code means: your boiler has stopped because the water pressure inside the heating system has dropped too low to operate safely.. It appears on 1 Ariston model in our database.
Technical description: Safety shutdown due to insufficient water pressure
DIY fix possible
Locate the external filling loop, which is usually a flexible silver hose under the boiler.Open the valves on both ends of the loop to allow mains water into the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically between 1 and 1.5 bar).Close both valves firmly and ensure the loop is disconnected if it is the removable type.
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Gas Safe Register →Ariston models that show the Err / 108 fault code
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Source
Ariston Err / 108 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