BoilerFaultCodesAriston E02 Fault Code
The Ariston E02 fault code means: your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.. It appears on 5 Ariston models in our database.
Technical description: The PCB checks the pressure of the primary circuit, if the pressure measured is 0.8 bar or lower, the boiler will lockout after 40 seconds. The error code E02 will appear on the LCD and the pump will stop.
DIY fix possible
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the valve(s) to allow water into the system while watching the pressure gauge.Close the valve(s) tightly once the pressure reaches between 1.0 and 1.5 bar.
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Ariston models that show the E02 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston E02 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