Ariston 1p2 Fault Code
Also written as 1P2 — same fault.
The Ariston 1p2 fault code means: your boiler is not circulating water correctly, meaning it is sensing that the temperature is rising too quickly and has stopped to prevent overheating.. It appears on 1 Ariston model in our database.
Technical description: All Boilers
DIY fix possible
Check that your boiler pressure is between 1.0 and 1.5 bar on the display.Ensure all radiator valves and isolation valves under the boiler are fully open.Bleed your radiators to remove any trapped air that might be blocking water flow.
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Gas Safe Register →Ariston models that show the 1p2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ariston 1p2 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