BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because it has detected an overheating issue within the main heat exchanger.
Turn the boiler off and allow it to cool down for 20 minutes.Ensure all radiator valves are fully open and there are no obstructions to water flow.Press the 'Reset' button on the front control panel to restart the system.
Your boiler is likely having trouble circulating water properly, which is causing it to overheat and shut down for safety.
Check that your system pressure is between 1 and 1.5 bar on the display.Ensure all radiator valves are fully open to allow water to flow.Attempt to reset the boiler once pressure and valves are checked.
Your boiler is struggling to circulate water properly, which is preventing it from heating up safely.
Check that your boiler pressure is between 1 and 1.5 bar on the display.If the pressure is low, use the filling loop to top it up.Ensure all radiator valves and isolation valves under the boiler are fully open.Reset the boiler after checking these steps.
Your boiler has detected that water is not circulating properly, causing it to overheat and shut down for safety.
Check that your boiler pressure is between 1 and 1.5 bar on the gauge.Ensure all radiator valves and isolation valves under the boiler are fully open.Try bleeding your radiators to remove any trapped air pockets.Restart the boiler using the reset button.
Your boiler has detected that there is not enough water pressure or circulation to function properly and has shut down for safety.
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is too low, use the built-in filling loop (often blue levers underneath) to top up the water level.Ensure all radiator valves are fully open and restart the boiler using the reset button.
Your boiler has detected that water is not circulating properly through the system, often caused by trapped air or a blockage.
Check that your radiator valves are fully openBleed your radiators to remove any trapped airCheck the boiler pressure is between 1 and 1.5 bar
on the Ariston Alteas One
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Ariston shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue