BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the heating system has dropped too low.
Locate the filling loop, which is usually a metal braided hose underneath the boiler.Open the valves on the filling loop to allow cold mains water into the system.Watch the pressure gauge on the front of the boiler until it reaches 1.5 bar, then securely close the valves.
Your boiler has detected that the water level inside the heating system is too low to operate safely.
Locate the filling loop, which is usually a silver braided hose under the boiler connected to two valves.Slowly open the valves to allow mains water into your heating system.Watch the pressure gauge on the front of the boiler until it reaches the green zone, typically between 1.0 and 1.5 bar.Close both valves tightly and restart the boiler.
Your boiler is failing to light the gas flame, which means you currently have no heating or hot water.
Check if your gas meter has credit and the isolation valve is open.Try resetting the boiler by pressing the 'Reset' button on the front panel.Verify that other gas appliances in your home, like a hob, are working correctly.
Your boiler has failed to light the gas burner properly, meaning it cannot provide heating or hot water until the issue is resolved.
Check that your gas meter has credit and the gas emergency control valve is in the 'on' positionPress the Reset button on the front of the boiler onceIf the boiler is in a cold location, check if the condensate pipe (outside white plastic pipe) is frozen and thaw with warm water
Your boiler has detected that water is not moving through the system properly, which is often caused by low water pressure.
Check the pressure gauge on the front of the boilerIf the needle is below 1 bar, use the filling loop valves to top up the pressure to 1.5 barRestart the boiler using the reset button
Your boiler has sensed it is getting too hot and has shut itself down for safety.
Check that all radiator valves are fully open to allow water to circulate.Ensure there is enough water pressure indicated on the gauge (usually 1.0 to 1.5 bar).Turn the selector switch to the reset position for a few seconds, then back to the on position.
on the Ariston Euro Prisma 24
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