BoilerFaultCodesThe 6 most common faults
Your boiler has tried to ignite to provide heat but failed to detect a flame, causing the system to shut down for safety.
Check that your gas emergency control valve is in the 'on' positionCheck if other gas appliances in your home, such as a hob, are working correctlyPress the 'R' or Reset button on the control panel to attempt a restart
Your boiler has switched itself off because it reached an unsafe temperature to prevent damage to the internal components.
Check that all radiator valves are fully open to allow water to circulate.Ensure your system pressure is topped up to between 1 and 1.5 bar.Wait 15 minutes for the system to cool down and gently press the reset button.
Your boiler has stopped working because the water pressure inside the system has dropped too low to operate safely.
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the small valve(s) on the loop to allow water into the system.Watch the pressure gauge until it reaches 1.5 bar, then close the valves tightly.
Your boiler has failed to start because it cannot detect a flame, which is likely due to the gas supply being interrupted or a problem with the ignition system.
Full guide for A01Your boiler is failing to register that it has cleared its internal air safely, meaning it is preventing itself from igniting for your protection.
Full guide for A21Your boiler is failing to detect that the internal flue fan is starting up, which prevents the unit from firing up to provide heating or hot water.
Full guide for A22on the Ariston Genus 24 Rffi
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