BoilerFaultCodesThe 6 most common faults
Your boiler is struggling to move enough water through your radiators, which prevents it from heating your home safely.
Check your radiator valves to ensure they are all in the 'open' positionCheck the central heating system pressure gauge on the front of the boiler to ensure it is between 1.0 and 1.5 barIf the pressure is low, locate the filling loop under the boiler and top up the system to 1.5 bar
Your boiler has detected that water is not moving through your heating system correctly, which is preventing it from heating your home properly.
Check all radiator valves in your home are fully open.Ensure your system pressure is set correctly, typically between 1.0 and 1.5 bar on the gauge.Turn the boiler off at the fused spur for 30 seconds and then back on to reset the system.
Your boiler has stopped working because water is not moving through the system quickly enough to prevent it from getting too hot.
Check that your radiator valves are fully openEnsure your boiler pressure is between 1 and 1.5 barGently bleed your radiators to remove trapped air
Your boiler is struggling to move water through the system, which is causing it to shut down to prevent overheating.
Check that all radiator valves are fully openEnsure your boiler pressure is between 1.0 and 1.5 barGently bleed your radiators to remove any trapped air
Your boiler is struggling to move hot water around the system, often caused by trapped air or low pressure preventing it from flowing correctly.
Check the pressure gauge and top up to 1.5 bar if it is lowBleed all radiators to remove any trapped air pocketsEnsure all radiator valves and the boiler isolation valves are fully open
Your boiler has lost water pressure and needs to be topped up to work properly again.
Locate the filling loop (usually blue levers) underneath the boiler.Slowly open both levers until you hear water flowing into the system.Watch the pressure gauge and close the levers firmly when it reaches 1.5 bar.
on the Ariston Clas ONE System
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
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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