BoilerFaultCodesThe 6 most common faults
Your boiler is struggling to push water around your heating system, likely due to low pressure or a blockage.
Check your boiler pressure gauge and ensure it reads between 1.0 and 1.5 barIf the pressure is low, use the filling loop to top it up to the required levelEnsure all your radiator valves are fully open to allow water to circulate freely
Your boiler is not detecting enough water circulating through the system, likely because the pressure has dropped too low or there is a blockage.
Check the pressure gauge on the front of the boiler; if it is below 1.0 bar, you need to top up the system.Locate the filling loop (usually two silver flexible hoses with valves underneath the boiler) to add water.Open the valves slowly to increase the pressure to approximately 1.5 bar, then ensure they are closed tightly.
Your boiler has detected that there is not enough water inside the heating system to operate safely.
Locate the filling loop, which is a flexible silver hose connecting two pipes under the boilerOpen the valves at both ends of the hose to allow water into the systemMonitor the pressure gauge on the front of the boiler until it reaches 1.5 bar, then securely close both valves
Your boiler has failed to start up on its first try and may need a quick manual reset to get it running again.
Locate the 'Reset' button on the boiler control panel.Press and hold the reset button for 2-3 seconds.Wait a few minutes to see if the boiler initiates a new ignition sequence.
Your boiler has stopped because the water pressure inside the heating system has dropped too low to operate safely.
Locate the external filling loop, which is usually a flexible silver hose under the boiler.Open the valves on both ends of the loop to allow mains water into the system.Watch the pressure gauge on the front of the boiler until the needle reaches the green zone (typically between 1 and 1.5 bar).Close both valves firmly and ensure the loop is disconnected if it is the removable type.
Your boiler is experiencing a communication fault between its internal control systems, which prevents it from operating correctly.
Full guide for 547on the Ariston HS Premium
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