BoilerFaultCodesThe 6 most common faults
Your boiler has switched itself off because it has detected that it is getting too hot inside.
Turn the selector switch to the reset position for five seconds and then back to 'On'.Check that all radiator valves are open and not blocked by furniture.Ensure your system pressure is between 1 and 1.5 bar on the pressure gauge.
Your boiler has detected that the water pressure is too low for it to operate safely and has shut down as a result.
Check the pressure gauge on the front of the boiler; it should ideally be between 1 and 1.5 bar.Locate the filling loop (usually two silver braided hoses under the boiler) and open the valves until the gauge reaches the green section.Ensure the valves are closed tightly and reset the boiler using the control knob.
Your boiler is struggling to move heated water through the system, often caused by a blockage or a pump issue.
Check that your radiator valves and isolation valves are fully openBleed your radiators to remove any trapped air pocketsGently restart the boiler using the reset button
Your boiler has failed to light because it either cannot get enough gas or cannot detect the flame properly.
Check if other gas appliances in your home, like a hob, are working correctlyEnsure your gas meter has credit if you have a prepayment meterCheck that the white condensate pipe outside hasn't frozen in cold weatherPress and hold the reset button for five seconds
Your boiler's internal thermometer for the heating system has stopped working, so the unit has shut down for safety because it cannot track water temperature.
Full guide for E20Your boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.
Full guide for E28on the Potterton Gold Combi ErP
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 Potterton 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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