BoilerFaultCodesThe 6 most common faults
Your boiler has stopped working because the water pressure inside the system has dropped too low to allow it to run safely.
Locate the filling loop (usually a silver braided hose with small valves under the boiler).Slowly open the valve(s) until you hear water entering the system and watch the pressure gauge rise.Close the valves tightly once the pressure gauge reaches between 1.0 and 1.5 bar.
Your boiler has failed to ignite, which is usually caused by an issue with the gas flow or the air exhaust system.
Check that your gas emergency control valve is in the 'on' positionIf you have a prepaid gas meter, ensure you have sufficient creditVerify that other gas appliances in your home, such as a hob, are working correctlyPress the reset button once for 5 seconds
Your boiler has stopped working because it cannot light the burner, likely due to a gas supply issue or a blockage in the drainage pipe.
Check if your gas supply is active by testing another gas appliance like a hob.Inspect the white plastic pipe under the boiler for any blockages or freezing if the weather is cold.Press the Reset button once to see if the system restarts.
Your boiler has sensed that the water returning from your radiators is too hot, which usually means the heat isn't being transferred into your rooms properly.
Check that at least 2 or 3 radiator valves (TRVs) are turned to the highest settingEnsure all radiator valves are fully open if you have recently closed themCheck that the bypass valve, if visible, hasn't been accidentally adjusted
Your boiler has stopped working because the water pressure in the central heating system has dropped too low.
Locate the filling loop (usually a silver flexible hose) underneath or near the boiler.Slowly open the one or two taps on the loop until you hear water entering the system.Watch the pressure gauge on the boiler until it reaches between 1.0 and 1.5 bar, then close the taps tightly.
Your boiler has stopped working because the water pressure in the system has dropped too low.
Locate the filling loop (usually a silver braided hose underneath the boiler).Open the small valve handle(s) slowly to let fresh water into the system.Watch the pressure gauge and close the valves when the needle reaches between 1 and 1.5 bar.
on the Pro A28
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 Pro 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