BoilerFaultCodesThe 6 most common faults
Your boiler has switched itself off because internal sensors have detected that the water inside is getting too hot.
Check that all radiator valves are fully open to allow water to flow.Ensure your system pressure is between 1.0 and 1.5 bar on the gauge.Turn the boiler off and on again or press 'Reset' to see if the fault clears.
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 tap or taps on the filling loop until you hear water entering the system.Watch the pressure gauge and close the taps once the needle reaches between 1.0 and 1.5 bar.
Your boiler has stopped working because water is not moving around the system properly, which is causing the unit to overheat.
Check that your radiator valves are openEnsure your system pressure is between 1.0 and 1.5 barGently bleed your radiators to remove trapped air
Your boiler has lost its flame while it was running, which means it has stopped providing heating and hot water for safety reasons.
Check if other gas appliances, like a hob, are working to ensure gas is reaching the propertyCheck that your gas meter has credit if you have a prepayment meterPress and hold the 'R' or Reset button for five seconds to see if the boiler restarts
Your boiler has failed to light because it either isn't receiving gas or cannot detect the flame it has created.
Check that your gas emergency control valve is open and you have credit on your gas meter.Try resetting the boiler by turning the selector switch to 'R' for five seconds.In winter, check if the white plastic condensate pipe outside has frozen and thaw it with warm water.
Your boiler has failed to ignite or has lost its flame because it isn't receiving the gas it needs to stay lit.
Check that your gas emergency control valve is in the 'on' position.If you have a prepay meter, check that you have sufficient credit and that the meter is not 'locked'.Check if other gas appliances in your home, such as a hob, are working correctly.Restart the boiler by pressing the reset button for five seconds.
on the Baxi 624 Combi
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 Baxi 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.
Affiliate links. We may earn a commission at no extra cost to you.