BoilerFaultCodesThe 6 most common faults
Your boiler has likely overheated, causing a safety sensor to automatically shut the system down to prevent damage.
Check that all radiator valves are open and not blocked.Allow the boiler to cool down for at least 30 minutes.Press the 'Reset' button on the control panel once to restart the boiler.
Your boiler has stopped working because the water pressure is too low for the system to run safely.
Locate the filling loop (usually a silver braided hose underneath the boiler)Slowly open the valves to let water into the system until the pressure gauge reads between 1 and 1.5 barClose the valves tightly and press the reset button on the boiler
Your boiler is overheating because the water is not moving around the pipes properly.
Check that all radiator valves are fully openEnsure the central heating bypass valve is openCheck for any blockages or air pockets by bleeding your radiators
Your boiler has failed to light because it either cannot get enough gas or it cannot detect the flame it has sparked.
Check that your gas emergency control valve is open and you have credit on your meter.Check if other gas appliances, like a hob, are working correctly.Press the reset button for five seconds to see if the boiler restarts.
Your boiler is struggling to move water through the system properly before it starts the heating process, often caused by a blockage or a pump issue.
Check that your silver radiator valves (lockshields) and thermostatic valves are open.Ensure your system water pressure is topped up to between 1 and 1.5 bar.Gently bleed your radiators to remove any trapped air pockets.
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Wait for the boiler to cool down completelyCheck all radiator valves are open and bleed any trapped air from your radiatorsPress the reset button on the front of the boiler control panel
on the Baxi Suprima 40
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