Your boiler has stopped working because it cannot light a flame, most likely due to an interruption in the gas supply or a part that has worn out.

DIY fix possible

Check if other gas appliances, like a hob, are working to confirm your gas supply is onIf you have a prepaid meter, ensure you have sufficient creditPress and hold the 'Reset' button for five seconds to see if the boiler restartsIn freezing weather, check if your white plastic condensate pipe outside has frozen and gently thaw it with warm water