Your boiler has lost its connection to your digital wall controller, meaning it no longer knows when to turn the heating on or off.

DIY fix possible

Check that the Alpha Climatic controller unit has fresh batteries if applicable.Ensure the controller is within range of the boiler and check for any physical obstructions.Power cycle the boiler by switching it off at the fused spur for 60 seconds and then turning it back on to reset the connection.