boiler not working ideal response 80 combi boiler?

my boiler was working perfectly well till i saw the pressure go down so i topped it up and bleed the radiators till i had 1.6 bar on the pressure gague the boiler worked well for about 24 hrs, then when i got up in the morning saw that the boiler had gone off and water pressure had gone down to 0 so would u let me know what is the problem and can i solve it myself or have to get corgi to repair it