i had a few problems like this,i work on a building site so i allways go ask the plumbers.once my light went out and heating didnt work and that was a fuse.my fuse is like a small glass tube with a wire running down it,check to see if that has a gap in it or lucks burnt.another time my heating didnt work was due to bleeding a radiator and it messed all the pressure up,so check the pressure if you can it should be between the 0 and the 1.if not then you need to pull on a leaver to let the pressure out.another time somthing had blown and had to be replaced but i cant remmember the name!! sorry if this is not much help but i dont know too much about plumbing myself and i could have a differnt boiler system to you but thought id give it a shot just in case.