Hi, If you can get to your water tanks, [there should be two] one is larger than the other,look in the small one it should be the expansion for the boiler,the ball valve may be stuck up and the tank empty,If so push ball valve down so water enters stay with it to make sure it shuts of, bleed the rads making sure that there is water in the expansion at all times,if this is the case the boiler should relight,If this is the case it would be wise to replace the ball valve some time soon.
jayc
May 2007