My boiler supplies a tank which then supplies the radiators and hot taps. Suddenly the pilot light no longer stays on, as soon as i take my finger off ignition it goes out, and it never flares up. Aslo have electric switch which heats the hot water but not the radiators (not sure if its meant to) also had new tap fitted, i fitted new kitchen mixer tap but no hot water will come out (thats when the hot water is on electrically) any advice????