Ok so I solved the problem with the above boiler fusing repeadidly, It was the timer switch, Now after a day of normal use the boiler refused to fire up, the power on light comes on, manually switching the boiler to on, them the fan runs for a second or two, then the boiler clicks three times, the fan goes off, them the whole thing repeats over and over, needless to say without providing and heat. Any thoughts? The manual fault finder is not much help. V. cold. Rob.