My Glow Worm Ultimate 50FF boiler will not start. Nothing happens when activated. When I unscrewed the PCB, I tapped the string of electrical connectors and, at a certain point, the neon light glows and the boiler starts and works OK. After a short time (an hour or two) the unit stops working altogether and I have to do the same again. I am presuming it is fair to assume the problem is with the PCB. I have checked all of the electrical connections - at least all that I can see. My question is do I need a new PCB or can this one be fix? If so how? If anyone can shed light on this prob I would be very grateful.