can anyone help me?im having problems with my central heating.my boiler fires up and the temperture rises normally till it gets to 80degrees and ten knocks down.i thought it was a fault with my boiler.my rads dont get hot.its like there is no circulation around my heating pipes.can anyone give me some advice on how to fix the problem before we freeze our selves..ive a vokera condensing boiler.initially the fault was sayin that the flow temperture is too high,or differential between primary and return too high...would it be a fault with the pump circulating the heatin water..who ever replys cheers inadvance