Hi All I recently fitted a new shower and since then, everytime my hot water kicks in to get up to the set temperature, there is a knocking / banging noise that continues until it reaches the temperature. I have read a few things online about completely draining the tank and then turning the water back on. But I have also read about switching everything on in the house, all taps, dishwasher, washing machine etc... to flush out any air. So both kind of contradict each other. Any advise would be greatly appreciated because the banging is driving the whole family and next door neighbour insane. many thanks in advance.