Thanks both for your advice much appreciated, someone had said heat exchanger to us before but when last boiler man came round we asked about that & he said it would and be more eratic and on all taps, but he was also wanting to start ripping up floorboards to find a leak saying it would cost...
Help !!! Our boiler drops in pressure over a period of 3-4 days it will drop from 1.5 bar to almost zero so we are regularly refilling the boiler. There is no water coming out of the outlet outside. also not sure if its connected to the boiler pressure dropping the temerature fluctuates but...