I have a Vokera Excel 80 combi boiler and the problem I am having is that when I run hot water the heating also comes on. I have read the post from larry the dwarf who is having the same problem and the divertion valve seems to be suspect. I am very confident with plumbing, can you tell me which parts I would need to replace in the divertion valve. I have the manual with exploded diagrams and there seems to be quite a few parts inside this valve.
Thanks Slim