Hi Paul, Update: After a month without heating or hot water & for the last 3 days no water at all, I can now say yippee, it`s back on.
I ended up changing diverter valve assembly & the inlet manifold assembly, I had to change the latter as the grub screw into the brass fitting that connects the two would not move.
So now I have really hot water & heating.............but..............the boiler when on heating, comes on & off all the time, so the radiators do not get a chance to get really warm ? I have isolated room stat, it is not this. Do you have any ides what might be up with it now!!
I was wondering if one of the thirmisters could be at fault, there are 2, one at the top & one at bottom, not sure which one does the heating.
Be glad of any advice you can throw my way.
Cheers
Steve