M
MalcolmD
Thanks so much guys for your advice. Looks like I might finely solve this problem after living here several years. I have had 3 different engineers look at this and none of them spotted this problem. I have just turned the pump down to its lowest 'proportional' setting and that has helped enormously and almost fixed the problem. I will try and find a local heating engineer to move the feed upstream of the pump to join the vent.
