Hi I was just wondering if anyone can help please, my halstead finest platinum boiler which is getting on a bit has a pressure problem, I swapped over the heat exchanger as I do from time to time as it blocks and normally no problem, but this time I checked the expansion tank and was a little low on pressure so pumped up to 1 bar with bike pump, then topped system up to 1 bar and ran and everything seemed ok as normal but then when cold pressure increased over night so made sure the loop fill pipe was shut off and thought it was passing so worked it a few times and also shut the other end of it so two isolations on it , reduced the pressure to 1 bar and seemed ok, but when it’s used for hot water only and not CH it seems to creep up over a period of time any other way it can increase ? Other than fill loop .
Thanks any ideas appreciated please thanks.
Thanks any ideas appreciated please thanks.