Quick update Gents (before I mark this thread as solved.....),
After I initially pumped up the expansion tank a couple of months back, the boiler and central heating have been absolutely fine. I had also drained and flushed the system and radiators a couple of times, added the relevant Fernox inhibitor and it's been absolutely perfect since. All radiators have been getting hot very quickly and there's been no loss of pressure or leaks at all.
Anyway, the BAXI engineer came out on Thursday and, as Tony predicted, did a very thorough job. He seemed like a very decent chap and spent well over an hour working on the boiler.
He said the expansion tank was a little low (0.5 bar) and pumped it up. When he had finished the service though, he increased the overall pressure to 2.5. I had mentioned to him that I'd downloaded the manual and read up on the boiler and questioned why he was setting it so high when the manual (and sticker on the boiler) both state 1.5 bar.
He said something along the lines of adding more pressure so that if the pressure does go down over time, it'll last longer / have some leeway before the safety cut-out kicks in.
I didn't want to question him any more - after all - he's the professional heating engineer and I'm not.
Again - everything's working fine, but for the last couple of days when the heating's on, the digital display now reads 3.2.
I thought the PRV kicks in at 3.0 so I wasn't expecting to see such a high reading.
Does this sound OK or is something not quite right?
