All fixed. The tube cleared with some garden wire thankfully.
Got to two bar at maximum which was just under one bar cold. Prv didn't do a single drip so connected the pipe which connects it outside.
Going to give it a few days.. if all is well I will close off a towel rail at both ends, drain it down and add inhibitor rather then a full drain down of the system.
I got a feeling the gauge got blocked due to full drain down in first place. I might be wrong.
Thanks for all the advise Ian.
