Had it at 1.5, after 30 mins it was 2.5, another 30 mins later it was down to 1.5 just looked at gas safety record and it was defected as "filling loop was in open position" so it looks like some one who lived here before me had a problem and by-passed it.
Thanks again.
I rent a flat that has the subject boiler, it has a 15mm flexi pipe from the mains cold to a "T" in the 22mm Outlet pipe ( second from left looking at it from the front ). this flexi pipe is fitted with a tap,
It has worked fine for the 10 month I have lived here but now I have to turn on this...