Having consulted this page, I spoke to my gas supplier and a Baxi engineer (0870 606 0955) with regard to my similar problem. As "HI-SPEC PLUMBING" mentioned, the pressure can be brought down by bleeding the system a little. The Baxi engineer said that you want to release a "slow dribble" & collect it with a cloth/shallow tub and that this could take a while (I got the impression that he meant 20+ minutes as opposed to a few seconds). He also pointed out that the valve on the "braided loop" of the system should be closed. -The valve was open on ours which I beleive is the reason for the high pressure. We moved into our new house 4-5 weeks ago, the valve was probably (incorrectly) turned then.
Our boiler is a Baxi Combi 105e, which I understand is the bigger sister to the 80e.
Chris Murphy, September 2006
