Ok so I am new to this site. I have worked on mine and customer's Pavonis for many years but can't seem to figure this out!
My machine, La Pavoni Modello Professional Pre Millenium 1997 or 98
The issue.........The 2nd and consecutive shots, coming out the portafilter spout are way too hot and therefore I get steaming hot froth-looking espresso (at that point it's not really espresso anymore) spraying out of the spout.
Normally, at home my machine is only used for the first pull, unless we have guests over or I happen to want a 2nd or 3rd. I was wondering for those that pull consecutive shots until the boiler is near empty, has anyone experienced the same condition? If I run the portafilter under cold water between pulls that seems to eliminate the problem.
But weird thing is I have never had to do that with any other Pavoni I have used. Then again as I said I don't pull consecutive shots.
Boiler temp is set to .7 bar, which I had lowered a while ago, down from .9bar, to try to solve the issue. That didn't work .. Other things I have checked out:
All gaskets in entire machine are new and functioning properly, siphon tube is new, brass piston ok, no scale inside grouphead, etc.... All other possibilities have been exhausted with the exception of replacing pressurestat, which periodically malfunctions letting boiler pressure go to high but that is occurring independently of the main issue. So that's the deal any shared experience is welcomed! Thanks....