kautivo As @kautivo says, his machine was sent to my home some weeks ago. Same problem. Steam boiler under pressure and you’ll get trouble; cold steam boiler and you’ll be fine. I do not know why the problem didn’t show at the factory but I guess the pump settings were changed. The machine arrived to my home with factory settings and the problem was evident. 100% of times failure with hot steam, 100% free of failure with cold steam boiler (does not matter if it was on or off)
Paolo asked us to change pid settings again and we managed to get a nice ramp up with no preinfussion, using a plain 9 bar profile and tweaking pump settings and acceleration again. Next step will be to get rid of the pressure problem with a regular 10″ preinfussion profile, will see…
After 6 years, always with this problem with steam boiler, I decided to sell my Vesuvius and just get another machine. I sold it very cheap and letting know the new owner about this. This is a great machine and I can not understand why this inconvenience is so complicated to overcome but… . I can’t understand how this is happening just with four machines, the four machines I know well, and another one in the British coffeeforum as I posted in this thread a long time ago.
I just want to thank the forum for the help provided, hope this will be solved soon!