About that strange pressure issue of our machines (4 of 4 fail in the very same way): do you remember that machine that flew to Naples to be tested and seemed to work spotlessly there? Update: I’m glad to say it’s working perfectly now.
Problem was not software related as we tried to explain so many times. Problem was in the water circuit design. There was an obvious interference between boilers: when steam boiler was hot, from about 125ºC, the machine didn’t work smoothly. This is part of an old coffeeforums post that explained quite precisely the problem (not mine):
The machine starts making pressure but stops just shy of 2 bar even though the pump is still running at the same speed. Then when it ramps up to the next stage the pump spins but the pressure doesn’t increase for a few seconds, ultimately overshooting and ruining the shot. No problem with steam boiler at 120º or less. No difference if hx is on or off.
It was the HX circuit fault. The design, not if HX is on or off, that doesn’t make any difference. We asked Paolo how to bypass the HX serpentine and the machine works fine now. When steam boiler is hot the hx gets hot as well. Water in the hx expands and this pressure ends in the brew circuit. Why? I don’t know but no hx - no problem. When I got my machine serviced some time ago I changed the HX electrovalve just to discard problem was there but… that didn’t solve anything. The problem was the way this circuit is designed. Now there is nothing in the hx. No water, no connections. It’s just empty and opened on the two sides. The electrovalve is disconected. Water goes now directly from the water distributor to the coffee boiler. No stop at 2 bars, no fast spinning on the pump, no overshooting, NO difference whether steam boiler is on or off.
And not just this: now the machine works perfectly with factory settings PID and pump acceleration. I tried to explain this many times: yes, you can play with pid settings, you can play with pump acc. But this has to be a personal choice and not a way to avoid this problem, machine must work fine with factory settings. Now it does. And yes, I prefer to low some pid values and pump acc but it’s just this, something I prefer not something I need to do to get things working fine.
I’m very glad problem is sorted but, to be honest, I’m really upset with this machine. I have been asking for this issue for years (I bought my Vesuvius in 2018). I talked many many times to factory, I sent the machine for servicing where they asked me to do it, the workshop video-talked to their tecnician, spares required where sent and installed but… the problem was always there. I wasted time, I wasted money. Nobody seemed to understand where this came from and nobody trust us when we said it was not an electric or software related issue but a physical one. I have made thousands of shots with my Vesuvius and I can say, 100% sure, machine worked fine with steam boiler cold but didn’t when steam boiler was hot but ACS insisted it could be just a coincidence. I’m very reluctant to believe this is happening only to our machines, four of four as I said before. Every machine with this design will fail in the same way. Why this didn’t show up at the factory? Easy, pid settings made the pump working in a ultra tamed mode, slow and lifeless.
I ended selling my Vesuvius and I’m very happy for the new owner, now he’s going to be able to make espresso without fighting with the steam boiler temperature.
