As I told in this thread, what I’m doing to avoid this “extrange” pressure interference is not letting the steam boiler to go over 120º before making the espresso. Just to get sure the problem was still here, I have been making my morning capuccinos during this week letting the steam boiler at full pressure. My pump PID settings are 7,5 kP, 0,24kI 80.0kD and the pump acceleration is set at 180.
When steam boiler is hot (mine is set at 128º) this interference is almost always here. Sometimes more evident, sometimes less. I have no manometer in the group but in the screen you can notice it as well. Pressure starts slowly building up but at 1,4 - 1,5b it stops for some seconds. Then the overshoot arrives. Not as high as 12 bars because of pump settings are now different from the videos I uploaded in the forum, it goes up to 10 bars approximately (barely 8 bars with steam boiler under 120º)
Rest of the day: no steam boiler, no stop at 1,4-1,5. First coffee in the morning with steam on but taking care of not surpassing 120º, no stop at 1,4-1,5 bars (and no overshooting).
No water returning to deposit for many months but my question is the same: could this pressure escape through the one way valve?
