Odd pressure profile

[brandon]

Feels like I'm bombarding this forum but one thing after another keeps popping up since I took my Mini out of storage. I solved a pump priming issue only to have the steam boiler trip the GFI, and even with the steam boiler turned off the machine is acting funny -- pressure while I'm pulling a shot reads only 7.5-8 bars, but after I cut the flow it actually rises into the 10-11 range for a bit and then slowly decreases.

What could be causing this to happen?

[chas]

Feels like I'm bombarding this forum but one thing after another keeps popping up since I took my Mini out of storage. I solved a pump priming issue only to have the steam boiler trip the GFI, and even with the steam boiler turned off the machine is acting funny -- pressure while I'm pulling a shot reads only 7.5-8 bars, but after I cut the flow it actually rises into the 10-11 range for a bit and then slowly decreases.

What could be causing this to happen?

Nothing wrong is happening here. What you're seeing is perfectly normal. The pressure on a Mini group pressure gauge when not pulling a shot is just measuring the pressure inside the group boiler. The only important thing is that it does exceed 12 bar. When you are pulling a shot, the 7.5-8bar reading means that you need to adjust the pressure up to 9bar.

[brandon]

Hm, okay, thanks. I never remember seeing pressure continue to increase after I've stopped a shot but maybe I'm just getting jittery from the issues which keep popping up. Thankfully the group pressure adjustment looks easy.