New machine, with less than 20 or 30 shots. 1st shot this morning, using the same grind and dose that seemed to work before. Drop the lever and enaged the pump and hit the clock. And the pump never shut off, just kept going and going, no flow, and the expansion relief valve(over pressure valve?) tripped and started flowing into the tray after 10-15 seconds. After bout a minute I released the lever, the pump shut off and I got a slow choker that took 2 minutes or more to extract.
Never experienced this pump behavior before with other "chokers" and am curious if that is a normal sequence of events or does the pump or ERV need adjusting? Shouldn't the pump pressurize the portafilter up to "x" lbs and then shut off, especially with a choker and no flow bleeding off pressure.
Anyway, backed off the grind a little and got a more normal sequence with the pump shutting down around 10 seconds into the shot, which was also about the same time the flow began.
Any ideas or is that relatively normal with "some" chokers?