The S1 Cafe - Helping Your Espresso Dreams Become Reality

Just had a look at THIS OLD THREAD and listened to the video. Having the exact same sound. And I bought it from the same dealer! Hmmmm. Anyway, my first thought was the expansion valve, so I recalibrated it, which resulted in opening it a bit more. She gave me one more whistle, perhaps for old times sake, now she's quiet.

Still hating the drain kit. There must be a better way.

After adjusting the expansion valve (opening it a bit so water comes starts coming out at 12.5 bars), the whistling is much less often. But it still happens. Usually about 45-60 seconds after pulliing a shot. It goes on for some time, like maybe 10+seconds, but if I run water thru the group for a just a second, whistling stops and stays stopped.