Nuova Simonelli Oscar Isn't Pulling Water Through Grouphead Like It Should

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
ricky analog

#1: Post by ricky analog »

So the other day my machine stopped heating up. I assumed it was the heating element and I usually have a spare Oscar or 2 around for parts. So I went to pull the heating element and while I had it apart I did a full teardown/descale. But then when I went to grab the extra oscar I realized that it had the other type of heating element that has a different type of thermal fuse. So long story short, I had to do a full boiler swap. But then when I was putting the machine back together, I realized that the wiring is slightly different to account for the separate thermal fuse.

So I did what I thought was the correct way to wire it back up and account for that. But now the machine doesn't pull water through the grouphead like it should. I thought it was maybe the solenoid by the grouphead, so replaced that. That wasn't the issue. Then I thought maybe the pump was bad. But the grouphead pressure gauge shows it pulling just under 8 bars of pressure, and that's with NO portafilter or coffee for the water to push through. Kind of worried it has something to do with the way I accounted for that wiring situation. I've attached a video so you can see exactly what I mean. Any ideas of what could be wrong or help with addressing this is greatly appreciated.

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#2: Post by HB »

Since the gauge says 8 bar, the pump is working. Since some water is flowing, the solenoid is opening. My guess is there's an obstruction, e.g., scale clogging the gicluer (upper red tube in diagram).

Dan Kehn