Nuova Simonelli Oscar II high brew pressure issue?

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

#1: Post by Xenner »

Having issues with a ~3 year old direct plumb Oscar II.

The machine seems to have way too much pressure (I do not have a gauge to measure it)
I've likely been over compensating my grind and tamp due to this, but water will shoot out around the portafilter when brewing.
This even happens when using a different portafilter & basket -- It even happens when back flushing with a blank plate, the machine just blows out the group head gasket!

I've had to replace the vacuum valve recently due to hissing noises and not fully sealing the boiler.

I've also taken apart and cleaned (descaled with citric acid) this valve that seems to be an OPV like valve (maybe it still needs to be replaced??)-- Nuova Simonelli Oscar - how to lower the brew pressure?

Any other thoughts on my issue?

Thanks!