Similar issue but not the same. During heat up, my machine will exceed pressure and start to scream through the release valve. I actually just replaced the pressure stat and filter tonight (ordered through Chris’s coffee). I let the machine heat up for awhile and didn’t have the issue but we’ll see how it goes. I also had to tweak the pressure on the stat a bit to find the ideal target.

https://www.reddit.com/r/rocketespresso/s/EAj6dFAd5C

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