MediumRoastSteam Theres been so many comments I have lost track a bit. There are a number of possibilities and you need to be careful with diagnosis. If we start with some basics…based on assumptions especially that the OP of the problem is doing everything as we expect.
- Is the pump making pressure properly (it seems to be making 9 bar, so playing with the adjuster won’t do anything)
- Is the pump making pressure fast enough (let’s look at other machines)
- Is the guy using a metal blind filter or a rubber blanking disk
- Is the expansion valve set correctly (check if water is passing through the tube attached, if it’s set to 8-9 bar this is exactly the effect you might see)
- Is the water path to the pump OK, no kinks, good water flow, nothing stuck in the tank valve at the bottom?
- Is there a filter fitted on the pump inlet pipe?
- What’s the flow rate out of an open group (measured for 5 seconds, how much water comes out in grams)
Initially, let’s go back to some basics and get those questions bottomed out in a structured way.. before we rush ahead. There is the noise issue as well, which could, or could not, be a red herring. This will give us a baseline where possibly we spot something that doesn’t look right, or can discard some things.
I looked for videos, where an unedited shot was pulled so you can see the gauge, sadly pretty much every so-called “review” doesn’t show that….amazing really, you would think a tripod would be set up and an unedited shot showing gauges etc… would be done so people could see “normal” operation and operation against a blind filter. I try and remember to do that, but will make a personal not to make absolutely sure I show shots not just against coffee, but a blind filter as well. I lost patience, but perhaps people can find better ones than these.
Start at 1042, just before he scurfs his rough cup bottom on the drip tray, you can just see the reflection of the guage in the group.