Try keep the reduction of heat a bit less aggressive, so the RoR decrease is smoother. Also, DTR of only 15% is pretty low. Do 20% and see if that improves the taste. The sharp drop in RoR makes the DTR even lower than calculated, from my limited understanding

Ok, perhaps try flushing a minute earlier, or flushing for half the time, and see if that makes a difference. If it does, it also indicates a too low brewing temperature. Again, I have a very different machine, but for a long time I flushed for too long too close to brewing the shot, and also had sour

Just a comment: you mention flushing. I don't know your machine, but I was once stuck with a similar problem of sour shots. It turned out my machine, although a HX that should do well with cooling flushes based on all I read needed no flush if a shot was pulled in a minute or three before

I've got a super auto at the office, for times I can't wait for the manual machine. I've found two things help for sour taste, besides what you've done. Firstly, make sure your cups are hot. Flush with hot water, then leave a bit in the cup. Secondly - remember that it isn't espresso. You can't

In Heidelberg, you can also try Janssen Kaffee. Enjoy, it's beautiful this time of year

I tend to argue take the bargain option. Whichever way it goes, you can always sell it without major loss, and it might do the trick as is for the first how long of roasting. If you really get into roasting, you can use it, pay the bargain forward to someone else, and buy whatever upgraded, larger s...

Hello, The grounding I'm referring to is the boiler's grounding. See if that is good, it is critical for the level probes to function correctly. If the probes are clean, that's the next step in my experience

Hello, The level sensors are just probes, and when the water touches them it conducts to ground. I had the same unit, with the same problem, and adding some extra, and cleaning existing ground connections sorted it. Might be simpler to try than replacing the probes!

Hi, I'm no expert, but this is what I've encountered on similar units: You can try descaling. Take the valve apart, check for buildup, or any possible blockage. They usually just leak, though. On the brew group, have you taken off the metal sift and cleaned below that? I've seen some units incredibl...

For what it's worth, I've had cases where triacs die, and cause symptoms like this. If you have the skills to replace it, the small cost will be worth the gamble