@depone @jwildeboer 30 years ago I bought an Italian Saeco bean-to-cup 14 bar, espresso machine. Electromechanical. And simple. I was advised to use only filtered water. Which I did. After 26 years of daily use with Munich water, and never de-calking, ever, it was still working well. Just a bit leaky. So I upgraded. And still always filter the water in the new one. Which has electronics this time. LED lights. But no essential OLED display, showing cup filling animations.
So I'm hugely convinced of filtering Munich water.