Originally Posted by patrickBOOTH
I don't have any hard water testers, but NYC water is notoriously hard. I am not sure what the kind of heating mechanism has to do with it though.
This is what I found out when I last googled it.
"I've just checked and ThermoBlock systems are very resistant to chalk since the "pipe" where the water gets heated always gets emptied after the shot is pulled so the precipitated chalk can't really build up."
I didn't invest a lot of time into said research, so take it with a grain of salt, but overall it kinda makes sense.