This is a single stainless steel boiler machine (single-circuit). You can see it in technical description here: https://www.delonghi.com/en...
The other De'Longhis like the dedica are thermoblock.

It is definitely a thermoblock machine and not a single-circuit machine.

I don't know. The machine works perfectly.

To be honest, I have no idea. But I use the machine almost every day.

It is a machine with a Thermoblock system and 15 bar pressure pump