What type of heating element is inside the unit and what is it made of?

The KitchenAid Semi automatic espresso machine with burr grinder has a one-piece thermocoil unit.

The aluminium heating element runs alongside a stainless steel water pipe that flash heats the water. Water runs in a circular motion through the pipe until it's heated to the optimum, consistent temperature.

The thermocoil serves a double purpose – heating the water in the brew chamber, and for steaming too.

Good to know: thermocoils are less likely to suffer from leaking problems than other heating methods as the water circulates through one closed tube.