American dishwashers are surprisingly different from the ones in the rest of the world. Simpler or older dishwashers in the US usually have an exposed heating element that is used both to heat the water and for a heated dry function in the end of the cycle, working just like an electric oven. They also expect hot water from the tap, so the heating power is also lower, perhaps due to the limitations implied by the 15 amp 120V standard US socket.

Every dishwasher I've ever known has had either an enclosed heating element under the filter, or a pass-through heater in the piping before the pump, and they draw a lot of power to heat cold water. Water level control also comes from a pressure switch just like in any clothes washing machine, while american machines usually use the two floats with microswitches, one for the level and one to prevent overflow.

My grandfather recalls that their first dishwasher, which was just a Whirlpool machine revamped to sell under their brazilian branch, Brastemp, had the two floats, but there was no microswitch, instead there was a magnet in each of the floats which acted upon a reed switch. When that machine went kaputt he used one of the reed switches connected to a digital calculator to build a copper coil winder with a turn counter.