We don't need high voltage actually. By pumping cold water through the block of an honest American diesel V8, it can be heated quickly. Every house includes one for this purpose. I love the sound of it starting in the morning to heat water for my shower.

I mean you could get a 240V line to your dishwasher in North America since a split phase 240V is what comes into the house. I'd rather the 240V water heater just do it instead.

We use the the same heating element that runs the drying cycle to add extra heat to the incoming water. It works, but it isn't enough to add all the heat needed to start from cold fast enough.