240v 3800 watt electric water heater?

DrewE wrote:
Sounds typical. Both elements are 3800 watts, but the thermostats are wired such that only one can be active at a time. I don't remember whether the upper or the lower typically has priority--I believe it's the one closest to the water outlet. This setup allows for more even hot water temperature/better recovery as the tank starts to get depleted (and refilled with cold water) than having a single 3800W element would or than having a pair of 1900W elements would.

A 20A 240V circuit, per the NEC, should only be used for a continuous load of 80% of that, or about 16A. That works out to 3800W. Of course, for a 240V circuit, you need a pair of ganged breakers.

If you have two separate 240V 20A circuits, it should be possible to hook them up to the two elements independently and bypass the sequencing circuitry. I'm not sure whether this would be permissible per electric codes, or rather how one would go about wiring it up in a way that meets all the code requirements. It may be necessary to have a single 40A circuit going to the heater so as to have a single shut-off, and use a sub panel for the two 20A circuits, or something like that. I'm not sure I see much benefit to doing so, though, at least in the majority of cases.