We've seen a few of these and I really don't understand why someone would want one. I know they only run when hot water is needed, but they draw so much more than a standard water heater when in use, I doubt there is an energy savings. One of our customers put in one of these with a recirc pump, so it runs constantly. The same customer had us install a steam generator that draws 126 amp constantly when in use. He was surprised when I told him he had to have a service upgrade.
