I just got done reading most all the threads on domestic hot water-a fine Saturday morning activity! My current 7 year old setup is an indirect tank (BoilerMate) operated as a separate zone of an oil-fired Burnham boiler. I'm somewhat unclear how much savings a heat pump or resistance electric heater would provide, esp. with the additonal hassle of wiring it up. I've gotten a timer to turn on the heater aquastat maybe a couple of times a day, maybe locating the timer somewhere convenient in case one needed hot water out of the usual time slot. I recall reading a thread on this but haven't been able to find it yet. I wonder how living with this would be. Like, how long before getting hot water when switch on out of time slot? Or, does it really save that much? I do hear it go on periodically during the day, but haven't quantified it as others have. I guess I could insulate the tank more, and maybe jack it up and replace the concrete block underneath with and insulating frame, as another poster has done.