[img]/forums/images/icons/tongue.gif[/img] That's a neat setup, Gary, and retrofittable to existing homes. I lived in a nice home in CA that was on a slab and the H.W. heater was a day's ride from the bathroom. A setup like that would have done nicely. PAT......how about this.....I get a small electric H.W. heater and use one of the thermostats IN THE HEATER to trigger a circ pump. The circ pump keeps the tank full of hot water from my other unit. The other thermostat and heat element in the heater comes on IF NEEDED. Is that a workable setup? [img]/forums/images/icons/tongue.gif[/img]