again thanks.
im putting a pellet stove in and what id like to do is. run something close to the chimney. either have a coil around it or something like a radiater or tranny cooler type thing above it in the floor joist. i just dont know how i would keep the liquid from boiling when there is no flow going thru the system. if i were using a solinoid. or do i just work on finding a flow to keep my tanks at the desired temp. and keep the water circulating thu the exchainger. if i used copper i could just use an aquarium in my sump(which is a 300 gal stock tank).