Long story short, I am thinking how to hook up my (future) wood stove to my hot water heating system. Yeah, a good stove will have a hot water coil in it, true. But I was thinking that a bit of plumbing into a tank, with an independant pump, a blow off valve on the tank, (and probably on the coil), and a heat exchanger in the tank hooked to my existing hot water system. Diagram attached as PNG file. It's pretty crude, please forgive. That tank in the middle needs to be well insulated, hot water resistant. Can it be plastic? Like those 300 gallon tanks they use for power washing trucks? Anybody know?