Well, finally got this done, made from propane tank for a friend hooked up to his wood boiler. Ran it last night hes happy with it, it does heat water good. Put couple shut-offs so can heat house or just the tank.All in all hes got around $700.00 in all of it said it pay for itself in only 3-4 months with price of oil.There 65 feet of 5/8 copper in the coil .the tank is 60 Gal. We ran it threw the oil boiler coil second to use the mixing valve and use for backup if fire goes low in wood, he leaves his oil idle on anyways for his mom,it really is hooked up to two houses that are built side by side, has one long run but we turned up well preasure a little took care of that.