New here, seems like a great resource. I've got a idea to throw out there. I"ve got a small laundrymat in Northern MN, and propane cost are killin' me. Installed a solar hot water heating system that works great from mid march to Oct. but winters are tough, and am thinkin' about plumbin' a wood boiler into the system to A: heat the buildin', and B: plumb it thru the heat exchangers to pre heat the hot water. Anyone have any experience or thoughts on this one???