Anyone have any experience or opinions on these? http://cgi.ebay.com/Hot-Water-Tank-Wood-Pellet-Coal-Stove-Add-On-Boiler_W0QQitemZ120227795001QQihZ002QQcategoryZ115968QQssPageNameZWDVWQQrdZ1QQcmdZViewItem I am considering purchasing one of these for my harmon P61A installed in the basement. I've been running it 24/7 with good results this winter and I wonder if I could save a few bucks with one of these boilers. Currently we have a standard 40 gallon (LP) hot water tank. My domestic hot water costs for last calendar year were around 350 dollars. I'm sure it would take at least a few (4-5?) years before the boiler would pay for itself. Thoughts?