May 28
For a small home, using electricity, or propane, or natural gas, to heat the house, or just for hot water, this “Munchkin” boiler is among the very best purchases on the market.
http://www.radiantheatproducts.com/store.asp?pid=3408&catid=10050
However, much depends upon the destination and use of the hot water in your building. If you want to research the rest of them, the same website is a good place to start.