i have a hardy h2 outdoor boiler i burn it from about september to may , i heat a 1800 sq ft home and my domestic hot water , i did the install myself and it cost me $6700 total . During january and feb i burn a cord of wood every 2.5 -3 weeks the year before i installed the boiler i spent $2300 on propane . works well for my needs as i cut my own wood and have a nearly endless supply for free