The difference between the osburn 2200 and the 2400 is pretty amazing. I'm running a but late this morning so I will just post a pic of energy use. Yesterday was first day running osburn all day. It was in 30's outside. Not to bad. Using the same wood as before. Waiting until next year to use truly seasoned wood, this year it was all bought and I know it good be better quality. Still check out this difference