Most people on here complain about the "LOW" heat pellets. After finishing my first winter with pellets. I have found I need a lower heat pellet. I tryed the Somersets from lowes and it as -15 outside and i had the windows cracked open. That was while running on 1-1. The pellets i have found that work the best for me are H.E.A.T. out of Mt Vernon,MO. They smell like they have quite a bit of bark in them and are really dark. but they kept my house at a very comfortable temp.