Ours is doing an ok job. It has been well below zero with the wind chills for almost a week. We are running at about 70-72 degrees on level 4 when home. The problem we are having is we have to drop the stove to level 3 while we are at work or we will run out of pellets. Those darn hoppers only hold so many pellets. Then it drops to 65 - 68 .