I am at a loss. I have a Dovre wood stove that was installed in 1994. It used to get the room 80 degrees+ easily, and recently I can hardly make it comfortable. Here are a few pieces of information that I DO know: -The stove pipe and flue are as clean as a whistle -The wood is well seasoned - The stove will heat to about 500-600 degrees - Aside from the factory vent on the stove, there is no damper in the chimney Here are some things I DON'T know: -Could the heat be getting sucked right up the chimney (and if so, why? because nothing has changed) - Do fire bricks have a service life (they have never been changed), and if so, could this cause this symptom? Thank you for any feedback! I am at my wit's end. I've pulled out the stove, stovepipe, inspected the stove, and can't find anything wrong!