After burning wood now for 2.5 months in my brand new Jotul f602, I finally figured out why I could never a burn lasting more than an hour or 2. I believe when the stove got delivered, crated, the window was installed too loose, hence, way too much air was getting in. I noticed one day that the top of the windiw was hanging so low, I could see the top of it with a gap above as well as a displaced piece if gasket inside the doir. I lifted the window way up, placed the gasket under and tightened the damper’s screws quite a bit more than it was. Resulting in the window being higher up not so loose and the stove burning like a normal stove. Long slow burns if needed, or nice and hot when needed. Much more enjoyable and safer.