Question: We are making an initial purchase of an Alaskan Coal Stove. The dealer is going to install it, as well as putting in the stovepipe. We are going through a wall and then going straight up, until we hit a second floor window, then he is proposing to use two 45 degree bends to get around the window , and then continue up to the roof line. He is following manufacturers directions for everything else. I have never heard of putting bends in stove pipe.. Is this safe? Answer: In general, a chimney should not bend more than 30 degrees (not 45). However, if the stove is an automatic stoker there might be an exception. Look at the chimney specs and stove specs. Chances are that 30 degrees is the max.