Question: We just moved into a house built in the early / mid 1940s, and we have two wood fireplaces. The first is in the living room, and the second is in the refurbished game room in the basement, directly (one floor) below the living room and sharing the same chimney. There is a flue for each fireplace. My question is, for a fireplace in the living room, do I keep the basement fireplace flue open or closed? The basement seems to fill up with smoke either way. Conversely, for the basement fireplace, do we keep the other flue open or closed? In the first case, I would think we would want the bottom flue closed to prevent reverse flow of smoke into the basement, and in the second case, I would think we would want to keep both flues open. What are your thoughts? Thank you. Answer: The best thing to do is to keep any flue closed when you are not having a fire. As far as the two chimneys, the best solution might be to raise one chimney termination so it is higher than the other. This might eliminate smoke going up the warm chimney and down the other cold one..this smoke will even seep through a closed damper.