See now I had the opposite response with the baro. Before I installed the baro, my furnace would yo-yo hot and cool and had me running up and down the basement stairs several times a day to adjust the air feed. As it would heat up the draft would pull harder causing it to heat even more which created a run away train effect. If I closed the air feed too much it would cool and keep cooling as the draft in the chimney weakened..
After installation of the baro, I set my air feed and it keeps a steady heat output for the duration of the burn, 12 hours
The baro keeps a steady consistant pull on the furnace which results in a steady consistant amount of air feeding the coal which then translates into a steady consistant heat output. I make a lot fewer trips up and down the basement stairs now and my furnace is MUCH more easier to manage. I would advise everyone to try a baro, if it doesn't work out then sure try the manual damper..