- Oct 3, 2007
- 1,539
Last night I got a small fire going in the furnace just to take the chill off in the house before we went to bed. It was in the low 50s outside and the house was at about 67 and dropping, so I figured a quick fire with some pallet wood would do the trick. After I got it going my wife called me upstairs and I committed the cardinal sin of wood burning-walking away from the stove with the door open. About 15 minutes later we were about to sit down to dinner when I heard a noise coming from downstairs like a vacuum cleaner running. It then hit me that I had left the door on the furnace open and I took off like a shot down the steps. When I got down stairs the firebox was raging and the noise sounded more like a small jet ready to take off. I closed the door on the furnace along with the air control and then looked at the adapter where the double wall stove pipe transitions to the Class A-it was just beginning to turn a dull red. At this point I figured that there was a fire raging inside the chimney (which still didn't seem right considering I cleaned inside and out a month ago and have burned extremely dry wood ever since) and that the best course of action would be to hit the firebox with dry chemical while my wife called the fire department. After cursing loudly I bolted went for the extinguisher sitting between the wood furnace and the oil furnace. It was then I realized that the noise was not coming from the wood furnace but rather the ductwork. I looked at the fire which had nearly gone out as a result of my closing off the air and then at the stove pipe which had returned to black again, took a breath, and walked around to the rear of the furnace plenum where the wood furnace ties in. The damper in the wood furnace ductwork (in the summer it keeps cold air from the AC unit from being pumped into the wood furnace) had come loose and closed. The noise I was hearing was the wood furnace blower struggling against the closed damper and the air escaping from any tiny opening in the duct. I opened the damper, re-secured it, and just to be safe went outside, looked up at the chimney outlet and saw no sparks or flames, and felt the outside of the pipe about 6' up from the tee-very warm to the touch, but not unusually hot. At that point I went inside and explained to the wife why I was running around like a maniac for the past 10 minutes 
