Help Smoke Smell In Basement

Old 11-12-17, 08:03 PM
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Help Smoke Smell In Basement

We have a wood burning fireplace on the first floor, last night when we burned it there was a heavy smoke smell (but no smoke we could see) in the basement room directly below the fireplace. Originally I thought the furnance was creating some pressure and pulling in smoke from the ash trap, but it's sealed tight with gorilla tape (too much macgyver as a kid). There are no other spots for smoke smell to enter this room.

Any ideas?

  1. Wood burning fireplace with standard screen doors
  2. Fireplace has a fresh air intake at the front which was open
  3. Their is an ash clean out trap door (easily tripped open) at the back of the fireplace which empties below. I gorilla taped the clean out access door shut last season when we had a lot of smoke in the same room, thinking it was coming from the ash clean out. The clean out is in the room where we smelled the smoke.
  4. The room with the smoke smell is semi finished and contains the furnance and air handler as well as tankless hot water heater. The furnance has an external intake that is a few feet off the ground towards the back of the house and the tankless has a similar intake (neither are anywhere near the chimeny which is 40 feet above)
  5. Chimney is attached to the outside of the house
Old 11-12-17, 08:26 PM
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Welcome to the forums.

A toughie !

Is the furnace and the water heater in the basement ?
I'm wondering if the furnace is drawing in the smoke.
Old 11-13-17, 11:19 AM
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Outside chimneys are the toughest and it sounds like this isn't a new problem.
Assuming the chimney has a tile liner there is still the gap between the tile and the masonry structure. If that gap is filled with cold air and smoke leaks into that cavity it could be pulled down towards the cleanout. Even though you have sealed the door there will still be some leakage especially if it is a block foundation.

Have you had a pro in to inspect it knowing there is a smoke concern?

Is or has there ever been anything else connected to that chimney?

Old 02-13-18, 08:07 AM
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Update here: I sealed up the ash clean out door in the furnace room with silicon caulk and it seems to have fixed the issue. This would mean that smoke was coming down the ash cleanout door and seeping/being sucked out the door in the furnace room.

Plan is to seal up the ash clean out trap door since we don't use it.

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