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Unused flue downdraft

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by WNelsonIII, Nov 13, 2012.

  1. WNelsonIII

    WNelsonIII New Member

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    Nov 13, 2012
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    Just trying to see if anyone else has had the same problem. I just purchased a Harman Oakwood for this winter. The stove is installed in the basement and there is a fireplace on the first floor above the stove. I never intend to use the fireplace with the Oakwood in the basement. Both these flues are in the same chimney with one chimney cap. Occasionally there is some smoke that downdrafts through the fireplace flue and out of the fireplace. I was wondering if anyone knows of a way to prevent this without completely closing off the fireplace.

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  2. begreen

    begreen Mooderator Staff Member

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    Welcome to the forums. Was this install inspected? It's against code to have this on a common flue with the fireplace. The air from the fireplace is most likely diluting draft and cooling down the chimney. That's a recipe for creosote buildup. I would drop a liner all the way down to the stove. With a proper top cap that will stop the downdraft. The fireplace damper should be screwed shut with a sign in it saying that it can not be used as a fireplace.
  3. corey21

    corey21 Minister of Fire

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    Sounds like the fireplace is being a draft hog.

    Welcome.
  4. WNelsonIII

    WNelsonIII New Member

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    It is a single chimney with two flues with a single chimney cap covering both flues. One flue for the fireplace and a separate flue for the wood stove. It seems as though the fireplace damper is not closing tightly allowing smoke to come in from the fireplace flue. Is there a way to seal off the fireplace flue that I am not using without completely closing off the fireplace?
  5. begreen

    begreen Mooderator Staff Member

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    Ah, ok, that is a different animal. This is a common issue. There needs to be a height separation between the two flues. Otherwise the idle flue can siphon the smoke from the adjacent flue. Here is a product to solve the issue.

    http://www.extendacap.com/
  6. Beer Belly

    Beer Belly Minister of Fire

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    Maybe two Chimney caps, with the unused one installed lower ?
  7. EatenByLimestone

    EatenByLimestone Minister of Fire

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  8. Lewisthepilgrim

    Lewisthepilgrim Member

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  9. branchburner

    branchburner Minister of Fire

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