1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Jotul Cast Iron Stoves
    Woodstock Soapstone Stoves
    Hearth and Home (QuadraFire and Harman Stoves)

Unused flue downdraft

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

  1. WNelsonIII New Member

    joined: Nov 13, 2012
    2 posts
    CT
    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.
    WNelsonIII, Nov 13, 2012
    #1

    Helpful Sponsor Ads!

  2. begreen Super Moderator

    joined: Nov 18, 2005
    36,113 posts
    South Puget Sound, WA
    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.
    begreen, Nov 13, 2012
    #2

  3. corey21 Minister of Fire

    joined: Oct 28, 2010
    2,208 posts
    Soutwest VA
    Sounds like the fireplace is being a draft hog.

    Welcome.
    corey21, Nov 13, 2012
    #3

  4. WNelsonIII New Member

    joined: Nov 13, 2012
    2 posts
    CT
    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?
    WNelsonIII, Nov 13, 2012
    #4

  5. begreen Super Moderator

    joined: Nov 18, 2005
    36,113 posts
    South Puget Sound, WA
    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/
    begreen, Nov 13, 2012
    #5

  6. Beer Belly Minister of Fire

    joined: Oct 26, 2011
    878 posts
    Connecticut
    Maybe two Chimney caps, with the unused one installed lower ?
    Beer Belly, Nov 14, 2012
    #6

  7. EatenByLimestone Minister of Fire

    joined: Jul 12, 2006
    4,114 posts
    EatenByLimestone, Nov 14, 2012
    #7

  8. Lewisthepilgrim New Member

    joined: Oct 5, 2011
    49 posts
    East Kingston NH
    Use them BOTH problem solved !
    Lewisthepilgrim, Nov 14, 2012
    #8

  9. branchburner Minister of Fire

    joined: Sep 27, 2008
    1,694 posts
    southern NH
    x2
    branchburner, Nov 14, 2012
    #9

Share This Page