1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)
    Caluwe - Passion for Fire and Water ( Pellet and Wood Hydronic and Space Heating)

Do we need a stovepipe damper ?

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by Bretonburner, Nov 11, 2011.

  1. Bretonburner

    Bretonburner New Member

    Joined:
    Oct 28, 2011
    Messages:
    39
    Loc:
    Nova Scotia
    We are new to this forum , but not new to wood burning.
    This past September we replaced our old 1930's Enterprise Wood Cookstove with a Jotul 50 TL Rangely. We never had a problem either getting a fire started or maintaining a fire when we had the old stove. Now we are having problems. The one difference in our set up is that we used to have a damper on the stovepipe. Now we have none.We have a brick (inside) chimney with a clay liner, 25 feet high. We have no problem getting the fire started. The fire burns quite vigorously and the stove top temperature goes up to maximum 350 to 400 and then stalls at that point. Reducing the combustion air draft has no effect on increasing temperature in the stove and very little heat is being generated.
    After an hour or so, the brick chimney seems to get considerably hotter to the touch than it did with our old stove. So, it looks like we are losing most of our heat up the chimney.

    Our feeling is that we need to install a damper in the stovepipe to control the draft like we had with the old setup.

    But, now, here is our dilemma: I use the top-down method of starting the fire, and as I said, the fire burns very well, working it's way down from the kindling, through the smaller splits and then down to the larger pieces. However, when I later add more wood on top of the hot coals, the wood just seems to sit there forever and refuses to break out into flame. Only by opening the door and giving it a bit of a blow, will it start to combust. But even then, it is far from being a vigorous fire. It will burn right down eventually, but never bring the stove top temp. back up.

    It seems that the fire likes to burn, top-down, but not bottom-up! And on the one hand, initially, we're getting too much draft, but then later on, not enough!
    We are using well seasoned Maple, Birch and some Beech

    Does anyone have any ideas what our problem may be ??.

    Helpful Sponsor Ads!





  2. shawneyboy

    shawneyboy New Member

    Joined:
    Oct 5, 2010
    Messages:
    1,592
    Loc:
    NE PA
    How large is the chimney? Newer stoves are designed to run with specific size flue. I am gonna step out here and guess, since the specifics are not given, that your flue is to large for the stove and the gasses are slowing down (due to large flue), when exiting and you may want to look at a full liner in the chimney. Of course I am assuming by your description that you do not have it lined.

    Shawn
  3. Bretonburner

    Bretonburner New Member

    Joined:
    Oct 28, 2011
    Messages:
    39
    Loc:
    Nova Scotia
    Yes, you assumed correctly. The chimney is not lined and the size is 6x6 ".
  4. shawneyboy

    shawneyboy New Member

    Joined:
    Oct 5, 2010
    Messages:
    1,592
    Loc:
    NE PA
    Ok a 6x6 chimney is 36 square inches...
    a 6 inch round is... (3*3)*3.14 = 28.26 square inches...
    difference is 7.74 inches so that is 27.38% larger than it should be.

    That stove is designed to run with a 6 inch round.

    That may be at least part your problem. I would venture a guess that it is a BIG part of the problem. A flue damper is designed to slow the gasses, which would only exacerbate the problem.


    Oh and BTW Welcome to the forum !!!!!

    Shawn
  5. BrowningBAR

    BrowningBAR Minister of Fire

    Joined:
    Jul 22, 2008
    Messages:
    7,607
    Loc:
    Doylestown, PA

    I agree, another issue the poster could be dealing with is the quality of fuel since the poster was working with a Pre-EPA stove.
  6. pen

    pen There are some who call me...mod. Staff Member

    Joined:
    Aug 2, 2007
    Messages:
    7,058
    Loc:
    N.E. Penna
  7. oldspark

    oldspark Guest

    My Summit stalled out at about 500 or so with a 18 foot inside chimney with a 7 1/4 inch round clay liner that had 2 90's, started well with no smoke in the room but no top end, I could even turn the air all the way down for the most part. Replaced it with a straight up 18 foot steel chimney and the fire is much more active and have hit 675 stove top and the stack temp is much cooler than last year (which were very high at times). You can see I have made 3,000 or so posts and 2500 of them were about my problems. :)
  8. oldspark

    oldspark Guest

    I forgot, NO to the damper ( I tried one) and they will bug you about your wood till you prove otherwise, been there done that.
  9. shawneyboy

    shawneyboy New Member

    Joined:
    Oct 5, 2010
    Messages:
    1,592
    Loc:
    NE PA

    True.... funny.... but true....

    Shawn
  10. Bretonburner

    Bretonburner New Member

    Joined:
    Oct 28, 2011
    Messages:
    39
    Loc:
    Nova Scotia
    There have been several suggestions that we are not using seasoned wood. We have used a technician"s wood moisture meter and found out that depending on the stick of wood , our wood is between 15 and 17 on the meter. So it does not seem to be the wood causing the draft problem.
    Here in Nova Scotia we are still burning in a shoulder season. We are waiting until the end of this week before we can get a fire going again and try some new ideas.
  11. oldspark

    oldspark Guest

    I dont think you have a wood problem I think you have a chimney problem.
  12. Bretonburner

    Bretonburner New Member

    Joined:
    Oct 28, 2011
    Messages:
    39
    Loc:
    Nova Scotia
    Thanks Oldspark, That will be our next step, to install a liner.
  13. BrowningBAR

    BrowningBAR Minister of Fire

    Joined:
    Jul 22, 2008
    Messages:
    7,607
    Loc:
    Doylestown, PA

    Was this measured on a wood that was re-split for an accurate reading?
  14. Todd

    Todd Minister of Fire

    Joined:
    Nov 19, 2005
    Messages:
    9,226
    Loc:
    Lake Wissota
    I think it may be a combination of both. A 6" clay tile chimney should work fine if it's in good shape and inside the house, if it's an outside chimney it can take a long time to heat up and maintain draft. When you turn the air down the chimney cools along with the fire. A 6" liner won't fit down a 6x6 tile chimney. If you reline I would bust out the tiles and install an insulated 6" liner.
  15. oldspark

    oldspark Guest

    Could be I was going by what happened to me with plenty dry wood and a 7 1/4 in. round clay liner, I think what hurt me the most was the 22 feet chimney with two 90's making the chimney "6ft or so shorter".
  16. maple1

    maple1 Minister of Fire

    Joined:
    Sep 15, 2011
    Messages:
    3,907
    Loc:
    Nova Scotia
    I think you may indeed have too much draft - makes for easier fire starts but also sucks the heat up the pipe. That's a fairly high chimney. Is there a draft recommendation in the manual? This is just a wild guess, but I'd guess that chimney would be pulling over 0.1 in. at least. I have a manometer on the way to check mine.

    EDIT: And, if that is the case, I would think a baro damper would help.

    EDIT AGAIN: Found the manual on line. It specs .05-.1 in. draft, with .07 ideal. I'd guess you might be over that, but again it's just a guess. From reading the manual I'd also say that your chimney construction is OK the way it is - it's not too big.
  17. leeave96

    leeave96 Minister of Fire

    Joined:
    Apr 22, 2010
    Messages:
    1,112
    Loc:
    Western VA
    FWIW, I had a 6-5/8 inch id square clay liner in a brick chimney and thought it was OK. Later, we had the liner knocked out to make room for a rigid 6 inch liner with 1/2 inch insulation around it. The draft was day and night better with the new liner. The change made my stove installation many times better. My chimney height is about 16 ft.

    Good luck,
    Bill

Share This Page