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)

Symptoms of a Chimney Fire?

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by azsteven, Jan 31, 2010.

Thread Status:
Not open for further replies.
  1. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    My daughter's room is upstairs from the room with our insert, and the chimney runs through her closet. This evening when I was getting her ready for bed, her rooms felt unusually warm. I felt the wall behind which the chimney runs, and the plaster wall was warm to the touch -- I checked against another interior wall, which was cold to the touch. Inside her closet, the upper section of the wall next to the chimney was quite warm. Not hot like hot water from the faucet, but very warm. I read about the symptoms of chimney fires, and went outside just not to see if there were any flames/heavy smoke coming out the chimney, but fortunately none. I don't think this was a chimney fire, but what else could this be from?

    Background:
    Vermont Castings Montpelier insert, installed in a 1900 masonry fireplace. We had it installed this past October, with a full stainless 6" steel chimney liner. The installer wrapped some kind of insulation around the liner before running it into the chimney. He installed block off plates at the top and bottom. We've been running the insert a lot this week, as the temperature was a daytime high of 15 and nighttime low of 5 or below. We had a very hot fire this afternon, as I just scored a bunch of 2 year old oak.

    I've burned about 2 cords of wood since we got the insert installed. 1 cord of this was well seasoned, and 1 cord was sold to me as "seasoned", but I've since learned it was quite green, about 30% moisture content. The oak I just picked up today was 11%. Anyway, it's certainly possible that the green cord created some creosote, but I tried to run the fire hot and mix it in with the well seasoned wood.

    Any ideas? I'm letting the fire run out tonight (it's down to mostly ashes right now), and I'm planning to call the chimney sweep to come inspect/clean. Any one seen similar symptoms and have some idea to share?

    Helpful Sponsor Ads!





  2. ckdeuce

    ckdeuce Feeling the Heat

    Joined:
    Feb 11, 2008
    Messages:
    264
    Loc:
    Western, PA
    I'm no expert, but I think you would have known if you had one. If you were home when you think it may have happened......... The easy way to tell is to check your underpants. You would have known. Warm wall might be something to check into, but I doubt you hade a CF unless it was minor.
  3. BotetourtSteve

    BotetourtSteve Member

    Joined:
    Feb 7, 2008
    Messages:
    188
    Loc:
    Western Virginia
    How hot are you burning your stove? Even with above-average moisture, a hot fire will cure a lot. Have you heard a roaring sound in the stove/flue (a classic sign of a fire)? With the liner you had installed (assuming it was done correctly), there shouldn't be much to worry about as far as a structure fire, but I can understand you pulling in a sweep to check things out. It'll cost you a few bucks, but piece of mind can be priceless sometimes!

    As an fyi, I have a very similar set-up that you describe, and the walls fronting my chimney upstairs retain some warmth too - just kinda the nature of the beast.
  4. Scotty0844

    Scotty0844 Member

    Joined:
    Dec 7, 2009
    Messages:
    37
    Loc:
    Eastern Shore,Maryland
    My chimney runs up through my sons room. I check it every night when they go to bed. It's usually just slightly warmer than the rest of the walls in his room. Not quite the temp you were talking though
  5. cmonSTART

    cmonSTART Minister of Fire

    Joined:
    Nov 29, 2007
    Messages:
    2,284
    Loc:
    Antrim, NH
    I doubt its anything to worry about but its probably wisest to have your sweep come and check it out just in case. Sounds like a good install!
  6. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    When we first got the insert and I was new at this, I would turn the air all the way down after it got good flames.
    Recently (last month+) we've been burning it hot, air full on for first 30-60 minutes after we load the wood, then down to about half-way until bed time. Last 3 days, I've been running it as hot as possible.

    I haven't heard that kind of roaring sound, but I'll admit the fan's been running load so I might have missed it.

    indeed. But i hate to not run a fire when it's 10 degrees outside. :long:
  7. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    I've been thinking about it some more.... Could it be that the stove got really hot, and the outside of the stove heated the air/bricks in the chimney (outside the liner) -- not smoke, just hot air in the cavity inside the chimney but outside the liner? Maybe the masonry in that section of the chimney has cracks, and the heat escaped into the wall cavity? I'm just casting about.
  8. fbelec

    fbelec Minister of Fire

    Joined:
    Nov 23, 2005
    Messages:
    1,661
    Loc:
    northern massachusetts
    i've been in a lot of old house like your houses age and older. those old chimney had no clay liner so any amount of heat in the chimney comes thru the wall. also some people in the old days plugged up chimney holes from old stoves with the plaster that is your finished wall. if the plaster feels and sounds really solid that might be you. and you want to replace those bricks.
  9. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    That makes sense, that the plaster wall inside the closet might be plastered right over the bricks.
    How would I even find out if that's the case?
    I thought the liner + insulation would make the old masonry chimney irrelevant.
  10. jharkin

    jharkin Minister of Fire

    Joined:
    Oct 21, 2009
    Messages:
    3,247
    Loc:
    Holliston, MA USA
    If its just warm and not hot, I also think you are probably fine. BUt it never hurts to get a professional opinion....

    FYI, I have a similar setup, except its a hearth mount freestanding stove. 6 inch liner wrapped in insulation up through a 150+ year old unlined masonry chimney. Its an interior chimney that passes through an uninsulated attic. My setup was inspected and passed by the fire department on install 10 years ago (I have the certificate) and was given the OK by a CSIA certified sweep I hired to inspect it when we bought the house last year.

    If I go into the attic when the stove has been burning all day the chimney is warm to the touch. 1 or 2 inches of insulation is not going to stop all heat loss from a 400+ degree flue so I don't worry about it.
  11. fbelec

    fbelec Minister of Fire

    Joined:
    Nov 23, 2005
    Messages:
    1,661
    Loc:
    northern massachusetts
    looking down the chimney from outside the sweep my not see what use to be the thimble if you want to call it that. go up in your attic and see if you can see down beside the chimney. alot of times there is about 1/2 to 1 inch of space. use a strong flashlight. you might be able to see what's there. if you really need to know and if it is getting as hot as you say i would break open that spot and see. it's a closet and if you do a bad patch no one will know but you. i have seen people leave the opening into the chimney wide open not using anything to block it up and then sheetrock over it. i think i would check it.
  12. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    Indeed it was warm and not hot, and this morning (fire long since out) the plaster wall was cold as expected. There's no attic above that part of the house -- the room is in a craftsman-style front-to-back gable with a shed dormer giving it 8' headroom (see picture below, right-hand side of house). The chimney goes through the closet and then the roof, and as you see in the picture it extends about 8' from there (to be above the ridge of the main roof). So if any heat was radiating up outside the liner, it would make sense that it would trap there, e.g. below the top block off plate.



    I'll call the chimney sweep tomorrow, and hopefully they can come yet this week. Do you think it's safe to use the stove in the meantime? I just got almost 2 cords of very well seasoned oak just waiting to use it!

    Attached Files:

  13. pen

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

    Joined:
    Aug 2, 2007
    Messages:
    6,967
    Loc:
    N.E. Penna
    What do you mean by running it hot as possible? Do you mean leaving the primary air fully open all of the time? Do you have a thermometer on your stove top? Or on exposed single wall chimney?

    pen
  14. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    Thursday-Friday-Saturday were our coldest days of the year so far, with nighttime temps in the 0 degree range and we had significant wind gusts so windchills in the -10 or -20 range. For these 3 days, I was loading the stove more often, maybe every 2 hours (rather than waiting until there were only small coals left), and leaving the primary air at about halfway or a bit more all the time. It was producing great heat :)

    No, I don't have a thermometer on the stove.
  15. pen

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

    Joined:
    Aug 2, 2007
    Messages:
    6,967
    Loc:
    N.E. Penna
    I'd recommend you get a stove top thermometer and place it on that stove. (I'd ask around to see what other are doing with that insert as far as thermometer location, or refer to your owners manual) With it being that cold, you would have had a tremendous draft in the chimney. That accompanied with leaving the air control open that much, you may have just been running the stove at or above it's max potential.

    We don't know that however unless you have a thermometer on there.

    I know if I left my stove open 1/2 on the air control with a full load of wood on top of hot coals, it would way overfire within minutes. Closing the air down to about 10% will keep my stove top at 650 for hours. Leaving it open more than that and I'm pretty certain I'd turn it into a light bulb. Many people on here recommend keeping the stove top below 650 degrees.

    To me, it sounds like you were just running the tar out of that stove and as a result, wound up with a very warm chimney as well. I'd say other than the warm chimney (which is most likely explained by running the stove too hard) you have no other symptoms of a chimney fire. Therefore, I wouldn't be too worried about the chimney, but maybe worried about damage to the stove if you continue to run it so hard. (Again, I am only ASSUMING you are running the stove too hard based on your description, you'll need a thermometer to verify)

    pen
  16. firefighterjake

    firefighterjake Minister of Fire

    Joined:
    Jul 22, 2008
    Messages:
    14,949
    Loc:
    Unity/Bangor, Maine
    Random thoughts:

    I am a big fan of thermometers . . . both the stove top and flue thermometers. They help keep your temps in the Goldilock Zone -- not too hot (risk of damaging the equipment), not too cold (risk of causing creosote build up) and keep things "just right." Without some type of thermometer it's kind of hard to tell when a fire is hot, really hot or way too hot.

    My guess . . . probably not a chimney fire. None of the classic signs . . . but why risk things . . . buy some peace of mind and have a competent chimney sweep do an inspection of your chimney. Pay a little now, pay a lot less in the future . . . in other words, it may cost a bit for a full inspection now, but an inspection now is a heckuva lot cheaper than rebuilding a home and having to buy all new stuff if there is a fire.

    Fuel . . . ah, the first year burner's lament of having less than ideal wood. There are many threads here offering some advice on what you can do for better burning . . . not best burning . . . but better burning (i.e. pallets, splitting smaller, "speed" drying, etc.)
  17. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    Thanks. I'll look for one...

    Indeed. The installer/sweep is coming by Tuesday morning to clean/inspect and discuss what happened. I'll report back on what I learn.

    Ain't that the truth. It takes a lot of learning to figure out what "seasoned" wood looks like, how to judge, etc. I've learned so much over this first season: not to trust vendor's description, how to use a moisture meter, how to haggle with the guy who says he's got seasoned wood but shows up with stuff registering 30% moisture on the outside, and how to recognize a deal when you find one. Now I've got 2 cords already stacked for next year, so I know it'll get easier.
  18. azsteven

    azsteven New Member

    Joined:
    Nov 6, 2009
    Messages:
    87
    Loc:
    Boston Suburbs
    So the chimney sweeps came out today. After running the brush in the chimney liner, there was only about 1-2 cups of debris -- so obviously the fire's been hot enough and not too much buildup/creosote. Definitely no chimney fire here. Phew!

    I described to the the hot wall upstairs, and they said that the liner would be hot, but that the insulation would prevent the brick chimney from getting hot. I suggested to them the idea about the heat radiating up from the stove, around the liner and they said no -- there's a block-off plate for prevent that. Well when they took the surround off the stove to double-check, I took a look with the work light and saw a gap of about 3" by 8" on one side of the flue collar. That might be how some heat got up outside the liner. So they filled in the block-off plate with some of the fireproof insulation (looks like R13 but it's white). We'll see if that prevents the hot wall symptoms.

    Since I'm only gonna burn about another 1-1.5 cords this season, they told me to have them back after next season, in May/June 2011. Thanks for all the ideas!
Thread Status:
Not open for further replies.

Share This Page