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sparks come out the exhaust pipe

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by feather, Mar 1, 2010.

  1. feather

    feather Member

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    We had an Enviro Mini A installed about a month ago, and it's seems to be working good. However, a couple of days ago, at night, we noticed we could see sparks coming out of the exhaust pipe. The sparks float around in the outside air for a few seconds and then blink out. There seems to be five or six sparks a minute -- not a lot, but enough to make it seem dangerous.

    It is normal for sparks to come out the exhaust pipe? We had the stove professionally installed by the dealer. The pipe comes away from the house by a couple feet and terminates at a 45 degree bend.

    More sparks come out when the flame in the stove is tall, and less sparks come out (or no sparks) when the flame is small. Our house is wooden, and there are some trees around -- not a problem with sparks during the rainy season, but we can't have sparks if we happen to run the stove on a cool fall night, when it's dry.

    Thanks for any advice.

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  2. Excell

    Excell Feeling the Heat

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    I have heard people with this concern before .It is normal ,the only way to stop it would be to run the pipe out farther or up higher .I think higher would be better .
  3. DAKSY

    DAKSY Patriot Guard Rider Staff Member

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    Averill Park, NY, on Burden Lake II...
    Sparks are normal from a pellets vent - it's fly ash...
    That's why most pellet stoves require AT LEAST 36" to combustibles
    from the end of the cap. That gives the fly ash a chance to extinguish itself
    BEFORE it can land on something and ignite it.
    Check your install manual to make sure your install is compliant.
    If it is, you're gonna hafta make sure that you keep the 36" area clear of leaves in the fall...
    If it isn't call your installer.
  4. hossthehermit

    hossthehermit Minister of Fire

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    Ya don't have a bush right there, do ya?
  5. Snowy Rivers

    Snowy Rivers Minister of Fire

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    Most install manuals (and codes) state that a direct vent pipe on a pellet stove must be no closer than 12" to the house.

    I have 3 stoves here that direct vent and two of them will put out sparks every so often.

    Just make sure you dont have grass or other things that could burn close by the outlet

    A baffled outlet can and will stop much of this.

    Its really not a biggy though as these little sparks are very tiny and dont last long.

    AS mentioned, a longer/taller pipe will help.


    Just keep the area under the exhaust clean and free of combustibles for about a 8-10 foot square area.

    Snowy
  6. imacman

    imacman Guest

    OH no....not "sparks from the pipe" again......where's slickplant??


    Feather, there was a "discussion" about this last year, and while it could be a problem if your vent is close to the ground, we also had a little fun with the original poster.

    www.hearth.com/econtent/index.php/forums/viewthread/27591/
  7. feather

    feather Member

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    Thanks for your replies. Now that I know it's normal, I won't worry so much. There are no trees or brush closer than 30 feet, but under our house is a concern -- stored lumber and misc. The exhaust pipe sticks out just 12" from the house, and three feet from the ground. I think I'll close off the under-the-house pathway, and in the fall, run the stove only on low.

    Here in western Oregon we have a "fire season" in the late summer and early fall, before the winter rains. Any machinery that can throw a spark is strictly regulated as to when and where it can be operated and we are required by law to keep the edges of our driveway and near our houses clear of flammable debris.

    So I'm a bit surprised sparks from the exhaust are normal, AND not mentioned as a problem in our fire regulations.
  8. Snowy Rivers

    Snowy Rivers Minister of Fire

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    I live in western Oregon and my house is in a heavily forested area with grass and other burnables fairly close.

    I keep a buffer zone to prevent any issues.

    Been here for many many years and have had pellets stoves in this house for 17 years.

    Just part of life me thinks/

    If you are really worried, you can put a spark arrestor cap on the vent pipe. You will need to keep oit clean though.


    Snowy
  9. woodsman23

    woodsman23 Minister of Fire

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    Hello i am the sparky arrester and i am here to arrest any hot loose sparks that try to cause problems here!!!!.. Really there is little chance of a tiny spark starting a fire, simply place some flat cheap bricks under your exhaust or place a bucket of water under it.. do you know slickplant??...
  10. Phatty

    Phatty Member

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    i hope this one doesnt go the way the other one went :bug: .i'm not sure i can laugh that much in one day :lol:
  11. sydney1963

    sydney1963 New Member

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    If you have a bush underneath, make sure you trim it close. You can put paving stone underneath the vent if you're worried. I have seen sparks also and it's fine. You guys are too funny. Have a happy spring, winter is coming to a close. Slickplant would be proud.
  12. tomasulo

    tomasulo New Member

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    I have an Enviro EB3 pellet stove and have ran into some spark issues this winter. Can anyone reassure me?? Over a month ago, noticed quite a bit of grey smoke coming out of the exhaust pipe on the side of my house. Went out to investigate and tapped the termination cap. Some soot came out and then some bits of what looked like creosote or flakes that were actually embers/sparks. I felt the exhaust pipe, and it was boiling hot. The termination cap actually turned color it got so hot, from silver to a brownish. Shut everything down, my stove was just cleaned by myself that day, as I do it weekly. I had not done the pipe in a year. Took apart the pipe and cleaned out, some black buildup inside the cap/bend at the top. Called out the service tech next day and he did the same thing, cleaned the pipe, etc. and adjusted my damper which was stuck. All was fine until a few days ago. Saw more smoke coming out of the pipe, and it was quite hot, also a few embers. Shut stove down and took apart pipe, now I have a proper 4" cleaning brush. Very little ash inside, but some more greyish ash buildup in the bend before the termination cap. Took and cleaned everything again. I have also been burning last year's pellets mixed with new stuff, as I had a carry over from last year. These pellets were stored in my basement on a pallet all summer, would this have any factor?? Can anyone advise what is going on? I am getting paranoid now....Thanks
  13. summit

    summit Minister of Fire

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    sparks also mean you got a lot of fines in the bag, as they float out easilly, and more often than not, your stove needs a cleaning... they do happen, but it should be only an occassional thing with good pellets and a clean system.
  14. krooser

    krooser Minister of Fire

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    I'd worry more about cigarette butts than the few sparks from your stove...relax and enjoy the heat.
  15. woodsman23

    woodsman23 Minister of Fire

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    you starting it again....

    may i suggest a nice spark containment bin...
  16. imacman

    imacman Guest


    No, No, NO! Don't get her off the subject....I love it when she starts talking about trimming her bush. ;-P
  17. sydney1963

    sydney1963 New Member

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    In macman's own words:

    “I have never had a firepot full of pellets”, macman

    Remember?
  18. imacman

    imacman Guest

    LOL....no, but I'll take your word for it..... :lol:
  19. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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  20. tomasulo

    tomasulo New Member

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    my stove is cleaned weekly, and since the first spark issue, I have cleaned the stove pipe out twice in the last month, just to be proactive. As I say, last week, it did the same thing, noticed some grey smoke coming out of the pipe, went out and tapped the cap, some sparky pieces of junk came out. The pipe was boiling at the termination cap. Is this normal?? Fire is burning fine.
  21. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Please describe your venting system starting at the stove. Also a picture of the outside portion of the vent might help.

    All vents get hot and the termination caps are generally only single walled so they tend to get very hot on the end.

    It is possible however that other things are going on. For example, if creosote is building up inside the venting and gets torched off it will become extremely hot.

    Also can you give us some idea of the number of bags of pellets you have burned since you last cleaned the venting.
  22. woodsman23

    woodsman23 Minister of Fire

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    Your exhaust should be only hot to the touch never as hot as you are saying here. Are you burning with to much air??. Do you have a short exhaust (no wise bracks here), ie: horizontal, vertical and how long is it. I think the gray smoke you are seeing is just hot air hitting cold air but if it is indeed smoke then you have issues with your stove and need to address them right away.
  23. tomasulo

    tomasulo New Member

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    I will get some pics this weekend for you. My stove is in my living room corner, vents directly horizontal through the wall, then on the outside of the house about 4 feet vertical, then bends sharp with the thin termination cap on the end. The really hot parts on the pipe were the bend before the term. cap and the cap itself. Both times happened shortly after I was out tapping the pipe to release any loose soot, etc. I am thinking both times that maybe I loosened creosote on the inside of the bend and cap, then it started to catch fire or spark, therefor heating up that part of the pipe?? I burn only around 4-5 bags of pellets per week, Eastern Embers, which are Premium softwood pellets here in Atlantic Canada. I clean the inside of the stove weekly. Last month when I first had the issues with the pipe smoking and sparking, the damper was stuck on the stove and the wood was burning improperly, leaving a really hard black, tarry mess on the inside of the stove. Once the service tech came and loosened and reset the damper, the stove is 100 times easier to clean again. Again, I have been mixing my pellets. I had a pallet leftover from last winter and bought new stuff this winter too. The old has been in my basement, which is dry, all summer and into this winter. Would that older wood have any affect??
  24. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Sounds like you just loosened up some fly ash and soot and while doing that you had a few embers exit the pipe.

    I get several that exit my vent over the course of watching it for a while.

    If that had been creosote your venting not only would get extremely hot but would likely permanently discolor on the outside.

    You should not tap the vent while the stove is burning, if there is a large amount of soot stuck to the venting it is possible you could dislodge enough to cause a blockage in the clean out area of the tee and thereby suffer a loss of vacuum and a stove shutdown.

    The places that direct the exhaust usually will run hotter than a straight run of pipe. I expected the termination to be hotter because of it only having a single layer of metal and no insulating dead air (such as dead air insulates).

    You mixing pellets wouldn't make enough of a difference nor would burning older pellets, the only effect I'd expect from the different pellets might be a difference in ash levels.

    Now if the damper is too open it is possible that more embers will exit the venting because of the increased air flow, and if the damper is closed too much then you'll condense various things (such as creosote) out on the surfaces of the firebox, heat exchanger, and vent pipes, however when these light off there is absolutely no mistaking it. It is recommended by a number of pellet stove manufacturers to burn your pellet stove at a firing rate past its midpoint for 20 to 30 minutes every day or so to keep any danger of creosote and other buildups down.

    Creosote build up is usually minimal when burning a decent pellet and is usually present only when burning for long times at a low firing rate.

    If you still wish to cut down on the embers getting out of your vent add a couple of feet to the vertical section.

    But those embers you have seen are not likely to cause any problems.
  25. tomasulo

    tomasulo New Member

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    I thank you so much for your great information!! Now, you mentioned discoloration. I think the first spark issue I had in early January may have been creosote. The bend and termination cap got very hot. In this case, until the smoke and sparks stopped, the termination cap got so hot that it turned from silver aluminum to a brownish color. This was at the same time that my stove was not burning correctly, with the damper stuck. As I said before, the inside of the stove was terribly hard to clean, with hard black tarry buildup everywhere. My heat tube cleaning rod was seized that time too, and I had to scrape the tubes down, along with the stove itself for a long while until I got the buildup all cleaned off. Again, once the service tech came and fixed the damper, it is much better, with no more black buildup. So, like I mentioned, the inside of the term cap was also buillt up with black stuff which I spent a long time scraping out (took the cap off and did a deep clean). So, this may have been creosote on the iside of the pipe??

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