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Wood pellet stove exhaust plenum goo! What is the cause?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Don2222, Jun 9, 2013.

  1. Don2222

    Don2222 Minister of Fire

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    Hello

    Put the manometer on the hose barb behind the fire box and got -0.27 wg after cleaning out the top of the upside down horseshoe ash chamber. So I cracked the cover to the exhaust plenum and to my dismay saw some very shinny creasote. It looks real sticky because it is real sticky! See pics.

    I removed the combustion blower and got out the Acetone and paper towels! Then some dry moly when clean!

    I do not see this very often. I know bad pellets can cause this. Could there be any other cause?

    Attached Files:

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  2. smwilliamson

    smwilliamson Minister of Fire

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    You know, you can use hot water instead of acetone. At least for the initial cleaning.

    Is this the same piece of crap baby-m that had the hopper fire?

    Let's see....

    1. had a hopper fire
    2. has creosote in the exhaust
    3. needs a new burn pot
    4. needed a new auger stop plate
    5. Needs a new heat exchange raker
    less than 4 years old

    Sounds like a stove worth paying 2k for.
    will711 and libirm like this.
  3. Don2222

    Don2222 Minister of Fire

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    The new stoves come with all these improvements and they did not raise the price! So what A line stoves will you have in your new store?
  4. will711

    will711 Minister of Fire

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    Hello,
    Stupidity, think about it;)
  5. will711

    will711 Minister of Fire

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    Does it matter you're not qualified to work on them .:p
  6. smoke show

    smoke show Guest

  7. Defiant

    Defiant Vermont Castings Geek

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    Hello,
    What stove is this Donny?
    Eatonpcat and will711 like this.
  8. Don2222

    Don2222 Minister of Fire

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  9. Defiant

    Defiant Vermont Castings Geek

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    I bet they were burning those new oil-infused Inferno pellets:cool:
    Eatonpcat likes this.
  10. Don2222

    Don2222 Minister of Fire

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    Could be. LOL

    The interesting part is the fact that it was most liquid at the bottom of the round exhaust plenum. The ash chambers and other parts were dirty with ash but not shinny and goopy like where it is in the pics.
  11. Defiant

    Defiant Vermont Castings Geek

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    Hell O

    If it is creosote, here is a study done by Uranus University on how it is caused in a wood burning appliance. I feel the same issues are also applicable to pellet stoves.:cool:
    Creosote may build up to a considerable thickness on the interior surface of the chimney and the draft opening may subsequently be reduced. A serious fire may be ignited if creosote is allowed to build up. Most problems with creosote are due to poor chimneys with a low draft and cold walls.

    You can reduce the creosote problem several ways. Smoke density can be lowered somewhat in an airtight stove by using small amounts of wood and stoking more often or by using larger pieces of wood. Creosote formation can be limited by leaving the air inlet or stove door slightly open after adding wood to promote more rapid burning until the wood is mostly reduced to charcoal. Then close the inlet as desired.

    Allowing this extra air causes more complete combustion lowers the potential creosote-forming gases and generates additional heat to the surrounding area. Vapor in the flue gases may be controlled by using the driest wood possible and using only small pieces of wood during mild weather when combustion is relatively slow. The stack temperature can be raised by insulating the stove pipe connection so that it cools as little as possible before reaching the chimney. Using an insulated pipe also aids in increasing the stack temperature.

    Draft can be increased by having as few bends as possible between the appliance and the chimney, having the proper height and diameter, keeping the chimney in good repair and by having a separate flue for each appliance. Also use proper sized stove pipe. In a large chimney, draft can be increased by decreasing the flue size. This can be done by installing a new smaller flue or a stainless steel stove pipe liner.

    In many airtight stoves, a sealed overnight fire will deposit creosote even with dry hardwood. To dry the creosote always open the draft caps and let the fire burn hot for at least 5 minutes every morning and again before bedtime.
  12. DexterDay

    DexterDay Guest

    Baby Countryside is all that needs said.

    Almost all are a danger to run unless updated or modified.
    Eatonpcat, smoke show and Defiant like this.
  13. Don2222

    Don2222 Minister of Fire

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    Trading information here to help each other is what this forum is all about. Thanks Defiant.
    It makes sense that insulating the chimney liner to maintain stack temps helps to eliminate creasote buildup
    Also what is key here pertaining to pellet stoves is that good air flow is also needed to properly run stoves and prevent buildup.

    Therefore the fact that creasote has built up in front of the original 85 CFM exhaust blower may be telling us that the new upgraded 105 CFM exhaust blower is truly needed here. After installing the upgraded blower, the manometer read -0.84 that is approx .55 difference! Interesting I only read 0.62 at first but then I realized the firebox door was not shut tight. LOL Also there was no change in the reading when the new ash pan door gasket was installed. I still have the original door gasket but I plan to change that and take another reading.

    I seems now this 7 year old stove will work better than it ever did before!

    See pics, click to enlarge.

    Attached Files:

  14. Don2222

    Don2222 Minister of Fire

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    thanks Dexter, I have been working very hard on updating these stoves
  15. DexterDay

    DexterDay Guest

    As the gases cool(further in the system).... The goop starts where it cools enough to Sote up.

    SOTE in box? Nope. Sote in plenum? Yep. Cooled gases. Add in that Babys burn Chitty? And it all makes sense
  16. Don2222

    Don2222 Minister of Fire

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    Good point Dexter.
    Why do you think the exhaust gasses maybe cooling in the exhaust plenum so quickly?
  17. DexterDay

    DexterDay Guest

    Um? Why did it have a hopper fire?

    Inefficient combustion and a chitty burn.

    Incomplete combustion causes a bad burn? Which causes the nasty stuff.
  18. Don2222

    Don2222 Minister of Fire

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    The background is:
    It had the corn pot in the stove and the control board jumper on pins 2-3 which is better for corn
    Wood pellets were used and there were some burned pellets in the hopper. Also the venting went straight thru the wall and then a 3 foot vertical rise on the outside of the house. The Magnum Baby CountrySide stove manual specifically states NOT to install it with the vertical rise outside!

    The venting going straight outside could definitely contribute to cooling the gases in the exhaust plenum! Thanks for helping think of that Dexter. :)

    You guys are good!

    There are alot of factors here!

    See diagram in manual below
    "This type of installation is NOT recommended cold climates unless closed in and insulated properly!"

    Attached Files:

  19. Lousyweather

    Lousyweather Guest

    hm, as you do more of these, Don, you'll actually "get to know" each stove and installation, just like their owners, and, you'll see that certain units behave differently for a myriad of reasons....a properly burning stove for several years, THEN some creosote? Somethings changed.......I wonder what? (usually a cleaning issue, but can be indicative of a failing part, or that &*^% squirrel again!).....

    Also water versus acetone......both work on creosote- water is cheap, but can cause rust...acetone is more spendy, smells, and cause cancer (but arguably works faster)....we use soapy water
  20. Don2222

    Don2222 Minister of Fire

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    Thanks for the tips
    Since I must use Acetone to cleanup good before painting, I have plenty around. To me the Acetone is much faster and for $7 a can that lasts a long time, my time is worth much more! I also have one of those painters breathing masks. The ash chambers in this baby were pretty clogged when I brushed and blew them out with compressed air. That buildup could have been the change that trigger everything. The new upgraded exhaust blower will help. Proper installation and proper maintenance is the only way to keep any stove running well.

    I will be replacing the door gasket today which is frayed and worn today. Then the fun part of firing up and testing. :) I will let you know how it performs now!
    The control panel membrane had holes from wear. You could see the micro switch buttons. Luckily, I had a good one from a junk panel I swapped in. Magnum does sell just the membrane cheap unlike other companies which is good for my customers that do have these stoves for a long time. Even though the auger motor was working I put a new 2 RPM Gleason-Avery in there for good measure. :) It did run for 7 years, I have seen very good stoves quit after 3 years from no maintenance! This the fun of fixing pellet stoves I guess. :)

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