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Damper slide bar and the combustible air settings? M55

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by bostonfan49, Oct 7, 2012.

  1. bostonfan49

    bostonfan49 Feeling the Heat

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    I am starting my 2nd season but I am still confused about the difference/relationship between the adjustable slide damper bar and combustible air settings on the panel. Again, I have never had anyone use a magnahelic gauge to properly set up the air because (unless someone chimes in with a name) there is no one in Chittenden county Vermont ( Burlington area) who does this. My slide damper is about 3/4 pulled out and I see no difference with my flame if I have my combustion flame setting on the lowest setting or the highest. I can only tell you that after about 3 days, I have a fairly black arc on my glass but it is easily removed with paper towel and water. I did just have my Chimney flue cleaned and I was told that for a usage of 3+ tons the flue looked in great shape with an even light gray coating. Sometimes I feel like I want to run outside to my OAK, with the cover removed....and see where my air flapper is with different settings. After the stoves initial run up "before" the convection blower kicks in, I have a huge flame that extends beyond either side of the burn pot. But once the convection blower kicks in and the stove is now heating my house I seem to have a pretty small flame. My defaults setting are usually, Convection air on 3, Pellet feed on 3 and combustion air on 3. Sorry for the long post.... Thanks, Bill

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  2. jtakeman

    jtakeman Minister of Fire

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    Bill,

    For what it would cost to have a tech come out and set it. I'd just go buy(ebay) the gauge and set it up. Its not that hard even I can do it! ==c

    As you open the damper, More air passes thru the stove creating more vacuum. When you raise the damper trim it has the same effect but in a smaller scale. Best to set the damper with the gauge and use the trim setting to tweak for pellet variance.

    Pellets that burn slower may need more air trim and pellets that burn faster need less trim. What you try to do is get a steady flame(once its burning for 20 to 30 minutes). If the flame starts to die down before the next auger feed, Reduce the trim. If you have a steady fire but the ash on the glass is more towards black than gray, Increase the trim.

    Hope it helps!
  3. Woody1911a1

    Woody1911a1 Feeling the Heat

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  4. bostonfan49

    bostonfan49 Feeling the Heat

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    Thanks Woody, I just may try to get it...my only question is if the probe will fit the M55 cast insert. I believe I have everything I need = # 8 hex screwdriver, and run the stove on high for an hour with feed and trim on default level 3 and adjust the slide bar to get 0.15-0.17 inches....I just want to be sure this gauge is OK or some other one.....thanks, Bill
  5. Woody1911a1

    Woody1911a1 Feeling the Heat

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    the only thing these gauges come with are fitting you screw into the gauge to attach vacuum tubing to . you have to supply the rest . there is no "probe" necessary that i know of unless you mean a fitting like i made , but that would depend on where you need to hook up on your model stove .

    see my thread here http://www.hearth.com/talk/threads/new-install-magnehelic-reading.91405/

    that gauge retails for $179 so you might want to snag it before someone else here does :)

    btw my stove is made by Enviro too .

    cheers Woody
  6. flynfrfun

    flynfrfun Minister of Fire

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    The combustion air settings are to fine tune the amount of air. Like you, I've never really seen much, if any of a difference changing that setting. Actually, you can drop the combustion trim down to 1 and then just open the damper enough to make up the difference. The benefit here is that the combustion blower is running at a slightly lower rpm and "may" last longer and run quieter and use less electricity. And typically as the stove gets dirty you have to increase the air flow, so you have all 4 combustion trim settings you can increase if wanted. The feed rate of the pellets is not even enough to get these settings down to a "knat's ass", so I've learned to only change things if the fire seems to be consistently off (lazy or active & low) for a long period of time (days).

    Sounds like your stove may have a little too much air. My damper is roughly 1/2 way out, maybe a little less. You will probably see a taller flame if you close the damper a little. I try to go for the tallest flame possible without it getting too lazy. Seems to put out more heat that way too. My mag readings tend to be a little below what they recommend of about .14ish.
  7. flynfrfun

    flynfrfun Minister of Fire

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    J,
    I've chased settings all over the place trying to get a nice even flame, but on my M55, the pellets fall at such a variable rate that it's impossible to not have a flame that builds and then wanes. Each "shot" of pellets are of differing #'s of pellets with no pellets falling sometimes and more than average other times. Is there any kind of fix for this or is it normal?
  8. jtakeman

    jtakeman Minister of Fire

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    You also have the adjustable plate over the auger tube. You could try raising it slightly to allow a bit more fuel in. I don't have the adj plate on mine, So feed rate trim and damper are my only adjustments for fuel variance/flame height. I can't get mine perfect either, I just to get it close as best I can. I worry more on glass color and burnout on idle/low heat #1 setting.

    I don't think there is any way to get em perfect(a continues fire would probably be on the rich side).
  9. bostonfan49

    bostonfan49 Feeling the Heat

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  10. bostonfan49

    bostonfan49 Feeling the Heat

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  11. flynfrfun

    flynfrfun Minister of Fire

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    Actually, I don't have the adjustable auger cover plate. Never saw the need for it since the new convection blower came out. I can run my stove wide open and not trip the high limit. And that's with Douglas Fir pellets. I've often wondered if the "paddles" at the top of the auger are affecting this (variability in pellet shots)? What are they for? I was thinking they are to keep fire from propagating beyond that point, down the chute and into the hopper?
  12. Woody1911a1

    Woody1911a1 Feeling the Heat

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    you'll need a length of 3/16" vacuum or fuel line (auto parts store) and a fitting like i made in the thread i posted the link to earlier . from the tech manual which is available on the enviro www :

    "This unit is designed to operate within a negative pressure range of 0.15-0.17 inches of water column (37-42
    Pa). This can be measured using a Magnahelic pressure gauge once the unit has been running on heat level 5
    setting after one hour of burn time. This adjustment is necessary for varying venting configurations. The reading
    can be taken from the ⅛” hole located above the top right corner of the door. A #8 screw must be removed in
    order to access this hole. "

    i'm not sure but i don't think any commercially available fitting is available but i might be wrong . that's just how i did it and it worked great . my guesstimate was wayyyy off .

    cheers Woody
  13. jtakeman

    jtakeman Minister of Fire

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    Kickers, I think they are just to make sure the pellets get out and don't try to go back around. But I could be wrong.

    One would think with the DF you'd be the one with the most over fire issues?
  14. flynfrfun

    flynfrfun Minister of Fire

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    Yes... strange, I think I've only had it trip the high limit switch once since I've owned it (2yrs now). Of course, I rarely ever got over heat level 3 before changing out the blower, so that may be why.
  15. jtakeman

    jtakeman Minister of Fire

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    Ahh, Most were having issues once they used the 4th and 5th heat setting.
  16. Millsk

    Millsk Member

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    So I gotta say that I did not adjust my damper with a guage.

    That said, I moved that thing all over the place trying to see a difference and I didn't see much. Closed and wide open the difference is noticeable...somewhere inthe middle, it all looks and acts the same.

    *shrug*
    bostonfan49 likes this.
  17. DemonGT

    DemonGT Member

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    my stove seems to be the same. i have my air damper shut as far as it goes and the fan turned down 3/4 of the way and it still has a brisk fire? *shrug*
  18. jgrz0610

    jgrz0610 Burning Hunk

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    I'm just made I overpaid for my mag gauge. I tried to find one for $35 bucks but bought the same one $78...the same EXACT one. Oh well, I suppose if you need it you need it. For the record if you have more money than ingenuity Dwyer does make what they call their "Portable Kit" which is usually listed on websites as a case but it comes with hose, static pressure tips etc. I was going to get it but then I realized I work in machine shops 5 days a week and could probably get somebody to make me something spiffy for free. I had mine set with the gauge at install then I moved the damper with my vacuum during cleaning...never worked as good after that. There is a noticeable difference especially when it is on low burn in the amount of black soot etc.

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