Newbie Secondary Burn Question

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joninvermont

Member
Oct 24, 2010
7
Vermont
Hello everyone - website is awesome and full of tons of useful info!

I have a new VC Defiant NC and still trying to figure out the secondary burn issue. I just started burning this year for the first time, so most of my wood (maple, beech, and oak) is still green as it only had 6 months outside in the wind.

Through the help of the forum, I've come to assume that some of my troubles achieving secondary burn is because the wood is indeed still somewhat green. I have had a couple secondary burns, but it seems to be a moving target, even with a full bed of coals. Regardless, it is a source of enjoyable frustration as I learn what my stove wants and needs. I have a few questions:

1) When burning (after leaving bypass open and slowly turning down the damper and then closing the bypass when the fire has caught enough), I'm constantly going outside to check the color of the smoke. Can you achieve secondary burn and still have white-tinged smoke? Does secondary burn by definition = clear smoke? My wife thinks I'm not after repeated trips outside...

2) In the Defiant, it's very easy to hear when the secondary burn has initiated or not; it actually sounds like the furnace is on when it's working, and then I know it's functioning. However, sometimes it appears to stall, the smoke turns lightly white (not billowing white, but just that grey bluey white), and the rumble dies away. BUT the temp in the stove actually slowly increases to 600, then levels out around 650, after which I then turn the damper down. At this point, there is no rumble, the smoke is not clear, but it appears that I am achieving a partial secondary burn. The flames inside the stove are not bright orange, but that eery purpley-blue. Knowing my wood isn't 100% seasoned, should I be happy to settle with this situation? Or is there something else I'm doing wrong?

Thanks for your input!
 
Jon, it sounds like your stove is one that features the "everburn" or "down draft" secondary combustion system. The other non-cat secondary combustion method involves a series of tubes in the top of the firebox under the baffle which deliver preheated, secondary combustion air to the fire.

Of the two designs, you'll find that the "everburn/down draft" is by far the fussier of the two. I've never operated the type of stove you have, so I don't have any practical advice, unfortunately. Just hang around, and someone with experience will chime in. And, as suggested, search for "everburn" here on the forums.

Six month seasoned wood will make things more finicky as well, unfortunately. The good news is that with some work on your fuel supply this winter, you'll be well ready for next winter.
 
Hey thanks for the support. There is indeed a lot of info under "everburn." It's for sure a bunch of trial and error, and hopefully with colder temperatures the draft will be better and things will turn around. Looking forward to next year with much better wood, 60% already cut and stacked (yay!).
 
Jon
Last year was my first with a downdraft stove. Actually my first wood burning stove period.
I've already had more success this season than I did all last winter. Primary culprit? Wood that hadn't been seasoned enough. They call it wet wood here at Hearth, but that is misleading to new burners. It isn't wet, doesn't look wet. But it isn't as dry as it needs to be.

In the last week I've achieved good, controlled, combustion everytime I've tried. Can't believe how much different the stove behaves over last year (take a look at some of my old posts). No, you shouldn't see much of anything visible from the flue. Maybe some wisps in the early going.
These stoves need deep coal beds. That's how they work and why they are "fussier" than burn tube types. With partially seasoned wood you will need really deep coal beds to get combustion, and that isn't a promise.

Downdrafts, or cross-draft in the Leyden's case, have taken some burners to the brink on this site. I was one of them last year. Like I said, better already. I saw my combuster glowing red maybe 3 or 4 times all last winter. I've had it glowing without fail each time I tried this year.
Go to the Harman woodstove site and watch them operate the Oakwood on video.

Gonna be a long year for you with that wood and any stove I'm afraid.
 
Jon, perhaps don't pay quite so close attention to what is coming out the flue and stick to how the stove is operating. If it gets up to temperature it will take care of itself.

As for the wood, you know it is not ideal so you can't expect perfection just yet. Next year will be much different but you should still be able to get through this year.
 
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