I have to shovel out my woodstove every other day, and when I empty it, I'm taking out mostly unburned charcoal. That is, my wood isn't burning all the way down to ash, even when it's burning full tilt for several hours. Any thoughts on why this might be and what I can do about it?
Too much charcoal
- Thread starter markinvt
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The wood's pretty well cured - kiln-dried and sitting 6 months. What do you mean by primary air? There are times I run it with the door open a crack just to get it burning as fast and hot as possible and that doesn't seem to make a difference.
If you are burning an EPA certified stove, it will have a primary air control on the front of the stove somewhere. Once your wood is in the coaling stages, you can open the primary air to full, thus allowing more air to pass over the coals and further burn them.
Okay, let me ask you this: At night, before bed, I fill up my fire box and close everything down (forgive my lack of knoweldge around proper terminology) - I close the door tight, and there's an airflow regulating handle below the firebox that I push in (maybe that's the primary air?), thus damping things down completely.
In the morning, I have a great bed of coals to work with. I fill up my firebox again, and these days, with the temp staying in the teens, I run the stove pretty much full tilt all day long (with the airflow handle pulled out to allow for max. air flow). By the end of a day, maybe two days, the coals are starting to build up to a point where I can't fit a reasonable amount of wood in to get me through the next night. And when I empty my firebox to make room, what I'm getting is mostly black charcoal and some hot coals.
So, is it perhaps the case that I just have the wrong expectations of my stove and that if i'm going to use it in this way, I shouldn't expect the wood to burn down to a fine ash?
In the morning, I have a great bed of coals to work with. I fill up my firebox again, and these days, with the temp staying in the teens, I run the stove pretty much full tilt all day long (with the airflow handle pulled out to allow for max. air flow). By the end of a day, maybe two days, the coals are starting to build up to a point where I can't fit a reasonable amount of wood in to get me through the next night. And when I empty my firebox to make room, what I'm getting is mostly black charcoal and some hot coals.
So, is it perhaps the case that I just have the wrong expectations of my stove and that if i'm going to use it in this way, I shouldn't expect the wood to burn down to a fine ash?
In the morning, when you open it up, throw one log in and open up the air flow all the way. You may have to do this two or three times, but it should get rid of the coals. Also try giving it a little more air during the overnight burn.
A hot fire with very little air is how people deliberately make charcoal. You need to provide more air if you don't want to make as much charcoal. If you want longer burn times and less coals, a larger stove is in order.
Here's a couple of things I've discovered burning my Lopi Endeavor the last month: I have some seasoned pine (15-20% moisture content) that easily burns to a fine ash. I have some oak (20-30% moisture content) that leaves much larger chunks of coals. In milder weather, I have fewer coals with either wood, because I am more apt to go through a complete burn cycle before reloading. That is, I let the stove usually run at 550F-600F for a while, then it cools to around 250F-300F before I reload. This reduces my coals. In really cold weather, I'm apt to reload before completing a full burn cycle. This gives me a much, much larger bed of unburned coals. If I am going to load her up to the gills for the night, I just sacrifice these to the ash bucket. A waste, more than likely, but the only way for me to get adequate room in a 2.2 cubic ft. fire box.
Also, I see that you say you leave the handle pulled out for max airflow during your burn cycle. The only time I have my air control fully open is: 1.) when reloading the stove, 2.) when a fresh load of wood is still charring, or 3.) when I open it to let coals burn down. Once I have a fresh load charred, I start closing the air control down in stages. I end up getting my best secondary combustion and heat when I have the primary air closed down around 80% or so. If you are leaving yours fully open, I think you are wasting some heat. Just food for thought.
Also, I see that you say you leave the handle pulled out for max airflow during your burn cycle. The only time I have my air control fully open is: 1.) when reloading the stove, 2.) when a fresh load of wood is still charring, or 3.) when I open it to let coals burn down. Once I have a fresh load charred, I start closing the air control down in stages. I end up getting my best secondary combustion and heat when I have the primary air closed down around 80% or so. If you are leaving yours fully open, I think you are wasting some heat. Just food for thought.
Okay, that's a nifty piece of info about charcoal making. Thanks! And I think that solves my overnight issue. But even when I burn with a lot of air during the day, the coals build up pretty quickly, especially when I want to keep the thing pretty hot. That is, if I let a load of wood burn all the way down, I get to ash, but if I pile more wood on top of a good bed of coals, and keep doing that through the day, by the end of the day, even if I've kept the air open, I have a lot of coals and charcoal.
Is it perhaps the case that once the coals start to pile up, if I just keep adding more wood, the stuff at the bottom is never reallygoing to get a chance to burn down to ash?
Is it perhaps the case that once the coals start to pile up, if I just keep adding more wood, the stuff at the bottom is never reallygoing to get a chance to burn down to ash?
Middle, TN - I think you just nailed it! And you kind of anticipated my next post. And thanks for the airflow info - I'll give it a shot.
Thanks!
Thanks!
Sure thing, hope that helps. It is at times frustrating with the buildup of coals, as I feel like I'm wasting good wood and some heat when I shovel those out, but in really cold weather I have to push my Endeavor to keep up the heat in my house. If I had designed the house around a wood stove, I'd have designed it so I could easily accommodate something with a 3 ft. fire box or better. But, as it is, the stove was an afterthought. Fortunately, our winters are relatively mild, so I will have fewer nights that I am battling the coal buildup.
Many people that have had coaling problems also have draft problems. What is the hieght and diameter of your chimney? What type of stove? Any 90 degree bends?
Ja, your coals are getting buried and insulated from the air. Try running your poker through them to float the coals up to the top. Move the grey ashes to the back and the coals to the front where they can get more air and adding one stick at a time of fast burning softwood will help to burn down the coals.
If the house cools down too much during your coal burn-down sessions, you might need a bigger stove or else let the furnace pinch hit for the duration.
If the house cools down too much during your coal burn-down sessions, you might need a bigger stove or else let the furnace pinch hit for the duration.
Pyro in Wisconsin - I have an 8 inch diameter stovepipe, about 30 feet long, and yes, I do have a (almost) 90 degree bend.
Instead of throwing wood on top of a deep coal bed rake the coals into a tall pile across the front of the firebox. Open the air all the way and let it burn this way for 45 minutes or so. Now with the back of the rake push the ash and coals back and then rake the remaining coals forward again. You should end up with a good hot manageable sized coal bed at the front for reloading. Too much ash can cause over coaling as does over loading at frequent intervals. If you are home and want to keep the heat high try burning slightly smaller loads (medium full) more frequently along with the coal raking well before reloads.
What kind of wood are you burning? I've been told Locust and other equally dense wood will coal a lot. I can vouch for the Locust it will coal but it burns a long time. I have a similar problem when it's cold out. The stove keeps getting loaded before the coals burn down making a mountain of coals. As far as the black ones i just turn the coals with the shovel and they get burnt up.
markinvt said:
30' should draft like a Hoover. Maybe try what others are saying, rake the coals forward during reload, burn on high longer before turning down.
Like I said, if you run the poker through the ashes, the coals float to the top so you can then rake them to the front for air. If you then put on a fast burning softwood that tends not to coal, it will help the coals to burn down much faster than if you just wait.
(broken link removed to http://www.woodheat.org/tips/toomuchcharcoal.htm)
(broken link removed to http://www.woodheat.org/tips/toomuchcharcoal.htm)
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