Heating With Wood in Coal Stove?

If you happen to have an insulated chimney rather than masonry I think it helps prevent the creosote buildup. The flue gases don't cool as much. In all the years we burned wood along with coal, we never had any kind of creosote in the chimney. I burned a lot of pine and pallet wood along with the oak, maple and poplar. Also our chimney only has to clear a ranch house and isn't going 35' to clear a 3 story home so the exhaust isn't in the chimney very long which means less time to cool down.

It is all about maintaining a sufficient stack temperature to prevent the gasses from condensing in the flue. If you must burn wood in a coal stove, leave some coal ash on the grates to protect them and keep the fires short and hot.

I've been burning some wood in my HMK 2 and I'll tell you what, get your underpants ready cause it gets hot as heck, quick. It rips through wood however.

Mark II, ran thru wood fast, took high temp bricks and put them on the grates really close together . Seemed to slow down the burn though I was somewhat concerned about the long term effects (cracking?) of exposing the cast grate to hot and cold spots along their lenghts...

Never did get a lot of consistent heat out plus pretty much every time the top door was opened, smoke came out.

Failed experiment.

Recently purchased a used Mark III coal stove for a new home, masonry chimney never used. The crock coming through the wall is 8". My plan is to install the Mark III in our basement with 6" stove pipe and manual damper then use a thimble for connection to the crock. Any problems burning wood in this thing for a few years until I switch to coal? Reason being...I purchased several cords of wood summer of 2012 and would like to use it a bit during colder months as a supplement to our geothermal. Once I install a coal bin and barometric damper, i'll burn coal. Any thoughts? Thanks.

i used a Mark III for about 18 years burning a mix of wood and coal at different times. It will go through the wood faster than a dedicated wood stove. you really need to cut down on the ash door air. you may even need a manual damper to keep some heat in the stove, depends on your stove / chimney draft situation. the one downside is there is no way to control over the fire air since the source is the air wash gap at the top and bottom of the door glass.

the wood was a good fit for us in the shoulder months where a once a day fire to take the chill off is what was needed. we had cleared many trees on our property so it was convenient to use them up and served as good exercise.

Get a manometer and connect it so you can manipulate the air and damper (if installed) to an actual draft number rather than a guess.

We have a Gibraltar SCC and we've switched back and forth a bit between coal and wood this winter. We recently bought this house so everything with the stove has been a learning experience. Love the coal but unfortunately, we don't yet have anywhere to store a large amount, so we've gone through the few bags we picked up quickly. Been keeping wood on hand as well. Once the fire gets going, it's gotten quite warm and heats a few rooms nicely. Does burn quick and too hot, though, if it's not carefully watched. Once it's going I find that leaving the secondary draft open just a bit is enough to keep it going, but not out of hand. Just cleaned down to the grates to get a few old pieces of coal out, but I think I'll shovel a little ash on the grates before I start today's wood fire.

I'm trying to remember the details of burning wood in my coal stove when I used to do that years ago. Not sure I remember everything, but here goes with what I can. First, wood likes to burn in a nice bed of fluffy ash, unlike coal. So when burning on top of coal grates, I'd let a nice bed of ash get laid down (unless I wanted a really hot fire). Then I'd run mostly the top door air feed (secondary air) to control the fire. I would only shake the grates when the ash bed would get hard - I don't remember - maybe like once a week or even less often. For my stove I used to cut short pieces of wood, only 10 to 12 inches long. They would lay nicely cross ways and I could fill up to the top of the stove. Once I had a nice fire going, I'd fill the stove all the way to the top, even taking off the top piece and stuffing in more wood from the top plate down. That's if I was going to bed or off to work. When hanging around the house, I'd just throw wood in and keep the fire nice all the time. I used to like that. Now I like forgetting about the fire and just being warm...

dj

when burning wood in a coal stove put aluminum foil over the barometric damper like you would if you were preparing a casserole for the oven this will slow down the burn and keep the stove and stack temps up as well as more controllable and the creosote down. I only wish it didn't take me 25 years to figure this out. adding a woodstove damper also helps but cover the barometric damper anyway. doing this my Gibraltar gives off very little if any smoke and I can keep the stack at 400 degrees and the stove is around 600 at the collar.

Black Nostrils wrote:Hi, I have a Harman Mark 3 coal stove that I use to heat with each year. I have been heating with wood in it for a week now trying to save my coal for the colder months. My problem is im burning through wood very fast even if I open the knob up a 1/4 turn. Any tips and advice on burning wood more efficent in a coal stove or is this a bad idea to begin with? Also when I switch back to burning coal Do I need to clean my chimney?

Thanks for the help
Kenny

Unless its specifically designed as a dual fuel stove, don't do it.

morso wrote:It says on the back of my Moso stove that it is a offense to burn anything on a stove than it was designed for, so I could be viewing the board from the prison library any time soon,
I some times burn wood, wood likes to sit on a bed of ash to burn slowly , it sounds like you are getting to much air, the problem is that if you get it to burn slow enough, unless you can get the chimney real hot,(hard to do with a slow fire), you may get tar build up which can be hard to remove, if you do get the wood to burn make sure the wood is very dry, hard wood like oak is best, pine fir ect make more tar.

Yeah, it says that on the back of my Morso too...while the stove itself is specifically designed to do both. Its more of an EPA pollution thing to be honest.

I burn wood in mine during shoulder seasons with zero problems and it burns quite well...the only issue is cutting the wood to 12 inches to fit in the firebox.

My Yukon-Eagle is designed as a dual fuel wood/coal furnace. It's ducted into the same ducting that the (now) backup propane furnace uses. When I heat with wood exclusively for a day or so, it will certainly use a fair amount of wood. I use about 8cu ft of wood per 24 hour period when I just use wood. My usual procedure is to heat with coal for 36-48 hours, then after a really good shakedown, I burn wood for about 4 hours. The hot coal bed made by the burning wood really helps burn up any unburned coal nuggets left in the bed. With a really hot bed of wood coals established, they I load up with coal again and repeat the cycle.

anthony7812 wrote:I agree with most on this topic. Im new to coal, but not to burning wood.The hotter the better for green or pine type wood to keep creosote minimized . Nice dry oak or maple would be less of a worry for creosote build-up. I wouldnt worry too much about creosote build-up unless you have more than a month or 2 burning wood nonstop. I burned wood all last season, now I only had a tiny insert so I had a horseshoe makin fire tryin to keep up with heat demand. I had almost no creosote after 4/5 months burning.

I wouldn't burn anything remotely 'green' in my house. Period. That's begging for a gummed up chimney.
Also, pine does not create creosote issues. This is a commonly repeated and often believed fallacy. You can get creosote buildup from ANY wood and you will get much more creosote buildup from a 4x4x16" piece of 'green' hickory/oak and you will from a similar sized piece of properly seasoned pine. Pine pitch isn't an issue. Wet wood is (of any species).

Just an idea to throw out there.

Some of the antique coal-burning Oak and base burner stoves came with a drop-in "wood plate" that sits on top of and covers the coal grates. It only has a few small holes in it. My guess is it is designed that way to somewhat restrict primary air from below, while also holding more ash ?

Anyway, maybe a drop-in version of those wood plates to fit the modern stoves can be made that would give better control when wood burning ????

Paul

SB, that was back when we used to get the stoves roaring every couple day to clean out the creosote--AND I do mean roaring--flames shootin out the chimney, the whole kit & ka-boodle