Can I burn coal in my woodstove?

Can anyone tell me if it’s safe to burn coal in a wood stove? Mine is a freestanding one, in my living room, not absolutely air tight. But pretty close. Also, is there a cost savings over wood? I live in California, where coal burning isn’t common. Firewood costs about $125 a cord for soft wood (pine) and $175 for hard wood (oak). I have no idea what coal costs here, or even where to get it.

Negative on the coal or charcoal, do not burn it in a wood stove. Its a prescription for carbon monoxide poisoning. You need an entirely different type of furnace for burning coal. It probably wouldn’t be cost effective anyway, although with the warnings of this winter’s oil prices…

You need a slightly different type of stove, and it can be critical. It also means paying attention to your flue, which might not be up to the needs of the hotter fire.

Also, learn to love gray. It needs to become your very favorite color.


The problem is not carbom monoxide. The problem is that coal burns much hotter than wood and it will make your wood stove red hot and warp. A stove designed to burn coal is different in that the part that holds the fuel is smaller and constructed of heavy cast iron.

I have damaged a stove designed for wood just by overloading it. After a while what you have is pretty much coals making the stove red hot. If it is built of sheet metal it will warp fast.

As far as CO2 is concerned, as long as it is drawing correctly there should be no problem.

There are stoves designed to burn either coal or wood. My uncle used to have one. He bought his coal from the same place he bought the stove, IIRC.

Another problem with wood stoves is they are not designed for the higher ash content of coals relative to woods. Many woods have an ash content of only 1-2% on a wet basis, whereas a typical anthracite “home coal” will have an ash content of 5-7%. Often, people sell normal bituminous coal in place of anthracite to people, which can raise the ash content to as high as 13-15% on a wet basis.

I love it when you use terms like “wet basis”, Anthracite.

I do not think ash content would be much problem other than emptying the ashes more often which would be just slightly inconvenient but nothing major.

I am not sure why you have an interest in burning coal. Wood seems more available (and pretty much free if you do the work yourself). In any case, depending on how the stove is built you could burn a mixture of wood / coal. Even in a stove built strictly for wood you could probably add the occassional coal rock in a load of wood.

I have a slightly similar problem which is that the ideal chunk of wood for my stove is the size of one or two bricks. Anything larger just does not burn well because you would need several at a time to keep the reaction going. OTOH splitting and cutting all wood so small is a hassle. I have discovered I can burn large chunks pretty well so long as I keep small chunks burning at the same time. The large chunk is slowly eaten away by the fire but it could not sustain an efficent fire on its own.

Especially with wood you need a good temperature to maintain an efficient fire. A fire burning badly is inefficient and a cause for smoke and creosote.

In the years I have been using wood burning stoves I have become quite an expert in stoves, how to make them burn efficiently, how to make them draw well, etc. I love playing with fire.

Increasing the amount of ash produced by potentially up 10 times would lead to having to do much more emptying than with wood. I said it was just another problem, not a BIG problem. Just one people might not have thought of when considering a fuel switch in their stove.

Coal stoves draft from the bottom, wood from the top. Coal can burn very very hot, if it gets away from you, hot enough potentially to melt through the bottom of a stove. This is a recipe for disaster. In order to prevent this coal stoves also need what’s called a barometric damper.

If the wind is blowing over your chimney it can draw air through your stove in just the same way that a coal fire in a forge gets fed with a bellows. Meltdown! THe barometric damper counteracts Chimney draw and keeps the coal fire stable.

Burning coal in a stove not designed for it is a good way to burn your house down.

In a proper stove, it’s great heat. I fill mine twice a day, and that’s it. THe heat stays consistent all 12 hours, and you can really fine tune the output. I have a big house ans will burn 2-3 tons of coal in a year. Cost? About $400.00. Our stove is prety modern, and we don’t have any trouble with everything getting coated with ash, and it beats the hell out of burning $2,000 worth of heating oil!

You need the right stove though. Seriously.

Wood has several advantages. It is pretty much free and it heats you twice around. First while you are cutting it and splitting it and later when you burn it. Splitting wood is one of the few workouts that does not bore me to death. In fact I enjoy it.

Wood is easier to start burning.

OTOH, you have to pay more attention when burning wood to make sure you have a good high temperature that is not just making smoke and creosote. Coal is more forgiving in this respect.

I believe some metropolitan areas have outlawed old wood burning stoves because, contrary to what hippie types think, burning wood pollutes a lot, especially if they are not burning properly. Newer stoves have some catalitic “afterburner” to improve this.

BTW, the ashes have made the best fertilizer for my yard. The weeds grow much bigger and stronger now.

Despite the fact that my great-grandfathers on my mom’s side were coal miners and worked the coke ovens, I don’t know jack SHIT about coal.
That said, I do believe, IIRC, that coal dust is highly combustible…in fact, Robert Ballard said that a coal dust explosion was probably the cause of the second explosion on the Lusitania after she was hit by a torpedo.
Of course, I don’t know if that would be a problem in your stove, but I’d still worry about it.
Not too mention that coal smoke is a terrible enviromental hazard.

[That said, I do believe, IIRC, that coal dust is highly combustible…in fact, Robert Ballard said that a coal dust explosion was probably the cause of the second ]
coal dust is not ash, it is powdered coal and it is explosive

Coal dust is very explosive - at heart, it’s how all pulverized coal power plants work. They grind the coal so that typically 70% to 80% will pass through a 200 mesh screen (74 micron holes IIRC), so it feels like rough talcum powder. Then this is blown through burners into the furnace, where it burns with a flame that looks a lot like a GIANT gas flame.

Coal dust explosions have happened at several power plants around the world, both in the furnace and in the ash collection systems. If there is way too much unburned combustibles, the fly ash silo becomes a big 80,000 cubic foot hand grenade. A fatal explosion in the fly ash handling system of a coal power plant just occured in the last few months here in the Midwest, at a cyclone coal plant that had terrible combustion problems. Depending on the coal and the situation, it can be as dangerous as black powder. AND, if it’s a high-volatile high moisture coal (such as a Wyoming Powder River Basin coal), it can and will easily spontaneously combust. I’ve seen this happen many times.

In spite of the incident being used as a pretext to start a war, I believe it has been established the explosion was caused by a fire in a coal bunker which seemed to be quite common. I think it was National Geographic where I read an article about this.

The rule is: if you are trying to burn coal it will fail to ignite no matter what you do. If you want it to not burn, then it will self ignite and produce as much damage as possible.

stuff you wouldn’t want to deal with…
coal ash
coal dust

The threat of mercury in coal is not really that great. And it is non-existent when dealing with very low capacity non-industrial uses.

Typical mercury content for an anthracite coal is about 0.05 to 0.1 ppm of the ash. With a typical ash content of 5%, this equates to 2.5e-9 to 5.0e-9 lbm/Hg per lbm/coal. Now, this really adds up if you are burning 300 tons an hour, but in a small stove there is really not much danger.

OTOH, there can easily be from 5 to 6 ppm lead in the ash, or about 50 to 100 times as much. Still a pretty small exposure.

THe coal I buy is lightly sprinkled with heating oil to keep the dust down. I don’t think the exhaust is any worse than with wood stove, probably less frankly since it does have a catalytic burner on it. The exhaust is clear and odorless. We keep carbon monoxide testers plugged in near the stove, and one has never gone off.

I would probably prefer would if I had the leisure to chop it, and the time to fill the stove up 4-5 times a day.

I find the coal stove very convenient.

I got a little story to tell. I was living on my sailboat in New York and winter was close. Somebody gave me a marine coal stove. After installing it I asked around for a source of coal. Somebody told me that I could pick it up along the RR tracks.

I HAD A HARD TIME LIGHTING IT AND IT NEEDED A FAN TO KEEP IT BURNING. Not knowing anything about coal stoves that didn’t make me concerned. It warmed the boat quite well. After a while I noticed the stove turning orange, red, pink them WHITE. That white didn’t look good so I shut off the fan and the stove went out. I went to find some body I should have talked to before I even started.

That coal along the RR track, it wasn’t coal. It was COKE like they use to melt steel in the steel mills. It would have melted my stove.


A standard forum for coal users is:

Coal is a regional fuel. I briefly considered it but the nearest dealer was 100 miles away. How far is your closest dealer?