Harman SF-250 Draft Problems W/Bitum. Coal

Sounds to me like you are burning bituminous coal instead of anthracite. I have never had any visible smoke from burning anthracite and certainly no soot buildup in the house or stovepipe.

we burn lump coal (anthracite) the fires are started with wood and then coal is added after it gets going. We can keep a fire going but every time that it needs to be tended huge clouds of black smoke escape the door.

Lump as a size does not apply to Anthracite. Details please on the coal you are using.

I have a SF-260 boiler. The knobs on the front are basically the same. In addition to what JB said, are you opening the two knobs on the door? I've found these to kill efficiency with wood or anthracite. I also advise against burning bituminous coal in these because it's so dirty. I will keep sime around to get the anthracite lit if the fire goes out but it's just not worth the mess to burn it regularly. I've never seen anthracite "roar". I don't think I want to either (think: surface of the sun). It burns with a quiet blue flame.

Hmm, maybe I don't know my coal types! the coal we burn comes directly from a mine. I did some research and it is bituminous after all. I agree with the "it's too messy" comment but it is very cost effective an is what we have avail. in this area. This stove should work fine with this type of coal, I would think anyway.

In regards to the knobs on the door we open them a bit to get the fire going and then close it down as much as possible with out starving it out.

There is smoke coming out of the chimney when we have a fire lit, and we have checked to see if santa got stuck in there numerous times.....No dice!

Our flue hook up starts with a 90 directly from the stove to an 18" vert. pipe then another 90 and another 18" to the chimney. We tried replacing the 90's with 45's and this did nothing but make the transition look silly! (I've included a pic of this)

Our chimney is flu-tile, masonry block, a wood frame and then rocked so I would think that this would be enough insulation... Maybe not?

Here are some pics of the chimney. The rock portion is 16' tall and at its highest point it is 10' away from the roof. Then we have a 2' extension (tile & masonry block stucco) above that. We also added a 6' extension (6" galv. pipe) and wrapped the joint to ensure no air leaks. I don't think that the height of the chimney is an issue? Is it?

Could the clean-out be causing us problems?

helpmeharman wrote:Hmm, maybe I don't know my coal types! the coal we burn comes directly from a mine. I did some research and it is bituminous after all.

I think your problem would be mainly solved if you burned anthracite rather than Bit coal. Hopefully you didn't buy allot of the Bit coal but if so, maybe the dealer will take it it back & credit you towards anthracite coal.

No dealer, we live in rural Utah and pick it up directly from the mine. We also have a stokermatic in our shop and do buy our pea-coal from a dealer I will call him and see if he has anthracite. I just can't believe that this "mega-stove" would not be able to function well on any fuel type?! We bought it because it is the "biggest and badest" stove we could find! Frustrating!!!

I think it will burn bit. It is a wood/coal stove. Bit burns with the characteristics of wood or so I have read here on these forums. I've never burned it. Is your house tight? Meaning is it new with no leaky air? Were you running the clothes dryer or a bathroom vent while running the stove? Try opening a window a little to see if that helps with draft. Looking at the picture of your stove I see or think I see creosote leaking out the joints. Make sure that is cleaned out and seal the joints. The joint from the adjustable 90 to the horizontal pipe has a dent. I bet there is an air leak there. The only air you want going in the chimney is through the stove. Have you read the manual?
**Broken Link(s) Removed**Do you have a CO detector? Make sure you do. If you have draft problems and that stove leaks enough co in you home while your sleeping, You won't wake up.

The problem can't be with the coal type. We burned the same coal in our old stove in a different part of our house and it burned just fine. As for the dent in the pipe, it maybe sucking air but the dent wasnt there the first time we fired the stove up. We have the same problem now as we did then. The dealer tells me he doesnt think the chimeny is tall enough, so I am gonna extend the single wall pipe up another 4-5 feet to see if that helps with the draft. I am almost positive it is a draft problem, is it with the stove or is it with the chimney? Maybe I will hook up our old stove to this new chimney and see if the old stove drafts and burns "good" that would tell the tale! Maybe I will just burn my house down and won't have the problem anymore!! lol

Hello helpmeharman. The problems you have are the result of the way Bituminous coal burns.

Most Bituminous coal has lots of 'volitiles' in it.. this is the burnable product that we see as that gray/black smoke that pours out of the coal when it is first heated..this is the volitiles boiling out of the coal.. To burn these volitiles you need HOT fresh [oxygen rich] air added above the fire in the area of the smoke.. without this added hot air, the volitiles remain as soot and smoke,, and will clog the heat exchanger in the top back section of your SF250. You can open the spinner knobs on the loading door a very little amount, this might help burn off some of the soot and smoke..But these over-the-fire air vents should be open only for the first say 20-30 minutes after fresh coal is added to the fire, after this time, close them so the only air getting to the fire comes through the ashpan door's air control spinner knob.

Each vein and mine of Bituminous coal is different,, some have more volitiles than others.. do you have a different source for coal that might have less volitile content??

Is your stove located on the main floor or in the basement?? If on the main floor, you have an effective chimney of only about 12-14', that is marginal for burning a coal that needs lots of air to burn well.

Your Stokermatic you mentioned heats the coal as it reaches the bottom of the burn area [feeds from the bottom]. As the coal is heated, the volitiles are pushed through the hot coal be and burned very well, this usually eliminates the soot problems from high volitles coal.. In the Bit forum, read the thread about combustion air to the Prill stoker.. this will help explain some of the fuel/volitiles/ air relationships.

Since this is really a Bituminous coal burning issue, I'm moving this to the Bituminous forum.. maybe the Bitum guys out west can help with a different coal source. or burning suggestions.

Greg L

the chimney is way too short. using 6" pipe anywhere in the setup will dramatically reduce your draft as well, extend the chimney properly using 8/8 flue tile and brick, use 8" pipe between the stove/chimney and bust out the thimble to allow a full 8" connection to the flue tile. until you do these things, you will continue having problems.

The connection on the stove is for a 6 inch pipe. Why would the manufacturer of the stove make the connection a 6 inch if it called for 8 inch??

The flue from the stove can be an inch or two smaller than the chimney and when the gases

go up the chimney some of the heavier particles will settle to the bottom of the clean out at

the base of the chimney.From what I see the chimney is of marginal height for a good clean

burn of Bit Coal.

Is that pipe on the top of the chimney 6 or 8 inch,this pipe will catch a lot of carbon if your

not burning clean.When you had other stoves hooked to this chimney did the gases coming

from the chimney smoke a lot? When you are burning you should barely be able to see any

smoke except a little more after adding coal.

BigBarney

helpmeharman wrote:The connection on the stove is for a 6 inch pipe. Why would the manufacturer of the stove make the connection a 6 inch if it called for 8 inch??

This stove was designed to burn anthracite coal. Which it does very well. I think with the built in heat exchanger the SF250 has it will NOT burn Bit coal that good. just my $.02

the stove was designed with anthracite in mind, it may burn bituminous ok, but not with that tiny chimney and a 6" pipe. after the flue coller on the stove, imediately increase it to 8", and get rid of that six inch pipe on top of the chimney and extend it properly, a single wall 6" pipe on top of the flue will reduce the cross section availabe to flue gasses and allow them to cool toward the top of the chimney reducing velocity which is not what you want. as far as smoke goes, smoke is normal with bituminous coal in a hand fired stove.