Harman SF-250 Draft Problems W/Bitum. Coal

Re: Harman SF-250 draft problems w/Bitum. coal

PostBy: BigBarney On: Wed Jan 14, 2009 5:30 pm


A stove does not create draft only a proper chimney can do that.

A chimney has to be tall enough and installed to guide line that

have been established by years of data and trials to best use the

natural flow of heat rising and drawing air through the firebed

to burn the coal.It is important to setup your chimney draft with

a manometer to get the proper setting on the draft.Another place

to check the draft thats not talked about much on the forum is to

also check the draft at the ash pan to see if the flow through the grate,

coal bed,and stove, are adequate to get a clean burn with enough air to

prevent soot and unburned carbon from going up the chimney and

wasting your coals energy.This is especially important with bituminous

coal because of its burning characteristics with the volatiles and the

need for enough air for complete combustion.The burning of anthracite

is much simpler because it is mostly carbon and if enough oxygen is not

present at the grate it burns at a level commensurate with the available


I have a 33' chimney with an 8" clay tile liner and get a good draft

all the time,since I burn 24/7/365.I even have a good draft in the

mid summer with 90* weather and can burn just as good then as in

winter.I notice that my barometric damper is closed more to keep

the draft up to levels needed for good combustion.

If your house is in unusual terrain,like a valley with high hills around

it,that could cause draft problems but usually you can extend the

height to overcome these challenges.I also have a few lower draft days

when the air is wet and heavy it takes a little more to get a good

draft started.

I also burn mostly all bituminous coal so it can be done.


Re: Harman SF-250 draft problems w/Bitum. coal

PostBy: fireguy On: Tue Jan 27, 2009 9:21 am

Hi,i have a Harman fs-250 also,i have burned coal in warm morning heaters for about 15 years with success then I got this stove,i had a little
trouble at first with it but it was me,this stove heats my whole house and I tend to it twice a day,i have no idea what your problem may be
but mine is connected with 6"pipe,2-6"elbows and goes into a 8x8 masonry chimney on the ext of the house that is approx 3' taller than the peak
I burn nut size coal and did in my other burners,on my fs-250 in my case the bottom ash dr draft is always about 1/2 way open and the two on
the loading dr about a 1/6 of an inch cracked open,pretty much stays like that all winter,i lit it in oct and its been going since,also I have no
type of damper on the stove pipe,its just straight thru,this what my dealer told me to do,no damper.
Stove/Furnace Make: warm morning +Harman
Stove/Furnace Model: 460+528E+fs250