Short Burns, Fire Going out

OK, I'm having some really frustrating experiences with my Harman Mark II. If I don't get almost all of the coal going, the fire just piddles along around 300 all day. If I let the ash pan door open for 10-15 mins, then it will stay going but only will get a 6-8 hour burn. So I'm trying to figure out what is going on.

This morning, after staying up til 1:30, getting back up at 5:30 to check the fire (which seemed AOK at just under 400), at 9 AM, the fire is almost dead. Now, the only place I had live coals was in the back left corner. The center had good coals on top, below them, coal that had not completely burned but all grey and crumbly looking. I ended up dumping the whole mess and started all over again. GRRRRR.

I started over with the newspaper and wood kindling, got my coal started, good base of it all red and fired up, added another 4" on and let that get going with the door open a few mins and then topped it off with the door opened back up again after that load put on. I took about an hour from the start until the top off load was put on. I left the draft spinner open 3 full turns for a while now, say, 40 mins. - the fire bed settled down and I added 3 shovels (the coal hod shovel), to the fire and turned the draft spinner back to 1 turn where it held a nice fire yesterday all day for 12 hours. For some reason, it does not like to hold at night.

What am I doing wrong ???

Another question:

How long do you let the coal bed burn with the ash door open/draft open wide after you have added new coal to it?

Not sure I'm following you? Did you fill the entire stove with coal up to the top of the firebrick? (Coal needs a deep bed to burn correctly)

Yes, it is full now. Running at 450 with 1 1/4 turns open on the draft spinner.

Hi MP, as devil5052 says,, you must have a deep firebed.. fill the firebox to the top of the firebrick..
Next: what does the ash in the ash pan and in the bottom of the firebox look like?? Is it hard and cruchy, and hard to shake down into the ashpan??

If you aren't getting all the ash shook out of the fire, then it will sit on top of the grates and restrict the airflow to the coal fire.. this will necessitate you opening the air to the fire more than normal, to get a hot fire to create a strong draft which is needed to pull the air through the fire...

If the grates are not clogged by ash, then you will get easy flow of air through the coal and a good fire.

The other possibility is your coal... do you know what brand it is or where it came from.. all coal is not the same.. so may look the same, but will be very difficult to burn well... You may want to try a few baggs of a known brand of coal to see if it helps your situation.

Next,, is the air damper control on the loading door closed... for anthracite you do not want any air entering the stove above the fire.. this reduces the draft available to pull air through the fire from the ashpan spinner air control. Are your loading door gaskets in good shape, are they leaking?? Use a candle or a cigarette and go around the perimeter of the door, if the gasket isn't sealing the flame or the cigarette's smoke will be pulled into the stove...

Hope this helps.. Greg L

As i understand it you get a 6-8 hr burn with the ash door open the entire burn time? If so then you just burned through the coal load, leaving just ash above the grate? I suspect your lazy fire is due to a low draft condition. On my Mark II if I leave the ash door open the stove will hit 500 in 20 minutes if it was at 300 before. Do/did you have a manometer hooked up to see what kind of draft you have?

CapeCoaler wrote:As i understand it you get a 6-8 hr burn with the ash door open the entire burn time? If so then you just burned through the coal load, leaving just ash above the grate? I suspect your lazy fire is due to a low draft condition. On my Mark II if I leave the ash door open the stove will hit 500 in 20 minutes if it was at 300 before. Do/did you have a manometer hooked up to see what kind of draft you have?

Oh mercy, no! I shut the ash door and give it 2-3 turns open on the vent. Yeah, more like 700 in 20 minutes with this Mark II and my 30' chimney. I don't have a manometer nor have I had one on it to check it - this may be some of my prob.

LsFarm wrote:Hi MP, as devil5052 says,, you must have a deep firebed.. fill the firebox to the top of the firebrick..
Next: what does the ash in the ash pan and in the bottom of the firebox look like?? Is it hard and cruchy, and hard to shake down into the ashpan??

If you aren't getting all the ash shook out of the fire, then it will sit on top of the grates and restrict the airflow to the coal fire.. this will necessitate you opening the air to the fire more than normal, to get a hot fire to create a strong draft which is needed to pull the air through the fire...

If the grates are not clogged by ash, then you will get easy flow of air through the coal and a good fire.

The other possibility is your coal... do you know what brand it is or where it came from.. all coal is not the same.. so may look the same, but will be very difficult to burn well... You may want to try a few baggs of a known brand of coal to see if it helps your situation.

Next,, is the air damper control on the loading door closed... for anthracite you do not want any air entering the stove above the fire.. this reduces the draft available to pull air through the fire from the ashpan spinner air control. Are your loading door gaskets in good shape, are they leaking?? Use a candle or a cigarette and go around the perimeter of the door, if the gasket isn't sealing the flame or the cigarette's smoke will be pulled into the stove...

Hope this helps.. Greg L

Ok, here we go. I have always run this stove full to the top or a bit higher of the firebricks in the back.

I had a few Klinkers in the middle of the coal bed this morning, with several unburned peices above them on top. There was a good bit of ash on the bottom. However, above the was a good bit of coal that had not broken down to ash - hard and crunchy like you say.

I did have some coal still burning in the back left corner. The rest was out.

I'm burning Reading Anthracite coal.

After restarting it at 10 AM, it is still going very nice at 5:30. I have 425 degrees with 3/4 open. 28 degrees and calm outside.

There's no vent on my stove door and all gaskets are AOK - new stove.

I'm a newbie and missing something that's probably right under my nose!

And THANK YOU for taking the time to help me - is is MOST appreciated!

HI MP, glad to be helping [hopefully helping ]
OK, so the new Mark II's don't have an air spinner knob on the loading door?? I thought they did. Maybe I'm confused with the older ones or the SF 150/SF250 models.

It sounds like it could be your coal... can you buy a few baggs of Blaschak or some coal from a different source?? And give the different coal a try..

If coal has a real high ash content, it will require more frequent grate-shaking to keep the air passageways clear... A few years ago I burnt Reading nut and Stove mixed in my big boiler. The coal had a lot of ash content.. I had lots of hard crunchy pieces of ash that looked just like the piece of coal it used to be.. you could break each piece apart, but it was prety hard, and the piece had a black center.. appeared to be partially burnt..

I burnt a few bags of Blaschak nut coal, and it burnt allmost completely to a fine powder ash,, it was MUCH easier to shake down and keep the air flowing through the fire. There are lots of good mines and breakers selling very good bulk coal, but only a few with bagged coal available...reading and Blaschak that I know of.

You may have better luck with Pea size coal as well, it will definitely burn longer, with usually a little less heat output.

Take care, Greg L

Sorry if I missed it, but all those temperatures you are quoting -- where and what is your thermometer? Is it a magnetic thermometer on the side of the stove? On the stove pipe, and if so how far above the stove outlet? Above or below the barometric damper (if you have one)? Or is it a probe thermometer in the stove pipe?

The Harman Mark Series doesn't have any air vents on the loading door, Greg, only on the ash door, so that eliminates one problem.
Mountain, based in your description I see two problems.
First: You need to get a manometer and check the draft on that chimney. A 30' chimney can work up quite a draft. That could contribute to your problem.
Second: I am very wary of Reading coal. I've burned it in the past and the quality is not all that good. It will form large clinkers that won't shake through the grates. I see you are in PA, are you anywhere near where Anthracite is mined? Your best bet is to try a different coal. Let the stove go out and empty it completely, then restart it with a different coal.

rberq wrote:Sorry if I missed it, but all those temperatures you are quoting -- where and what is your thermometer? Is it a magnetic thermometer on the side of the stove? On the stove pipe, and if so how far above the stove outlet? Above or below the barometric damper (if you have one)? Or is it a probe thermometer in the stove pipe?

On the top of the stove. It's a magnetic Rutland Stove Thermometer.

Not to be too anal here, BUT ... the Harman Mark series DOES have non-adjustable air intakes on the loading door, in the form of narrow slots at the top and bottom of the glass. I think the way it works is that the glass has thin gaskets at the sides, but not at top and bottom, so the spaces where top and bottom gaskets would be result in a narrow gap that lets in a controlled amount of air. Unfortunately (IMHO) it's never the RiGHT amount of air -- too little with a new load of coal, too much with a mature fire.

All of which is irrelevant to MountainPreacher's problem....

Having used a Mark III for a few years, I had the same problems. It was a combination of problems.

- Poor draft or so I thought. Solution: Installed a SS liner
- Some unburnt coal around edges. Solution: Drilled two .5" holes on either side of ash pan door to allow more air to flow along sides. Holes can be plugged with .5" bolts.
- Wasn't filling firebox to top. Solution: Send wife into basement to fill firebox. She'd stuff it!