First season with coal

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Vadgemontana
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Posts: 2
Joined: Tue. Dec. 12, 2017 10:43 pm
Hand Fed Coal Stove: Harmon sf250
Coal Size/Type: Nut

Post by Vadgemontana » Fri. Dec. 29, 2017 1:18 pm

I have a Harmon sf250 which I have burned wood the last 4 years and decided to try coal(nut coal). It's been a few weeks now and I have no problem getting the initial fire going. The problem i am running into now is getting the most out of the stove. I'm still working on finding the sweet spot for air.

Here's some of my questions I'm sure you guys can help with, I will get some pictures tonight of the stove set up:

1. Should you always see the glow from the coal when the ash pan door is open? On the initial fire I can always see it, but on day 2,3, so on, I have no glow in the ash pan and it seems I need more air getting to the coal to get it burning as hot as needed to heat the whole house. It seems that maybe I might have a build up of ash but when I shake it, it gets to the point where fresh black coal goes into the pan(i usually stop shaking when i see glowing coals hit the pan) . I use short choppy shakes every 12 hours or so and fill what's needed to top of fire brick.

2. Should I ever need to open the secondary air inlets on the door? I have been messing with it a little bit but haven't seen to found the answer on my own. Just curious if there is any benefit from cracking them open a bit. I have had them closed the past week or so.

3. I have a thermometer on the stove pipe(about 1 foot above the outlet from stove) and one on the top of the stove. They are consistently about 200 degrees off from each other, stove pipe cooler obviously. Is that normal for most folks?

Thanks in advance.

 
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nepacoal
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Location: Coal Country
Stoker Coal Boiler: Keystoker KAA-4 / "Kelly" and an EFM 520 at my in-laws
Hand Fed Coal Boiler: Harman SF-260 - retired
Coal Size/Type: Buck

Post by nepacoal » Fri. Dec. 29, 2017 2:42 pm

I used the boiler version of this stove for 6 years and can tell you it will get ash bound after 3 or 4 days if you just shake it and refill. Once per day i used what I called the stoke and poke or shake and rake method. I had a 3.5 foot prybar that I ran front to back on each side and down the middle once a day, usually during the evening refill. I would push it down to the grate and just rake it to the back after the shakedown. It would run for months at a time unless I ended up with a rock stuck in the grate and needed to let it go out for cleaning. I always ran it with the secondary vents barely cracked. It seemed to run better and keep the draft going with them just barely cracked. I only noticed the glow underneath after a shakedown and refill. I never timed how long it would glow but there was not a glow underneath after 12 hours of running. I did not record temperatures but did use a magnehelic gauge to make sure the draft was between -.04 and -.055
Last edited by nepacoal on Fri. Dec. 29, 2017 2:48 pm, edited 2 times in total.


 
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Lightning
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Location: Olean, NY
Stoker Coal Boiler: Modified AA 130
Coal Size/Type: Pea Size - Anthracite

Post by Lightning » Fri. Dec. 29, 2017 2:44 pm

Vadgemontana wrote:
Fri. Dec. 29, 2017 1:18 pm
Should you always see the glow from the coal when the ash pan door is open?
Directly after shake down you should see a glow in the ash pan and that should be the case at every tending. But before you shake down you should let the coal bed rev up first by opening the ash pan door for a few minutes. The glow in the ash pan will fade as you get further into the burn cycle as ash deposits on the grates.
Vadgemontana wrote:
Fri. Dec. 29, 2017 1:18 pm
On the initial fire I can always see it, but on day 2,3, so on, I have no glow in the ash pan and it seems I need more air getting to the coal to get it burning as hot as needed to heat the whole house. It seems that maybe I might have a build up of ash but when I shake it, it gets to the point where fresh black coal goes into the pan(i usually stop shaking when i see glowing coals hit the pan) . I use short choppy shakes every 12 hours or so and fill what's needed to top of fire brick.
It sounds to me like you aren't clearing ash quite well enough and over time it's building up in the fuel bed to the point you are trying to counter it by allowing more combustion air. Don't fret about loosing a little coal on shake down, it's more important to get the ash cleared properly so you can get the heat output you want. A few percent loss is well worth a healthy fire. From my experience with these bigger units the stove size coal is more forgiving to work with when it comes to clearing ash and not loosing a lot of coal to the ash pan, you might wanna try it. I'm not saying the nut size won't work, it will... Keep with the short choppy strokes on the grate handle. Another thing you can do to aid with clearing ash is jab the top of the coal bed with a poker tool to agitate ash to fall towards the grates.

My tending routine goes like this -
1) rev up the fire
2) shake grates
3) jab and heave the coal with a poker and do some raking
4) shake the grates again

It might seem a bit excessive to some but you might wanna try this to some extent.
Vadgemontana wrote:
Fri. Dec. 29, 2017 1:18 pm
Should I ever need to open the secondary air inlets on the door? I have been messing with it a little bit but haven't seen to found the answer on my own. Just curious if there is any benefit from cracking them open a bit. I have had them closed the past week or so.
The secondary inlets will help provide oxygen to the top of the fire for burning volatile gases out of the fresh coal and decrease the possibility of a puff back. What I normally do is run more secondary air for the first couple hours after a fresh load is added and then less secondary air after that till next tending.
Vadgemontana wrote:
Fri. Dec. 29, 2017 1:18 pm
I have a thermometer on the stove pipe(about 1 foot above the outlet from stove) and one on the top of the stove. They are consistently about 200 degrees off from each other, stove pipe cooler obviously. Is that normal for most folks?
Stove vs. Pipe temps will vary from person to person depending on many factors, but yes that sounds reasonable to me.
nepacoal wrote:
Fri. Dec. 29, 2017 2:42 pm
Once per day i used what I called the stoke and poke or shake and rake method.
Amen to that my coal burning brother... :yes:

 
Vadgemontana
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Posts: 2
Joined: Tue. Dec. 12, 2017 10:43 pm
Hand Fed Coal Stove: Harmon sf250
Coal Size/Type: Nut

Post by Vadgemontana » Fri. Dec. 29, 2017 3:51 pm

Thanks for the quick replies. I will give these methods a try over the next couple days. Much appreciated.

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