Unburnt Coal

I seem to have unburnt coal in my ash . I had to reduce my stack pipe down to 6" because that's what my chimney out let is that a problem. It seems to be burning well the feed is 3 teeth and the air at 5. I do have a carbon dioxide sensor in the basement and it hasn't gone off yet. It's a 520 and it been running since the end of October. It's installed as per efm'm specs with boiletr bypass except for stack pipe reduction.I have all breaches sealed very well nothing seems to be leaking other wise the CO detector would sound. Any help would be greatly appreciated.

Thank you Bill S.

It probably just not you, I get unburnt coal in both of my stoker stoves.

You must have a very good draft or a tall chimney. Have you checked the draft when the unit is running? Unburned coal can occur when the air and feed aren't adjusted properly. What is the width of the ash ring? Can you see the dark spot in the center of the pot? Is the rest of the pot fully glowing inside the ash ring? Your air and feed settings are unusual. Why not try 4/4; you can always go back. Allow at least 45 minutes of continuous runtime between adjustments. Maybe the "unburned" coal really isn't coal.

Another thing: Is your clean-out lever all the way back against the boiler and are the slots in the clean-out cover completely closed at the same time? Is this a relatively new unit?

My chimney is about 3 stories high and my clean out lever is all the way forward I had to lengthen the linkage because it would not fully open it opened about 1/2 way. I checked my draft several times and I get 0 - 0.1 don't seem to be + or -. The middle is always red and the feed pipe is warm at the breech (at the side plate) I set it that way because of the unburnt coal. It doesn't seem to matter where I set the air there is always unburnt coal.

If the middle is always red, then you must have some non-coal in your mix. The draft should be checked at the door or the breech when your unit has been running for a minute or two. If you have 0/.01 at the door, you are really marginal. Check for that darker area in the center. You don't want to burn down into the pot with your low feed and high air.

It's more important that your clean-out cover fully closes than that it fully opens. If necessary, shorten the spring a bit.

I checked my draft several times and I get 0 - 0.1 don't seem to be + or -

Where are you checking the draft? Do you have a barometric damper installed? Where is the coal you are burning from?

Most stokers leave what looks like unburnt coal in the ash pan. It could be 'bone", looks like coal but isn't. Does it snap in half easily? If not it probably isn't coal. Collect some of it and put it back on the fire,in the hottest place. If it doesn't burn it isn't coal.

grab some ash in your hand and crumble it up.......i am burning buckwheat and i can crumble the ash into powder.....i get some unburnt coal from the front of my pot but i suspect that the grates are worn out......they were iffy last year.

1st the clean out lever fully opens and closes. I check my draft with a slack tube manometer in the e on the front door. Yes I have a barometric damper and it run slightly open. I could increase the coal feed to get the dark spot but 1st have to work out if this is unburnt coal or shale. I'll have to check with Hendricks my coal supplier what kind of coal it is and see if he has the same problem because he's running an efm too.

How far from the outlet of the EFM is the baro? You should measure the draft between the unit and the baro when adjusting the baro.

Let me know if I' correct on how to use a manometer one end goes in the door and the other goes in the pipe by the baro ? If this is correct then I've been doing it all wrong by sticking one end in the door and the other to atmosphere .

One tube connects to a port between the boiler and the baro damper, leave the other connection open to the atmosphere.

You can also adjust from the door measurement. Close off the baro until you get at least a negative .02 at the door, once it's warmed up. The breech end should automatically come in at neg. .04. The draft can also tell you if your unit is blocked with ash. There's supposed to be about 18" between the breech and the regulator.

Thanks for the clarification, Chris. Us stove guys don't know a lot about boilers...yet.

Will have to wait until boiler goes into a long burn to check -pressure at worst scenario I can pull the baro and plug it with a cap temporarily to see what I get. I appreciate all your help thank you very much.

Bill S.