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Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 8:21 pm
by saxony
Excited to be able to heat with coal, but not getting the results yet.
Using a nice wood/coal stove, keep a deep bed of glowing embers, flue pulling pretty good, but stove is not putting out the kind of heat I'm reading about.
I check/empty ash tray morning and evening, refrain from poking except to remove ash in stove.
Feed lump regularly (work at home) but it just does not put out enough heat to raise the room temps more than a degree an hour.
Going into my first winter with coal and would like to be warmer.

Re: Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 8:35 pm
by Rob R.
Welcome. Are you burning bituminous coal? How deep is the coal bed?

Re: Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 9:20 pm
by Lightning
What make and model is the stove?

Re: Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 9:46 pm
by saxony
Plaque on back of stove says Vermont Hearthstone Wood/Coal.

Re: Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 9:47 pm
by saxony
Yes, bituminous. Coals are one to three inches in depth.

Re: Coal newbie needs advice

Posted: Mon. Dec. 04, 2017 11:59 pm
by McGiever
You say flue is pulling good but stove is not putting out the heat...might be sending most/too much of the heat out/up the flue.
Forget your old wood burning habits as they do not apply with using coal.

You need to have a slowed down draft for coal compared to burning wood. And bit coal needs over the fire air, especially when adding a new fresh coal charge, in order to have the oxygen/air to burn up most of the thick smoke or soot generated at that time. Later after most of the volatiles have burned off you can then trim the over the fire air back some to get a better burn till the next coal charge gets added.

Poking a bit fire is not as detrimental with soft/bit coal, as bit coal can become "plastic like" due to reaching the coal's "fusion temp" and can hinder bottom air from flowing through the restricted hot coals, this too can cause poor heat output. So "poking" can be required from time to time in order to bust up the fused coal and/or clinkers and get the proper air up through the coal bed from the bottom.

Do you have a barometric damper installed? And owning and installing a manometer will allow you to see your actual draft reading that you adjust with the installed barometric damper and this lets you know if excess draft is sending too much heat up the pipe.

Re: Coal newbie needs advice

Posted: Tue. Dec. 05, 2017 9:58 am
by saxony
Thanks for all this info. No on the barometric damper. I sense this is the problem, the heat is all going up the flue. House is 54 degrees. Going to adjust the damper and see if I can get the heat to stay in the stove long enough to do its job. Will investigate manometer. Thank you!

Re: Coal newbie needs advice

Posted: Tue. Dec. 05, 2017 11:20 am
by saxony
I closed down the flue damper and the one over the box. The box is now filled with smoke and the coal is not burning as it has been with flames, etc. Is that what you meant by "trim the over the fire air back some?" (The house was 54 degrees at 5 am, it's now 57 degrees at 9 am.)

Re: Coal newbie needs advice

Posted: Tue. Dec. 05, 2017 1:10 pm
by McGiever
What size is your flue/chimney?

It is a tuning of fuel to air ratios. And coal doesn't respond anywhere near as quickly as to how a wood fire will respond...you need to make small changes and wait a while to see how it responds to that change.

You could keep a log book to record how many turns on spinner or how much air gap you adjusted to to have a better recall of how to get to the "sweet spot" easier in the future.

Without the baro you will always see fluctuations affecting the fire as the draft is ever changing due to multiple outdoor variables such as day to day temps and wind changes and this will be an ordeal to "chase" to keep a stable fire/draft. The baro will do wonders on this front to do make this part of the burning process less erratic.

Re: Coal newbie needs advice

Posted: Tue. Dec. 05, 2017 2:42 pm
by coaledsweat
Get a thermometer for the stove and one for the stovepipe. They will tell you what it likes.

Re: Coal newbie needs advice

Posted: Tue. Dec. 05, 2017 8:59 pm
by saxony
Closing the damper inside the box has helped. I will look into the baro and get the thermometers. Thank you for taking the time.

Re: Coal newbie needs advice

Posted: Sat. Dec. 09, 2017 9:43 am
by saxony
Still struggling here. Owner doesn't want any modifications, so negative on a baro. Got a flue thermometer, which reads between 150 and 200 degrees. I can touch the flue and stove, warm but not hot. There's a box at the ceiling that the flue goes into. Might that be another damper? There's a damper inside the firebox and when I closed it, the coals got hot and the stove got warm, but it didn't last. At a loss. Winter's coming.

Re: Coal newbie needs advice

Posted: Sat. Dec. 09, 2017 10:10 am
by Rob R.
saxony wrote:
Mon. Dec. 04, 2017 9:47 pm
Yes, bituminous. Coals are one to three inches in depth.
That does not sound like nearly enough coal to me.

Re: Coal newbie needs advice

Posted: Sat. Dec. 09, 2017 1:34 pm
by Lightning
saxony wrote:
Sat. Dec. 09, 2017 9:43 am
Still struggling here. Owner doesn't want any modifications, so negative on a baro.
Owner? That's nice. He won't show you how to run the stove?

Re: Coal newbie needs advice

Posted: Sat. Dec. 09, 2017 2:15 pm
by corey
It sounds like there not much coal in the stove witch mean less BTU's last night i loaded a hod full of bit.