Too many coals in an insert after 18 hours of cooling down

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Brokk

Member
Dec 9, 2008
126
Central/Eastern Mass
I have a Lopi Answer insert. Just installed for the new year. I've only been using it for about a week and I had a question

After the first 52 hours of continual burning, I stopped feeding it and let it die out overnight. I'm not sure if I kept the air flow open over night. Next morning, wonderful. Only ashes, slightly warm cleaned it all out, washed the window and started it up again. Perfect.

36 hours later, I try to repeat the process. I leave the air supply open overnight, because it looks like there is still a lot of coals in there and I want to burn them down. The next morning (18 hours after stopping feeding it), it's still loaded with coals. The are hot, but not actively red and burning. I shovel them out into a metal pail. I put the pail out in the snow and check it 6 hours later. Still hot and melted through the snow pile. I'm guessing it took it about 8-10 hours in total to cool down. Add that to the 18 hours in the stove and that's a really long time.

Clearly something went wrong, but I don't know what. I'm using the same mix of wood as in the first batch of time. My wood is fairly well seasoned (though not the 2-3 years I've seen recommended by some). Large pieces of Maple, about 2.5 years old. Some tiny chunks of Mulberry about a year old (I know it takes longer to season, but this is split into very small chunks, so I'm assuming it dried quicker) the pieces are about 6-8" long, 6-8" wide and about 1-1.5" thick. Smaller pieces of beech, 1.5 years old (it was from some large branches that got pruned off our trees, they are also split).

I have a long run for my flue, about 35', very straight except for the bottom where it does a small jog just as it reaches the fireplace. Strong draft, even when dead cold and no fire.

I'm getting a good secondary burn going during the day (hard to tell at night since I'm asleep). I'm not sure if somehow the airflow has gotten impeded by ash or unburnt coals.

I like to keep the stove temp around 400 and the pipe temp under 200 when I can. Obviously I don't always get that, and the stove temp goes up to 650 when the fuel is really going strong and falls as low as 200 when the coals are dying and it is in desperate need of more fuel.

Any thoughts?

Brokk...
 
You will almost always have some coals left over. Do you have to clean your stove out every time you burn? I would not. The ash & coals help to insulate the bottom of the box and if hot or active, they help to make the light up easier. If you are concerned about room in the box you may be amazed at how far down those remaining ashes and coals will be if you just stir them around. Most newer wood stoves will amaze you at how long they will last. It does not sound as if your doing anything wrong. I do not clean out for at least 2 months some times 3 or more. :)
 
Brokk, though I do not own the same stove as you do, i too experience lots of coals overnight. I have come to realized that this tends to occur mainly when i turn the air all the way down. I have tinkered with the air settings and have it to where I have just the right amount of coals in the mornings to get the fire going again by just throwing a few small splits. I clean out the ash every Saturday afternoon, its better to have a bed of ash to insulate the firebox.
 
As soon as you get up, turn the draft to fully open. If Nature causes you to wake up a bit sooner than you'd like, check the stove. If it is down to coals or very close to that, open the draft full. You'll get some good heat and the coals will burn down nicely.
 
Backwoods Savage said:
As soon as you get up, turn the draft to fully open. If Nature causes you to wake up a bit sooner than you'd like, check the stove. If it is down to coals or very close to that, open the draft full. You'll get some good heat and the coals will burn down nicely.
Click to expand...

Yet oddly, the night I had a lot of unburnt coals left over, I had opened the air all the way and left it like that for about 8-10 hours. You'd think, since I was starting with *only* coals, that it would have all turned to ash by the next morning.

To others, yes I am concerned also about how much space those large chunks of charcoal are taking up. Since they weren't burning down. Maybe I just need to work on burning off the charcoal in the evenings, then bank up a good fire again overnight.

It seems the large coals are left at the back.
 
How does this stove feed air to the coals? Is there a manifold in the bottom front of the firebox? If so, make sure it's not blocked by ash.
 
BeGreen said:
How does this stove feed air to the coals? Is there a manifold in the bottom front of the firebox? If so, make sure it's not blocked by ash.
Click to expand...

That's a great question to which I wish I had an answer. I know from watching the burn (and smoke path when first lighting), that most of the air comes from the front. I *think* it's just the air wash that comes down the glass then feeds into the front bottom of the fire. I have no proof that air is coming in from anywhere else, and the pattern of unburnt coals at the back of the stove seems to support this.

So if the coals are surrounded by ash, it could significantly cut down on the oxygen getting to them. I'm trying to develop a pattern of pulling the larger chunks to the front to let them burn down first before adding more wood.
 
RNLA said:
I do not clean out for at least 2 months some times 3 or more. :)
Click to expand...

Really? That's just amazing. How frequently do you run your stove? Is it 24/7 like a lot of folks here seem to do?

The manual says to clean it out when it gets to 1 1/2" of ash. It certainly won't take 3 months for me to get that much in my little stove.
 
Brokk said:
The other concern is that I want to dig out the ash. How can I do that when 50% of it is unburnt coals?
Click to expand...

Pull the ash and coals to one side. Use your shovel/ rake or whatever to pull the larger coals into the hole you just made. Someone in another thread said to mound them up and 'treat them like a split'. Once you've done that, you can remove a couple shovels of ash if you need to.

Gabe
 
Brokk said:
I'm trying to develop a pattern of pulling the larger chunks to the front to let them burn down first before adding more wood.
Click to expand...

I have figured out that I need to move the coals to the front of the stove every time I reload, or else I will have coals building up too much. I pull the coals to the front and put wood on top of them, and this helps burn them down. If I don't need a lot of heat, I find a wide, flat split and lay it over the coals so that air coming down the glass moves under the split and the coals burn. If I need more heat, I just load the stove, but still put the coals front and center. Still, I get a lot of build-up and have to empty the stove every couple of days. When I empty the stove, at least half of it is charcoal. I sift the charcoal from the ash and put the charcoal in the garden. I'd rather it burned up, but at this point I can't burn down the coals and keep the stove hot at the same time.
 
Wood Duck said:
Brokk said:
I'm trying to develop a pattern of pulling the larger chunks to the front to let them burn down first before adding more wood.
Click to expand...

I have figured out that I need to move the coals to the front of the stove every time I reload, or else I will have coals building up too much. I pull the coals to the front and put wood on top of them, and this helps burn them down. If I don't need a lot of heat, I find a wide, flat split and lay it over the coals so that air coming down the glass moves under the split and the coals burn. If I need more heat, I just load the stove, but still put the coals front and center. Still, I get a lot of build-up and have to empty the stove every couple of days. When I empty the stove, at least half of it is charcoal. I sift the charcoal from the ash and put the charcoal in the garden. I'd rather it burned up, but at this point I can't burn down the coals and keep the stove hot at the same time.
Click to expand...

Same for me. When its cold out, burning the coals down doesnt provide enough heat, so every morming, I shovel out the majority and toss them. For me, its not worth the trouble and heat loss to fool with burning them down. If the weather is so that I dont need alot of heat, I rake the to the front and burn them down.
 
With my stove I've found small hot fires produce less coals then loading to the top and cutting air down. when it gets really cold I have to fill it more to produce more heat and therfore have to clean it more. usually once every
week or two when it's really cold out. I also stir the coals and rake some to the front before loading. Another trick is to just throw in one or two small splits to get some heat allowing the coals to burn down some before
loading all the way. Hope this helps J.T.
 
BeGreen said:
How does this stove feed air to the coals? Is there a manifold in the bottom front of the firebox? If so, make sure it's not blocked by ash.
Click to expand...

Guessing it's similar to mine, which does have a primary intake at the bottom front. When I want to burn down coals, I open the air wide and pull them up front, making sure that I don't cover the little hole at front center below the door. The coal pile will begin to glow in the middle like a forge.
 
I bought a cheap ash shovel and drilled a bunch of holes ~ 1/2" in diameter in it. Scrape all the ashes and coals over to one side. Scoop up a shovel full, tap it against the other side wall so ash falls out and larger coals are retained on the shovel. Dump coals into the center of stove floor. Continue until all ash has been sifted. Scoop out most of the ash w/non perforated shovel , leaving enough to have an inch or so covering the bottom. Arrange the coals in front of the dog house air inlet, add wood.

Takes a bit more time than just shoveling it w/o sifting, but there's a lot of potential heat left in those coals and I rarely need any kindling to get the fire going quickly.
 
I come from a long line of tool makers. I think I'll grab my welder and build myself a couple of rake things, that will allow me to pull forward the charcoal while leaving behind the ash. Perhaps even a type of sieve/shovel that will let me take out the charcoal and put it in a separate bucket leaving the ash behind. Then I can shovel out the remain ash, put the charcoal back in for the next burn cycle.

I'm glad I'm hearing folks say they do some sort of cleaning every day or two. When RNLA said he cleans out the ash every 2-3 months, my jaw dropped... :)
 
Brokk said:
RNLA said:
I do not clean out for at least 2 months some times 3 or more. :)
Click to expand...

Really? That's just amazing. How frequently do you run your stove? Is it 24/7 like a lot of folks here seem to do?

The manual says to clean it out when it gets to 1 1/2" of ash. It certainly won't take 3 months for me to get that much in my little stove.
Click to expand...

Softwoods leave much less coals and ash. I can go a very long time between emptying ash when I'm burning lots of Doug Fir. I also don't mind letting it build up a little higher, as long as the primary intake isn't covered.

As to removing ash with a stove full of coals, I just flick the largest coals to one side with the shovel, and scoop out the ash along the other half. Then I level everything. I don't try to empty the stove of ash. I may scoop up a few small coals, but most of the usable fuel remains.
 
Brokk, If you look at the cut away drawing of your stove on line you'll see it draws at the bottom then up the sides in front then down the glass. If I am seeing it right. The picture is a generic "cartoon" in the PDF brochure. I would post a link but I do not know how.... :red: Anyway I burn more "soft" wood but in any case you need to leave some coals and ash in there. Lopi Answer is a small box but I can not imagine it to be a problem to have coals. Shovel them to one side and take out one or two scoops of ash and call it good. Correct me if I am wrong, are you worried about them? Are you new to burning efficient stoves?
 
If you are going to be around for awhile try just opening the door wide open and let them burn down that way.
Sometimes I will let mine burn down for a couple of hours and get a tremendous amount of heat from the coals.
This works good while you are getting your 1st pot of coffee down and watching the news.....
And also try saving enough to fill your grill for steaks or chops. This is 1st rate lump charcoal.
If loading the stove coincides with grilling for dinner just get a grill full out of the stove and have instant cooking!

David
 
I just started burning with an EPA stove last week and I have first hand experience with the coaling issue that so many write in here about. Pre EPA stoves that I used never had this problem but the burn times were shorter too. In order for my stove to put out the heat I'm reqiuring of it I need to add wood every 2-3hrs but I quickly run out of room for wood for the coals. Some say coals are heat too, yeh maybe when its 40 degrees out but not when its 10. Anyway I'm raking them forward and leaving the door cracked. It usually reduces them pretty fast. After an hour whats still in there gets scooped out for a reload.
 
RNLA said:
Lopi Answer is a small box but I can not imagine it to be a problem to have coals. Shovel them to one side and take out one or two scoops of ash and call it good. Correct me if I am wrong, are you worried about them? Are you new to burning efficient stoves?
Click to expand...

As an example, just from burning today (8am-4pm) I ended up with about 3" of solid black coals in the back. Given the small box, that eats into my space for wood quite a bit. Also I'm concerned that the coals in back simply aren't burning at that point. It's not generating heat, they aren't turning to ash. It's simply wasted space. All day long (since people started responding to this thread) I've been pulling the coals to the front as I load it. This evening, I've even refused to add any new wood and simply burned the coals. I've spent about 6 hours just burning coals. It's a time suck and it's not giving off much heat (just enough to keep the fans blowing).

Yes, I am new to efficient stoves, so I'm trying to learn the tricks/techniques.

In the future, I'd one day like to have a forge. At that point, saving all this hard wood charcoal will be great. For now, it's just a pain in my backside.

Time to add more wood, take a shower, then shut it down for the night.
 
Put a single, small split on the coals to hustle their burn down.
 
Have the same exact stove and have had it for 3 years.
I believe that there are some small inlets in the front of the firebox (Inside) right below the Lopi logo on the door.
My experience with coals seems to be on the wood I am using and how well it is seasoned...I seem to get a lot of coals left ofer with Birch, don't ask me why.
When the stove is cold, you should be able to put your hand and feel the air inlet holes....like OP have said, just make sure this isn't blocked up with ashes.
Like other posters have stated, I move the coals in the front of the stove to the right, then brings the stuff back from the front..like a big counter clockwise motion.
I really think the amount of coaling is specific to the wood I have, as it is many different species, but sometimes I get a ton of coals, and other times I get none.
Good luck

Edit, just saw your stove temps....I would try to get it up to 500-550 vs the 400 you are currently running it at...35 ft chimney should let you allow 500 for a good while
 
Hey now you guys got me thinking about the 9" spiral skimmer. I am out of place here and did not mean to insult. I do get lots of coals but my firebox is a bit bigger. The coals seem to just keep burning up. I realized I do stir the box every time I load without fail. I open damper, Slowly open door, stir box, load wood, close door, adjust damper. I guess I'm more a creature of habit than I realized. %-P
 
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