Lazy burn? I don't think so!

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rudysmallfry

Minister of Fire
Nov 29, 2005
617
Milford, CT
My frustruation over extemely short burns continues. I'm hoping you guys can help me out. I've posted a picture with this thread showing my stove's version of a lazy burn. I have the air completely shut in this picture and still have a healthy, racing yellow flame coming up dead center. I know these newer stoves aren't supposed to allow for a smolder, but this seems extreme to me.

To date, my longest burn time is 90 minutes. I've tried different types and sizes of wood, various air levels, etc. I've been burning wood for over 20 years. I have never had a stove that I had to tend to this much. It's driving me nuts.

I have checked the seals on both doors, and both are excellent. The dollar bill is impossible to pull out of either. I stuck it in the ash pan door this morning, and while it is more than snug from above, it does come out easily if I close it from below. I don't know if that's a clue. The underside of the stove clicks a lot when the stove is heating up. I'm not sure if that's normal since I've never had one with an ash pan. I lit a stick of incense and held it near the ash pan door as well as the other doors. In no case did the smoke track toward the stove. It pulled to the right constantly, but that might just be how it burns. If it is something related to the ash pan door, it makes me nervous that it will warp if I keep using it as is.

Is there any other ways I can check for unwanted air infiltration? I'm am so lost at this point and starting to not enjoy my new stove. The only constant seems to be that the healthy flame is always dead center. Most of you know my setup. Single wall pipe to thimble, the 18' of exterior chimney, 1 90 degree elbow involved. With just minimal chimney height, is it even possible that this is overdraft due to chimney? Can anyone point me in the right direction?

thanks
 

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How is your glass doing? Does it get dirty? I ask because my glass gets dirtier if I have my ash pan door cracked open (I occaisionally do this to cheat and get the fire going quicker). I think having my ash pan door open reduces my primary air path of blowing across the glass. So, this might be a clue.

You could lay a piece of sheetmetal across your slots leading down to the ash pan. This will force your air to come up and around the sheetmetal and burn differently IF air is actually coming up through here. You wouldn't have the center burn thing happening.

I would think you'd have a significant leak in your ashpan door for it to fan your fire like that. That would take more than a loose seal.
 
Do you have an ash cleanout door in that chimney liner? Air could be drawn there and cause it to draw out of the stove creating a very strong draft. What about the pipe connections? Nice an tight?
 
I agree with Wahoowad, I had that problem in my Homestead when I first bought it, and found the ash pan was loosening up on me occasionally. I guess from the heat expansion. I replaced the ash grate in the firebox with fire brick. Problem solved. I didn't like using the ash pan anyway. It was easier for me to shovel them out.
 
My glass doesn't get dirty. I'm actually very impressed with how clean it stays. I get one little area in the bottom left corner, but minimal buildup at best. If I can locate a piece of sheet metal, I'll try covering the ash pan and see if that center flame persists.

I don't even know what a chimney liner is, so I'll say no to that one. My ash cleanout is under the stove. I can't vouch for the pipe connections. I know that no cement was used, just 3 machine screws to attach each section. I did light the occasional smoker when I was getting used to the stove and the smoke did come out every section. Does that mean the connections are inadequate?
 
Rudy I need more info i do you have a very well sealed damper plate? From what I gather you are not running a ss liner?
also that your instalation is into a former fireplace ? If this is so then that block off plate may be introducing room air into your chimney and increasing your draft. Which also draw air from your stove causing the storter burn time. Just trying to figure your situation out. Are you burning oak or what kind of wood?
 
Everything with this stove is new. There was no pre-existing chimney. It's the stove with top exit single wall pipe, 90 degree elbow to the wall, out the thimble and then up a brand new class A packed insulation chimney. The chimney itself is 18'. I've been told to subtract anywhere from 3' to 6' for the elbow, which leaves me with the minimum height requirement (13') for my stove.

I have one pile of Maple from a tree I had taken down in early 2004. The wood that was delivered is crap. That much I know. It's an assortment of softer hardwoods, some of it a bit more green than I'd like. I was able to overcome the green part by resplitting a lot of it and stacking it for maximum air. I realized the softer wood will give me a shorter burn, but even if I put a fat piece of well seasoned Maple on there, it's gone in 45 minutes. (90 minutes is my longest burn time - the normal is under 60). Once they're back to off season prices, I plan on purchasing a load of just Oak to get ready for next year.

I've got no problem removing the ash pan. I sweep out the ashes too. How would I go about modifying it to a no ash pan setup? Do you literally remove the ash pan and replace it with something flat, or just cover the hole with fire brick? That area does click like crazy whenever the stove heats up or cools down. Maybe there is too much expansion going on. Maybe that dead center flame is from below, not above? I hadn't considered that. Hmmm. Sounds like a good area to pursue.

thanks for the input you guys. Now I'm gonna go do something I've never done in CT. Ski in 2' of powder!!
 
shut off your primary air supply and see if it continues to burn hot up through the bottom.
 
even with the elbows i still think thats a tall chimney. Did you put a inline damper in it? it wont hurt to try. then you can at least rule out your chimney system.
 
I have to say I find it hard to believe that air infiltration through gaskets is causing this, as was said earlier. If the longest burn you can get is 90 minutes, you've got a SERIOUS problem.

An inline damper will probably help remedy the situation, but I wonder if there isn't something more wrong with the stove?

I have a 20 foot chimney, all class A pipe and even without using my stack damper, I can control the burn down to smothering.


I'm sure you read this section of the manual, but it will help other to see what Hearthstone suggests:
UNCONTROLLED OR SHORT BURN
Unsealed or Open Door Close the door tightly or replace the gaskets.
Open ash grate Slide ash grate to closed position.
Excessive Draft Check the installation. Operate at LOW BURN. Install stovepipe damper.
Deteriorated Cement Seals Reseal the stove with furnace cement.
Extra Long Chimney Shorten the chimney. Install stovepipe damper.
Oversized Chimney Reline the chimney to the proper diameter.
High Winds or Hilltop Install a chimney cap.
Excessive Draft Draft in excess of 0.1 wc should be corrected with a stovepipe damper
 
I saw a Hearthstone burning recently and it was on medium low air and there were bright yellow flames that brightly lit the entire firebox, dancing evenly on the logs and just barely touching the top of the box.

Definitely looking extreme for full low, but there's no way to tell the temperature of those flames actually are just by looking at them. The manual says a stove top thermometer should run 200F - 300F on low burn, 500F on high burn and 600F NO GOOD. My dealer recommends Condar ChimGard thermometer. I had a Rutland thermometer, but found it burns 50F lower than the ChimGard above 400F so I take an average of the two now. Place the thermometer above that pillar of hellfire and see what you get.

Good luck!!
 
Rudy I read threw the post again. One comment Maple does not afford that long of burn. It is what it is, a medium grade softer hard
wood. Not a bad choice to burn, but what you are experiencing is to be expected. Now if your stove had 3 to 4 6" oak splits and burned out in an hour that really would point to a serious problem. It might just be you have an excellent draft, so much so an inline
damper maybe required, to slow the process down
 
Luckily the dealer I bought this stove from are good people. They're gonna send someone out to see if they can find anything obvious. They also gave me some firebricks to borrow and see if the ash pan might be playing a role in this. Once it gets cold again, I'll light up with the ash grate covered and see what I get.

It's the part where the raging yellow flame is always dead center and seemingly round in shape corresponding to the size and shape of the flue. What confuses me is that it's not like there's line of sight to the flue entrance. The flame hits that top plate and supposedly gets diffused somewhat. It makes no sense why that center flame is the shape that it is. Hopefully these guys will see something obvious when they come to check it out.
 
I hope so too. THe conditions you list definitely make me think it's a stove problem and not a flue problem. I know most others disagree. Hopefully we find out eventually.
 
This thread has me nervous. We have put down a deposit on a hearthstone heritage that is due to be installed next week. We will be running about 8 feet of double wall and another 16+ feet of class A insulated pipe all strait up. Would you in the hearth room suggest that we add on an in-line damper into the pipe set up?

thanks
 
I guess this is one of those disadvantages to the Phase II EPA stoves. Since the amount you can reduce the air input has to be limited to keep pollution to a minimum, you end up with installations where it is impossible to get the unit to function properly without the addition of a stack damper.
 
for whats its worth, my center flame is always aggressive. Only becase thats where the air enters in the front. But if i shut my stove down, it almost goes out. And thats on a 26 foot chimney strait up with no inline damper. My altitiude plays a big part in that.
 
We're using Class A chimney outside with 19.5 ft. above the tee and two 30 degree elbows. With stove on low we get a very lazy burn.

I have noticed on windy days that the flames pick up and looks like your picture. I did some research on this and found that wind currents can cause the chimney to overdraft. This overdraft is even greater if there a structure nearby that is higher than the chimney. We have a rocky hill behind our house that is about 12 feet higher than our chimney. We don't get windy days very often so not a chronic thing.

Do you live in a windy area? Do you have a structure in the area that is taller than the chimney? If so a turbo wind cap may help. Most chimney manufacturers have them special order.

Oh just wanted to clarify that even with minimal wind a structure taller than the chimney nearby can cause overdraft.
 
I do experience windy conditions more often than not. I'm 21' above sea level about 1/2 mile from Long Island Sound. I do notice that the flames dance around more considerably on windy days, sometimes to the point where I'm concerned about downdrafts. I'm not near anything tall. It's kind of marshy flat land.

The Maple I mentioned was a Norway Maple. It was not a split. We're talking a piece that was so hard to split that I gave up trying, a two headed 8" round piece with a T to two smaller branches. It took up over half of the firebox. I put it in as an experiment to see if the stove would make quick work of it. I put it onto hot coals and opened the air up full. It ignited and was burning strong within minutes. I waited 15 minutes to reduce the air to half, (stack read 400). I waited another 15 and closed the air down, (stack near 350), flames still dancing. The whole thing was reduced to coals in an hour.

I didn't consider that the center flame is a result of the location of the air intake. Duh, that does make sense. It does seem to tell me that the intake control on my stove does not produce the full result that is intended. I'd be actually happy if this can be solved by a damper. At least that way it's not a stove flaw. I do love the stove. I just would like it to function as advertised. These new setups are always hit or miss.

At the very least, I have plenty of clues to give the guys when they come out to look at the stove.
 
Dylan said:
Norway maple is VERY much like sugar maple. In fact, some plant geneticists claim that it is a sub-species of sugar maple. It's a very 'willing' species when it comes to breeding.

Oh great Dylan. You have brought the forum down to talking about slutty trees.

For a good time call Norway Maple 555-6475
 
I have a similar problem with my (new) Lopi Endevor stove running away from me. After filling the firebox a third to half full of maple and the temperature reaching 300-400 I shut down the stove completely. Over a time period of the next hour, the stove will run away up to 800 degrees -- a far cry from the "low burn" advertised in the manual. It starts off as a gentle flame, but then enough gases are given off to get the secondary combustion started. That eventually grows until I have a large fire, despite the air control being fully closed.

I've checked the door gasket, and its tight all around. There is no ash-pan.

The chimney is 18' or so. I do have an outside air intake, since the house is fairly tight (a dryer running will reverse my gas stove in the basement -- the wood-stove is upstairs). Draft is NOT an issue -- especially since here in da U.P. of Michigan getting -10 to -20F days isn't unreasonable. Could it be too much draft?

I called my dealer today, and he said that 800 degrees isn't too hot for the stove. I'm more concerned about the fact that I can't control the temperature. Having the stove go from 300 degrees when I leave for work up to 800-900 while I'm gone makes me a bit nervous. There's also the fact that in one hour I end up burning through what should be enough wood for six.

I'm fairly new to using wood-stoves, but everyone else that I've talked to up at work seems to think this isn't normal -- I should be able to load the firebox completely and not worry about the stove going 900+ on me.

Does anyone have suggestions or comments?

Thank you!
 
Sounds like you are blessed with strong draft Matt. If you are certain there are no air leaks, add a manual draft damper in the stack. I need one for my stove. Without it my stove can be hard to manage. It was a necessity for the Jotul 602 that the new stove replaced.

This is not a hard installation, the damper is usually available at the local hardware store. After it's installed, you'll have to experiment with the best settings. For my stove I start the stove with the damper wide open. When the fire is burning vigorously and a bed of coals is developing, I set the damper to half-closed. Once the fire is fully involved and burning hot, I close the damper almost all the way. My draft is strong enough that I can run the stove like this all the time after the stove has come up to full temp (about 550). Then I am able to regulate using the air intake on the stove and get the desired response.
 
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