everburn to AFTERBURNER!

[trailblaze]

so this has happened 2 times that i KNOW of...

last night, i get my DW up to temp (stove pipe 400ish- stove top 500-525ish), nice bed of ash, load it up, char the wood, and shut the damper. the temps drop a bit, stove top 450ish, stove pipe 300ish, i leave the air control just ever so slightly cracked open... like maybe 5% open, and the everburn rumble is going well.... i wake up like an hour later on the couch to the smell of paint burning, the stove pipe temps are 425ish the stove top is 500ish, and the back of my stove is GLOWING RED!

the rear has a metal shield from the factory... the cast iron behind this shield was glowing red!! WTF? nothing else was all too hot, just the rear!

i know my draft was pulling really hard last night, as i heard it making the "rumble" sound louder at times...

now i needed the air open (cracked) like 5%, when i shut the damper.... had i went upstairs to bed i am sure something bad would happen...

what am i doing wrong?? should my everburn turn into an jet engine afterburner with the air control hardly open??

i've kept the air control closed today while at work.... i hope i didn't damage anything too bad...

 

[ICY99]

What is your chimney setup?

 

[trailblaze]

from the stove-- 1 4ft single wall- then 14ft of double wall, straight up through the ceiling then out the roof

 

[ICY99]

If you haven't already, you should read this thread.

https://www.hearth.com/econtent/index.php/forums/viewthread/14104/

There's a link to an article about the "Florida Bungalow Syndrome". Should give you an idea of what might be happening. Something's definitely causing an overfire be it draft or gasketing.

 

[Diabel]

Get use to it. No idea why but it happens, with mine as well once in a while. My flue set up is near perfect 20' with couple of 45s. As the weather turns colder more people will report the same....the people that pay close attention to their stoves!

 

[mikeathens]

geeee...big surprise. I got rid of mine 'cause it scared the crap out of me (similar experience as you). Is that 400+ chimney temp surface or internal? Don't let anyone tell you you're doing something wrong. The only thing that I can think of that *might* make a difference: do you have a gasket or gasket cement where your connector pipe slips into the flue collar? If not, and you plan on giving this heap another chance, try sealing up that joint. Might help. Apparently, mine thought the fue collar would be a good place for tertiary combustion. Don't expect help from VC or whatever they're called. Tech people there are (were) clueless. Your setup sounds like mine.

Yes, I'm still bitter. Others here love their neverburns...might get some good advice from them.

 

[trailblaze]

the chimney temps were surface temps...and my stove pipe is not cemented into the flue opening... the crack is like 1/8 but it's tight....

i also did a "lighter flame" test on all the gaskets... the flame never got sucked in anywhere

it was in the low 20's last night.... 10-12 mph wind

i just don't like seeing RED cast iron....

it's soo unpredictable, i sat home all weekend and everburned, air control sometimes 75% open.... never had the problem then

 

[tradergordo]

After checking for and fixing any leaks, if you still have this problem, it is another clear example of someone with an excessive draft issue. And the fact that it is only glowing in the back is strong evidence that you don't have a door gasket leak which would increase combustion in the firebox, not the rear secondary burn chambers.

Back in the old days, many stoves had a built in "fix" for this problem, a secondary air control. You can see a pic of one at the end of this thread:
https://www.hearth.com/econtent/index.php/forums/viewthread/14104/#301299

Also from that thread you will note a quote from a 1984 Vermont Castings manual:

From the old VC Manual (pg 14):

“It is possible (though it occurs rarely) that you have excessive draft. This usually occurs with a tall interior masonry chimney that is located so the prevailing breezes blow across the top, as in the case of a house located high on a hill or near the shore. Should this prove to be the case, first experiment with closing down the secondary air control slightly. Easy does it here. A 30% closing is probably all that it will require. In extreme cases, try installing a flue damper to partially restrict the draft.”

Solutions to the problem are described in the "Florida Bungalow" article previously mentioned. And here's another little example of a custom retrofit secondary air control.

In an emergency - such as you described - you can quickly bring the stove back to normal operating temps by covering over the secondary air intake (bottom rear of stove, has a circular flange sticking down, you can't miss it) with a piece of tin foil. This happened to my stove exactly once. Other people have emailed me saying the same has happened to them. I haven't added a permanent secondary air control to mine yet, but I think its a good idea for safety reasons.

 

[Highbeam]

Is this the VC on which it was "normal" to see glowing red stove parts per the VC company?

 

[tradergordo]

Yes. I'm surprised their solution wasn't to just seal up that rear heat shield a little better so you can't see it glowing

But in all fairness to VC, pretty much any stove, given the right conditions, can overfire when draft is strong enough and there is no secondary air restrictor. From what I understand, the reason modern stoves don't have secondary air controls even though older models did, is because of EPA regulations (they didn't want people shutting down secondary air for no good reason, creating a lot of pollution not to mention fire hazard). So really the stove companies might not be able to offer a good solution unless they work with the EPA first. John Gulland said he has had to modify every stove he has ever owned (because of the extremely strong drafting chimney setup he has).

 

[trailblaze]

well, glad i wasn't doing anything wrong.... now i need you guys to tell my wife that.... she said i'm not responsible enough for a stove it i let it over fire like that.... ugh... women!

anyway... i guess these stoves are built to be OK if that happens.... i'm sure it's happened before that i don't know of.... i will never leave the air control open more than a crack when not at home!!


and to think i was afraid of my draft when installing the chimney!!

 

[Brian VT]

and to think i was afraid of my draft when installing the chimney!!

Me too. Stove in the basement, two 90 deg. bends, and a metal exterior chimney exposed to the weather.
It shouldn't draft well, technically, but it drafts like a jet engine. I just installed an inline damper to try to control it some and also add another way to restrict air supply if/when things get ugly. I may look into adding a control on the secondary intake.

 

[mikeathens]

well, glad i wasn't doing anything wrong.... now i need you guys to tell my wife that.... she said i'm not responsible enough for a stove it i let it over fire like that.... ugh... women!

anyway... i guess these stoves are built to be OK if that happens.... i'm sure it's happened before that i don't know of.... i will never leave the air control open more than a crack when not at home!!


and to think i was afraid of my draft when installing the chimney!!

Don't think that only leaving it open crack will prevent what you experienced. And I would disagree, it is NOT OK for the stove to glow red. That cast iron is not capable of handling repeated events like that. It is a failure waiting to happen. The only way I was able to get mine to stop was plug the air inlet with a welding glove or other non-combustible material, as mentioned.

Good luck.

 

[FireWalker]

I know exactacly how tou feel and the additional pressure you are getting from your wife just fans the flames. It's not her fault, she is supposed to worry about stuff like this. I can't count the number of times I have been confident about how something was going work out just to find the payback wasn't worth the stress put smack dab on my wife's shoulders.

Example you say, how about that really nice 2005 Suzuki DL650 I bought new a few years back. I"m gunna get 60mpg riding to work and back..................... I've been riding my whole life, I'll be safe, look I have all the gear, no worries right...................... Now there are people out there driving cars and trucks that can't see motorcycles, I successfully avoided two of them but lost confidence that I could keep it up so I sold the bike. I never let on my real reasons and told her we needed the extra money which we did. Her stress level was cut in half and it felt great for both of us and I still have 2 motorcycles (dirtbikes).

Now my wife can worry, you have never seen a person worry like my wife. Yea, she's a keeper!

I'm not sure but I think you can shut those primary air flaps completely and that stove like mine will still have access to all the secondary air it needs to keep itself everburning. The whole concept of this is kinda scary to me given the fact that at some point in time the most ideal chimney draft conditions will happen and you are left with little or no control over your secondary burn. Can you say pipe damper.

 

[trailblaze]

when you say plug the air hole, you mean the opening underneath? is this a temporary plug, like only plug it when the draft is too great?

i am wondering because what about the days when the draft isn't so swell? i've run the everburn with the main air control open 75% when i was getting down the end of the burn.... i don't want to hamper the stove in any way, but gain more control when i need it

i would think a stove pipe dampener would be the best fix....

any other thoughts....

 

[FireWalker]

I think he ment when the stove started to overheat and air control adjustments wouldn't slow things down, he stuffed the secondary air supply. Now try doing that when you are sleeping.

Now this stuff pisses me off to no end, these appliances should be idiot proof and tested in the factory for this. The whole concept of over-fire is hard for me to swallow, why not just build them to withstand what ever a full load of the hottest burning hardwood can do at full throttle under the greatest draft. Well there is probably a good reason.

Rant over, carry on.

 

[mikeathens]

I don't think the pipe damper would help (I could be wrong, wouldn't hurt to put one in, you'll be out a whopping $4 if it doesn't), but yes, I'm referring to the air inlet on the bottom rear. If I remember, it's circular where you would hook up outside air kit. I only stuffed this thing up to stop the meltdown, but I'll bet you could fabricate some type of damper there out of sheet metal - either a butterfly-type like you install in the flue, or maybe something like a piece of sheetmetal held in place with vicegrips that you could adjust as needed. I wasn't suggesting plugging this thing up permanently. Since I haven't been part of the everburn crown for nearly two years now, I'll shut my yap and let other that have had more experience chime in.

Be safe!

 

[trailblaze]

hmm... i think i could rig something up to cover that hole when i know the draft is really pulling

haha my wife will really think i'm nuts when i am laying behind the stove with vise grips and sheet metal and say "it's ok honey, i read this on hearth.com"

 

[mikeathens]

Hey, man. Keep in mind that I'm no expert...just an engineer with plenty of crazy ideas to share. the sheet metal idea might or might work (I got that idea from someone else having excessive draft problems). I have a feeling you'll just ahve to experiment - both with a flue damper and possibly an air supply damper. You'll hopefully figure out what will work. The beauty of either of these things is you're not going to make things worse.

Then, mabye in a couple months you'll decide to get a hearthstone mansfield, and all of your troubles will go up the flue.

Edit: be sure to seal up that connector pipe/flue collar joint with some gasket glue or stove cement.

 

[tradergordo]

First off, like Mike said, its NOT OK for the stove to glow red. This could potentially damage (crack) the cast iron.

Second - the primary air control is irrelevant in this situation. Completely closing the primary air control (which you SHOULD do when the stove is working well and everburning "sustainably" and you want the longest possible burn) cannot stop the excessively drafting stove from overfiring.

Third - a flue damper is basically the functional equivalent of putting a secondary air control on your stove, only the secondary air control is easier to add (don't have to take your flue apart), and it has other benefits which are described in the Gulland article previously linked here.

It might give your wife a little peace of mind if you added a flue alarm (goes off when exhaust gas hits a certain temp that it should never hit).

 

[mikeathens]

Flue alarm? That's something I'd be interested in. Tell us more. Never heard of it.

 

[tradergordo]

hmm... i think i could rig something up to cover that hole when i know the draft is really pulling

haha my wife will really think i'm nuts when i am laying behind the stove with vise grips and sheet metal and say "it's ok honey, i read this on hearth.com"

Like I said, a piece of tin foil works fine in a pinch, of course that is no permanent solution. Its easy to mount something to the secondary air intake because it already has mounting holes (intended for the outside air kit).

 

[tradergordo]

Flue alarm? That's something I'd be interested in. Tell us more. Never heard of it.

I've seen a bunch of different designs. There are fancy expensive digital ones like this:
http://www.cas4.com/Wood-Stove/Woodstove-Control-001.htm

Or the "do-it-yourself" kind like this:
http://www.motherearthnews.com/Do-It-Yourself/1982-01-01/Mothers-Flue-Alarm.aspx
Which could be built for $15 using a cheap walmart smoke detector and a simple flue probe thermometer.

I've heard that people use these as well:
http://www.partshelf.com/maet73.html
But I'm not sure how good they can be if the range only goes up to the 400's. I guess you'd have to find some part of the stove that only gets to 400 in an overfire situation (and you would not have the faster warning you would get from an internal probe).

 

[kenny chaos]

.. she said i'm not responsible enough for a stove !!

She really said that? That's really mean.

 

[FireWalker]

hmm... i think i could rig something up to cover that hole when i know the draft is really pulling

haha my wife will really think i'm nuts when i am laying behind the stove with vise grips and sheet metal and say "it's ok honey, i read this on hearth.com"

Like I said, a piece of tin foil works fine in a pinch, of course that is no permanent solution. Its easy to mount something to the secondary air intake because it already has mounting holes (intended for the outside air kit).

I'm thinking a spoon shaped piece of flat sheet metal with a mounting hole in the middle of the handle, attach to stove using stock holes and then rotate over air inlet to partially of fully close the port. The handle sticks out the back or side and you just reach back and make an adjustment. Then perfect the design and sell it as a kit. Well maybe skip that last part..........