Defiant NC Everburn Doesn't engage

[tradergordo]

Goose, that sounds interesting, because the stuff I have seen looks more like "spun" ceramics or pressed boards glued together as opposed to cast stuff. I mean, think about it, how are you going to pour a couple tons of iron at 2500 degrees into this stuff if your finger can go through it?

This is a fairly accurate description of the stuff that has fallen out of the everburn chamber in my stove. I'm somewhat convinced that it is the shoe gasket, after using a mirror to look up at the damage. Willing enough to pay the $40 for a replacement from VC with instructions. I'll post after I get it, to indicate whether or not this diagnosis is correct.

I thought ALL gaskets were fiberglass (like what you can see on the doors). Those are very different from the ceramic everburn chamber stuff. If you are talking about fiberglass gasket, then it should not crumble to dust when squeezed, basically it should feel like the gasket in your doors.

And why are you paying for something that should be covered by the warranty? Did they tell you it wasn't covered? If so, what was their reason. I'm just curious.

 

[swestall]

Hey All. The gasket below the refractory shoe is made of a fibrous material and it is about 1/8" thick. I've not taken it apart after a lot of heat to know if it would crumble. I have had it apart and it is the same dimensions as the shoe with cutouts for the air passages. I do believe it is covered by the warrantee. The fiberous box that the refractory package plugs into is another item yet; it is made of a very densly packed material "board" that resembles the asbestos board of yesteryear. It is about 3/8-1/2 inch thick. Then you have the refractory and shoe, they seem to be made of the poured and treated ceramic that has been discussed. It is hard and brittle. It is my understanding that the entire assembly is warranteed.
Another interesting thing I've learned in the past few weeks. (about Everburn) It needs to breathe; not just at the base where the opening is but along the back of the stove up and down the refractory block. I've observed that when the air path is not open (blocked by a split or two) that the gasses will flash and ignite in the stove causing a burst of pressure/smoke. Most of this is going up the stack, but you also will get a backpuff if any gasket seam is weak and it will momentarily puff out the air siphon holes in the shoe. Of course this gives you smoke in the house.. Easily remedied by rearraging the splits and giving it a tad more air: except that you have to get up (be awakened) at 3AM with a headache and do it.
And, getting the Eberburn to kick in. It seems that the siphon holes in the shoe need a pretty good draft to get the pull through for good ignition. Closing the primary actually aids in this process. But, not totally as you still need a fair bed of coals in front of the shoe opening and a 500+ stack temp. (600 actually works better) And, the greater the draft, the better the sipon: in fact that would also account for those who have had the "thermonuclear" experience. IN that case the draft is pulling like crazy. Since there is no draft control on the shoe the strenght of the draft is going to determine if you have Eberburn, too little, just right or way too much. Wonderful design....
CFM-Vermont Castings and Dutchwest should take note: this is a lot for people to have to go through to have their products.
Tradergordo: Do you know if CFM is still planning to do a real world evaluation regarding this situation?

 

[BJN644]

Another interesting thing I’ve learned in the past few weeks. (about Everburn) It needs to breathe

I find this interesting, I have a new Harmon Oakwood that I have been tring to figure out. I have been pleasantly surprised that the past few days I can engage the secondary burn and keep it going even with the air cut back to 1/4 open. The secret seems to be the thick bed of coals, takes about 1 1/2 hours from cold. I had been keeping the opening to the rear burn chamber clear of wood except for the coals on the bottom and was having trouble like everyone else. Now, I roll a piece of hot burning wood right up against the back of the opening of the burn chamber and load her up. The past few days it has worked great ! I have been measuring temps with an infared thermometer at various spots on the stove. With the air cut back back to 1/4 the stack is around 250, the top of the stove is around 300 and the back of the stove is just over 500 deg. we have igntion ! There is no doubt that there is secondary combustion going on with temps that high in the back of the stove, I rarely hear any rumble that others have spoke about. From what I can tell the secret seems to be keeping a burning log up against the opening to the burn chamber. It still is a little bit of a hassel to babysit for that first 1 1/2 hour though.

 

[tradergordo]

Now, I roll a piece of hot burning wood right up against the back of the opening of the burn chamber and load her up. The past few days it has worked great ! I have been measuring temps with an infared thermometer at various spots on the stove. With the air cut back back to 1/4 the stack is around 250, the top of the stove is around 300 and the back of the stove is just over 500 deg. we have igntion ! There is no doubt that there is secondary combustion going on with temps that high in the back of the stove, I rarely hear any rumble that others have spoke about. From what I can tell the secret seems to be keeping a burning log up against the opening to the burn chamber. It still is a little bit of a hassel to babysit for that first 1 1/2 hour though.

How long have you been using the stove? I don't know, I usually don't get very good results when I have any log (burning, charred, or anything but glowing red coals) up against the throat opening.

Also I'm curious - have you gone out and looked at what is coming out the stack when you say you are getting secondary combustion with no rumble and a 250 stack temp? I've never seen clean emissions with a 250 stack temp unless only coals are left. It doesn't surprise me that the back of the stove would be hotter when dampered down, because that's the first part of the stove all exhaust hits after it leaves the firebox (top of the stove is actually very isolated (probably too isolated) from the exhaust flow when dampered down, and of course the stack itself is the furthest point from the firebox.

Remember that secondary combustion only occurs at 1000+ degree temps without a catalyst.

 

[tradergordo]

Tradergordo: Do you know if CFM is still planning to do a real world evaluation regarding this situation?

I have no idea what they are doing. These stoves have been around for a couple years now, and I assume some of their employees are using them. I'd also assume they undergo extensive real world use before they are ever even sold to the public, but who knows? Then you have this supposed everburn instructional DVD - does it exist? Wish I knew.

 

[swestall]

Wish I knew too. You would think they would use their stoves, but perhaps they are too smart for that. I've decided to increase my draft with a SS one piece/8" oval liner and see what that does. Even if I replace the stove later, the SS liner will be easier to clean over time and will draft better for all stoves. In the meantime, I've become an Eberburn-sitter...

 

[BJN644]

Now, I roll a piece of hot burning wood right up against the back of the opening of the burn chamber and load her up. The past few days it has worked great ! I have been measuring temps with an infared thermometer at various spots on the stove. With the air cut back back to 1/4 the stack is around 250, the top of the stove is around 300 and the back of the stove is just over 500 deg. we have igntion ! There is no doubt that there is secondary combustion going on with temps that high in the back of the stove, I rarely hear any rumble that others have spoke about. From what I can tell the secret seems to be keeping a burning log up against the opening to the burn chamber. It still is a little bit of a hassel to babysit for that first 1 1/2 hour though.

How long have you been using the stove? I don't know, I usually don't get very good results when I have any log (burning, charred, or anything but glowing red coals) up against the throat opening.

Also I'm curious - have you gone out and looked at what is coming out the stack when you say you are getting secondary combustion with no rumble and a 250 stack temp? I've never seen clean emissions with a 250 stack temp unless only coals are left. It doesn't surprise me that the back of the stove would be hotter when dampered down, because that's the first part of the stove all exhaust hits after it leaves the firebox (top of the stove is actually very isolated (probably too isolated) from the exhaust flow when dampered down, and of course the stack itself is the furthest point from the firebox.

Remember that secondary combustion only occurs at 1000+ degree temps without a catalyst.

I have had the stove close to a month now. Like I said a thick bed of coals is the key, then I roll the burning log against the opening. I can get all of my temps. much hotter with more air, just wanted to show an example of what I could acheive with little air, and I get no smoke from the chimney. The 500 + deg temp seems to be the magic number, even with the air control wide open and stack temps over 500 the back of the stove had never gone over 600, but a drop into 400's and I start getting smoke out of the chimney.

 

[James04]

Gordo,

Ill tell you what I have found lately with my stove. Mine is the same design as the Oakwood only steal. Rolling a log in front of the thought will work. Only that log needs to be totally hot and glowing. Otherwise it is a crap shoot. However what I think it does is force the gases to go under the log and threw the hot coals. However unlike BJN if my stove top temp is under say 350 or so maybe a tad higher. I am heading for a stall. I cant comment on flue temp just yet though. I just installed a probe type thermometer only two days ago. It seems 500-600 is going to be the temp during secondary burn. I may need to move the flu thermometer a little higher. I have it at 18"'s and am getting some very high numbers when the bypass is open. Over 1000.

BJN,

Next time you are running at 300 for say an hour. Could you please open the top loading door and see if you are getting any shininess building up. This is what I have been experiencing. How seasoned is your wood? Some of mine may be a tad too under seasoned. I dont get any steaming or anything but my wood had only been split a month ago after being cord length rounds for two years. At least that is what I am told. This may account for the differences we are seeing.

James

 

[tradergordo]

OK - well we all agree on one thing - the thick coal bed is key (didn't we already know that? haha). But you guys might be onto something with the (well burnt) log ON TOP OF coals, pushed against the throat. In fact I just tried this tonight, and its burning nicely as I type. But I do have everburn rumble (very slight, you really have to stick your head up by the air intake to hear it) and internal stack temp is very steady at 600. Air about 1/2. Seeing some smoke out the stack but not a lot.

FYI: Over 1000 with bypass open isn't unusual, I pretty much always wait for 1000 before dampering down. My probe is also low though, I think its 14 inches.

Gordo,

Ill tell you what I have found lately with my stove. Mine is the same design as the Oakwood only steal. Rolling a log in front of the thought will work. Only that log needs to be totally hot and glowing. Otherwise it is a crap shoot. However what I think it does is force the gases to go under the log and threw the hot coals. However unlike BJN if my stove top temp is under say 350 or so maybe a tad higher. I am heading for a stall. I cant comment on flue temp just yet though. I just installed a probe type thermometer only two days ago. It seems 500-600 is going to be the temp during secondary burn. I may need to move the flu thermometer a little higher. I have it at 18"'s and am getting some very high numbers when the bypass is open. Over 1000.

BJN,

Next time you are running at 300 for say an hour. Could you please open the top loading door and see if you are getting any shininess building up. This is what I have been experiencing. How seasoned is your wood? Some of mine may be a tad too under seasoned. I dont get any steaming or anything but my wood had only been split a month ago after being cord length rounds for two years. At least that is what I am told. This may account for the differences we are seeing.

James

 

[James04]

This has come as a bit of a surprise. I have been watching the stack temps and I was shocked. Stove top at 400=stack700-800,top500=800-900,550 900-1000,600=1000-1100. This is of course when there is actual wood burning and lots of gases to burn. Once the load is down to coal stage the stove top and stack are dead on equal to each other. This seems like a lot of heat going up the chimney. Do you think this is right? Is it possible my draft is too strong? I have 36' of 6" insulated SS with a 30 degree off set before the last 6' of chimney. Or perhaps I need to move the temp probe up to 24"'s (its at 18"'s). What do you think? I am totally able to control the burn with the air control on the front of the stove. Even with a really aggressive burn going (650 stove top) I can cut the air and it will go into a smolder. I would think this means the draft isn't too strong. I think this stove was really designed with a blower in mind. If you have ever seen one you may think the same It has a built in duct going up the back and out the stove top. Then that has a shield over that. Seems that, that is were all the heat is supposed to be generated. Any comments are welcomed.

Man I wish I had gotten a cat stove. Seems that nobody is selling them. I haven't seen one in all of the local and not so local dealers.

James

 

[James04]

Correction. Not 36' it is 33' not including the hight of the stove.

By the way. Don't misunderstand. I still love this stove. I don't want to discourage anyone who might be considering a Harman wood stove. I am probably just too fussy. That is typical for me. The Harman's have great build quality. More than 9 hour over night burns with 400-450 stove top temp and 375-400 in the morning. Plenty of coals to just add splits and shortly after close the bypass. Then theres the indoor grill feature which we both love. Then there is the beautiful looking Oakwood model. We went for the larger fire box of the TL300.

James

 

[webbie]

James, I would agree that this design sends a lot of heat up the chimney when in secondary burn mode. I think the key is knowing to turn the air way down at that point (in many cases)....

Since the secondary burn starts in the back of the stove and heads upwards, you can only imagine that the top of the flame (the hottest part) is well on it's way out of the stove before long. But it is near impossible to build extra heat exchange into such a stove and still have it look good or fit into most rooms!

Maybe now that the process has been tuned a bit, Harman or - better yet - Corie at Englander will come out with a central furnace which uses this method. The idea would be to have a massive heat exchanger up higher in the unit to extract that secondary heat.

 

[James04]

Craig,

It may sound crazy. But, even with those high stack temps. If I turn the air down too much (less than 3/16) I will get a stall. This would be with a fairly new load of wood. I think that, with so much wood (large fire box) off gassing there is just too much gas that needs to be burned. Hence the need to give it enough air. It seem the only time I can really shut the air down to say a 1/8-1/16 the total travel is when the load has burned long enough to not have so much gas being produced. Perhaps after 2 1/2 hours after loading maybe longer.

James

 

[BJN644]

Craig,

It may sound crazy. But, even with those high stack temps. If I turn the air down too much (less than 3/16) I will get a stall. This would be with a fairly new load of wood. I think that, with so much wood (large fire box) off gassing there is just too much gas that needs to be burned. Hence the need to give it enough air. It seem the only time I can really shut the air down to say a 1/8-1/16 the total travel is when the load has burned long enough to not have so much gas being produced. Perhaps after 2 1/2 hours after loading maybe longer.

James

I have found with the Oakwood with a fresh load of wood you need to let it char up good before closing the damper. You can turn down the air with the damper open to control stack temps.

On your other question about low stove top temps for an extended time, yes I do get the shiney stuff inside the stove. This is due to a stall and the need to char up that load good. I'm still learning my stove and it's getting better. I have found, and I don't mean to be a smart ass, that if you burn the stove exactaly like they say in the owners manual, I have been having pretty good results.

 

[swestall]

I'm in agreement on the stalling issues. I think the draft is Everything on this stove. Too much, thermonuclear, too little, stall and die. I've got a great chimney, but it is 8x12 and 15feet. This is proving to not provide enough pull on the Defiant NC where it was perfect for the Defiant and Encore CAT stoves. The way the air sipon on the Eberburn shoe is designed it needs a good pull to give secondary air to the refractory. Combine that with a good initial light off and there you have it. The coals and coal like wood on top preheat the smoke for this little air devil. I've decided to reduce my flue by lining with stainless at 8 inch oval and think that will provide a much greater pull, Hopefully I'll hit that sweetspot and not enter Thermonuclear land. In the mean time, I am getting things to work with the existing setup until the liner gets here. I do think that the cold air also is contributing to this positive result. It still takes a lot of work to get things to go right, with the sometimes stalls, getting up to just the right temp, etc. The VC/DW stoves with CAT do not have these issues. I think the Harman folks have taken this technology a little further and that their air sipons look to provide a bit more boost to the combustion process.
As an aside, I happen to have an old pre-EPA steel stove in my shop: its called "the force". I was out there yesterday and had it fired up while my wife was in the house burning the Defiant. I had the shop up to 74 and used less wood with no smoke out the stack. Sometimes, it makes no sense at all.
All to say: the testing and refinement of user friendly operating for our new and compliant stoves has a way to go. We need good stoves, that last a long time and put out minimal GPH while providing a load and burn type operating environment.
Folks tell me that the Isle Royale and PE-T5 & 6 do that. What say ye: owners of those?
Thanks to Craig for all his hard work and Happy Holidays back at Ya!

 

[webbie]

Craig,

It may sound crazy. But, even with those high stack temps. If I turn the air down too much (less than 3/16) I will get a stall. This would be with a fairly new load of wood. I think that, with so much wood (large fire box) off gassing there is just too much gas that needs to be burned. Hence the need to give it enough air. It seem the only time I can really shut the air down to say a 1/8-1/16 the total travel is when the load has burned long enough to not have so much gas being produced. Perhaps after 2 1/2 hours after loading maybe longer.

James

Well, we are certainly learning a lot. It may be that this particular stove design (the original Acclaim), when "upsized" too far, does not turn down as easily as the original model. That is why it would make a great furnace!

At the same time, I think it can be said with fair accuracy that buyers of the downdraft or crossdraft stoves should not oversize (no one should, actually, but these seem somewhat more sensitive).

In my old acclaim, when we turned it down we'd have dancing flames in the firebox itself floating around.....then I guess the final burn even after that was made when the fuel gases were sucked through the ember bed. We really rarely had a stall problem.

 

[James04]

Craig,

It may sound crazy. But, even with those high stack temps. If I turn the air down too much (less than 3/16) I will get a stall. This would be with a fairly new load of wood. I think that, with so much wood (large fire box) off gassing there is just too much gas that needs to be burned. Hence the need to give it enough air. It seem the only time I can really shut the air down to say a 1/8-1/16 the total travel is when the load has burned long enough to not have so much gas being produced. Perhaps after 2 1/2 hours after loading maybe longer.

James

I have found with the Oakwood with a fresh load of wood you need to let it char up good before closing the damper. You can turn down the air with the damper open to control stack temps.

On your other question about low stove top temps for an extended time, yes I do get the shiney stuff inside the stove. This is due to a stall and the need to char up that load good. I'm still learning my stove and it's getting better. I have found, and I don't mean to be a smart ass, that if you burn the stove exactaly like they say in the owners manual, I have been having pretty good results.

I agree with this. It seems to go with my theory stated above. The new load of wood is putting out massive amounts of gas and if the bypass is closed and the air cut down too fast it will choke and stall. I used to do it just as you state here. The problem is that if you wait long enough for all the wood to char. You have lost allot of the heat up the flew with the open bypass. I am trying to refine at this point. So far what I have found is as long as you get the new load hot. Not completely charred. You can kick in the secondary first with full air for about 5 min. then cut back to half then a little less than a quarter. That is the second notch on our stoves. This is were I leave it for overnight burns.

James

 

[mettauercat]

The proof is in the pudding. What is exiting the top of the chimney tells me the truth of how clean the stove is burning. VC cat in all three chimneys in house and couldn't be happier. Large Winter Warm, Defiant 1945, Intrepid II. All of my Jotuls loved to go through the wood. Would not go back there again. I only burn when I come home in the evenings, I'am not trying to hold a fire overnight, just a little on the weekends. 3000 sq. ft. house and only burn 50-75 gals. propane a year with the help of heat pump and back up propane furnace. I don't fire the stoves when I'am in bed or away at work. That's why they made programmable thermostats. Happy heating season is just around the corner, oh yeah it's supposed to be 98 tomorrow

 

[swestall]

;-) Since I've installed the Mansfield, I have burned about 1/3 less wood; for two years.
I still have those VC stoves in the basement. I did love the catalytic stoves, they burned great.
Everburn, I just have no time to spend babysitting and figuring out if it is, is not or might be sometime today or tomorrow.
The stoves with the burn tubes are almost automagic, I'd never go back.
Just as a sidebar, I burn an old stove with no converter or afterburner, etc in my shop.
I just burn it hot and there is no problem; but use lots of wood when I'm there; not that much.
I hope that in the time that's passed folks have figured out how to use the everburners, I'm waiting till I can afford a good boat to make proper use of mine.

 

[BrotherBart]

The proof is in the pudding. What is exiting the top of the chimney tells me the truth of how clean the stove is burning. VC cat in all three chimneys in house and couldn't be happier. Large Winter Warm, Defiant 1945, Intrepid II. All of my Jotuls loved to go through the wood. Would not go back there again. I only burn when I come home in the evenings, I'am not trying to hold a fire overnight, just a little on the weekends. 3000 sq. ft. house and only burn 50-75 gals. propane a year with the help of heat pump and back up propane furnace. I don't fire the stoves when I'am in bed or away at work. That's why they made programmable thermostats. Happy heating season is just around the corner, oh yeah it's supposed to be 98 tomorrow

When ya actually gonna start using those stoves for heat? :coolsmirk: