What's HIS Problem??

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

soupy1957

Minister of Fire
Jan 8, 2010
1,365
Connecticut
www.youtube.com
I stumbled on this video this morning, and wondered what his problem is.........I see the smoke coming out, and I'm thinking, "ok, there's the first issue."

Then I'm wondering about how far down he has that fire dampered. I'm wondering if there is such a thing as being TOO far dampered (of course, you don't want to snuff OUT the fire, but what about the flare ups exhibited in his video??)?

-Soupy1957
 
Improper flue diameter? Outside temp too high?
 
Is that "back puffing"? This sort of worries me that I removed the top plate screws from my Firelight.
 
Yeah, that's exactly what I was talking about the other day when someone posted that their stove did something similar. If you dial back the combustion air too much when the firebox is full of volatile gases, they'll basically "explode" once they get enough oxygen, and the force will exhaust itself anywhere it can.
 
The back puffing is most likely due to loading too much wood into a hot fire box and then damping it down. The heat in the stove will keep gasifying the wood but there is not enough oxygen to burn. At some point a stream of hot gas fills up the chimney and gets enough oxygen that it ignites rapidly, creating a pressure wave down the stack which pops open the inlet air damper. This allows some oxygen in through the air damper which creates a flame which is rapidly extinguished due to lack of oxygen. The process then repeats. Depending on the chimney hookup, this process can be more or less "violent", a hard pipe from the back of the stove right up to the roof can cause some real aggresive backpuffing, while just dumping the gases into a block out plate into a large flue,wil puff less.
 
Yup that is back puffing. I have the same stove and it also happens for me on occasion when damped really low on a mild day.

Its coming out of the griddle because the stock wire wound gasket that Vermont Castings use may be durable but it sure doesn't seal very good. I bet if he put a light bulb in the stove cold he would see cracks of light there. I switched mine out for a regular rope gasket and no more leaks. Just have to not be dumb with you wood loading so as not to tear it.
 
I wonder what his chimney set up is? Maybe no liner, just a slammer install causing bad draft. Oh, nevermind, he says he has a liner, maybe it's the wrong size or is a direct connect to the damper?
 
I'm suprised folks here are suprised...........this is why I ditched my Dutchwest XL. I'm pretty sure it's a stove thing and not necessarily a setup thing as my Equinox will do the explosion shown in the vid but will not burp any smoke. It is running on the exact same chimney as my old DW. On my DW, the smoke would belch out the air intake flaps.........very stinky and I had nothing I could seal up. The condition is the result of an overly dampered fire that has just either come up to a temp that lights off the smoke but still not hot enough to sustain it, or a fire that has cooled to the temp at which the smoke will no longer burn but still has enough heat to build up and light off but not sustain the burn. The frustrating part of this condition is the user would like to maintain a low long lasting fire but can't because it will backpuff. Cold, dry outdoor temps and well seasoned wood help but with my old stove there was always the chance usually in the middle of the night this will get you out of bed to open the bypass and adjust the air supply. I found shoulder season was best run without engaging the bypass and thus the cat.

My good friend has the same stove shown in the vid (defiant yes?), much to my suprise, he replaced his vintage model due to backpuffing with the new version and he still gets this condition. He replaced his entire chimney as well.
 
Could be that or just a shorter chimney in mild weather. He's lucky this is not a big puffback. Get conditions right and they can be spectacular.
 
I have seen videos of the Dutchwest doing that also I would tend to think their chimney setup is not adequate or they have a draft problem. In all my years of using the Dutchwest I have never seen it back puff in my house or my parents house.
 
IMHO, its not a design flaw inherent to VC products. The stove operator is just asking for performance that is not available from the stove. If they want to solve the backpuff problem, drill a hole in the air damper so it cant be fully closed. This is the solution for most EPA stoves, hide a secondary airport that cant be closed off. Of course the stove will start overheating, but eventually it may train the owner to put less wood in and give up trying to get a long unattended burn.
 
peakbagger said:
IMHO, its not a design flaw inherent to VC products. The stove operator is just asking for performance that is not available from the stove. If they want to solve the backpuff problem, drill a hole in the air damper so it cant be fully closed. This is the solution for most EPA stoves, hide a secondary airport that cant be closed off. Of course the stove will start overheating, but eventually it may train the owner to put less wood in and give up trying to get a long unattended burn.

+1 Even a rookie like me can make our Encore run without back pressure. When I saw this video last year, my first thought was dispute between the owner and the dealer or VC. Since he couldn't get satisfaction on something, he posted the video marking him as a man who cannot out think a stove.
 
BeGreen said:
Could be that or just a shorter chimney in mild weather. He's lucky this is not a big puffback. Get conditions right and they can be spectacular.

I was wondering about that too BG. Can you imagine a big back puff and that pan of water spilling over?
 
We've encountered this situation several times over the years, and even made it happen ourselves in our showroom while test-burning a load of creosote-soaked railroad ties about 30 years ago (don't ask). Because there are so many situations that can be termed "back puffing", we named this specific phenomenon "whuffing." You can read more about it in our Sweep's Library at http://www.chimneysweeponline.com/howhuff.htm.
 
where does this particular stove get it's combustion air? If it is through a series of tubes or dedicated chambers leading from one place (I know nothing about this model of stove) it could possibly be accumulated dust and ash inside those chambers.....in that case no matter how much draft your setting indicated, if it was full of dust and ash that could make it starve for intake air...if that was the case a good compressor and a good shop vac could help solve the issue a little.....sometimes those secondaries get a little bit of ash in them and it needs blown out....
 
JimboM said:
peakbagger said:
IMHO, its not a design flaw inherent to VC products. The stove operator is just asking for performance that is not available from the stove. If they want to solve the backpuff problem, drill a hole in the air damper so it cant be fully closed. This is the solution for most EPA stoves, hide a secondary airport that cant be closed off. Of course the stove will start overheating, but eventually it may train the owner to put less wood in and give up trying to get a long unattended burn.

+1 Even a rookie like me can make our Encore run without back pressure. When I saw this video last year, my first thought was dispute between the owner and the dealer or VC. Since he couldn't get satisfaction on something, he posted the video marking him as a man who cannot out think a stove.

I'm with you on this, Jimbo. Relative rookie, less than one year on our 2550, and nothing like this. Must be something besides the stove itself.
 
Status
Not open for further replies.