# Resolute 'back puffing'



## edciem (Oct 27, 2007)

Have a Resolute from 1988 and put it in two different houses with two different flue configurations but one thing is consistent- if the fire burns hot and you damp down the damper with the diverter 'clicked' the gases will accumulate in the stove and explode at one time blowing the top lid up a 1/2 inch or so and putting flue smoke in the room.  Boy that is one seriously long run on sentence!  Anyway, has anyone heard of this?  Any fix?


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## DriftWood (Oct 27, 2007)

Apparently Vermont Castings produced two two Resolute models in 1988 any ideas which one you have? This link may help you find out the model.

http://www.discountstove.com/partsvcwbfreestanding.htm


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## edciem (Oct 27, 2007)

It is the #0041 Resolute Acclaim.
Since I posted yesterday, I've been to the Vermont Casting's web site and found a statement in the current owner's manual about 'back puffing'.  This is amazing considering I've talked to them over the years and several store representatives and no one ever admitted to hearing of the problem.  They imply blame on the user.  I'm disappointed.


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## begreen (Oct 27, 2007)

Hard to say with the stove not being in good condition. Might it be that the smoke exit path is partially blocked?

Even in a new stove, back-puffing can be the result of suddenly changing the air supply to a new fire. When the wood hasn't charred yet, it is outgassing intensely. If the air supply is suddenly cut off, it can fill with smoke that is rich with volatile gases. Once those gases ignite from the existing coals, they can literally explode. That force has to go somewhere. It can blow off stove doors, stove tops and pipes if strong enough. That's why the stove pipe is screwed together at 3 points at every joint. 

Once the stove has been rebuilt, wait a bit longer before engaging the bypass. Give the newly fed wood a chance to char a bit first.


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## webbie (Oct 27, 2007)

Do some searches on "flashback" or "wood gas explosion"  -

try them from our front page "google" box - at http://www.hearth.com

I had the same stove and rarely (if ever) had the problem. My guess is that:
1. Make certain all gaskets and door seals are tight, same with flue collar
2. Make certain all secondary air inlets are open - those holes at the bottom of the firebrick in the rear, etc.
3. Do a major cleaning of ash from back behind the ash pan, etc.
4. If all else fails - and maybe even anyway, install a barometric draft regulator on the pipe. 

This is basically an imbalance in the stove system (stove/chimney) - the gases should be getting ignited all the time, but instead they are building up and then lighting off.

PS, even a manual stack damper may help - but if you use it just set it and forget it, don't change it as folks usually do. All you are doing with it is cutting the draft down a tad.


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## Donna (Oct 29, 2007)

Hello,

The first winter I had my second hand Res. Acclaim 2490 I had that problem very often. I assumed it was me, learning curve of the first burning season. I was partially right, but blocked air flow turned out to be the real problem.

Before beginning the second burning season, after my husband had left for work one day, I very carefully took the inside of the stove apart, manual in hand but still very nervous that once apart I would not be able to get it back together.
I removed the cement inserts, then took the two plates on either side of the refractory package where air flows out of the stove to find about 5 inches of very fine grey ash in both passages. 
I cleaned them out, got the stove back together, and voila, problem solved.

In the three years since then, it has happened only once or twice, and that was definately our fault of dampening down the air too quickly.

Hope this helps,
Cheers,
Donna

7 cords of mixed apple/maple waiting for the winter.
Getting two cords of 2"x12" starter apple wood tomorrow.....


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## begreen (Oct 29, 2007)

thanks for the post Donna. There's no substitute for regular cleaning and maintenance. How long had it been since that area had been cleaned?


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## Donna (Oct 29, 2007)

Hi Again,

We bought the stove second hand, from a person who purchased a house with it installed and who did not want it. The house was built in 2000 and I think the stove was bought then. So that would make it 4 years old when we got it......so my best guess is 4 years, plus the one year that we ran it, or rather tried to run it........
The short answer is 5, laughing.

Since then, there has been little or no accumulation in these channels. I burn it hotter than the previous owners did and do not start with paper which causes no end of fly ash. I start with a Duraflame log cut up into chunks about the size of a walnut. One does the job. Two logs last the whole winter and it causes no ash. 

When we sweep the chimney, twice a year, once in the summer and once mid-way through the burning season, I put a plastic container in the space that the flap leaves when the damper is opened, which catches almost all of what falls down, which is very little, maybe a table spoon or so of dry brown powder.

It is a great stove, but the refractories are fragile, so be very careful loading wood and they will last much longer.

Cheers,
Donna


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## marchj (Dec 19, 2007)

I also have the same stove with the same problem of back-puffing.  I have had the flue cleaned and inspected, but found nothing wrong.  I have replaced (upon the recommendation from VC) the combustion chamber, gaskets, damper door, upper fireback and it still puffs.  Then they said my wood was the problem so I traded someone 2 cords of split hickory for split oak and it still puffs.  It puffs about an hour or 2 after loading the stove for the over-night.  It is loud enough to wake me (I can hear the explosions and smell the smoke in my bedroom on the opposite end of the house).  Needless to say that I'm very dissapointed with the company and the product.  When I called to complain, they said it was the first time that they had heard of a problem with this stove.  Funny, because I have a friend in Minnesota that has the same stove and problem and he's called many times to complain.  I won't buy another one.


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## begreen (Dec 19, 2007)

Donna and marchj: Can you describe the flue set up on your stoves in detail? I'm going to assume that you are doing all the right things. Still, it would be great to get to the root of the problem. That brings us to the flue system. Has your dealer witnessed this back-puffing? Have they discussed any other possibilities such as the potential of refractory crumbling and blocking or disrupting smooth smoke passage?


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## marchj (Dec 19, 2007)

I have a straight-run, double insulated 6" flue that runs about 12' through the inside of my great room and then goes another 6' above the roof. The exterior part is triple wall and stainless with a bird-proof cap. My dealer has gone belly-up and the next closest dealer is about 200 miles away so I don't think he'll be making the road-trip to my house to hang-out with me while we sing cumbaya around the wood stove. I just replaced the combustion chamber (my old one was pretty ate up and damaged) about a week ago and completely vacuumed out the ash and dust out of the fire box and resealed all the joints with cement and replaced the gaskets. The funny thing is my stove worked great for the first few years, but the last 2 years it has puffed like "Puff the Magic Dragon" most every night. Getting up in the middle of the night to baby sit my stove is not how I like to spend my sleeping hours...


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## Donna (Dec 20, 2007)

Hi,

My set-up is almost identical to marchj's. Straight run up from the stove, with a good draft on a shortish chimney which is about 14 feet long in total, inside and out.

My back puffing has greatly decreased over the years, with the innitial cleaning of the stove doing the most to stop the problem. That, plus the learning curve of learning to run it properly....when to close the draft is the most important. I was doing it by the thermometer reading and now I do it by feeling how the stove is running, and closing it when the stove is much hotter.

I, too, am about to replace my secondary combustion package...might wait till the spring, but maybe not.

The stove runs perfectly now, but the first year, I had to baby sit the stove all the time, and did not dare run it over night.

Thanks for all the good advice I have found here,
And Merry Christmas to All from Quebec.

Donna


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## Bill (Dec 20, 2007)

Would I be a happy camper, if when I came home from work, my wife had rebuilt the stove. Donna your my kind of gal.


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## swestall (Dec 20, 2007)

I had backpuffing on my Definat CAT stove. It always occurred late in the burn cycle when I had the air control set to let very little air in (damped way down). When the backpuff occurred, I would go down and open the control up about 1/3 and that would resolve the problem. It seemed to me that the wood was outgassing faster than the air I was letting in could evacuate it through the stack. Try burning with the control open a bit more at a time and see if you find a sweet spot. Hope that helps.


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## marchj (Dec 20, 2007)

I usually slide open up the lower draft, but the temp jumps up so quickly that it is hard to keep it under control.  I end up opening the lower draft until it stops puffing and then shutting it slightly, centimeter at a time, until it it balances out.  The process can take 20 or 30 minutes.  

Thanks for all the support.  I hate to get rid of the stove, but also hate to lose sleep babysitting it.

Zac


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## webbie (Dec 20, 2007)

march, it is worth trying a barometric draft regular on the pipe........pretty decent change (25 to 75%) that it could solve the problem.

http://www.woodmanspartsplus.com/product.asp?Product_Id=16689


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## begreen (Dec 21, 2007)

marchj said:
			
		

> I usually slide open up the lower draft, but the temp jumps up so quickly that it is hard to keep it under control.  I end up opening the lower draft until it stops puffing and then shutting it slightly, centimeter at a time, until it it balances out.  The process can take 20 or 30 minutes.
> 
> Thanks for all the support.  I hate to get rid of the stove, but also hate to lose sleep babysitting it.
> 
> Zac



What temp range are you trying to keep the stove within Zac? Where is the thermometer?


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## Brian VT (Dec 9, 2008)

BeGreen said:
			
		

> It can blow off stove doors, stove tops and pipes if strong enough. That's why the stove pipe is screwed together at 3 points at every joint.


I just read this and though it was worth dragging back out.
My interior double-walled pipe is pretty tough to pull apart so I didn't see any need for screws that would make cleaning take longer. 
I'm gonna throw a few in now and the rest tomorrow.


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## michaelthomas (Dec 9, 2008)

I have the same stove and have the same problem.  The stove definately needs to be at the right temp (mine is a solid 600 degrees stove top) before you close the damper and then it needs to have time (mine is about 1/2 hour to bring it back to halfway) to be able to cut back the air intake.  I find the problem much worse when I am using less than ideally seasoned wood.  I have never been able to get the intake down much past half way without a back puff.  I will smell a bit of smoke and will watch the stove for a few minutes and you can see the flames are gone and then a bit of secondary burn and a puff of smoke out the griddle lid.  I have sealed the stovepipe joints and the collar with furnace cement and this helped.  It is a tough stove to figure out but I love it.


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## Brian VT (Dec 9, 2008)

I get the same bit of puffs when trying to find the G-spot. Most aren't even strong enough to push any smoke out but I guess you never know. That's why I put the screws in.
600 seems the norm for me too when starting a new fire but when running 24/7 and loading onto a good bed of coals mine will often take at 400.


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## trk2 (Dec 9, 2008)

To follow up on what michaelthomas posted, my VC Vigilant will only back puff if I engage the damper when the stove is too cold.  The stovetop needs to be at a minimum 600° for at least 15 minutes before I can engage the secondary burner.  My stove is bigger, so you could possibly get away with quicker times.  If I try to rush the process, then the stove will start back puffing 10 or 20 minutes later.  Try running your stoves hotter before you engage the damper and see if you can consistently get the secondary to fire off.


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