What Just Happened and How Dangerous Was It?

[lumbering on]

Ok, so I am learning a lot from you guys, and building up some confidence. But...

Came home from work, started with a cold stove, burned some kindling, an envi-block and some small spits down to a coal bed, raked coals forward and then loaded the stove with as much wood as I could fit it the box. (top loading, downdraft non-cat).

Gradually turned the air intake down to almost all the way closed (bypass also closed). After 30 minutes fire had died down and thought I shut down the air too soon. I then opened the air control only to the next position (still almost all the way closed). 15 minutes later it was like a small explosion in the box, top door pops open and big puff of smoke blows out into my living room around the edges of the lid.

I am assuming this is the "puff back" I keep reading about, and I probably should have opened the bypass before opening up the air?

I've been very very careful as this is my first stove ever, but I don't remember reading in the manual anything about this, and now I'm worried about loading it up again like this and walking away. Is this operator error?

 

[fespo]

to much unburned gases then the gases lit up all at once.

 

[ChadD]

The more I read about these compressed wood blocks the less appealing they sound.

 

[HotCoals]

To me that's not a back puff.
Gasses were building up in your stove..then poof!
Prolly draft was not going strong enough yet.
Question though..were the tubes burning before this happened?

Opps..I see fespo beat me to it..I type way to slow!

 

[lumbering on]

I couldn't see back there with all the smoke and wood stacked up in front.

 

[Waulie]

I would worry about walking away in that situation. In general, never walk away until that puppy in cruising along nice and happy.

Yes, it was operator error. No, I don't think it was particularly dangerous. I've had it happen before and it did scare the crap out of me, but really it's a live and learn situation. I'm not real familiar with how your stove works, but I'd guess that if you think you turned it down too soon opening the bypass would probably be prudent. You might find if you just open the bypass you may not have to give it more air at all to get it rolling. I'm sure others who are more familiar with your stove will chime in.

 

[BrowningBAR]

The more I read about these compressed wood blocks the less appealing they sound.

It can happen with wood as well.

 

[BrowningBAR]

To me that's not a back puff.
Gasses were building up in your stove..then poof!
Prolly draft was not going strong enough yet.
Question though..were the tubes burning before this happened?

Opps..I see fespo beat me to it..I type way to slow!

Also, no burn tubes in a Lopi Leyden.

 

[HotCoals]

Also, no burn tubes in a Lopi Leyden.

Ah..thanks.

 

[BrotherBart]

It is called "woofing". Air turned down before a consistent draft and burn is established. Smoke builds up in the firebox and the second it gets a whiff of flame it all goes off at once. The reason for the three screws in stovepipe. To keep it from blowing apart.

Can happen with any stove. Of course if the top of my steel stove pops up I would be really worried since it is welded on.

Edit: Really interesting with a flex chimney liner. You hear it expand and contract all the way up when it happens.

 

[fire_man]

It's happened a couple times to the Progress, now I think I need to put my scared dog into therapy.

 

[BrowningBAR]

It is called "woofing". Air turned down before a consistent draft and burn is established. Smoke builds up in the firebox and the second it gets a whiff of flame it all goes off at once. The reason for the three screws in stovepipe. To keep it from blowing apart.

Can happen with any stove. Of course if the top of my steel stove pops up I would be really worried since it is welded on.

You gotta admit, that would be one hell of a "woof."

 

[BrotherBart]

You gotta admit, that would be one hell of a "woof."

When it happened in the 30 I was sitting at the table eating dinner. The show in that glass was a sight to see. That and the noise from the liner. I have not one doubt it would have lifted the lid on a top loader.

 

[stoveguy2esw]

BB hit it on the head, "woofing" or "precombustion" happens when heat is present but movement of air is not, the wood "outgasses' combustible fuel into stagnant air, there is not enough oxygen present to burn this as it outgasses, when the stove is opened again to allow it to breathe this unburnt fuel has the third element of combustion (air) it is literally a low order fuel air explosion.

best thing BB put in his post is the mention of the screws in the pipe connection joints. this is PRECISELY why this is required

 

[ridemgis]

The more I read about these compressed wood blocks the less appealing they sound.

It was the operation, not the fuel.

 

[begreen]

Ok, so I am learning a lot from you guys, and building up some confidence. But...

Came home from work, started with a cold stove, burned some kindling, an envi-block and some small spits down to a coal bed, raked coals forward and then loaded the stove with as much wood as I could fit it the box. (top loading, downdraft non-cat).

Gradually turned the air intake down to almost all the way closed (bypass also closed). After 30 minutes fire had died down and thought I shut down the air too soon. I then opened the air control only to the next position (still almost all the way closed). 15 minutes later it was like a small explosion in the box, top door pops open and big puff of smoke blows out into my living room around the edges of the lid.

I am assuming this is the "puff back" I keep reading about, and I probably should have opened the bypass before opening up the air?

I've been very very careful as this is my first stove ever, but I don't remember reading in the manual anything about this, and now I'm worried about loading it up again like this and walking away. Is this operator error?

Yes, operator error. The fire was shut down too aggressively and too soon. Don't beat yourself up about it. This has happened to many of us. Next time don't shut down the stove to the point where is snuffs out the flame. Try to keep at least a very lazy flame burning.

 

[bogydave]

When it happened in the 30 I was sitting at the table eating dinner. The show in that glass was a sight to see. That and the noise from the liner. I have not one doubt it would have lifted the lid on a top loader.

That's why Bart's location is on the military satellite 24/7/365 watch list. ( Infrared & thermal )
It was detected & they though it was a launch
Black cars with mirrored windows cruise his neighborhood frequently LOL

 

[BrotherBart]

That's why Bart's location is on the military satellite 24/7/365 watch list. ( Infrared & thermal )
It was detected & they though it was a launch
Black cars with mirrored windows cruise his neighborhood frequently LOL

The noise from the Blackhawk helicopters drives us nuts.

 

[corey21]

Had that happen once last year woke me up when it did. Build of gases then bang.

 

[bogydave]

The noise from the Blackhawk helicopters drives us nuts.

Better it than the "stealth one" ! When they use it, people disappear

Had that happen once last year woke me up when it did. Build of gases then bang.

Bet that leave tracks of black soot all over the roof & easy to see if there's snow.

 

[katwillny]

I know what you mean Brother Bart, We have Stewart AFB and we have large military C17 type plains flying right over our house. i can tell the time just by the noise of the planes. There is a 10:05pm plane that goes right over and its loud.
as far as the original post, ditto on the accumulation of gasses, perhaps next time wait a bit longer before you shut her down.

 

[remkel]

Have not had this experience to he extent described, but had some interesting experience when I have opened the side door on a smoldering fire.

There are three (well actually four) components that make a fire: fuel, heat, oxygen and chemical reaction. All need to be present for the fire to burn. Basically, what you had was heat and fuel. When you opened your draft you were gradually adding the oxygen. Eventually the mixture became ideal an WHOOF! You saw the chemical reaction.

Best to make certain you keep the appropriate mixture consistently.

 

[lumbering on]

Thanks everyone.

I think I also may have blocked the opening to the secondary combustion chamber in the back with the way I stacked the wood, worsening the draft situation.

I think the next time the flame dies down because I turned the air control down too soon, I'll open the bypass and vent the box before opening the air control back up.

Still not ready to go to bed with a full box yet, though.

 

[blades]

Might want to peruse the manual for your stove ( ya, I know, No one reads those) it just might tell ya not pack it floor to ceiling in order to keep a exhaust channel free.

 

[Pallet Pete]

Sometimes with wood will have a gas pocket that doesn't let go until the log falls and then boom it goes ! The next thing you know you are cleaning your drawers out. Once it blew the top load door of the jotul f50 open and that's a heave mother right there ! We where halfway through the burn. Yours was operator error but be aware it can happen other times too.

Pete