Back puff and smoke filled house.

[4seasons]

While I have used wood heat all my life and seen the occasional random puff of smoke from around the door, damper and flue pipe, last night our stove filled the house with smoke. Not enough to choke you or even burn your eyes, but way more smoke than anyone would accept in their house.

Here is the whole story. I have had a fire going for a month or so 24/7. Yesterday it got up to 47 degrees so I told the wife to let the fire go out and I would clean the chimney when I got home. So last night I used a mirror to look up the chimney and it looked fairly clean, just a little buildup right around were the stove pipe enters the chimney. So I get on the roof and run the brush down till I can't fell any resistance then go inside and scrape the stove pipe out with a putty knife. By then it was getting dark and the temp was dropping fast outside. So I built a fire with the same 2-3 year seasoned oak that I have been burning. It started raining a few minutes later and had turned to snow before we went to bed around 10:30. About 2:30 this morning the wife wakes me up to tell me that the stove had made several big clanks like when the wood shifts as the underside burns out and the wood on top drops. I immediately smelled smoke and ran to check. When I turned the light on I could see a little fog in the house from the smoke but not enough to set the smoke alarm off. When I open the stove to check I get that huge puff of pressurized smoke back at me. So I went out and looked at the chimney and couldn't see any smoke. It was still snowing and there was a 10-20 mph wind blowing. When I walked back in the stove puffed smoke from around the door and out the damper before I even touched the stove. I then poked the logs around ,opened the damper and got a good bit of fire in the box. Then I opened a window to let some smoke out of the house. After a few minutes I set the damper back where I normally keep it for a 20 degree night and went out to check the smoke from the chimney again. This time I saw a normal amount of smoke but it was falling as the wind was carrying it away rather than rising like normal. I have heard this being caused by barometric pressure falling and pushing smoke down around the chimney but I don't really know for sure. I went back in and closed the window and went back to bed. Didn't have any problems the rest of the night.

The nearest I can figure is that the weather had caused the chimney to lose temperature and stop drafting. I have never had a draft problem before except for at start up before I started using top down burning. Since the fire was going good when I went to bed the box had plenty of heat in it to keep the fire going but when the draft stopped it started smothering itself and with no place for the smoke to go the stove burped it back into the house. Once I opened the fire up and got it rolling again the chimney temps must have came up enough to reverse the draft and start working properly again.

Has anyone else had a problem like this? If so do you know what caused it and how to keep it from happening again?
Also am I correct in my theory blaming it on the weather? And I assume I took the right steps to fix the problem since it worked, but I would like to hear how others solve the problem as well.

 

[CrappieKeith]

It's not always just 1 thing...
Cold flue
Negative pressure in the home...lack of make up air
High winds
High pressure/barometer

 

[woodbooga]

I've had something similar twice. On both occasions, it was deep winter - mid-january once and late Dec. the other. On both days, it had been unseasonably warm - 50ish. And wet - precipitation and fog from melting snow.

First time, I swept the chimney, which yielded little in the way of soot deposits. The more recent time, I set the back dampre from the bake setting to the kindle setting in an attempt to heat up the flue. This seemed to work in inducing a draft.

 

[sunfish]

the wife wakes me up to tell me that the stove had made several big clanks

Back puff I've experienced was from choking the stove down too much at night. Flame goes out, stove fills with unburnt gases, then gases ignite. This cause big smoke puff and usually the clank noise your wife heard.

 

[Encore]

any back puffing we've gotten was on a super cold night when the fire had been out and the stove cooled completely (like you mentioned) and then getting a fire going and turning the damper down too far without letting the stove heat up appropriately

If I've let the fire go out, I make sure I get a nice 400 fire going or so before choking the fire down for the night. Even then I still don't shut it quite all the way.

 

[Hillbilly Rick]

Pretty much what they said. Wind, pressure, cold flue.
Wood is our primary heat source, we heat 1400sq.ft. with a Voglesang flat top stove. Our fires are hot most of the winter and in 6 yrs of burning here i've yet to have ANY creosote build up, loose ash in the 45* bend is all.

 

[4seasons]

Thanks to the response

Nice to know that I am not the only one that this has happened to and that I was right on the cause and solution. I guess next time I let the fire go out I better get it good and hot before it starts snowing.