What is going on with my wood stove??

[loadthestove]

Last night around 10 pm I loaded my stove for overnight.As usual I raked coals down and loaded stove with splits.
Around 11 pm I was sitting in room where stove is located and heard "WHOOF"followed by smoke coming out of every joint in stove pipe.I watched the stove for a few minutes and it done it again.the flame would get very small and then "WHOOF " many flames in stove and smoke evrywhere.its did this three or four time in about hour and half period.

Finally I just used tongs and removed the wood from stove.MY questions whats going on.I have used this stove for several years now and have never had this problem.I checked outside and no wind was blowing period.

The stove is a Century free standing with secondary burn tubes .I have about 2 ft of black pipe on it then a 90 elbow going into a thimble in a massonary chimney.Anyone every experienced this or have any ideas as to what happened

 

[Dalmatian90]

Did you check your chimney?

I'd think I'd go play the lottery, but maybe you've hit a sweet spot -- the flue is big enough for small fires when you light it, it's big enough that when the fire is hot it can force the smoke through, but you're somewhere making a fair amount of smoke but not a lot of heat it's allowing CO to build up (from incomplete combustion as the flames die down), and then hits a magic mixture where the fuel / air / temperature are all right to explode, suck in some fresh air in the aftermath, and repeat.

(I know, I'm probably crazy...that's why I said go play the lottery )

 

[Fyrebug]

What is the model? What is the size of your chimney and is it lined?

 

[haveawoody]

Yeppers sounds like a pluggy chimney.
Might be time for a quick clean before the lottery wins.

 

[milkman]

I think if you add the wood and leave the draft open enough to let the wood get started and then close it down, it will keep the smoke from building up in the fire box and then when it ignites it's like a mini explosion. It's tempting to leave it shut down, especially when I have some mild days.

 

[TreeTangler]

First and foremost, let me start by saying check you chimney. It is never a bad idea to start with that no matter what the problem.

The most likely scenario I can come up with is a lack of oxygen, let me explain. While most people believe it is the solid wood itself that burns, it is really the gasious state of the fuel that combusts. When you load your stove with new splits, the stove is starting to cool off. The splits start to smoke but are still not hot enough to ignite. Pretty simply your stove is filling up with fuel. If the heat is low and so is the oxygen, it will hang around instead of igniting or heading straight out the chimney. If there is still enough heat from the coals it will eventually ignite, and possibly all at once as you are describing. With the oxygen closed all the way as you would at night, it quickly consumes all the usable oxygen and snuffs itself out. Eventually an equilibreum will exist with heat, fuel, and oxygen and sustain a good fire.

Hopefuly I didnt confuse anybody or misstate anything to badly. My advice? When loading the stove, open the damper and the air fuel to get the fire going and then back it back down. This will also cut down on the creosote build up as well.

 

[stihly dan]

he has an epa stove, so there is always oxygen available.

 

[haveawoody]

stihly dan,

Could be as simple as the air intake is blocked on the epa stove.
That has happened to me when the night is a real cold one and heavy burning all day to discover the next day an unburned thing lodged in the air.

Bet it's creasote chimney though.

 

[TreeTangler]

he has an epa stove, so there is always oxygen available.

Didn't see that. Could still not be enough. You'd be surprised at just how much oxygen a fire can consume. Does it have an outside air intake?

 

[loadthestove]

I checked chimney about two weeks age during a warm day but after last nights episode I check it again today .I have used this setup for about 7-8 years now and this is the first this has happened,actually it happened one other time but we had monster wind that day and it seemed to be blowing straight down.That was first thing I checked last night and we had zero wind,not even a slight breeze.
I posted a few pics,I have not reinstalled the pipes yet.I 'm not going to use it again until this weekend when I can watch it very closely for several hours

my chimney is about 22-24 ft tall and has eight inch clay liners.I have a six inch thimble thru wall(sorrounded by 12 inches of concrete) As mentioned it has worked great small fire to large ones .

stove without pipes View attachment 279203
some pics of inside pipeView attachment 279204
View attachment 279205

the build up seen is very dry and flakey,the chimney itself has even less

 

[haveawoody]

loadthestove,

Check your air inlet then, bet its a clinker in the air inlet.
Pipes look fine to me so not much else it can be.

If you have a shopvac it will clean the inlet real fast.

 

[loadthestove]

I think if you add the wood and leave the draft open enough to let the wood get started and then close it down, it will keep the smoke from building up in the fire box and then when it ignites it's like a mini explosion. It's tempting to leave it shut down, especially when I have some mild days.

I considered your idea,stove had a large bed of coals when I reloaded,I had air control on lowest setting and just loaded and closed door.I could understand first flash over but I had several in a short time.everytime stove would fill full of flame then die back down and then basically blow up again.

 

[haveawoody]

loadthestove,

Try a small fire and see what it does.
If your inlet has problems a small fire will burn happily but once the air needs go up the fire will act strange.

 

[loadthestove]

loadthestove,

Try a small fire and see what it does.
If your inlet has problems a small fire will burn happily but once the air needs go up the fire will act strange.

That good advice I check asap,I'm ashamed to admit it but I've never clean them ...

 

[haveawoody]

loadthestove,

No worry has happened to me and left me scratching my head as to what it could be.
Them clinkers are sneaky.

 

[steve md]

I think if you add the wood and leave the draft open enough to let the wood get started and then close it down, it will keep the smoke from building up in the fire box and then when it ignites it's like a mini explosion. It's tempting to leave it shut down, especially when I have some mild days.

what he said it happened to me to just leave the air open a little more

 

[Muffler Bearing]

I believe they call this..."Back-Puffing".

Wood is out gassing, the available oxygen , for a steady fire. Gas finally lite s and Puff!

Usually will blow smoke thru the door seals also.

 

[Wife'nHubby]

It's called 'back puffing'. Lack of oxygen kills the fire, then coals ignite the gasses built up inside the stove and you have a mini explosion. Solution is open the air lever a little.

As far as other possible issues: Yup, check for clinkers, check the cap on your chimney to make sure it's not blocked (sounds like your chimney is clean/clear enough); make sure your air lever is working correctly; make sure your glass hasn't shifted off center of the gasket or has been otherwise compromised; check all your chimney connections as they might have been knocked loose.

In the future it's probably not a good idea to load up a stove on a good coal bed and then lower air intake down to minimum.

On a side note: Can you switch out your one 90 degree to two 45's? Draft would be increased if you did.

 

[Mac88]

Mine was puffing today and all I had in it was oak and hedge. It sometimes does it with silver maple but not with hardwood. Go figure.

 

[sunfish]

I think if you add the wood and leave the draft open enough to let the wood get started and then close it down, it will keep the smoke from building up in the fire box and then when it ignites it's like a mini explosion. It's tempting to leave it shut down, especially when I have some mild days.

I considered your idea,stove had a large bed of coals when I reloaded,I had air control on lowest setting and just loaded and closed door.I could understand first flash over but I had several in a short time.everytime stove would fill full of flame then die back down and then basically blow up again.

That's exactly what is happening. You have to give the fire more air, then when new load is burning good you can shut it down. Some stoves will continually do it if shut down too far.