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Stove pipe glowing red (non-emergency)  RSS feed

 
Zoe Stevens
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Hi all! I had an incident last night with my wood stove and although it seems resolved I was hoping to get some feedback from fellow wood stove users.

Two years ago, I had a new wood stove installed in my basement and a new chimney put in (it's an outdoor chimney, like you can see the metal tube from outside). It was professionally installed etc etc. We used it last winter with no problems. I use seasoned hardwood only and try to burn it on high at least once a day, and we had it cleaned this summer and there was minimal build-up at the time.

I started using it this year a few weeks go. Last night, my husband filled it with firewood and set it to "low" (for overnight). I went down a bit later and turned it up to high because it was just smouldering, not burning. When I returned a little while after that (20 minutes?) the fire was going well, and I noticed that the inner wall of the pipe was glowing red-orange (I can see the inner wall through slots in the outer wall), and it was glowing from the top of the stove to the wall (where I lose sight of it because it goes outside). It was quite hot - standing by the stove was tolerable but very warm. I turned it right back down to low and within 10 minutes the glowing had ceased and the fire's intensity was reduced.

There was nothing coming out of the chimney (minimal smoke, but I couldn't see because of the dark - no sparks or flames).

Nonetheless, I called the fire department because the only thing I know that causes a glowing pipe is a chimney fire and although I knew the creosote buildup from a month of use with hardwood had to be extremely minimal, I couldn't go to sleep not knowing if I'd wake up the next morning!

The 911 operator advised me to keep an eye on it, but that it was OK to wait indoors for the truck, which came shortly (with lights but sans sirens, thankfully). They came in, checked it out thoroughly (inside and out), and concluded that the pipe just got so hot from all the wood and from being on "high" that it glowed red from the heat. They came in prepared to extinguish the fire and take the pipes apart, but they didn't do that after their investigation turned up zero evidence of a fire.

Today, I called the company who installed (and cleaned) the wood stove. They suggested that probably something light like a piece of paper or bark had been sucked into the pipe and had burned there (there is a 90 degree bend in the pipe a few feet above the stove itself). I am disinclined to believe that because the stove pipe was uniformly glowing orange for the whole span which I could see. A piece of paper burning seems like it would cause one area to be redder than another, and also there was no paper or bark in there that I know of, but they said they would come check it out which I appreciate! Unfortunately they can't come out before Dec 7. They were reticent to give me a straight answer about whether I should discontinue using the stove, but said to follow the firemen's advice (which was to keep using the stove but just be careful about filling it up and blasting it... and to not store my ashes indoors. Oops!).

So - I am not really sure what I'm asking. I guess I'd feel better if someone said "oh yeah that's normal" but as yet I no one seems to have encountered this before. I would appreciate your input - if you made it through the novel!
 
R Scott
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Location: Kansas Zone 6a
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Too much wood, damped down so it is all hot and then opened up to oxygen puts off a LOT of woodgas that will burn well up the pipe. It wasn't creosote on the pipe, but would have been if you didn't open up the air when you did. I have seen flames shooting out of freshly cleaned 15' chimneys when someone has done that. A properly installed modern spec pipe can handle that once or twice, but don't make a habit of doing that!!! Definitely get it inspected to be sure, and keep the fires small.

This is what you are doing on purpose in a rocket stove, and why you need such good materials for the heat riser.




 
Zoe Stevens
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R Scott wrote:Too much wood, damped down so it is all hot and then opened up to oxygen puts off a LOT of woodgas that will burn well up the pipe. It wasn't creosote on the pipe, but would have been if you didn't open up the air when you did. I have seen flames shooting out of freshly cleaned 15' chimneys when someone has done that. A properly installed modern spec pipe can handle that once or twice, but don't make a habit of doing that!!! Definitely get it inspected to be sure, and keep the fires small.

This is what you are doing on purpose in a rocket stove, and why you need such good materials for the heat riser.


Oh wow! I did not know about woodgas. From now on we will doing much smaller fires, and using the big logs for overnight rather than piling the stove full of wood. Maybe that will help conserve the wood as well...
 
Miles Flansburg
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Location: Zones 2-4 Wyoming and 4-5 Colorado
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Welcome to permies Zoe !

It all has to do with how much air you are letting in to your woodstove. Do a little experiment for me. The next time you have a fire, open the dampner and let the air in. The fire should get really big and even make a roaring sound. (the rocket sound) Then close the dampner down. The fire will slow down and burn quietly.

So when you opened the dampner that night you added lots of air and the fire burned really hot. The flames would have been going up your stack and this would cause the stack to get hotter and hotter.

When a fire gets that hot it is using up all of the wood fuel including the smoke or "wood gas".

When you turn it down it is cooler and much of the fuel goes up your stack in the form of smoke.

So it is all a matter of getting the airflow right.

All of these things are what makes a "rocket stove" work so well. Check it out. http://www.permies.com/forums/f-125/rocket-stoves
 
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