Dangerous Burn?!

[brianbeech]

Last night I had a meeting and just before I left the house I loaded up the stove, let it get pretty warm, then shut down the air and went to my meeting.

I came home, everything being fine, loaded up the stove again, got the fire hot and shut down the air to my 'normal' mark - perhaps just a little more than usual.

In about an hour, I walked into the kitchen and smelled smoke (curing paint smell from pipe). I ran downstairs to see my 6' run of single-wall black stove pipe billowing off smoke. Without thinking, I cut the air off and then ran outside to see if I had a chimney fire.

Well, I saw no evidence of that - perhaps because I had already killed the air?! I pointed a fan at the stove pipe for just a few seconds and the temp dropped dramatically. I felt the brick above where the pipe enters the chimney, and it was warm, but not overly hot. I could keep my hand on it indefinitely.

I'm leaning away from chimney fire, but I can't figure out what went on. My stove top temp was around 400f and my stove pipe surface temp was 600f. 600f doesn't sound too high, but considering that when my stove is at 400f my pipe is typically at 200f, this gives me cause for concern.

I can think about the variables that changed: a little more air, windy night, ... that's about all. I've also burned my stove when it's been much more windy without any adverse affects.

Now I don't feel safe enough to burn the stove while sleeping or leaving; I don't feel like I know my stove anymore. Any thoughts or suggestions?

 

[joecool85]

Not sure what happened, but is your stove pipe single wall or double wall?

 

[brianbeech]

Not sure what happened, but is your stove pipe single wall or double wall?

single

 

[zzr7ky]

Maybe it was 'puffing'. The warm pie is trying to draw well. The low, low air setting doesn't allow enough oxygen so after a while many embers go out, but not all.... Time passes and the chimney continues to draw, and hot coals are putting off gas until there's a sparking ember that set's off the burnable mixture. It can 'go off' like that strong enough to be alarming, but when mine did it it was just a quick, loud 'huff' noise but it did push smoke smell ou the top loading doar and the vent pipe joints.

I cured it be taking care not to clamp down so tight on the air, especially on a load of wood that's a bit on the fresh side. seems like more heavily coaled loads were less inclined to do it.

I'm guessing that it doesn't take but a tablespoon of exhaust gas to smell up the house.

ATB,
Mike

 

[shawneyboy]

Last night I had a meeting and just before I left the house I loaded up the stove, let it get pretty warm, then shut down the air and went to my meeting.

I came home, everything being fine, loaded up the stove again, got the fire hot and shut down the air to my 'normal' mark - perhaps just a little more than usual.

In about an hour, I walked into the kitchen and smelled smoke (curing paint smell from pipe). I ran downstairs to see my 6' run of single-wall black stove pipe billowing off smoke. Without thinking, I cut the air off and then ran outside to see if I had a chimney fire.

Well, I saw no evidence of that - perhaps because I had already killed the air?! I pointed a fan at the stove pipe for just a few seconds and the temp dropped dramatically. I felt the brick above where the pipe enters the chimney, and it was warm, but not overly hot. I could keep my hand on it indefinitely.

I'm leaning away from chimney fire, but I can't figure out what went on. My stove top temp was around 400f and my stove pipe surface temp was 600f. 600f doesn't sound too high, but considering that when my stove is at 400f my pipe is typically at 200f, this gives me cause for concern.

I can think about the variables that changed: a little more air, windy night, ... that's about all. I've also burned my stove when it's been much more windy without any adverse affects.

Now I don't feel safe enough to burn the stove while sleeping or leaving; I don't feel like I know my stove anymore. Any thoughts or suggestions?

I am not sure what happened there but....... I am wondering about your "normal" temps. It would seem to me that a surface temp of 200 on a single wall pipe is a pretty cool temp. Because of the temps listed I have to wonder if you had a creosote situation. I may be wrong but 200 on the surface of single wall seems really cool. Especially when you figure how the temperature drops as the gasses raise up the flue. By the time you reach the top of the flue even if it is an internal flue those gasses are really not going to be hot and will condense. Not to hijack but just wondering if any one else is thinking the same thing?

Shawn

 

[thewoodlands]

Did you have any high winds in your area?





Zap

 

[Fsappo]

He mentioned that the wind shouldnt have been an issue. I'm guessing he had a small creostote pipe fire or he just let the stove get a little hot before shutting it down with a good load of wood and the stove got a little carried away.

It's good to be careful after an incident like that. I would say you dont have too much to worry about. Just monitor it for a while until you get to know your stove all over again. Sometimes a break is good for a relationship when things get too hot.

 

[thewoodlands]

He mentioned that the wind shouldnt have been an issue. I'm guessing he had a small creostote pipe fire or he just let the stove get a little hot before shutting it down with a good load of wood and the stove got a little carried away.

It's good to be careful after an incident like that. I would say you dont have too much to worry about. Just monitor it for a while until you get to know your stove all over again. Sometimes a break is good for a relationship when things get too hot.

I was just wondering with the low pipe temp with some higher winds wOOd that cause some problems?


Zap

 

[brianbeech]

...I am wondering about your "normal" temps. It would seem to me that a surface temp of 200 on a single wall pipe is a pretty cool temp...

I am wondering the same things. Typically I run my stove at around 600f and my stove pipe 18" up usually runs around 350f. Maybe this is too cool and I am having that build up. As the weather breaks, I'll be on the roof inspecting the chimney and taking apart the pipe to check that.

Someone else mentioned a small pipe fire - is this possible? This is truly what I thought might have been happening. Never have heard of anyone talking of this, but it sure would seem to make sense.

 

[thewoodlands]

...I am wondering about your "normal" temps. It would seem to me that a surface temp of 200 on a single wall pipe is a pretty cool temp...

I am wondering the same things. Typically I run my stove at around 600f and my stove pipe 18" up usually runs around 350f. Maybe this is too cool and I am having that build up. As the weather breaks, I'll be on the roof inspecting the chimney and taking apart the pipe to check that.

Someone else mentioned a small pipe fire - is this possible? This is truly what I thought might have been happening. Never have heard of anyone talking of this, but it sure would seem to make sense.

We have single wall that comes out of the stove then into our double wall thimble, we run the pipe temp just below 500 @ it's high and the stove top temp @ 600. So far it's worked with our setup.




Zap

 

[Woody Stover]

I'm thinking small chimney fire too, seeing as how the flue temp was higher than normal.
My chimney temps are pretty much in line with what brianbeech is reporting, 250-300 when cruising, but I'm running a combustor stove. I've only had the new liner in for a few weeks. Perhaps I should take a peek down the flue...
How about your wood, brian, well-seasoned? If it was indeed a flue fire, I'm wondering what could be causing a dirty flue besides a possible low flue temp...

 

[leeave96]

Sometimes you will get a little fire in the flue pipe coming out of the stove. Smoldery fires can deposit creosote on them not unlike inside corners of the stove. I've had this happen and my stove pipe temp jumps up right fast and I can hear something crackling/burning in that part of the pipe. I cut the damper, it goes away. Pull the pipe - nothing.

Bill

 

[zzr7ky]

I bet you can duplicate it. Clamp down the damper on a good reload that's just getting going pretty well. Wait a half hour or so and tighten damper down further... just below where you have seconday flames. After a few minutes many stoves will have momentaty secondary flames flash off every few minutes. These flashes can produce a smoke smell because they generate positive vent stack pressure. Chimney fires occur with vent stack under strong negative pressure, so no smoke smell is leaking out.

I do agree the temps seem low. I'm guessing a bit more draft and it will not happen.

ATB,
Mike