out of control stove pipe temps

[Nutmeg Warrior]

I am trying to understand why the single wall stove pipe shot up to 800+ (surface temp measured with IR) for about an hour last night. It was pretty unnerving and I had to just ride it out with the primary on the stove completely closed. After an hour it finally calmed down and quickly dropped to 500.

I was at the beginning of a burn with a full load of brick fuel, which I have done without issue in the past. The stove never seemed out of control. I was dialing back the air incrementally when the spike in pipe temps happened. The catalyst was engaged the entire time.

Setup is this: dutchwest 2462 catalytic, 3.5' horizontal stove pipe connected to a 25' liner.

Any ideas? Could this have been a chimney fire? There was no sound and no smell other than burning paint. I didn't see smoke coming out of the chimney, only steam. I can't believe there would be much build up since I am new to burning. It's been mostly night and weekend fires for a few months. Much of this has been brick fuel. I guess I did burn some 30% wood early in the season.

Also, should I be concerned about damage to the pipe? I certainly could hear the metal contracting as it cooled down.

Thanks

 

[Huntindog1]

If you leave your input air wide open the heat is being flushed up the flue pipe heating it to a higher level.

Check you door gasket could be its not sealing well.

Or if you have a ash door in the bottom of the floor that is not sealed completely it will let too much air flow thru stove and flushing extra heat up the flue.

 

[Nutmeg Warrior]

Thanks Huntindog. I will check door tightness when I get home. And maybe I just need to dial the air back more quickly. The odd thing is that I was dialing it down in the same way I had done before. Of course it was much colder last night. Maybe my draft was really strong.

 

[ridemgis]

Internal temp on my double wall often gets to 800 degrees. And that's within the optimal burn range according to the thermometer. At that temp on the pipe I'm generally seeing 500 to 550 on the stovetop and that's just about maximum healthy burn with this stove.

 

[Jasper 83]

My flue temps have been running noticeably higher in this cold snap weve had even with the cat engaged and the air shut way down.

 

[Backwoods Savage]

I am trying to understand why the single wall stove pipe shot up to 800+ (surface temp measured with IR) for about an hour last night. It was pretty unnerving and I had to just ride it out with the primary on the stove completely closed. After an hour it finally calmed down and quickly dropped to 500.

I was at the beginning of a burn with a full load of brick fuel, which I have done without issue in the past. The stove never seemed out of control. I was dialing back the air incrementally when the spike in pipe temps happened. The catalyst was engaged the entire time.

Setup is this: dutchwest 2462 catalytic, 3.5' horizontal stove pipe connected to a 25' liner.

Any ideas? Could this have been a chimney fire? There was no sound and no smell other than burning paint. I didn't see smoke coming out of the chimney, only steam. I can't believe there would be much build up since I am new to burning. It's been mostly night and weekend fires for a few months. Much of this has been brick fuel. I guess I did burn some 30% wood early in the season.

Also, should I be concerned about damage to the pipe? I certainly could hear the metal contracting as it cooled down.

Thanks

Welcome to the forum Nutmeg Warrior.

I'd just like to comment on the above in red. Because you are new to burning, that usually will cause a lot of buildup! In addition to that, you are burning mostly nights and weekend fires. This will add to the creosote problem because of all the cold starts. Every time you start a new fire that chimney is cold; there is part of the problem. Good luck.

 

[Nutmeg Warrior]

Thank you Dennis.

It turns out the ash door is ever so slightly loose along the bottom edge. It doesn't pass the dollar bill test. I'm skeptical that is the cause of flue spike the other night, but what do I know. I say this because the fire never seemed out of control inside the stove. Anyway am certainly going to tighten that up!

I checked the stove pipe and it has a fine layer of soot. I can't safely check the chimney because the roof is covered with snow and ice.

I haven't lit a fire since. I'm way too freaked out knowing that I potentially had 1600 degrees of flue gasses in that pipe!

 

[webby3650]

More like 1200. Was the by-pass closed when these temps happened?
Hitting those temps on single wall isn't uncommon, but it shouldn't be a common thing.

 

[Nutmeg Warrior]

By-pass was closed the entire time.

 

[mikesin]

Internal temp on my double wall often gets to 800 degrees. And that's within the optimal burn range according to the thermometer. At that temp on the pipe I'm generally seeing 500 to 550 on the stovetop and that's just about maximum healthy burn with this stove.

+1

 

[Backwoods Savage]

Thank you Dennis.

It turns out the ash door is ever so slightly loose along the bottom edge. It doesn't pass the dollar bill test. I'm skeptical that is the cause of flue spike the other night, but what do I know. I say this because the fire never seemed out of control inside the stove. Anyway am certainly going to tighten that up!

I checked the stove pipe and it has a fine layer of soot. I can't safely check the chimney because the roof is covered with snow and ice.

I haven't lit a fire since. I'm way too freaked out knowing that I potentially had 1600 degrees of flue gasses in that pipe!

For sure that ash door can cause big problems if it is not tight. We see every year folks who will open it to get a roaring fire going and sooner or later they forget it. That is some serious bad stuff and why it is not recommended to do it. But in your case it is probably just a case of replacing the gasket, which is pretty easy. Clean out the channel with a wire brush after you remove the old gasket. I like to use one of these. It fits in a drill.

 

[Nutmeg Warrior]

I can't seem to get the ash door sealed tightly along the bottom. I tried new gasket and even packed cement under the gasket to raise it up. I adjusted the latch. Nothing works.

I'm thinking of just cementing the door shut. I never use it as I keep the bin full of ashes. Can I seal it shut?

 

[dentman4411]

As mentioned probably air leaking but i will say while id be freaked out as well regarding temps, if its a duravent liner, they are rated for 1000 normal temp usage, 1400 one hour spikes and 3 quantity 2100 chimney fires for 15 minutes. I doubt your liner was damaged. I too had my flue get away from me when i first started burning, the pinging of the single wall contracting was scarey stuff for sure. Good luck in finding your weak link