Fire cone out of chimney

[Edav]

I have free standing Blaze King princess. I cleaned chimney a few months ago before season started. I've had roughly 10 burns so far this season and am only using 18% wood that is burning like a dream.

This afternoon I did a reload from this morning and had bypass open, t-stat on 3, and had the fire roaring pretty good within 2 minutes with door closed.

I decided to crack open the door to get a rush of air and get a nice char on the wood before I engaged the cat.

When I did, the air rushed in and made that "whoosh, whoosh, whoosh" sound that nearly sucked the door shut, but i had it propped open.

I then went outside to see what the stack looked like and i saw a few sparks and literally a flame cone about 6 inches out of the top of chimney.

I quickly went inside, closed door, and turned on bypass and then checked again and there was no plume and everything was operating normally. I also have access to the entire length of chimney pipe in the house and I felt it all the way to where it exits to roof and it was warm to the touch and not hot at all.

My question is whether this was an actual chimney fire or possibly the result of the smoke igniting from when I opened up the door and the flames rushing up the pipe.

My chimney liner was clean as a whistle and i barely used the stove so far this season, but I am kinda spooked about what I saw.

I am debating whether to recreate the scenario tomorrow to see what happens.

 

[fire_man]

The only thing that makes any sense to me is you had such a strong draft going with the door open, and a fully engulfed load, the flame was literally sucked up and out the flue, but even that is hard to imagine. It does not seem based on your description that you had a chimney fire.

 

[bholler]

My question is whether this was an actual chimney fire or possibly the result of the smoke igniting from when I opened up the door and the flames rushing up the pipe.

Well you had fire in the venting system so yes you had a chimney fire. But i seriously doubt you did any damage there simply was not enough fuel there to get high enough temps to damage anything

 

[fire_man]

Hmmm I always thought the official definition of a chimney fire was fuel coating the chimney liner burning. I guess any flame in the flue would qualify.

 

[bholler]

Hmmm I always thought the official definition of a chimney fire was fuel coating the chimney liner burning. I guess any flame in the flue would qualify.

According to the csia white page on chimney fires (which is what fire departments and insurance companies go by). The definition is fire in the venting system more than 18" from the heating applicable. They added the 18" part after the fact because many stoves send some flames into the base of the pipe. But like i said i doubt it did any harm at all

 

[Highbeam]

Since the bk, with open bypass, shoots flames straight up the pipe it seems pretty easy to have fire more than 18" up the flue. Compare to a tube noncat where there must be two feet of travel path forward and back before the flue outlet.

 

[BrotherBart]

Only time I have seen it was when I did this test out back with ten feet of stove pipe in my old stove to show people what happens in the pipe when you burn cardboard in your stove.

 

[bholler]

Since the bk, with open bypass, shoots flames straight up the pipe it seems pretty easy to have fire more than 18" up the flue.

And i am sorry but if that is true it is a design flaw. I have heard it here many times that it is normal for bk stoves to shoot flames out the top of the chimney and i am sorry but that is unsafe and i also don't believe it is normal.

 

[Corey]

Sounds like quite a show. Just curious... any chance this was just smoke out the flue, but happened to be lit from below / further down in the flue - making it look like a flame? Given the cleaning and low use 'till the 'incident' - it doesn't sound like a full-on flue fire, but some special circumstances making for the show.

 

[BrotherBart]

OK. I have been waiting for somebody to ask how he saw a flame cone coming out of the top of the chimney if he has a chimney cap?

 

[Highbeam]

And i am sorry but if that is true it is a design flaw. I have heard it here many times that it is normal for bk stoves to shoot flames out the top of the chimney and i am sorry but that is unsafe and i also don't believe it is normal.

Maybe you misunderstood. 18" up the flue from the stove. Not 18" out the top. That is bad.

 

[kennyp2339]

I like brotherbarts wood burning school

 

[bholler]

Maybe you misunderstood. 18" up the flue from the stove. Not 18" out the top. That is bad.

Yes 18 even 24 up the flue is not to bad but i have seen many people here say it is not uncommon for bk stoves to shoot flames out the top of the flue just like this poster said. All i am saying is that if that is true then it is a flaw in the design

 

[Ashful]

... had the fire roaring pretty good within 2 minutes with door closed.

I decided to crack open the door to get a rush of air and get a nice char on the wood before I engaged the cat.

Well obviously, don't do that. Manual states door should not be opened past the time it takes to get the load lit.

All i am saying is that if that is true then it is a flaw in the design

Design is identical to many cat stoves, in that you have a straight shot up the flue with bypass open. They rely on the operator to close the door once the load is exhausting > 500F. Maybe not idiot proof, but a well established compromise in place more than 30 years, and used by many.

 

[rdust]

Well obviously, don't do that. Manual states door should not be opened past the time it takes to get the load lit.

X2, no reason for the door to be opened after the fire is lit. That only leads to opportunity to forget it's open.

I have to be careful with my princess. If I load n/s and the splits leave a gap down the middle of the stove I'll get flames getting sucked right up the flue. If I see this happening I close the bypass if the cat is active or not to avoid overheating the pipe.

 

[Highbeam]

X2, no reason for the door to be opened after the fire is lit. That only leads to opportunity to forget it's open.

I have to be careful with my princess. If I load n/s and the splits leave a gap down the middle of the stove I'll get flames getting sucked right up the flue. If I see this happening I close the bypass if the cat is active or not to avoid overheating the pipe.

I have a flue gas thermometer so I'm not worried about the flue but that blowtorch sound when your fire is sucking up the flue tells me that I am not heating up the cat and I worry about melting those sensitive bypass gasket retainers.

 

[3fordasho]

Well obviously, don't do that. Manual states door should not be opened past the time it takes to get the load lit.


Design is identical to many cat stoves, in that you have a straight shot up the flue with bypass open. They rely on the operator to close the door once the load is exhausting > 50F. Maybe not idiot proof, but a well established compromise in place more than 30 years, and used by many.

This is the one thing I didn't like about my Fireview, with the bypass open the flames could shoot right up the flue. Forget it's open on a cold start or reload and it's real easy to touch off a chimney fire. It's suppose to be open until the stove top temp is 250F on the Fireview so it's not just open to start the fire. Not all cat stoves are like that thankfully, the Progress Hybrid for instance has a convoluted smoke path through the stove even with bypass open - I've never seen the flue temps spike to 1000F+ in minutes like my Fireview could with that bypass open.

 

[Ashful]

This is the one think I didn't like about my Fireview, with the bypass open the flames could shoot right up the flue. Forget it's open on a cold start or reload and it's real easy to touch off a chimney fire. It's suppose to be open until the stove top temp is 250F on the Fireview so it's not just open to start the fire. Not all cat stoves are like that thankfully, the Progress Hybrid for instance has a convoluted smoke path through the stove even with bypass open - I've never seen the flue temps spike to 1000F+ in minutes like my Fireview could with that bypass open.

Yep. My Jotul Firelight 12's had the bypass mounted on the back wall, instead of in the ceiling of the firebox. This provided a fire stop of sorts, to keep flames from shooting directly up the chimney. However, this prevents any possibility of N/S loading, as that damper assembly encroaches into the firebox depth at the top third of the firebox. BK has apparently decided to keep the firebox uninterrupted in width or depth, by placing the bypass in the ceiling, which I think most of us really appreciate.