Lake Girl
Moderator
What is the location of the OAK? Up chimney or other? If other, is it free of snow? Recall another poster had that issue...
Edit: Diameter and length of OAK run - EVL rules apply there too.
Hopper Fire last night
- Thread starter Eyball
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What is the location of the OAK? Up chimney or other? If other, is it free of snow? Recall another poster had that issue...
Edit: Diameter and length of OAK run - EVL rules apply there too.
Oak goes about 2 feet to the left of stove through the wall, up to ceiling joist level and then over a couple feet out through the sill. Seams to have good airflow. Maybe too good combined with negative pressure down exhaust?
LordmetalZ28
Minister of Fire
hyfire
Minister of Fire
I cant see the oak hurting only if it was same height or very close in height as the chimney .
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Yes it is a long one but not all that costly, well with the exception of going all 4" along with having someone who knows that stove go over it with a fine toothed comb and show the OP where all of the ash hiding places are.
I don't like these things happening and folks here are at a disadvantage when trying to help remotely.
I don't like these things happening and folks here are at a disadvantage when trying to help remotely.
Yeah, but us Mainers can take the lumps that are legitimately tossed our way.
air restriction in the exhaust pathway, combined with an unsealed hopper in a negative pressure situation (basement is ALWAYS below the zero pressure plane in a house)
for this to happen the fuel must stack up into the drop chute otherwise there isn't a "fuse" to the hopper. once in the "drop chute" the smoldering fire must be resupplied with air otherwise it cannot progress all the way back to the bin so for that to happen a less restrictive air pathway to the hopper than out the flue is generally necessary to burn it back.
trust me guys, I know burnbacks, heck I literally create them in my shop to study them. a single issue generally does not create one, it takes more than one issue that "work together" to cause this.
for this to happen the fuel must stack up into the drop chute otherwise there isn't a "fuse" to the hopper. once in the "drop chute" the smoldering fire must be resupplied with air otherwise it cannot progress all the way back to the bin so for that to happen a less restrictive air pathway to the hopper than out the flue is generally necessary to burn it back.
trust me guys, I know burnbacks, heck I literally create them in my shop to study them. a single issue generally does not create one, it takes more than one issue that "work together" to cause this.
was floating around both forums mostly catching stuff from my products, I skimmed this one and figured i'd go ahead and add a little direction to the diagnosis. haven't really pored over it yet. you guys have covered a lot of ground so far from what I see.
just a note on the OAK, remember the restriction I mentioned is "after" the fire, an OAK supplies "before" the fire so an OAK typically helps indirectly with preventing a lot of these situations by helping the stove burn cleaner before its gets outta hand, but its not a "do all end all" prevention for it happening
might want to see if we can get Owen in on this, he is far superior to me on the breckwell product lines, I can generalize but its his product so he would know more of the specifics for the model.
not bashing the product mind you, its my opinion that in the right set of circumstances a burn back can occur in literally any pellet stove, BUT its exceedingly rare and as I said above it takes more than one issue to make it happen.
I didn't see any pellets in the chute but the top back part of burn pot right below the chute was coated with goopy creosote so maybe pellets did back up & just burned completely? When I removed the plate over the auger it was full of partially burned pellets all the way up.
The OP understands the multiple event side of this and I would hope that folks looking for a single cause aren't getting disappointed by all of the questions and that nobody has pointed a finger at a single thing. Some folks seem to have a problem that way so for the record I'll tell you what the cause was ... Improper Air Flow ...
Yeah maybe he can lend a hand in chasing things down a bit more. I just ask a pile of questions looking for overlooked items that I know cause air flow issues. It might also be a good idea to get Eric in on it as well.
ETA: Invitations extended.
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Polar Bear
Feeling the Heat
Can one ton really clog the venting system that bad? I generally only clean mine every 2 tons and its pretty clean.
alternativeheat
Minister of Fire
Yes it can.
Depends, with DF's and 4" vent I can go two tons and not get a whole lot out of the vent. With a real ashy pellet like Green Supreme I do it at about 1.5 tons and get quite a lot out. But that is 4" vertical vent with satisfactory EVL and I have never had even close to a backup. . Take 3" vent and run it with incorrect EVL add 90's and horizontals and you got a whole different thing going on. It's under performing before you add any ash at all..
If the heat, gasses, smoke, pressure, exhaust and ash can't flow out the vent as intended and has someplace else to go it's going there. Just part of the scenario we have been discussing here.
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Air flow is the most important thing to get correct. That 20 pounds of ash (1%) is a large pile if it drops out of the exhaust stream outside the vent system no big deal, if it drops out just above the burn pot the stove will likely not light and flash its nice #2 led at you depending on controller. In between it does other things like make the stove high limit off and so forth and so on.
Just think how lucky you are, you have two air flows to get correct. Ain't life grand?
Just think how lucky you are, you have two air flows to get correct. Ain't life grand?
Owen1508
Minister of Fire
Yeah I agree you guys covered a great deal in this thread. I can not think of anything that was missed. Sometimes build up of fines can also contribute to a burnback (the fuse that Mike talked about). I agree with Mike it usually is a combo of various issues , including restriction on the draft, build up after a ton, some sort of downdraft which caused the heat to seek another way out, and possibly even a neg. air pressure issue in the basement. A "Perfect storm" type of event.You did state it was new old stock from 2008, Just so happens the 3 that I have available to me are early to late '09 models. I am putting a call into Al Breckel the man behind Breckwell to see what his take is on this. I do remember in '08 and '09 changes that helped reduce the amount of burn back hopper fires. Going away from Horizontal feed systems was one, this not being a factor in this case. A sealed hopper lid would cutoff airflow to the pellets and would be recommended. Although it appears that that hopper has a limited lip. I'll see if Al can contribute more to this topic.
In the end I'm glad that no one was hurt.
Thanks as well! The stove has no lip on the hopper plus a plastic pocket handle that melted in the fire so that allowed even more air into the hopper. It did do a good job of containing the hopper to smoldering pellets & not a flaming fire. I think if we were home the smoke damage would be much less. Good to know all my alarms work!
I did get my new 4" pipe ordered. Decided to go with a T right before pipe goes into wall thimble for easy clean outs!
Thanks again everyone, much appreciated!!
I did get my new 4" pipe ordered. Decided to go with a T right before pipe goes into wall thimble for easy clean outs!
Thanks again everyone, much appreciated!!
Looking at this "on paper" it sounds good. My concern is the stove. Has there been an issue with creosote, ever? Has there been an issue with unburnt pellets in the burn pot?
The Breckwell Classic Cast is a good unit and I have never heard of any issue about the hopper construction.
Eric
The Breckwell Classic Cast is a good unit and I have never heard of any issue about the hopper construction.
Eric
Thanks Eric, I asked Eyball what he did before first fire since the stove came through a party other than a dealer and I am always harping on people about really cleaning used stoves. I'll let him answer for himself. He also told us about how many pellets he had burned since installing the stove.
The stove was unused when I purchased it new. I never had an issue with creosote until the night of the fire. We did have a few times when running on low that the fire burned out and the pot filled with pellets but the stove just shut down and then restarted like normal after.
Francois
Member
Are you talking about this specific model of stove or in general? I'm almost at 3 tons this season. The installers told me to clean once or twice a year and the user manual talk about two times a year. Now it's more like once a month.
alternativeheat
Minister of Fire
Here is the deal. Without first cleaning your flue you can't really establish a good schedule. You are guessing. I know that I can go more than a month with mine because I have cleaned it to get a handle on when it should be done. And then sometimes I do it anyway because why gamble , it's not like it's hard to do.
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