BK Chinook update; One year later

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Hass

Minister of Fire
Mar 20, 2011
528
Alabama, NY
It's been a year since the Chinook has been installed, last year it was incredible. Way beyond everything I imagined, and surpassed everything people here said it can do. (40 hour burns on a load of pine? Wonderful!)

Starting out this year, it's been terrible.

I snapped a soot eater rod during my chimney sweep 2 weeks ago, waiting for a replacement yet so I haevn't been able to sweep the last 2-3 feet of my chimney + cap.

It can't maintain a burn below 1.5, the stack temp will drop to about 100 and eventually sputter out.
After it sputters out, the cat is packed tight full of ash. As far as I know BK says the best way to clean it is a good hot fire. So right now I'm burning the dickens out of the stove. Obviously a burn on 2.25 for 30-40 mins isn't their idea of a "hot fire"... So we'll burn it with a 1000F stack temp for an 30-45 mins and see what happens. Chimney is rated at 1k for 60 mins, so I don't want to push it too far.

I don't know if the tiny bit of creosote in the chimney in the last 2 feet is restricting flow or not. The temps are colder than before when I used to run the stove on 1 with no problems.

I'm not trying to bash BK by any means, since I assume this is an operator issue right now.
The wood I'm burning is leftover wood from last year... So if anything it's a year more seasoned then last year.

Anyone have any thoughts?
If this hot fire doesn't clear it up I'll give BKVP a PM to see what's up.
 
I have my doubts that the dirty chimney up top is the cause of your problems unless it is FAR dirtier than you think, which would be another problem entirely.
 
I don't think it is either... It's MAYBE 1/4" at most. It just looked a little fuzzy. I took the disconnected the double wall pipe (telescoping) to look up the chimney and down in to the stove to inspect it after I swept. It may be getting dirty now, the way I see ash building up in the cat and how it fizzles fires. I just turned the stove down, we'll see how it idles now... Boy, that Class A pipe sure gets hot on the outside. Couldn't even keep my hand on it.
 
Have you taken a look at the cat? Do you have a cat probe on it?
 
I've looked at it, but haven't pulled it out.
It gets plugged up bad, but a hot fire burns it all right off and it glows like normal. Yes there's a probe, the cat temp seems to run just fine. The cat temp seems to scale with the stack temp as you'd expect... As the stack goes down, the cat drops off... The question is why.

Is the cat not burning everything, dropping the temp, decreasing the stack temp, killing the fire...
Or is the stove losing draft, causing the cat to drop temp, killing the fire...

Hmm...
 
You sure the cap isnt plugged with creosote? I had a similar problem with mine one year and thats what the problem was.
 
It sounds like you should remove the Cat and give it a proper cleaning.You likely have a fly ash clog in and behind the Cat. It sounds odd that it gets so much as in it. Is there enough ash that you can see it after each burn?
 
You have to have air flow through the cat, if it is plugged up with ash or creosote, I would not think burning would clear it all out, I would take it out and give it a good cleaning. I would also want to make sure the top of that chimney is not plugged, or the wire screen plugged on the cap if it has one. I have had that wire screen clogged up to where it really slowed draft.
 
I'm going to throw my vote in for a restriction at the top of the chimney. That could cause things to get clogged up down below due to the lower draft.

Matt
 
I bet you cat is partially clogged with fly ash. Try blowing some low pressure air through your cat with one of those air cans before you remove the cat. I believe if you remove the cat to clean you also have to replace the gasket.
 
Thanks guys,

You sure the cap isnt plugged with creosote? I had a similar problem with mine one year and thats what the problem was.
As far as I can see from the ground it's not plugged. But I'll take a look at it later when it stops snowing.

It sounds like you should remove the Cat and give it a proper cleaning.You likely have a fly ash clog in and behind the Cat. It sounds odd that it gets so much as in it. Is there enough ash that you can see it after each burn?
The BK manual says the best way to clean it is a good hot fire. Aside from the maintenance of removing it...
Yes, when I will reload and engage the cat, after the cat warms up enough to start glowing I can see it is packed full. Like packed solid, where you can't really make out the individual honeycombs that make up the cat. It's also built up on the flame shield, I've never seen that before. After the cat gets burning hot enough all of it will burn off. I just reloaded for the first time after yesterdays HOT HOT fire, and it doesn't look like it's clogged up like it has been in days past. When I woke up this morning, I looked outside and there was smoke coming out of the chimney however... Not much of it and very slow/lazy moving, but I'm not used to seeing any. It was my understanding that BK says if you burn a hot enough fire it will burn off any fly ash/clog in the cat. The cat probe was pegged over yesterday. It was nice and toasty.

I bet you cat is partially clogged with fly ash. Try blowing some low pressure air through your cat with one of those air cans before you remove the cat. I believe if you remove the cat to clean you also have to replace the gasket.
Yes, if you remove it you need to replace the gasket... That's why I'm not really interested in removing it. Plus they're supposedly very fragile, and I don't want to risk breaking it. But at this point I may have to.
I'm curious if yesterdays fire cleaned up the cat a bit...
There's a significant amount of creosote/black buildup inside the stove on the walls/pipe, should I probably scrape all that off? It doesn't seem to want to burn off
 
The crap inside the stove bother anything.
I just can't figure why you are getting so much fly ash though.
I never get any on the shield or cat to speak of.
Do you stir the fire up during the burn at all..I know I don't.
Do you notice any back drafting?
 
I would brush the cat with a soft paint brush to remove the fly ash, maybe you can find something to clean out the honeycombs without damaging anything, not sure how you would do this though.
 
I would brush the cat with a soft paint brush to remove the fly ash, maybe you can find something to clean out the honeycombs without damaging anything, not sure how you would do this though.

I would run a vacuum over it with a soft bristled attachment on it or blow through it with low pressure air like Todd suggested.
 
Are you closing the bypass all the way? Sometimes I have to give a good tug on the bypass to get it to close completely. I saw the same type of smoke before I started giving it the tug. Havent see smoke coming put the chimney since.
 
Have you checked the bypass gasket and did a dollar bill test on it? Also as papa bears stove says maybe the bypass isn't closing all the way, have you pulled the pipe and taken a look at it?
 
The crap inside the stove bother anything.
I just can't figure why you are getting so much fly ash though.
I never get any on the shield or cat to speak of.
Do you stir the fire up during the burn at all..I know I don't.
Do you notice any back drafting?

It seems to be running pretty normal after the hot burn. However, the black flaky gook is packed in the stove EVERYWHERE. Behind the firebrick holders, on air tubes, everywhere.. packed thick. How hot does the darned stove have to get inside to burn all this off? Is this crap going to burn off at once and turn my stove in to a glowing inferno?
I don't stir the fire at all until it's time to reload, then I just pile the coals front/center and reload.

Ceramic cat or stainless steel?
Whatever the stock cat is, I'm not sure honestly.

Have you checked the bypass gasket and did a dollar bill test on it? Also as papa bears stove says maybe the bypass isn't closing all the way, have you pulled the pipe and taken a look at it?
I took it apart over the summer to check to make sure everything is intact... The bypass door seems to close nice and tight. I did do a dollar bill test on it and it seemed fine. However when I close the bypass it doesn't close ANYTHING close to what it used to. What I mean is I had to take some serious muscle to close it for the first few months. But now it loosened up quite a bit... I can do it with a pinky now, and before it took all my might. and yes, I make sure the bypass closes all the way to that last "click" or locking in... however you want to refer to it.
The door gasket is fine as well. I did have to tighten it up last year however... Still good now though.
 
That junk on the inside of the stove. I have everything from tarry soft, black and shiny, black and crunchy, brown and flaky, rust colored and powdery, inside the stove depending on where I'm looking. I don't ever expect it to burn off. In fact, I expect that it will fall off into the ash bed as it accumulates and just be a part of the experience. I grabbed a chunk of the black stuff and tried to burn it with no luck so I don't think it is going anywhere. Like the black glass, this stove has a dirty box.

This is only a question for me because it seems to pack in behind the heat shields. Not sure if that will lead to corrosion or somehow affect the function of the shields.
 
That junk on the inside of the stove. I have everything from tarry soft, black and shiny, black and crunchy, brown and flaky, rust colored and powdery, inside the stove depending on where I'm looking. I don't ever expect it to burn off. In fact, I expect that it will fall off into the ash bed as it accumulates and just be a part of the experience. I grabbed a chunk of the black stuff and tried to burn it with no luck so I don't think it is going anywhere. Like the black glass, this stove has a dirty box.

This is only a question for me because it seems to pack in behind the heat shields. Not sure if that will lead to corrosion or somehow affect the function of the shields.

Ditto here on the inside of the stove. I just give it all a good scraping with a putty knife whenever I use the soot-eater on the stack. It doesn't dent that last glaze of black but gets most of the other stuff. Maybe a chisel would be a better tool but I'm don't see the point if it's just going to gunk up again with the next set of burns.I bent a piece of 3/8" rod and use that to get behind the front parts of the heat shields. Haven't figured how to get to the back yet, but my dealer said it's nothing to worry about. Don't see how you could get any corrosion without a sustained moisture presence. I replaced a 30 year-old Earth stove with the BK a couple of years ago, and that thing was a creosote monster but the box was solid.
 
A length of plumber's tape or some narrow steel strapping works well to get behind the shields. It's flexible enough to get in there, but still stiff enough to do some good.
 
I read that thread and I did NOT say you were silly. I asked you a question and I still don't have the answer. Actually the same question, about corrosion back there.

I really don't know. When I asked the folks at Blaze King about it, they said I needed to clean it all out and burn dry wood. I guess 3-4 years isn't long enough? I burn it the way the manual says to, fill it up and regulate output with the thermostat. Used that way, creosote buildup is inevitable.

I cleaned it out as best I could. I don't think it will ever burn out. I have no idea what the long term effects will be. Maybe someone with one of the older cat models can shed some light.

And no, no mice in the stove ;lol
 
My guess is if it caused any long term corrosion the design would be different on the shields. I'm not worrying about it, I'm sure I'll want to try another stove long before it'll ever become a problem. ;lol

I think we're entering into a fun time for new stove designs so I'm sure a lot of us will be tempted by the fruit of another at some point. :)
 
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