Blaze King King 40 New Cat Stove 2020 Smoke Smell

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stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
The fact that the air inlet has a large volume does not imply backpuffing thru the inlet is not possible. In fact, the large firebox of the King would result in larger amounts of gas exploding. It depends on the relative volumes and impedances what the result is going to be.
 

broberts

New Member
Dec 5, 2021
8
Caledon, Ontario
well that sounds like a good install. head scratcher.
I'm left thinking the door got warped when it was welded or the gasket is screwed up.
Sorry ... hope you find and resolve the issues.
 

RogueChili

New Member
Feb 21, 2021
55
USA
A new door is on its way but I don't really believe that is the issue.

When the gasket seal fails what is the main symptom? I believe everyone will agree that the symptom is uncontrolled fire. So what does that imply? I say air is entering through the opening where the gasket failed feeding the fire.

If these statements are true, can someone offer an explanation has to how a failed gasket or warped door can possible allow gases to escape? Remembering that back puffing, explosions , and wind gusts are not in the discussion because during the burning these events did not occur.

Furthermore, the owners manual suggests to leave the door open a crack when first firing up the stove; no gases escape during this process so it supports the idea that air would be going into the stove if the gasket was failed or warped door.

Hey Stoveliker, I didn't say it was impossible to belch out smoke, I only want to bring out some of the technical details to maybe spark a thought from someone. I think if enough physics is applied to this issue it can be resolved. What are your thoughts about turbulences causing this issue?
 

jdonna

Feeling the Heat
Dec 16, 2008
274
mn
There have been a small number of people that have battled with the hinge side smoke smell.

I think some people have better sense of smell or more sensitive to it possibly.

I wonder if the common denominator is having 45-90 bends and a bit of horizontal going to the T?

I’ve had issue with our princess on and off with faint smoke smell occasionally on the loading door. You have to stick your nose up close to the area to smell it. Changing the gasket seemed to have helped some and adding a liberal amount of high temp RTV to bed it. Our setup is over spec on draft.

I’ve studied the air flow path carefully, both preheated air tubes dump to the angled slot on both the hinge side and latch side and there is always a creosote spot on both lower corners. There is possibly something to the pressure differentials theory that’s been discussed here before.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
A new door is on its way but I don't really believe that is the issue.

When the gasket seal fails what is the main symptom? I believe everyone will agree that the symptom is uncontrolled fire. So what does that imply? I say air is entering through the opening where the gasket failed feeding the fire.

If these statements are true, can someone offer an explanation has to how a failed gasket or warped door can possible allow gases to escape? Remembering that back puffing, explosions , and wind gusts are not in the discussion because during the burning these events did not occur.

Furthermore, the owners manual suggests to leave the door open a crack when first firing up the stove; no gases escape during this process so it supports the idea that air would be going into the stove if the gasket was failed or warped door.

Hey Stoveliker, I didn't say it was impossible to belch out smoke, I only want to bring out some of the technical details to maybe spark a thought from someone. I think if enough physics is applied to this issue it can be resolved. What are your thoughts about turbulences causing this issue?

Not a problem, just discussing things.

While you may be right, I don't get why you can rule out backpuffing. Earlier you said : "By definition above back puffing is not an issue in my case. The smell starts after the stove has reached full temperature and is being throttled by the thermostatic control".
It is precisely then that backpuffing can (also) occur.

Again, you may be right that it's something else, but I don't follow your argument here.
 

rdust

Minister of Fire
Feb 9, 2009
4,600
Michigan
I can get a smell when I’m burning the stove hot then turn it down where I get the floating flames at the top of the stove in front of the cat. It’s not enough to smell up the room but can smell it if I put my nose up to it. I believe @Highbeam has said it before(or similar) “I know my dogs butt stinks so I don’t go around putting my nose in it.”
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,272
07462
I can get a smell when I’m burning the stove hot then turn it down where I get the floating flames at the top of the stove in front of the cat. It’s not enough to smell up the room but can smell it if I put my nose up to it. I believe @Highbeam has said it before(or similar) “I know my dogs butt stinks so I don’t go around putting my nose in it.”
Me too, usually after doing a full char then going black box, the smell will dissipate as the cat adjusts to the burn rate and t-stat settings, eb & flo and its minor anyway, no smell if I do a hot reload and have little candle flames going because I need more heat
 

RogueChili

New Member
Feb 21, 2021
55
USA
Not a problem, just discussing things.

While you may be right, I don't get why you can rule out backpuffing. Earlier you said : "By definition above back puffing is not an issue in my case. The smell starts after the stove has reached full temperature and is being throttled by the thermostatic control".
It is precisely then that backpuffing can (also) occur.

Again, you may be right that it's something else, but I don't follow your argument here.
Yes, it can occur but it does not occur and the smell is present at the door. I have had the back puffing however now know how to avoid it. The key being keep the gasification process in check by making few and small temperature setting adjustments.

If you go from steady hi to low the log temp is high expelling gas but the oxygen is choked so there is no flame however at some point the fuel air mixture gets right and you see the flair up which can cause the pressure and back puff.

If you go from steady low the high there is a over shoot in temperature caused by response delay in the temperature sensing element resulting in the air being chocked off; at this point you are in the hi to low scenario for a few cycles until the system reaches steady state. This is my interpretation of how it works based solely on experimentation and observations.

These events are common in all types of electrical and mechanical systems however the systems are designed to overcome any type of adverse side effects. It would suck if the fuel injection system in your car had to spit out a little fuel when changing from full throttle to idle which changes the fuel pressure dramatically for a short period of time.
 
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broberts

New Member
Dec 5, 2021
8
Caledon, Ontario
You're right about the chances getting slim that a new door / seal will help but the comment that this happens when the stove is up to temp still makes me think that puffing may be the issue. The wood has to get real hot, ie like close to making charcoal, before it starts making wood gas. The wood gas burns like natural gas or propane with a mostly blue flame with bits of red / yellow mixed in.
We do open the door a crack to help get things going with a new load, letting it rest with the latch outside the hook and this has not resulted in much smell leaking.
I feel for you.
 

logfarmer

Burning Hunk
Oct 25, 2015
226
Ohio
I believe either it’s your gasket or the door! Where the door “pinches” your gasket, is it in the center all the way around it? If not, you might have to shim it if it sits too low on the hinges. I have a king (2005 model) running in the same size masonry flue you have but only 18’ tall and my rise off the stove in much shorter than yours with a 24” horizontal run into the chimney and drafts just fine!
 

broberts

New Member
Dec 5, 2021
8
Caledon, Ontario
with a new door coming you might want to try this to get a before and after comparison

I would cut some paper into strips ... maybe an inch wide. open the door. place a paper strip where the gasket should make a seal. close the door and gently
pull on the paper to feel for a seal. move the paper around to test different spots and you may find there is not pinch near the hinges where.
 

RogueChili

New Member
Feb 21, 2021
55
USA
Yes, I will test the seal / fit of the new door and compare to the original. It would be great if the door is actually the cause of the smoke issue.

I did have to tighten the latch, more than should be necessary, to create a complete seal around the poorly designed door. Inspection of the detent in the gasket shows uneven pressure around the perimeter, this is mainly caused by those studs sticking up in the gasket channel. Whomever designed the gasket channel should be embarrassed. This door is overall a poor design, flimsy, cheap to make and detracts from the overall good quality of the product. This stove really has great geometry, it is solidly built, and the welding is spectacular! Adjustable hinges and a solid door would be the cats meow..
 

ElderlyIron

New Member
Jan 6, 2022
3
Southern Oregon
Yes, I will test the seal / fit of the new door and compare to the original. It would be great if the door is actually the cause of the smoke issue.

I did have to tighten the latch, more than should be necessary, to create a complete seal around the poorly designed door. Inspection of the detent in the gasket shows uneven pressure around the perimeter, this is mainly caused by those studs sticking up in the gasket channel. Whomever designed the gasket channel should be embarrassed. This door is overall a poor design, flimsy, cheap to make and detracts from the overall good quality of the product. This stove really has great geometry, it is solidly built, and the welding is spectacular! Adjustable hinges and a solid door would be the cats meow..
I have the same issue with my King 40. My investment was nearly all I could afford, and I'm certain that my draft is withing spec, as all other previous stoves did not have this problem. I would definitely be interested in that manometer!
 

RogueChili

New Member
Feb 21, 2021
55
USA
The meter is currently with another local king owner, he is logging the values at HIGH, MEDIUM, and LOW settings on his King. When he is done logging the values I will send it to you. I might add, my neighbor says his King does not have any smoke smell issues; it will be interesting to see how our draft numbers compare. I will post the results when available and verified. I have a procedure for taking the measurements that must be followed in order to have meaningful data.
 

Slate Dale

Member
Dec 27, 2021
109
Slatington, Pennsylvania
My definition of low is between 3:30 and 4 o'clock on the dial.
For calibration reference, the dial fully clockwise, against the stop, is near 6 o'clock at the widest part of the band.
I have a new BK 40 also, and learning to use it the last few days. I can't go anywhere near 4 o'clock. If I move the temp control knob past the beginning of the white band on the dial, the cat temperature guage on the stovetop goes to the very end of the white "active" band and even a little beyond. If I see it go beyond, I turn the knob back and open the bypass for awhile to lower the cat temperature into the white zone, since I assume anywhere past the white band means the cat may be over-heating. I've been told on another thread that new cats can be overactive.

Your discussion is very interesting.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
I have a new BK 40 also, and learning to use it the last few days. I can't go anywhere near 4 o'clock. If I move the temp control knob past the beginning of the white band on the dial, the cat temperature guage on the stovetop goes to the very end of the white "active" band and even a little beyond. If I see it go beyond, I turn the knob back and open the bypass for awhile to lower the cat temperature into the white zone, since I assume anywhere past the white band means the cat may be over-heating. I've been told on another thread that new cats can be overactive.

Your discussion is very interesting.

Yes, don't open the bypass when this happens. Just let it go. Each and every BK owner (with proper draft) has seen this (with every new cat). Moreover, you don't want the bypass open when it's so hot - it could damage things in the mechanism of the bypass valve.
 

Slate Dale

Member
Dec 27, 2021
109
Slatington, Pennsylvania
Unfortunately, perhaps to have a very skinny door frame, BK chose to locate the glass hold down nuts, studs, and brackets under the door gasket so you can't check them until you remove the door gasket. The lumps and bumps from all of these nuts and studs under the door gasket surely create additional challenges with properly installing a door gasket so that it doesn't leak.

You can diagnose an insanely loose glass gasket seal by trying to flex the glass but not small leaks.
Yes, the door design is one thing I've noticed about my new BK King 40 that I don't like. Also the threaded length of the door latch hook is too short for when a gasket is new. The brand new door gasket is so thick that the door can't be closed until the nut is hanging on the very last threads, which would be a safety issue (even deadly) if it popped off and the door went free. Furthermore why even have glass on a cat stove? A plain solid door should be an option. The lower left corner of my door gasket is getting saturated with creosote, and I expect some smell will eventually emanate from there even though it passes the dollar bill test.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
Yes, the door design is one thing I've noticed about my new BK King 40 that I don't like. Also the threaded length of the door latch hook is too short for when a gasket is new. The brand new door gasket is so thick that the door can't be closed until the nut is hanging on the very last threads, which would be a safety issue (even deadly) if it popped off and the door went free. Furthermore why even have glass on a cat stove? A plain solid door should be an option. The lower left corner of my door gasket is getting saturated with creosote, and I expect some smell will eventually emanate from there even though it passes the dollar bill test.
Pic of the gasket corner you mention?
 

Nealm66

Minister of Fire
Sep 25, 2020
1,132
Western Washington
50 degrees out ! Plaaaa !! Of course I didn’t check the weather and stuffed her full this am lol. Just fir but big chunks and it’s on the flapper so it’ll probably still last quite a while
 

ElderlyIron

New Member
Jan 6, 2022
3
Southern Oregon
I have a new BK 40 also, and learning to use it the last few days. I can't go anywhere near 4 o'clock. If I move the temp control knob past the beginning of the white band on the dial, the cat temperature guage on the stovetop goes to the very end of the white "active" band and even a little beyond. If I see it go beyond, I turn the knob back and open the bypass for awhile to lower the cat temperature into the white zone, since I assume anywhere past the white band means the cat may be over-heating. I've been told on another thread that new cats can be overactive.

Your discussion is very interesting.
Dale,

While tis may be off-topic, in my limited (1.5 season) experience with the King 40, my biggest obstacle was following the directions in the manual to run it on high with the door unlatched for 25 to 35 minutes. Comparing it to any of the other 4 stoves I've had in the same location, it runs against what my brain wants to do! What I have found is, you have to bring the stove up to temperature, as in HOT, on the initial fire. In the beginning, I would close the door and bypass nearly as soon as it would reach minimum active temperature, thinking I was saving wood and burning smoke. While the cat was indeed hot enough to light off and go beyond the high range, the stove still seemed to not be hot enough to warm the house. (Rather disheartening when you dropped the major coin for this thing!) The glass would also darken quickly (relatively) and never clear off during normal use. I forced myself to follow the initial fire instructions, and I say force, because watching and listening to that roar is counterintuitive to "normal" (i.e. other types of) stove operation. It also freaks the wife out, so be prepared for that! Regardless of your cat being at light-off temp, close the door, but leave the bypass and thermostat open. The fire will nearly go out, it seems, but it's not, really. Wait 10 minutes, or when you see the smoke clear from the fire box and active flame again, THEN drop the bypass and throttle it back. If you turn the knob quickly, you can hear the flap close. Whatever the temperature of the stove is at that time, if you set the thermostat to where you hear the flap fully close, that is the stove temperature that it will maintain, give or take a bit. Conversely, if you light it and let it rip until you see the cat come up to light-off temp, then close the door and the bypass, the stove will still be "cold", and your (my) brain wants to keep the thermostat turned up to get the stove hot. At this point the cat glows like a light bulb as it tries to heat the bulk (mass) of the stove.

Long story short, if you heat the stove, the cat will maintain it. If you try to use the cat to bring the stove up to temp, it's going to take a lot more time and a lot of cat!

By the way, you cannot walk away from this stove during start-up. That REALLY freaks the wife out!
 

stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
Does the manual advocate leaving the door* open?? I'd be surprised. Bypass: yes. Door: I have a hard time believing that. (And no time to download and read the manual.)
 

RogueChili

New Member
Feb 21, 2021
55
USA
5. Light the fire and allow it to get a good start while leaving the loading door cracked open (approximately 3 to 5 minutes). DO NOT LEAVE THE STOVE UNATTENDED. 6. Once the kindling is fully on fire, place two or three medium size logs onto the fire. Keeping the loading door unlatched, allow the logs to catch fire (approximately 5 minutes). DO NOT LEAVE THE STOVE UNATTENDED. 7. Once the logs are burning, latch the loading door shut BUT keep the bypass door open. Leaving the loading door open after the wood load has caught fire may cause premature failure of the catalytic combustor
 

stoveliker

Minister of Fire
Nov 17, 2019
2,784
Long Island NY
5. Light the fire and allow it to get a good start while leaving the loading door cracked open (approximately 3 to 5 minutes). DO NOT LEAVE THE STOVE UNATTENDED. 6. Once the kindling is fully on fire, place two or three medium size logs onto the fire. Keeping the loading door unlatched, allow the logs to catch fire (approximately 5 minutes). DO NOT LEAVE THE STOVE UNATTENDED. 7. Once the logs are burning, latch the loading door shut BUT keep the bypass door open. Leaving the loading door open after the wood load has caught fire may cause premature failure of the catalytic combustor

Ok. This is for a cold start to establish draft. I'd never this for a reload.
 

moresnow

Minister of Fire
Jan 13, 2015
1,913
Iowa
Do not leave the loading door open for the initial hot burn. Poor decision. Hot cat. Cool room air. No good. Defeating the pupose of getting the stove/Cat up to temp.
Baby your pet Cats;) My opinion.....
 
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