Blaze King King 40 New Cat Stove 2020 Smoke Smell

[Nealm66]

Don’t give up. This is the place to figure it out. Where is your swoosh setting during this smoke problem. And would the chimney still have a good draft reading even though it had a creosote choke point? Like a 6” draft might give good readings but not sufficient for the king? I’m just throwing rocks trying to help

 

[moresnow]

BK specified venting area in square inches=50.25
your masonry chimney liner area in square inches=96

Expecting this stove to function correctly on a vent system that is just over 50% oversized could understandably be a issue. It appears that .04-.05wc is not the be all, end all for your current venting configuration.

Were you advised by a dealer that this stove would function on such a oversize chimney volume? Seems odd. Did you consider a liner as a potentially needed component when you committed to this stove? I'd like to say drop a liner in and eliminate that wild card completely. The expense sucks but it would be worth it to me.

I'll bet if you get this ironed out you will be extremely satisfied and never look back. Keep at it!

 

[stoveliker]

Yes, intermittent draft issues was my initial thought and that is exactly why I purchased the gauge to measure the draft and prove it however the gauge tells me the draft is sufficient!

The gauge was attached during multiple burn cycles and never dropped below .04wc and on average was in the .05wc range. During these cycles the smell was noticeable and it always seems to start when the stove is up to temperature and the thermostat is satisfied.

What am I missing?

I think you are looking for an issue while refusing to do what you *can* do to bring the set up into compliance with the requirements of the vendor. To me this does not make much sense - however much you've measured, BK has tested more. However much you have theories (and I know I do often, so I understand that), the statistics underlying the specification requirements of the system show that you will almost invariably have zero trouble if the system follows the guidance provided to you in the installation manual (that was available to you before you shelled out the money for this stove).

There are issues, even if we don't understand exactly how/why they produce the problem symptoms, with your installation. BK warrants proper operation if the set up complies with their requirements.

Get the system into compliance first. Then IF the system then still has trouble, we have excluded the rest of the system (chimney), and we could think more about other causes (more importantly, the warranty provisions would kick in, I presume). Right now it seems a bit of a waste of time, knowing your set up is not "approved" and trying to find the cause elsewhere while disregarding the clear advice (in the manual) from the engineers at BK that have worked on this stove for a long, long, long time.

Sorry if this is a let-down. I understand your frustration and I'm not aiming to be annoying. I'm only pointing towards the only way forward towards a solution that I see - exclude the peripheral system by getting it into compliance. Maybe there are other folks that are smarter than me - I can only speak to my limited understanding.

 

[Highbeam]

How about this thought..,,,

Your flue is 8”. It has some vacuum strength say 0.05”.

The cat chamber openings (cat and bypass) are small. Assume they add up to 8” combined. This means your cat chamber feels 0.05” as you measured.

Your firebox loading door is huge. With that thing open, firebox has little or no vacuum so smoke spills out.

You have two separate problems. Smoke rollout with an open door and smoke smell during a burn.

I think both are caused by a huge, cold, masonry chimney.

 

[RogueChili]

Many good points, let me say yes, I did read the manual, snippet below, and what I saw where recommendations to use stainless liner not must use so I figured the reason for these recommendations was to guarantee the draft is above some number under all conditions. I then proceeded with the inspection and measurements of height and draft to verify my current chimney was not deficient. The results of the inspection convinced me, and the seasoned inspector, that low draft was not an issue.

As to why not install a insulated liner? It's not possible in this multi flue chimney, even if the 8x12 clay liner were to be removed the existing space is marginal and may not accommodate the equivalent 50.25sqin vent. In addition this chimney has a fireplace which the vent has to jog around near the smoke shelf. The current clay tile at that area is at about 30 degree angle, the thimble intersects this clay tile near the mid position. So with a steel liner the snout would have to connect to a tee leaning at 30 degrees. Of course anything is possible but the task at hand becomes quite involved and costly. I am open to any Ideas!

One thing about the current 8x12 clay liner, these dimensions are arbitrary, the outer dimensions are 7.5x11.5 and the actual inner dimension are 6x10 which yields 60 square inches, also the flow resistance in a rectangular area is higher than in a round area so the rectangular liner must be adjusted accordingly, the end result is the 8x12 clay liner is a very close match to the recommended 50.25sqin. Of course this is only my understanding, based on painful research over the last month in an attempt to understand how a simple chimney really works. Not so simple is it?

The comment on smoke spillage with the door open, here are some facts that force me to believe the venting system drafts perfectly:

• When the system is stone cold, light the kindling, the door wide open, all smoke is pulled directly out an up, no spillage whatsoever
• When exhaust smell is noticeable, open the door slightly, sound of air rushing in, no smoke spillage
• If you put a match against a hole in the flue the flame is pulled in

These are the anecdotal testing methods, and of course the pressure gauge measuring never less than .04wc.

The next step is to replace the existing door gasket, doing some research I found a company that makes air tight gaskets, these are glass rope covered with silicon coating and are 100% air tight. The downside is they are only rated to 500F continues duty so will not last for the long haul. What I hope to prove with the gasket is this; if turbulence around the door are causing the leak then installing the gasket will eliminate the leak, if draft is causing the leak than the leak will move to some other location and still be detectable. Will post results when available.

I agree that installing the stainless chimney system will most likely cure the issue by providing higher draft numbers. It is obvious these new stoves are working on the edge, it may be a matter of .01 wc that makes all the difference. In my mind that is just not good design practice.

Snippet, If you read more of their literature there is actually a picture showing masonry chimney with a clay liner as acceptable.

CONNECTION TO A MASONRY CHIMNEY Masonry chimney*** Ensure that a masonry chimney meets the minimum standards (NFPA) by having it inspected by a professional. Make sure there are no cracks, loose mortar or other signs of deterioration and blockage. Have the chimney cleaned before the stove is installed and operated. When connecting the stove through a combustible wall to a masonry chimney, special methods are needed. In Canada, the wall cut away is to provide 18” clearance for the connector. The resulting space must remain empty. A flush mounted sheet metal cover may be used on one side only. If covers are to be used on both sides, each cover must be mounted on noncombustible spacers at least 1” clear of the wall. ***Blaze King recommends the use of a Stainless steel liner, preferably insulated, inside a masonry chimney. This is to maintain proper draft and overall better operation of the unit.

 

[moresnow]

Was your stove equipped with the new continuous one piece door gasket? I believe this is new (possibly not in production?) and I am not even sure if all models do or will get it? If may be worth inquiring.
Would a ovalized liner fit if it comes down to it?

On another note entirely. How long are you burning in, or charring your fresh loads? You will likely find this interesting. I was in a hurry to get to bed last night and rushed my loading routine. I let the fresh load twist the Cat needle over to about 2pm and STT was up to 600F. This happened in 10 to 15 minutes max. I was anxious to get to bed so I reduced my knob setting to the cruise position and went to sleep. 6 hours later I went back to the stove and I had the stink going on. Also some build up on the glass which has become very abnormal these days.

My bad. I just got in a hurry and didn't let the fresh load burn long enough/hard enough to be ready for air reduction. Just a example of how not putting a long enough burn on a fresh load can make my setup show similar results as yours. Many times I will "run in" a fresh load as described above (wide open throttle until STT of 600+)for 15 minutes or so, and then reduce throttle until I have lazy but active flame for another 15 minutes. Then reduce to cruise setting. Total burn in time with active flame is 30 minutes. Works like a charm every time for me.

No clue if this relates to your routine at all but its food for thought.

 

[Highbeam]

The next step is to replace the existing door gasket, doing some research I found a company that makes air tight gaskets, these are glass rope covered with silicon coating and are 100% air tight. The down side is they are only rated to 500F continues duty so will not last for the long hall. What I hope to prove with the gasket is this; if turbulence around the door are causing the leak then installing the gasket will eliminate the leak, if draft is causing the leak than the leak will move to some other location and still be detectable. Will post results when available.

That will be very interesting. I've seen those siliconized fiberglass gaskets used on wood boilers and they look like a big improvement. The old rope gasket has obvious drawbacks and I can't see why we're still using such old technology.

So 24' of masonry chimney. Two 90s, 2-30 degree bends, and some height above sea level (I thought I read 700 but couldn't find it).

There's draft strength and then there is flow rate. Chimney flow dynamics are not simple which is why my 6" chimney at any draft strength is still too small for a king.

 

[Rearscreen]

Not a window gasket by any chance?

 

[Highbeam]

Not a window gasket by any chance?

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.

 

[RogueChili]

That will be very interesting. I've seen those siliconized fiberglass gaskets used on wood boilers and they look like a big improvement. The old rope gasket has obvious drawbacks and I can't see why we're still using such old technology.

So 24' of masonry chimney. Two 90s, 2-30 degree bends, and some height above sea level (I thought I read 700 but couldn't find it).

There's draft strength and then there is flow rate. Chimney flow dynamics are not simple which is why my 6" chimney at any draft strength is still too small for a king.

That's not right, one 90 into thimble, thimble liner intersect into 30 degree to 60 degree to vertical. Seems like smoother transition (30/60) vs thimble liner intersecting at 90 to the vertical.

Let me ask, if the stove was producing gases at a rate higher than the flow rate of the venting system wouldn't I detect this with the pressure gauge as a drop in draft measurement?

 

[stoveliker]

That's not right, one 90 into thimble, thimble liner intersect into 30 degree to 60 degree to vertical. Seems like smoother transition (30/60) vs thimble liner intersecting at 90 to the vertical.

Let me ask, if the stove was producing gases at a rate higher than the flow rate of the venting system wouldn't I detect this with the pressure gauge as a drop in draft measurement?

You would detect it as your fire going out, shutting down. Because those gases won't pressurize the stove but push out through the chimney and the rest through the air inlet. Resulting in zero oxygen coming in and being available for the fire and in its shutting down.

 

[RogueChili]

Not a window gasket by any chance?

Checked it as recommended, when cold the glass is tight and it appears that the gasket is in place and proper.

I use a foil cone to try to fine the actual leak, when at the glass seal there is no smell, it seems to be at the door hinge side near the top but difficult to be absolutely positive because of the heat rising around the stove.

 

[RogueChili]

You would detect it as your fire going out, shutting down. Because those gases won't pressurize the stove but push out through the chimney and the rest through the air inlet. Resulting in zero oxygen coming in and being available for the fire and in its shutting down.

Sure, the stove is a slave to venting system, the venting system drives the stove, it's like positive feedback, chimney pulls in oxygen , feed fire and creates more heat, more heat creates more flow, this will continue out of control unless the damper slows things down. Based on the fact the my stove is working absolutely perfectly it should be safe to say there is good flow.

 

[stoveliker]

Sure, the stove is a slave to venting system, the venting system drives the stove, it's like positive feedback, chimney pulls in oxygen , feed fire and creates more heat, more heat creates more flow, this will continue out of control unless the damper slows things down. Based on the fact the my stove is working absolutely perfectly it should be safe to say there is good flow.

There is flow. But for the right flow, any leak would make air suck in, at all operation that is within specification. If not, one can fix the leak to get rid of the smell, but that would still not make the rice run as intended, run though it might do.

 

[RogueChili]

There is flow. But for the right flow, any leak would make air suck in, at all operation that is within specification. If not, one can fix the leak to get rid of the smell, but that would still not make the rice run as intended, run though it might do.

By the definition of how it works doesn't that imply that high pressure can not exist in side the stove? This is my point, if there is pressure in the stove it can' function, gases would be exiting the input and the fire would extinguish.

My just retired VC was in no way air tight, you could see the flame from the seams, no smoke ever cam out, air was only pulled in and made it impossible to control, that why I upgraded.

No matter how I look at this it just doesn't make sense and the only theory I could come up with , until proven write or wrong, is turbulence across the gasket area causing pockets of slightly higher pressures. Most likely where the creosote accumulates on the lower left and right sides of the glass where the inlet air wash doesn't seem to keep clean.

 

[stoveliker]

By the definition of how it works doesn't that imply that high pressure can not exist in side the stove? This is my point, if there is pressure in the stove it can' function, gases would be exiting the input and the fire would extinguish.

My just retired VC was in no way air tight, you could see the flame from the seams, no smoke ever cam out, air was only pulled in and made it impossible to control, that why I upgraded.

No matter how I look at this it just doesn't make sense and the only theory I could come up with , until proven write or wrong, is turbulence across the gasket area causing pockets of slightly higher pressures. Most likely where the creosote accumulates on the lower left and right sides of the glass where the inlet air wash doesn't seem to keep clean.

Precisely. High pressure does not exist. Your draft is not proper for this particular stove, because it should be behaving like your VC, sucking air in. It does not and your flue is not up to specs - 1+1=2.

 

[RogueChili]

Wait a minute, that isn't a logical leap! From the definition the stove would flame out

Just received the new gasket, curious to see the results!

 

[RogueChili]

Anyone with a new King 40 willing to take a flue draft measurement? I have the gauge and will ship it.

 

[kennyp2339]

Cherry picking here, read lots of good advice, see some stubbornness to, perhaps this isnt the right stove to fit your needs, an easy breather 3cu ft + epa reburn tube stove would more then likely suit you better due to higher flue gas temps with your current configuration.

 

[Highbeam]

Let me ask, if the stove was producing gases at a rate higher than the flow rate of the venting system wouldn't I detect this with the pressure gauge as a drop in draft measurement?

You aren’t measuring draft strength in the firebox. Your pipe has vacuum but apparently not your stove.

 

[RogueChili]

Unfortunate these stoves couldn't be designed to work with existing technology however it appears to be the case, just one of the side effects of progress. These BK stoves are spectacular in both design and functionality, definitely upsetting having to abandon the King 40.

I appreciate all the responses, lot of good knowledge here, great sounding board and very helpful! Great learning experience, I believe we all gained a little knowledge it the process.

The conclusion, no defect only inadequate installation.

 

[Nealm66]

Sorry to hear it. So even running at a more open setting it still has the smoke issues?

 

[Hoytman]

To me it sounds like you need a liner from your draft numbers. Has nothing at all to do with good clay liners. Trust me, I understand that thought process completely. I often go against the grain here against ripping out perfectly good clay liners. You do have options to helping the draft and it's called Heatshield applied to the clay liners...keeps it hotter inside, makes it clearance compliant as well, though I still don't believe this will fix your issue alone. You need an insulated liner.

Normally with a smoke dragon or even a tube stove I'd say you'd be fine, but you have two things different going on with that stove.
1. It's a CAT stove, which can idle low and very well. Most of your heat should be coming through the glass and off the top of the stove and not as much off the sides as would be during a higher burn rate.

2. Thermostat. The second important part of the equation with these stoves.

These two things alone make your stove operate as my coal stove does in that it can idle low without so much creosote as an older pre-epa stove. This is what sets BK wood stoves apart from the rest of the pack. It's not coal though, even though it's running similar. As you're aware, you still have creosote to contend with...particulate matter which needs heat to keep it from condensing on the walls of that chimney liner and becoming creosote. Your only means of fixing this, won't fix it. That is running the stove hotter more often, which is not why you bought the stove.

My stove breech and stove pipe are 7" into 8"x8". Burning coal I can get away with that and I can get low draft of -.005. (not a typo...below -.01) where manual says to run it between -.03 and -.06. Most wood stoves will have much higher draft settings and numbers. Apparently BK does not. First time I've seen any person give draft numbers mentioned with regard to a BK wood stove. I have no idea what their recommended draft numbers are.


However, using my coal/wood stove as an example I can tell you than burning wood in my stove even on a medium burn will give me much higher draft numbers than I currently run with coal...not even close. I didn't get my manometer last fall in time to measure a wood fire which is how I get the coal started, but I can tell you that if I tried to run my stove with the thermostat at the temps I currently have used over the last few weeks...300-360...there is no way I could prevent my chimney from creosoting up, simply no way as it would be burning much too cool and so I too would begin to smell it. In fact, I can almost guarantee this would be the case even if I put in a 7" liner or even a 6" liner to run the stove because all I have in my favor is the thermostat. I have no catalyst and no secondary air tubes...yet. All I essentially have is a wood burning smoke dragon with a thermostat. It's the combination of a catalyst and stat that makes the BK stove a wood burning game changer.

You spent the money on a quality stove. Now make it run like it supposed to and by the means necessary to get it there. Put in an insulated liner and be done and stop thinking about it.

 

[Hoytman]

By the way, I doubt you see a significant difference between taking draft readings from the fire box or the stove pipe. I know same made that argument to me with regard to taking reading with my coal stove. My stove has a unique design in that it has a built in stove damper. It essentially works like a bypass similar to a Lopi wood stove, but the plate doesn't fully close off the exhaust path. Even fully closed, it is not fully closed. It's always open 1/3rd of the way to prevent gas build up and violent explosions that can rip the stove pipe right off of the stove and out of the thimble, even cracking masonry chimney's. So, my delemna was drill the stove and take a reading from the fire box where it is most important, take a reading above the built in stove damper, and/or below the pipe damper. The issue is placing the probe where there was no turbulence from a damper plate or elbow. So, I ended up with a pilot hole between both dampers. Getting readings as low as -.005 in the stove pipe who needs or wants to drill a hole in their stove. I know I don't. I'm already getting dangerously low draft readings, that I can maintain, but really isn't safe...especially without and even with CO detectors. Why push that limit. It's not worth it.

I can tell you this though, even when closing the pipe damper (which is the highest damper in the system) I can barely see on the manometer that I closed the upper pipe damper...and sometimes I can can't see it at all. I actually think I could have placed the hole above both dampers and it wouldn't make a difference...or much of a difference. The only reason to place the probe in the fire box is to see what is going on just above the fire, not in the pipe. My concern was over all draft, so in the pipe it went and I never had to drill my stove.

By the way, the reason I added the second damper in the pipe was only for wood burning purposes and in case of a run-away draft. With coal the only time that upper damper is closed is during temps below 10F in order to hold more heat in the stove and prevent draft from going higher and maintain a low draft, which it does well. Most often the we only get a few days each year with temps that cold so the upper pipe damper remains full open 99.9% of the time. If I decide not to burn any wood at all in the stove and when I change out the pipe I may not even put that pipe damper back in place. Then again, it is there if ever I should need it to slow a stove down.

My analogy isn't an apples to apples, but it should give you some indications of what can be done.

 

[RogueChili]

By the way, I doubt you see a significant difference between taking draft readings from the fire box or the stove pipe. I know same made that argument to me with regard to taking reading with my coal stove. My stove has a unique design in that it has a built in stove damper. It essentially works like a bypass similar to a Lopi wood stove, but the plate doesn't fully close off the exhaust path. Even fully closed, it is not fully closed. It's always open 1/3rd of the way to prevent gas build up and violent explosions that can rip the stove pipe right off of the stove and out of the thimble, even cracking masonry chimney's. So, my delemna was drill the stove and take a reading from the fire box where it is most important, take a reading above the built in stove damper, and/or below the pipe damper. The issue is placing the probe where there was no turbulence from a damper plate or elbow. So, I ended up with a pilot hole between both dampers. Getting readings as low as -.005 in the stove pipe who needs or wants to drill a hole in their stove. I know I don't. I'm already getting dangerously low draft readings, that I can maintain, but really isn't safe...especially without and even with CO detectors. Why push that limit. It's not worth it.

I can tell you this though, even when closing the pipe damper (which is the highest damper in the system) I can barely see on the manometer that I closed the upper pipe damper...and sometimes I can can't see it at all. I actually think I could have placed the hole above both dampers and it wouldn't make a difference...or much of a difference. The only reason to place the probe in the fire box is to see what is going on just above the fire, not in the pipe. My concern was over all draft, so in the pipe it went and I never had to drill my stove.

By the way, the reason I added the second damper in the pipe was only for wood burning purposes and in case of a run-away draft. With coal the only time that upper damper is closed is during temps below 10F in order to hold more heat in the stove and prevent draft from going higher and maintain a low draft, which it does well. Most often the we only get a few days each year with temps that cold so the upper pipe damper remains full open 99.9% of the time. If I decide not to burn any wood at all in the stove and when I change out the pipe I may not even put that pipe damper back in place. Then again, it is there if ever I should need it to slow a stove down.

My analogy isn't an apples to apples, but it should give you some indications of what can be done.

I really wanted to install a high tech coal boiler but couldn't convince the wife. A good friend has a super installation, 40 tons stored in the back, coal pit against the house, auger pulls underground from outside pit and auto feeds the thermostatically controlled boiler.

What is your take on this; when the chimney is stone cold, the BK is stone cold, I light some kindling / birch bark under two 4" splits, the door is ajar, the smoke is raging off the cold splits but somehow all the smoke is evacuated?

I have to believe the flue, liner, and flue gas temperature are quite low at the initial start vs when the BK is running low and slow.