2022/23 VC Owner thread

[Woodsplitter67]

Agree with @Woodsplitter67 comments.... Mostly primary air is feeding the fire with bypass open.

If you are seeing secondary temps go from 100 to 1600 in 1 min that must be active flames being sucked up and through the secondary.

Couple ideas:

• Close your damper earlier before you have a raging inferno in the firebox.
• Try arranging the wood so it is not right up against the secondary smoke inlet. Make the active flames travel farther.
• May be excessive draft, possibly because your stack is too hot, again close the damper sooner to keep stack temps lower and reduce draft.

Minimal change in the secondary temp with bypass open is normal. Mine barely moves on a cold start till I close the bypass.

What is "normal" STT and stack temp?

Also.... with no cat installed you will have less pressure drop on the secondary side, which means you are sucking more smoke and air when you close the bypass. This may be exacerbating your problem.

There is also a good possibility that theres an issue with the thermocoupler.. going from 0 to 1600 in 60 seconds is a near impossibility.. im running an 8inch stovepipe.. draft would have to be super high and really hot with a massive fire in the box.. just cant see that happening..

I did have to replace my thermocoupler 2 years ago.. pretty sure it did the same thing.

 

[Woodsplitter67]

What I should have said is both primary and secondary are feeding the stove. I've run a catalytic stove for 30 years. The difference is I no longer have control with the Dauntless. Getting the cat to 600 degrees with the damper open will take hours.

Heres something you may want to do.. go back 5 pages.. around Christmas I did an in depth how to. There was alot of good feedback and seamed to help some people..
Check it out.. it has STT cat temperatures and flue temps and setting the air control.. read up on it.. There were also a few posts after that with some in depth stove running also.. This probably will help you out also along with the manual reading

 

[arnermd]

There is also a good possibility that theres an issue with the thermocoupler.. going from 0 to 1600 in 60 seconds is a near impossibility.. im running an 8inch stovepipe.. draft would have to be super high and really hot with a massive fire in the box.. just cant see that happening..

I did have to replace my thermocoupler 2 years ago.. pretty sure it did the same thing.

Yeah I did not consider that.... couple be a thermocouple issue. Easy to check, pull it out and stick it in the stove pipe.

Last night I... I mean a friend of mine.... fell asleep on the couch, woke up and reloaded the stove with the bypass closed and a really hot bed of coals. Cat went from 600 to 1200 in less than 2 minutes..... When I finally came to my senses I thought... something is not right..... duhhh.... Can't believe I (I mean my friend) did that......

 

[Catesy]

Just to clear things up, I don't have a cat yet. They're on back order. So the temp swing I'm seeing is raw flames hitting my thermocouple when closing the bypass. I'm learning as I go with the Dauntless. I try to calm it down before I close the damper. The manual says to have a 3" coal bed before closing. As I remember it took a while to master my old stove.

 

[arnermd]

Heres something you may want to do.. go back 5 pages.. around Christmas I did an in depth how to. There was alot of good feedback and seamed to help some people..
Check it out.. it has STT cat temperatures and flue temps and setting the air control.. read up on it.. There were also a few posts after that with some in depth stove running also.. This probably will help you out also along with the manual reading

Read this....
https://www.hearth.com/talk/threads/2022-23-vc-owner-thread.193685/page-29#post-2643145

And this:
https://www.hearth.com/talk/threads/2016-2017-vc-owners-thread.156768/page-3#post-2131197

 

[Woodsplitter67]

Read this....
https://www.hearth.com/talk/threads/2022-23-vc-owner-thread.193685/page-29#post-2643145

And this:
https://www.hearth.com/talk/threads/2016-2017-vc-owners-thread.156768/page-3#post-2131197
[/QUOTE

I think that @Diabel did a graph of operation .. maybe he can post that also

 

[arnermd]

Just to clear things up, I don't have a cat yet. They're on back order. So the temp swing I'm seeing is raw flames hitting my thermocouple when closing the bypass. I'm learning as I go with the Dauntless. I try to calm it down before I close the damper. The manual says to have a 3" coal bed before closing. As I remember it took a while to master my old stove.

Coal bed, schmoal bed.... I do not do worry about that.... when the exhaust gas and STT is hot enough (400 -450 for me) I throw the cat in. Without the coal bed it may stall out, but then you just open the bypass, heat it up and try again. Without a cat you may need more heat to get the secondary burn to sustain.

 

[U235]

hahaha.... we are thinking along the same lines....
Obviously I would trust the manual, at least until proven wrong.


Yeah, good question, I do not know the answer. I think the conservative answer is to target same temps as with a cat. 1200 - 1400 peaks. Sure would be nice if VC would give us a number....

Open it up and look in there. You want to check for cracks in the refractory or evidence of things moving around, look for any gaps that might have opened up around the joints in the refractory.

I also like to keep an eye on the surface spalling. Spalling is a surface condition, the refractory had a smooth finish when new, as it ages you get pits and the surface gets rough. I suspect this is causes by direct flame impingement, but that is only a theory of mine. If you look in past year threads you should find some pics posted by me that shows the surface of some of my failed refractories.

I am sure some amount of spalling is normal, hard to say how much.... I have never changed out refractory due to spalling, I just keep running it till it cracks or breaks. So just because you have some spalling does not mean it is destroyed. Just something to keep an eye on top qualitatively assess how much "stress" the refractory has seen.

Just my 2 cents.... I am not an expert and I have limited experience. I would be curious to hear what others think.

@arnermd unfortunately I think you might be VC R&D as far as temperature exposure and refractory life. I understand that the data logger is new this year - Hopefully you’re defining the 20 year refractory life setup now. Any idea what you were running the 3 years between failures?

I know a couple people mentioned that they anchored their Auber to the fan cord. Wondering what your experience has been using forced convection on these stoves. Do you just always leave the fans running? Any luck using the convection fans to quench a runaway catalyst (instead of opening the bypass to cool things down)? For a given level of inferno, primary closed, I’m guessing that the convection fans would lower flue temps, decrease draft, and eventually decrease catalyst temps.

I’m rolling Auber on the catalyst, no name magnet on the stove top and a new Condar flueguard for my DW pipe. Hoping to be confused and delighted at how I too can see 1000 degree temperature drop in the 3 feet between catalyst exit and flue probe.

I went back and re-read every post from this years owners chat. Made so much more sense the second time through. Tons of knowledge shared and help given.
-Thanks from the 22-23 Freshman class.

 

[Woodsplitter67]

Read this....
https://www.hearth.com/talk/threads/2022-23-vc-owner-thread.193685/page-29#post-2643145

And this:
https://www.hearth.com/talk/threads/2016-2017-vc-owners-thread.156768/page-3#post-2131197

I think that @Diabel did a graph of operation .. maybe he can post that also.. i

Edit.. it was a flow chart.. Im much better after some sleep...

 

[Woodsplitter67]

Yeah I did not consider that.... couple be a thermocouple issue. Easy to check, pull it out and stick it in the stove pipe.

Last night I... I mean a friend of mine.... fell asleep on the couch, woke up and reloaded the stove with the bypass closed and a really hot bed of coals. Cat went from 600 to 1200 in less than 2 minutes..... When I finally came to my senses I thought... something is not right..... duhhh.... Can't believe I (I mean my friend) did that......

We all have friends that do this.. my friend has made some mistakes in the past..lol

 

[JohnDaileyNH]

@arnermd unfortunately I think you might be VC R&D as far as temperature exposure and refractory life. I understand that the data logger is new this year - Hopefully you’re defining the 20 year refractory life setup now. Any idea what you were running the 3 years between failures?

I know a couple people mentioned that they anchored their Auber to the fan cord. Wondering what your experience has been using forced convection on these stoves. Do you just always leave the fans running? Any luck using the convection fans to quench a runaway catalyst (instead of opening the bypass to cool things down)? For a given level of inferno, primary closed, I’m guessing that the convection fans would lower flue temps, decrease draft, and eventually decrease catalyst temps.

I’m rolling Auber on the catalyst, no name magnet on the stove top and a new Condar flueguard for my DW pipe. Hoping to be confused and delighted at how I too can see 1000 degree temperature drop in the 3 feet between catalyst exit and flue probe.

I went back and re-read every post from this years owners chat. Made so much more sense the second time through. Tons of knowledge shared and help given.
-Thanks from the 22-23 Freshman class.

My fan is temp controlled. But I pretty much always leave it running to move the heat. Rarely does my stove get cold enough it turns off. The only time I turn it off is if I want to watch a movie I can't hear. Otherwise it stays on full speed all the time. I have the stove in a hearth and a less than ideal layout so I need to move air. Tried running it no blower and the far parts of the house stay too cold

 

[Diabel]

I think that @Diabel did a graph of operation .. maybe he can post that also.. i

Edit.. it was a flow chart.. Im much better after some sleep...

It was not me, but there was one member back then that was charting the cat activity. Can’t remember his name.

 

[arnermd]

@arnermd unfortunately I think you might be VC R&D as far as temperature exposure and refractory life. I understand that the data logger is new this year - Hopefully you’re defining the 20 year refractory life setup now. Any idea what you were running the 3 years between failures?

I bought the data logger last year, mid season. But your point is valid, I do not have recorded data from the refractory failure days.

As with all things my memory is a little fuzzy and there are no definitive conclusions I can draw. Pretty sure all my refractory failures are documented in prior year threads, but here is what I recall....

• When new I only had STT magnet. So I had no idea what the cat was doing, ignorance was bliss.... My guess is the cat was running consistently in the 1600+ range.
  • The original refractory lasted 3 years I think. It did not crack, the rear piece (VC calls it a Refractory, Engine) actually warped causing smoke to bypass the cat. I plugged it with some insulation and ran the rest of the season. The surface showed heavy spalling, indicating it was running hot.
• The second refractory actually cracked, again it was the refractory engine. At this time I had cat temp monitoring but no data logging. As best I recall my over-temp alarm was set to 1650+ so I could sleep once in while. I did run for a while with no cat. It too showed spalling but not as heavy as the first one.
• I am not entirely convinced the failures were a result of over firing. There is part of me that thinks they were manufacturing defects that were exacerbated by the high temps. Very hard to know for sure.
• I just looked through my records and I replaced cats in 2015, 2017, 2020, 2022. I installed the stove in Feb 2012. So the life of the cats were: 3, 2, 3, 2 years. That's 2.5 years on average. I know some of them I stretched by piecing some broken ones together.
  • Failure mode is always ceramic crumbling, the ceramic grid cracks and chunk simply fall out of the frame. I suspect this is a result of flame impingement.
  • The steel frames always warp on the lower back side of the cat. I started making either bands that slip over the cat frame or wrapping the frame in stainless wire to help the frame keep its shape. Definitely helps..... but then the ceramic just falls apart.
  • This years cat is not looking so good after only 3 months of service..... it has several cracks and one small section has already broken. Next cat will be steel for sure.....
  • I only mention cat life as I think it is an indirect indicator of secondary temps. The cat life has been pretty consistent so that tells me the stress level on the refractory has been consistent through the life of the stove.....
• I also would be remiss if I did not mention that VC replaced the refractory, both times, under warranty. The biggest inconvenience is that it takes months to get the new parts, and then I had to rebuild the stove, twice.
  • My stove has a lifetime warranty on refractory, but not the cat. I do not believe this was offered for too many stove models.

Wondering what your experience has been using forced convection on these stoves. Do you just always leave the fans running?

I do not use, and never have used, convection fans. I have a peltier fan that sits on the stove top but that's it. One time I experimented with secondary air. I forced air, with a blower, into the secondary inlet. It definitely worked, I could control secondary temps by forcing more air to run on the lean side of stoich. I did not run it unattended or for long, forcing air into a firebox with no safety's is a bit to risky for me.....

I have considered using my Watlow controllers to run closed loop control and vary blower speed to regulate secondary temps. Just have not had the time or motivation to try that. Seems excessive for something that should just work.... and the failure modes for forced air combustion are very ugly.

Tons of knowledge shared and help given.

Yep for sure.... this is a really great forum. I really wish we had a stove designer participating in the discussions. Sometimes I feel like we are just a bunch of monkeys trying to figure out how to drive a car.....

Eventually some of us will (and have) figured it out....

 

[Lorde]

Make sure you follow the directions and do your break in fires.. probably best to crack some widow's and close Adjacent doors.... You need to make sure the moisture content of your wood is correct 20%MC or less on a freshly split face with pins going with the grain.. Sub par wood will lead you into poor stove performance.

Tell me about you chimney set up.. sounds tall or a steep roof

It's a liner going in a masonry chimney. Two story colonial, maybe 25'. They told me they would access with an extension ladder but it was drizzling the day of install so they brought a lift. They couldn't set up where they wanted to because the ground was so wet after a few days rain, tried it from a patio but couldn't reach. Overall it was a comedy show - took them two hours to set up and realize it wouldn't reach. They are coming back today.

I'm going to post some pics of the cat probe penetration when I get home, hopefully it is not an issue but it sure has been bothering me. Thanks for the help, first wood stove of my own.

 

[gthomas785]

I bought the data logger last year, mid season. But your point is valid, I do not have recorded data from the refractory failure days.

As with all things my memory is a little fuzzy and there are no definitive conclusions I can draw. Pretty sure all my refractory failures are documented in prior year threads, but here is what I recall....

• When new I only had STT magnet. So I had no idea what the cat was doing, ignorance was bliss.... My guess is the cat was running consistently in the 1600+ range.
  • The original refractory lasted 3 years I think. It did not crack, the rear piece (VC calls it a Refractory, Engine) actually warped causing smoke to bypass the cat. I plugged it with some insulation and ran the rest of the season. The surface showed heavy spalling, indicating it was running hot.
• The second refractory actually cracked, again it was the refractory engine. At this time I had cat temp monitoring but no data logging. As best I recall my over-temp alarm was set to 1650+ so I could sleep once in while. I did run for a while with no cat. It too showed spalling but not as heavy as the first one.
• I am not entirely convinced the failures were a result of over firing. There is part of me that thinks they were manufacturing defects that were exacerbated by the high temps. Very hard to know for sure.
• I just looked through my records and I replaced cats in 2015, 2017, 2020, 2022. I installed the stove in Feb 2012. So the life of the cats were: 3, 2, 3, 2 years. That's 2.5 years on average. I know some of them I stretched by piecing some broken ones together.
  • Failure mode is always ceramic crumbling, the ceramic grid cracks and chunk simply fall out of the frame. I suspect this is a result of flame impingement.
  • The steel frames always warp on the lower back side of the cat. I started making either bands that slip over the cat frame or wrapping the frame in stainless wire to help the frame keep its shape. Definitely helps..... but then the ceramic just falls apart.
  • This years cat is not looking so good after only 3 months of service..... it has several cracks and one small section has already broken. Next cat will be steel for sure.....
  • I only mention cat life as I think it is an indirect indicator of secondary temps. The cat life has been pretty consistent so that tells me the stress level on the refractory has been consistent through the life of the stove.....
• I also would be remiss if I did not mention that VC replaced the refractory, both times, under warranty. The biggest inconvenience is that it takes months to get the new parts, and then I had to rebuild the stove, twice.
  • My stove has a lifetime warranty on refractory, but not the cat. I do not believe this was offered for too many stove models.

I do not use, and never have used, convection fans. I have a peltier fan that sits on the stove top but that's it. One time I experimented with secondary air. I forced air, with a blower, into the secondary inlet. It definitely worked, I could control secondary temps by forcing more air to run on the lean side of stoich. I did not run it unattended or for long, forcing air into a firebox with no safety's is a bit to risky for me.....

I have considered using my Watlow controllers to run closed loop control and vary blower speed to regulate secondary temps. Just have not had the time or motivation to try that. Seems excessive for something that should just work.... and the failure modes for forced air combustion are very ugly.


Yep for sure.... this is a really great forum. I really wish we had a stove designer participating in the discussions. Sometimes I feel like we are just a bunch of monkeys trying to figure out how to drive a car.....

Eventually some of us will (and have) figured it out....

I'm curious.. what is your source of catalysts?
I ask because I ordered one from a certain vendor recently that was listed as being compatible with the VC 2040, and yet when it arrived it was a very snug fit, lengthwise, enough that I was not comfortable installing it. I checked the dimensions in the vendor catalog, it should be 13" and it was. But then I checked the VC manual and it says the catalyst should be 12.75"! I emailed customer support and they did not seem to have a clue about this discrepancy but were remarkably willing to make me a custom 12.75" catalyst and sent it out within a day. I could see that it has the same refractory cells as the 13" but the frame was just welded in a bit closer.
Your post made me think of this because it stands to reason that a tight-fitting catalyst under thermal expansion could stress the refractory engine enough to pop it. You probably have a different issue, just thought I'd mention it.

 

[Woodsplitter67]

It's a liner going in a masonry chimney. Two story colonial, maybe 25'. They told me they would access with an extension ladder but it was drizzling the day of install so they brought a lift. They couldn't set up where they wanted to because the ground was so wet after a few days rain, tried it from a patio but couldn't reach. Overall it was a comedy show - took them two hours to set up and realize it wouldn't reach. They are coming back today.

I'm going to post some pics of the cat probe penetration when I get home, hopefully it is not an issue but it sure has been bothering me. Thanks for the help, first wood stove of my own.

Assuming 6 inch liner..

 

[Eman85]

Yep for sure.... this is a really great forum. I really wish we had a stove designer participating in the discussions. Sometimes I feel like we are just a bunch of monkeys trying to figure out how to drive a car.....

Eventually some of us will (and have) figured it out....

Wouldn't it be great if VC actually had someone that answered the phone and a tech department! Pretty frustrating when you call they automatically refer you to a dealer for tech assistance. I can't see being a VC dealer unless the profit margin is big enough to have to be their tech line too.

 

[arnermd]

I'm curious.. what is your source of catalysts?
I ask because I ordered one from a certain vendor recently that was listed as being compatible with the VC 2040, and yet when it arrived it was a very snug fit, lengthwise, enough that I was not comfortable installing it. I checked the dimensions in the vendor catalog, it should be 13" and it was. But then I checked the VC manual and it says the catalyst should be 12.75"! I emailed customer support and they did not seem to have a clue about this discrepancy but were remarkably willing to make me a custom 12.75" catalyst and sent it out within a day. I could see that it has the same refractory cells as the 13" but the frame was just welded in a bit closer.
Your post made me think of this because it stands to reason that a tight-fitting catalyst under thermal expansion could stress the refractory engine enough to pop it. You probably have a different issue, just thought I'd mention it.

The first two catalysts were ceramic from Hearth and Home, they were as purchased and warranty replacement from VC. The next three were from Condar (CC-800). None of them were a tight fit, snug I would say but easily slid into place if it was squared up.

My personal opinion is that a cat frame would not pop the refractory, the frames are too flimsy especially when hot. I think the frame would just deflect.

I measured the length of my old one and it measures 12.75" at the corners but 13" down the middle. I think it probably was 12.75" when new but then warped over time to 13" in the middle.

I have been happy with the Condar cats, seem to perform as well as the factory ones. Never had a problem with activity, unless they fell apart.....

In general my cat complaints are: (I do not think any of these are the cat mfgs fault)

• Cat falls apart in 2 years (they are not terribly expensive so I am not too bothered by this)
  • I think this is just a result of direct flame impingement with these 2n1 stoves
  • As far as I know none of the cat suppliers offer any warranty on these cats for 2n1 stoves..... that tells me something.
• The lower back edge of the frame warps so bad the catalyst blocks fall out of the frame.
  • There is no refractor support along the lower back corner of the cat frame, so when things get hot the frame deflects that way.
  • On all my new cats I install either SS wire loops or metal bands usually in three places to help the frame hold its shape.
  • If any cat mfgs are reading this: please add additional cross straps to hold the frame in place....

 

[Woodsplitter67]

Heres 1 thing that gets overlooked alot, its been covered somewhat in years past.. Cleaning the stove pipe as well as seeing first hand How well your burning the stove and stove performance.

Most years I do a mid season cleaning. This year especially. I made sure that I got a January cleaning in because of the warmer temperatures and burning low.. alot...

The first picture is the crumbs from the cap. This is what it should look like and expected. Your cap will have some.. not alot and ahould basically tap right off.. there is never any scrubbing evolved

The 2nd picture is the SS 8 inch double wall pipe. The top of the stove pipe will tell you your story. There is no glazing or creosote of any kind. If you see glazing thats bad, the other variety is the black chunky flaky creosote, Iaa of that is saying.. incomplete combustion Notice how clean the inside of the pipe is

The 3rd picture is of what I I got out on my stovepipe. Nothing but basically a cup or so of black soot.

All of this is saying that no matter how Im running my stove Im getting complete combustion, my cat is running perfectly fine

I burn sometimes with out the cat, especially when its just a fire here and there. For the one's that are not running a cat Its probably in your best interest to sweep often. It only took another member here to have his first chimney fire after 2 months of burning with out the cat and turning the air back.

I encourage all the fokes here not running the catalyst to put one in. Having the catalyst in will enhance stove performance and safety. Your not saving anything if you accidentally burn the house down.

Many of you who are burning as primary or supplemental heat and purchased wood or going through 2/3 cords per year should consider a mid season sweep

 

[Catesy]

First month with the Dauntless Flexburn without the cat. I've been burning wood for many years, never seen it this bad in such a short time. Guess I need to run a little hotter. Going to do another sweep this weekend.

 

[dmccoole]

I'm curious.. what is your source of catalysts?
I ask because I ordered one from a certain vendor recently that was listed as being compatible with the VC 2040, and yet when it arrived it was a very snug fit, lengthwise, enough that I was not comfortable installing it. I checked the dimensions in the vendor catalog, it should be 13" and it was. But then I checked the VC manual and it says the catalyst should be 12.75"! I emailed customer support and they did not seem to have a clue about this discrepancy but were remarkably willing to make me a custom 12.75" catalyst and sent it out within a day. I could see that it has the same refractory cells as the 13" but the frame was just welded in a bit closer.
Your post made me think of this because it stands to reason that a tight-fitting catalyst under thermal expansion could stress the refractory engine enough to pop it. You probably have a different issue, just thought I'd mention it.

FWIW, I've cobbled these catalysts sources together from this forum:
New Catalytic Combustor:
(broken link removed to https://appliedceramics.com/industries/wood-smoke/)
https://www.firecatcombustors.com/category-s/1287.htm
Ceramic or Steel: https://midwesthearth.com/products/...exburn-2-5-x-12-75-x-1?variant=19888841687169

 

[arnermd]

FWIW, I've cobbled these catalysts sources together from this forum:
New Catalytic Combustor:
(broken link removed to https://appliedceramics.com/industries/wood-smoke/)
https://www.firecatcombustors.com/category-s/1287.htm
Ceramic or Steel: https://midwesthearth.com/products/...exburn-2-5-x-12-75-x-1?variant=19888841687169

You missed one:

Condar: https://www.condar.com/Combustors.html

 

[arnermd]

The 3rd picture is of what I I got out on my stovepipe. Nothing but basically a cup or so of black soot.

Wow that is really nothing.... how many cords since your last sweep?

For comparison I sweep once per season and I generally get 1-2 gallons of crumbs, not gummy. Usually mostly at the top, where it is colder. My stack is 8" liner about 23' tall and I burn 4-4.5 cord per season.

Last year was the worst year ever because I blocked off the secondary air.... not doing that again.

I would do mine more often but I am not getting on the roof anymore. Need to figure out how to clean from the bottom. I have to go through the branch of an 8" tee into the vertical liner. Not sure the flexible rods can make that bend, never tried.

Maybe a soot eater would work? Would love to hear from others who clean from the bottom on what works.

Good topic for discussion @Woodsplitter67.

 

[Woodsplitter67]

First month with the Dauntless Flexburn without the cat. I've been burning wood for many years, never seen it this bad in such a short time. Guess I need to run a little hotter. Going to do another sweep this weekend.

View attachment 307982

This is kinda bad.. you probably should go with a catalyst.. Whata the MC of your wood.. have you checked.. just Curious

 

[Woodsplitter67]

Wow that is really nothing.... how many cords since your last sweep?

For comparison I sweep once per season and I generally get 1-2 gallons of crumbs, not gummy. Usually mostly at the top, where it is colder. My stack is 8" liner about 23' tall and I burn 4-4.5 cord per season.

Last year was the worst year ever because I blocked off the secondary air.... not doing that again.

I would do mine more often but I am not getting on the roof anymore. Need to figure out how to clean from the bottom. I have to go through the branch of an 8" tee into the vertical liner. Not sure the flexible rods can make that bend, never tried.

Maybe a soot eater would work? Would love to hear from others who clean from the bottom on what works.

Good topic for discussion @Woodsplitter67.

Im about 2 cords in.. I was kinda concerned because of the amount of low burning al the time.. and to be honest.. I dont baby sit the stove so If the stove stalls at the end I dont catch it

I feel better and am assured my stove runs well

My wood is dry.. really dry.. Obviously from the pictures I split my own and don't rely.on others.. All my wood sits in sheds I know for sure my wood is sub 15%MC

I did a kinl test one year and over did it.. I was burning wood .. oak. that was sub 5%MC
I can see why your drafting super hard.. 8 inch pipe 23ft high is a monster vacuum machine..

I have the white soot eatter rods.. I bet you can do the T bottom down

Just out of curiosity whats your woods MC