Buck 91 Help me understand my first burns

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Got the new probe in Friday, it appears to be reading the same as the other on the last burn.
Started a fire Sat evening around 7, top down with 4 splits. Once the fire was going good, shut the shotgun air and dropped the main air half way. Once the wood started coaling good, loaded the stove loosely, opened the main air all the way and let the new splits get a good burn. Shut the main down about half way for a few minutes, and then all the way down. A little bit of flame and then just glowing. Probe temp got up between 1800 - 1900. Woke up about 12:30 inside temp was 78 and checked the fire and probe was around 1200. Had heavy coaling, and spread everything out to fill again. Filled tightly this go round, and as before let the wood get going good before shutting the air down. Watched it for bit, and probe went back up to 1800. Temps outside at start were in the high 30's.

6am temp was 77 and probe was at 1200 and still had solid fuel on the sides and towards the back with big coals in the middle front. Temp outside was in the high 20s. Was going to let it go for the day, but decided to put 2 - 12" 4x4 pine scraps in a couple hours later. Let it get going and shut the air down again. Probe got up to 1600, but through the day it was in the 1000-1200 range. Raked the coals a couple times during the day and inside temp stayed at 77 most of the day. Outside temp got up to mid 40s.

5pm had a nice bed of coals. Cat probe was at 800. Put in some thicker pieces of kindling and 4 splits on top. Both air controls open until a good flame going then closed shotgun air. Loaded the stove and let it get going good. Closed air down 1/4 let it burn some more then closed it 3/4 down and finally all the way. Cat temp moved up quickly and looked like it was going to peg out again, but stopped just past the 2000 mark and then settled down at 2000 after a few minutes. Inside temp jumped up to 81. Cat stayed around 2000 for a while and then dropped to 1600. At about 9mp it looked like the wood was being consumed faster than the night before so I added 3 splits and after shutting air down cat went back to 2000. Fell asleep, but woke up about 12. Cat had settled down to 1500, inside temp at 76. 6am still had some small hunks of wood that were still burning, the rest was coals. Temp inside was still 76 but dropped to 74 a couple hours later. Outside temp was to get into the high 50s, so didn't reload the stove. Opened both air controls to help burn the coals down.

The first burn was good, put out steady heat and lasted longer than I expected. Thought adding the 4x4 scraps would make it burn quicker, but seemed to help longevity of the burn? Second burn I think I added the new splits too soon and didn't let the starters burn down far enough. This is similar to what I've done in the past when the cat has gotten hot, and assume it's due to too much off gassing at once?

It appears that adjusting the air control plates has made some difference, and maybe still new overactive cat since I'm not burning continuously? Attached some pictures as maybe they tell a story about how I'm burning that someone can interpret. I understand the darkened glass is due to low burn, but looks like one hot spot in the middle. That is where the shotgun air control is and it has 2 holes drilled in the plate as compared to one in the primary control plates. I may try to play with blocking off one of the holes or part of one and see if that makes a difference.

IMG_3721.jpg IMG_3723.jpg IMG_3725.jpg IMG_3726.jpg
 
Sure seems that you are futzing around a lot with your loading/reloading routine?

Why are you reloading a Cat stove when it has heavy coaling and a Cat gauge at 1200F? That makes zero sense to me. Your house temps sound crazy hot.

Let the stove chew on that load of coals until they are reduced to just enough for a restart (without all that useless kindling). Let the load run until your indoor temps have dropped to a point you should be adding heat, your Cat gauge is going to go inactive, or you need to go to sleep, work, leave the house etc.

Then put a complete load of "only full-size splits" in. Close the loading door completely. Open the air controls. Wait for the coals to start the load. It may take 2-30 minutes to restart depending on how long you let the last load melt down. If you have time and your home is not freezing who cares. Forget the useless kindling and all the opening/closing/adding splits etc. Opening the loading door on a hot Cat stove is hard on the Catalyst. Keep it minimal.

Once the new load has a good burn on it (fully involved with STT's at a safe spot and Cat gauge in active zone) reduce the air controls to their happy place and walk away. If your loads/reloads are making the stove to hot, reduce air sooner.

I think perhaps you are inadvertently pushing the stove with a tendency to over-tend. This would keep any Cat stove temps overly high.

My observations from reading this thread. No offense and good luck getting things ironed out.
 
No offense taken, I put the info out there to hopefully get suggestions on how to improve what I'm doing.

It has given me the idea to try full load start again instead of the small fire reload start Buck suggests. That would help cut down on the number of times I need to open the door.

As to the crazy hot house temps, that's why we wanted a wood insert. Having lived in a tropical climate for several years we have become accustomed to warmer temps and wanted the stove to allow us to increase heat during the winter months and also to take some of the load off our aging heat pump.
 
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Got the new probe in Friday, it appears to be reading the same as the other on the last burn.
Started a fire Sat evening around 7, top down with 4 splits. Once the fire was going good, shut the shotgun air and dropped the main air half way. Once the wood started coaling good, loaded the stove loosely, opened the main air all the way and let the new splits get a good burn. Shut the main down about half way for a few minutes, and then all the way down. A little bit of flame and then just glowing. Probe temp got up between 1800 - 1900. Woke up about 12:30 inside temp was 78 and checked the fire and probe was around 1200. Had heavy coaling, and spread everything out to fill again. Filled tightly this go round, and as before let the wood get going good before shutting the air down. Watched it for bit, and probe went back up to 1800. Temps outside at start were in the high 30's.

6am temp was 77 and probe was at 1200 and still had solid fuel on the sides and towards the back with big coals in the middle front. Temp outside was in the high 20s. Was going to let it go for the day, but decided to put 2 - 12" 4x4 pine scraps in a couple hours later. Let it get going and shut the air down again. Probe got up to 1600, but through the day it was in the 1000-1200 range. Raked the coals a couple times during the day and inside temp stayed at 77 most of the day. Outside temp got up to mid 40s.

5pm had a nice bed of coals. Cat probe was at 800. Put in some thicker pieces of kindling and 4 splits on top. Both air controls open until a good flame going then closed shotgun air. Loaded the stove and let it get going good. Closed air down 1/4 let it burn some more then closed it 3/4 down and finally all the way. Cat temp moved up quickly and looked like it was going to peg out again, but stopped just past the 2000 mark and then settled down at 2000 after a few minutes. Inside temp jumped up to 81. Cat stayed around 2000 for a while and then dropped to 1600. At about 9mp it looked like the wood was being consumed faster than the night before so I added 3 splits and after shutting air down cat went back to 2000. Fell asleep, but woke up about 12. Cat had settled down to 1500, inside temp at 76. 6am still had some small hunks of wood that were still burning, the rest was coals. Temp inside was still 76 but dropped to 74 a couple hours later. Outside temp was to get into the high 50s, so didn't reload the stove. Opened both air controls to help burn the coals down.

The first burn was good, put out steady heat and lasted longer than I expected. Thought adding the 4x4 scraps would make it burn quicker, but seemed to help longevity of the burn? Second burn I think I added the new splits too soon and didn't let the starters burn down far enough. This is similar to what I've done in the past when the cat has gotten hot, and assume it's due to too much off gassing at once?

It appears that adjusting the air control plates has made some difference, and maybe still new overactive cat since I'm not burning continuously? Attached some pictures as maybe they tell a story about how I'm burning that someone can interpret. I understand the darkened glass is due to low burn, but looks like one hot spot in the middle. That is where the shotgun air control is and it has 2 holes drilled in the plate as compared to one in the primary control plates. I may try to play with blocking off one of the holes or part of one and see if that makes a difference.

View attachment 287845

We had a Buck 91 installed in 2008. I had a bit of a learning curve to navigate before arriving at the optimal operating methods for our application, and getting the most heat out of the insert. I used the relight last evening to document and describe those methods, with the intention of giving you some ideas. Yesterday was a pretty nice day with a high of 62, so the stove was allowed to burn down with no daytime reload. Lows were forecast to be in the lower 30s.



This pic shows how virtually every cold start begins, a couple of red oak splits around 2 sheets of newspapers crumpled up under a handful of twigs. Shotgun air (left side) is closed, air wash (right side) is fully open, bypass open, CAT temp @ fire-up is roughly 100. Time was 6:15.



I put a couple of smaller splits on top, of the twigs after fire-up and started supper. The next pics show the progress after 15 minutes. CAT temp up to almost 300,, bypass still open, I closed air wash by half.




About a quarter to 7:00, the CAT was up to 500. I put a couple more small splits on top of the pile, closed the bypass, and closed the air wash about 1/2". The air wash is still open roughly a little under 1/2 of what adjustment it has.



The last picture was taken @ 7:23. Note the CAT temp of 1400. I let it burn for another hour, evened out the coals then loaded it fully for the overnight, and closed the air wash to about 1/2"-3/4" from fully closed. Slight adjustments to keep the CAT temp from getting above 1500 before going to bed about 10:00.



Here's what it looked like this morning, a good bed of coals and CAT temp of about 900. I put a couple more splits on to carry out the rest of the day. Note the slight smoke smudges in the lower corners. The glass looks like this most all the time.

Not trying to be critical, but I'd suggest you go back and reread the manual. Several things you've said about how you operate are confusing. Based on what you've posted, you're operating the stove too hot to allow it to get above 1700. I'm not sure what an overactive CAT is. I had to get a new CAT probe this fall, when the chimney was swept, and the stove checked. On my probe, and in my manual, recommended operation is up to 1700. Looking at the picture of your glass, it appears you closed down the air wash (right side) completely, the CAT stalled, or the wood was too wet. One of the biggest variables in operating my stove is wood. Most all I burn is red/white oak and hickory that has been seasoned as needed. About the only time I ever have to open up the shotgun (left side) is from a total cold start. I tend to push closing the bypass a little sooner than instructed, but it works for me. In the years we've heated with this stove, the CAT has been replaced twice, the door gasket twice, and the chimney swept yearly. I've never had to adjust anything more than the door latch. For us, the Buck 91 has been one of the best investments we've made. It's simple to operate, built like a tank, and has readily available parts/dealer support. I hope this helps, and I hope you take this post in the spirit it was intended.
 
Thanks for the detailed reply, I appreciate the effort to show your process. As I said to moresnow, I appreciate any help as I try to figure this thing out.

Learning curve indeed.

According to info on the forum, new cats can tend to go over the max recommended temp for a while before settling in, therefore overactive.

How much space are you heating and what temps can you keep? We like it warmer, and not sure we'll be able to get consistent overnight heat like we would like.

I have actually read through the manual several times, and have tried to follow it, though I have done some full load starts. I may have missed it, but I can't find anywhere that states a max temperature which is surprising. It mentions minimums and also states that the catalyst will maintain temps in excess of 1000. Attached a screen shot of that and the burning instructions which say to shut the bypass after 3-4 minutes after shutting the door on a cold start. By the way, that doesn't work very well. From looking through old posts, I do know the burning instructions have changed some, and wonder if some info got left out in the switchover to the newer stove.

I've started fires 2 ways, similar to what you show, and also with a loaded box with top down start. From testing fresh splits inside what I have been burning is in the 15-20% range. Mixed wood; some ash, cherry, and oak with some other I'm not sure of. I was probably shutting down a little too quickly instead of in stages, but as far as I know the cat has never stalled. I always shut the shotgun all the way once the cat is active (with exception of one time leaving it on low), and then the main air after the fire has been burning good. Last few fires I've turned down in stages, but the result always seems to be the same. Once I shut the air completely there is usually a little flame for a few minutes and then just glowing wood. That lasts for about 30 minutes with the cat hanging in the 1200 or little over range. Then I start to get the flowing flames and the probe jumps up and the cat begins to glow and produce it's own flames, which according to the CS rep at Buck is doing what it's supposed to. He said if the heat shield wasn't there I would see the catalyst shooting flame downward. That's when it shoots into the too hot zone on the probe.
It has seemed to settle down some during the last fires, and may post more about it after a couple more. My seasoned wood is at the end, so I've been supplementing with compressed bricks from TSC, and only burning when it gets into the 20's or below at night.

91 catalyst info.png 91 Instructions.png
 
ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssThanks for the detailed reply, I appreciate the effort to show your process. As I said to moresnow, I appreciate any help as I try to figure this thing out.

Learning curve indeed.

According to info on the forum, new cats can tend to go over the max recommended temp for a while before settling in, therefore overactive.
sss
How much space are you heating and what temps can you keep? We like it warmer, and not sure we'll be able to get consistent overnight heat like we would like.

I have actually read through the manual several times, and have tried to follow it, though I have done some full load starts. I may have missed it, but I can't find anywhere that states a max temperature which is surprising. It mentions minimums and also states that the catalyst will maintain temps in excess of 1000. Attached a screen shot of that and the burning instructions which say to shut the bypass after 3-4 minutes after shutting the door on a cold start. By the way, that doesn't work very well. From looking through old posts, I do know the burning instructions have changed some, and wonder if some info got left out in the switchover to the newer stove.

I've started fires 2 ways, similar to what you show, and also with a loaded box with top down start. From testing fresh splits inside what I have been burning is in the 15-20% range. Mixed wood; some ash, cherry, and oak with some other I'm not sure of. I was probably shutting down a little too quickly instead of in stages, but as far as I know the cat has never stalled. I always shut the shotgun all the way once the cat is active (with exception of one time leaving it on low), and then the main air after the fire has been burning good. Last few fires I've turned down in stages, but the result always seems to be the same. Once I shut the air completely there is usually a little flame for a few minutes and then just glowing wood. That lasts for about 30 minutes with the cat hanging in the 1200 or little over range. Then I start to get the flowing flames and the probe jumps up and the cat begins to glow and produce it's own flames, which according to the CS rep at Buck is doing what it's supposed to. He said if the heat shield wasn't there I would see the catalyst shooting flame downward. That's when it shoots into the too hot zone on the probe.
It has seemed to settle down some during the last fires, and may post more about it after a couple more. My seasoned wood is at the end, so I've been supplementing with compressed bricks from TSC, and only burning when it gets into the 20's or below at night.

View attachment 289869 View attachment 289870
Our home is 1800 sqft with a full basement. We try to keep the temp around 70-72. We also have a HE propane furnace.
I noticed some obvious differences in the manuals we have to refer to. I downloaded a PDF for the 91 in 2016, my paper copy is the same. Below is a copy/paste from that download ( couldn't figure out how to link the PDF page) for "Building a Fire:" In particular, # 8. I can guarantee if I closed the bypass after a couple of minutes, before it reached around 500 or so, it would stall. Then I'd have to open up the air wash to reestablish a good burn rate. I NEVER close all the air controls completely. The air wash is usually closed to the last 1/2" to maybe 3/4" of adjustment, and the shotgun air control is always closed once the bypass is closed. To not do so for my stove would bring about high CAT temps, and fast burn rates of fuel in the firebox. I've never started a fire with the newspaper on top of the kindling. Something else that is different in our manuals. BTW, I looked all over mine for the max temp recommendation. Didn't find one like I thought I'd seen. I reference the range of operation by the CAT temp probe. That is actually how the dealer said to operate the stove. Both of the ones I've had are marked like the one in my pictures. Inactive below 600, normal range 600-1700, and too hot above 1700. The one shown in your pictures is similar, with "operate catalyst " markings between about 500-1500 highlighted by the silver/grey background. According to your probe, anytime the stove is operating above 1500 is in overfire condition and under 500 is inactive. Possible damage is done to the CAT above 1500. I second the quote from Highbeam in his post on 11/18/21, "I don't understand why anybody would close the bypass after 3-4 minutes. The stove temperatures as indicated by that cat meter need to be in the active region above 500 before you engage the cat whether that takes 10 minutes or an hour." I'm not sure what differences there would be in a stove as basic as the 91 to have the operations variables in our manuals. I'm going to talk to my local shop, see if they have any answers. They've been selling/servicing Buck products for over 25 years.

I don't understand the definition of "overactive CAT", aren't they designed to eliminate/reduce the byproducts of combustion like smoke and particulates? (Rhetorical) :) Since they are new, won't they work better than after be subject to harsh conditions for a given length of time? (Again rhetorical) Again, hope this helps.

BUILDING A FIRE:
1. Place “Manual/Off/Automatic” switch in “Automatic” (bottom) position for thermostat control operation. Turn
rheostat knob clockwise (it will click from “Off” position to “On”) so you can vary the speed of motor.
2. Open door.
3. While looking inside firebox, operate damper bypass plate in and out observing movement. This should operate
freely and close completely. Open damper bypass.
4. Open air controls on each side of stove (pull out).
5. Twist 4 or 5 pieces of non-colored newspaper in a roll and place on floor of firebox.
The Model 91 Bay is not designed for use with grates, andirons or other methods of supporting the fuel.
NOTE: Do not use grate or elevate fire. Build wood fire directly on inner bottom of fire box.
3. Lay several pieces of dry kindling on top of newspaper.
4. Place three or four small pieces of firewood, 2-3" in diameter, on top of kindling.
5. Light newspaper, close and latch door. Don’t leave fire unattended at this point. The draft should start quickly. If
not, it may be necessary to preheat the chimney to get draft started. To do this, open door and add newspaper to
top rear of the wood. Light or let this paper ignite and allow to burn while holding door slightly open. Do not leave
the stove unattended with door open! Once draft has started, close and lock door. A direct connect (option) usually
solves this problem. Check with your dealer.
6. After embers and a coal bed have been established, load heater with natural seasoned hard wood, placing it from
front to rear. DO NOT BUILD A LARGE ROARING FIRE! Initially, build 2-3 small fires in order to cure the
paint on your stove.
7. Within a20 minute time frame, you can begin to add your wood. Remember—DO NOT FILL firebox during your
first 2 to 3 fires!
8. Once your fire is burning well, and probe has reached 600ºF, close bypass damper completely (push in). Gradually
close primary air controls (push in). You will have to experiment with primary air controls to accommodate your
draft. If you close them to soon, your fire may die down to quickly and go out. Close them gradually, a little at a
time, until you can close completely
 
Our home is 1800 sqft with a full basement. We try to keep the temp around 70-72. We also have a HE propane furnace.
I noticed some obvious differences in the manuals we have to refer to. I downloaded a PDF for the 91 in 2016, my paper copy is the same. Below is a copy/paste from that download ( couldn't figure out how to link the PDF page) for "Building a Fire:" In particular, # 8. I can guarantee if I closed the bypass after a couple of minutes, before it reached around 500 or so, it would stall. Then I'd have to open up the air wash to reestablish a good burn rate. I NEVER close all the air controls completely. The air wash is usually closed to the last 1/2" to maybe 3/4" of adjustment, and the shotgun air control is always closed once the bypass is closed. To not do so for my stove would bring about high CAT temps, and fast burn rates of fuel in the firebox. I've never started a fire with the newspaper on top of the kindling. Something else that is different in our manuals. BTW, I looked all over mine for the max temp recommendation. Didn't find one like I thought I'd seen. I reference the range of operation by the CAT temp probe. That is actually how the dealer said to operate the stove. Both of the ones I've had are marked like the one in my pictures. Inactive below 600, normal range 600-1700, and too hot above 1700. The one shown in your pictures is similar, with "operate catalyst " markings between about 500-1500 highlighted by the silver/grey background. According to your probe, anytime the stove is operating above 1500 is in overfire condition and under 500 is inactive. Possible damage is done to the CAT above 1500. I second the quote from Highbeam in his post on 11/18/21, "I don't understand why anybody would close the bypass after 3-4 minutes. The stove temperatures as indicated by that cat meter need to be in the active region above 500 before you engage the cat whether that takes 10 minutes or an hour." I'm not sure what differences there would be in a stove as basic as the 91 to have the operations variables in our manuals. I'm going to talk to my local shop, see if they have any answers. They've been selling/servicing Buck products for over 25 years.

I don't understand the definition of "overactive CAT", aren't they designed to eliminate/reduce the byproducts of combustion like smoke and particulates? (Rhetorical) :) Since they are new, won't they work better than after be subject to harsh conditions for a given length of time? (Again rhetorical) Again, hope this helps.

BUILDING A FIRE:
1. Place “Manual/Off/Automatic” switch in “Automatic” (bottom) position for thermostat control operation. Turn
rheostat knob clockwise (it will click from “Off” position to “On”) so you can vary the speed of motor.
2. Open door.
3. While looking inside firebox, operate damper bypass plate in and out observing movement. This should operate
freely and close completely. Open damper bypass.
4. Open air controls on each side of stove (pull out).
5. Twist 4 or 5 pieces of non-colored newspaper in a roll and place on floor of firebox.
The Model 91 Bay is not designed for use with grates, andirons or other methods of supporting the fuel.
NOTE: Do not use grate or elevate fire. Build wood fire directly on inner bottom of fire box.
3. Lay several pieces of dry kindling on top of newspaper.
4. Place three or four small pieces of firewood, 2-3" in diameter, on top of kindling.
5. Light newspaper, close and latch door. Don’t leave fire unattended at this point. The draft should start quickly. If
not, it may be necessary to preheat the chimney to get draft started. To do this, open door and add newspaper to
top rear of the wood. Light or let this paper ignite and allow to burn while holding door slightly open. Do not leave
the stove unattended with door open! Once draft has started, close and lock door. A direct connect (option) usually
solves this problem. Check with your dealer.
6. After embers and a coal bed have been established, load heater with natural seasoned hard wood, placing it from
front to rear. DO NOT BUILD A LARGE ROARING FIRE! Initially, build 2-3 small fires in order to cure the
paint on your stove.
7. Within a20 minute time frame, you can begin to add your wood. Remember—DO NOT FILL firebox during your
first 2 to 3 fires!
8. Once your fire is burning well, and probe has reached 600ºF, close bypass damper completely (push in). Gradually
close primary air controls (push in). You will have to experiment with primary air controls to accommodate your
draft. If you close them to soon, your fire may die down to quickly and go out. Close them gradually, a little at a
time, until you can close completely
Definitely more detail in your instructions.

I know it's getting hotter than recommended for the catalyst, I just don't know what I can do differently to get it under control.

Found a shop that sells many different brands just outside the search parameters I used when trying to find a dealer. Made a visit there yesterday. Talked to one of the owners who offered some ideas. She said I may not have been letting it get hot enough before shutting down. She also said to look for leaks around the flex liner connection. Started a fire this morning, and let the fire burn on the high setting before shutting down, and the probe climbed to 1800 within 30 minutes of shutting the bypass. Shut to med high and kept climbing. Closed it all the way and went just over 2000. Put the fan on high at that point and it put out great heat, but at what cost to the catalyst. Stove top got to 400 and the front face just above the door was at 650 at the highest. Opened it back up little by little to get a little flame which was about 1/2" from closed and it dropped down to 1900 and then climbed and hung out at 2000 for about 4 hours. This was with 2 splits of wood, 1 cherry one ash, and the rest was compressed bricks.
 
Could a vacuum leak in liner connection be a cause of the cat running so hot? If not, what issues would it cause?

Was recommended to check for vacuum leak at the flex liner connection with a match flame a few minutes after starting a fire. Sure enough about a 3/4" section drew the flame in. Area is marked on the picture. I couldn't check all the way around in the back, but this seemed to be the only area that leaked.

Is there a way to seal this area or seal around the whole connection?

IMG_3784_LI.jpg
 
If your draft is abnormally high that would cause your cat to run hotter (I don't think that is your issue with 8" 16ft run). What you are seeing with the match(I like to use incense sticks) is the draft sucking up the flame (good thing to have). You could try using furnace cement on the appliance connector to seal it but it usually doesn't stay long since it sees high temps. I still say you need to figure out how to best limit the incoming primary air supply if the stove is in fact running hot.
 
If your draft is abnormally high that would cause your cat to run hotter (I don't think that is your issue with 8" 16ft run). What you are seeing with the match(I like to use incense sticks) is the draft sucking up the flame (good thing to have). You could try using furnace cement on the appliance connector to seal it but it usually doesn't stay long since it sees high temps. I still say you need to figure out how to best limit the incoming primary air supply if the stove is in fact running hot.
Would mil pack work? I know it will eventually harden and crack, but at least in the short term to see if it helps.

I don't know if the draft while starting with the door cracked is an accurate indicator, but it was really strong yesterday to the point the flame burned through the paper so fast and with a force that I thought was going to blow the flame out. Had to keep adding some paper to get the front kindling ignited. Normally I can light in the front and the draft pulls the flame through to the back pretty strongly, but not like yesterday. Temp in the mid 30's with rain snow mix.

I don't know what else to do to regulate the incoming air other than blocking off the holes they drilled in the slider plates. I put a magnet over half the holes in the shotgun air control as I can only get to half due to the main slider arm in the way. This seemed to help some on the previous fires as the probe only went up to 1800 once, but mostly stayed at 1600 or below. That was with the main air shut all the way. It didn't help at all yesterday though.

I've read so many threads, I'm not sure I understand correctly, but what I think I've understood is that if the cat is getting too hot, to open the air up to a flame where the flame burns more but not as efficiently and therefore the cat doesn't have to be as active, or is that incorrect?
 
If your cat is running at a higher temp than you would like you can open the bypass slightly to help cool it off.

Mil pack would work but man does that stuff turn into concrete, you would have to chip it off.

Usually we see issues with overdraft from taller chimneys (20ft+), but the wind would have been a major problem, we had 50mph gusts here last night. Usually you will see your toilet water sinking down, that will give you an idea of how it is affecting your chimney.

I still recommend really checking out your ashpan to see if it is leaking air.
 
If your cat is running at a higher temp than you would like you can open the bypass slightly to help cool it off.

Mil pack would work but man does that stuff turn into concrete, you would have to chip it off.

Usually we see issues with overdraft from taller chimneys (20ft+), but the wind would have been a major problem, we had 50mph gusts here last night. Usually you will see your toilet water sinking down, that will give you an idea of how it is affecting your chimney.

I still recommend really checking out your ashpan to see if it is leaking air.
Thanks mellow. I wasn't sure about opening the bypass as some say it's not good for the cat.

I checked again after your last reply with an incense stick and found another section about 2" sucking smoke. I did start another thread hoping some others that may have had leaks might chime in on how they handled it. Only thing I could find on searches was for class a pipe.

So now I know why the toilet does that! ;lol

I tried the incense stick around the ash pan but couldn't see anywhere it was being drawn in. I will check again though, since I missed the other section at the connection. What confuses me is when I shut the main air all the way, the flames will die with maybe a wispy flame, then nothing but glowing. Then 20 to 30 minutes the cat starts to really glow, and the big rolling flames start, sometimes intermittently and sometimes continuous. In my limited understanding, it would seem that if there was air leaking in, I wouldn't be able to shut down to just a glow. Just shows how much I have to learn on this. Nothing like growing up with a woodstove we just put wood in and it heated like crazy.
 
Not sure what is happening now. Realized there was a gap between the collar and stove and the company came out and fixed it last Wednesday. Prior to this cat probe temps were getting up to 2000 range a few times, but was attributing that to overactive cat, but now not sure.

Since the fix, I've had fires that maxed out the cat probe thermometer. First was on Friday morning after a cold start. Once the fire was going good I left both air controls set at low burn to get some good heat started and walked away. About 30 minutes later I checked and the probe was pegged out and had strong flame (secondary flame?) as shown in the first and second pictures below. Shut air controls all the way and then checked the stove temperature. Top was 400 in the middle and dipped down on both sides. Front of the stove highest temp was 663 with slightly lower temps farther out from center. This lasted about 30 minutes then the probe started to drop and eventually got into the normal range.

Second time was after a big reload later for that night. Once the new wood had a good char I shut down the air supply and flames died down with just one small flame that went for about 20-30 minutes then no flame and just glowing wood. At that point the probe was in the 1800 range. Fell asleep in the chair and woke up to strong flames similar to the picture, but top third of the glass was clear, and the rest was completely dark (both lower corners of the glass had some build up already). The probe was again pegged out. This again lasted for about 30 minutes and then slowly began to settle down and eventually get back into the normal range. Stove temps were similar.

Did it again the next night after a big reload. Once again let the wood get a good char and then shut the air controls all the way. A little flame for a while and then just glowing wood. After 30 minutes or so the secondary flames start suddenly and the probe got into the 1800 range and then a little while longer it was pegged out again. Once again this lasted for about 30 minutes and then it started to settle down.

Am I still getting too much air somehow even with the supplies shut all the way, or shutting down too soon? Hopefully haven't done too much damage to the cat.

On another note, I'm suddenly finding more older threads on the 91 that for some reason didn't come up in the way I searched before. Or maybe didn't look back far enough. Just put in 91 instead of trying to search based on the issue. Even when trying to decide on whether to buy the stove, I never saw as many threads as I recently came across. A lot to read through still. So just want to apologize for not being more thorough in my searches.

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try this old buck 91 thread