Thanks Randy. I cleaned it as much as I could when I had it out of the stove. Regarding the rabbit hole...hah! I'll start with the analog probe, but I plan on using wood to heat this house for the foreseeable future, so a digital probe is probably on my Christmas list. Thanks for the recommendation.
2021/22 VC Owner thread
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RandyBoBandy
Minister of Fire
Just don’t put anything through the cells of the cat. Like Q tips or anything.
Get a cheap mechanics mirror with the extendable/teloscopic handle. Normally available for next to nothing at a NAPA, Orielly's or similiar. Believe mine was in a bucket on the counter for $5 a piece. Worth a try.
I can't find anything in the user or service manuals about the proper length for the probe. Assuming I put on in, how do I know what the appropriate length is for an analog probe, or how far to insert a thermocouple if I go digital?
The AT100 looks pretty affordable, but I'm lost in the weeds on which components it needs.
I'm looking at this unit: https://www.auberins.com/index.php?main_page=product_info&products_id=279
It looks like it takes almost any kind of temperature sensor, but I'm not sure which to pick.
K type high temp thermocouple w/ mounting adapter [WRNK-193] - $30.00 : Auber Instruments, Inc., Temperature control solutions for home and industry
Auber Instruments, Inc. K type high temp thermocouple w/ mounting adapter [WRNK-193] - This K type transition style high temperature thermocouple probe can be used for glass kilns and heat treatment ovens. The maximum working temperature is 1100°C (2000°F). The maximum insertion length is 3"...
www.auberins.com
Woodsplitter67
Minister of Fire
your looking for the K type thermo coupler 6 inch.. I have the AT100 and this is what i use.. You will need to attach it to the original bi mettle temp guage bracket the stove came with or your going to need to rig one up
K Type Thermocouple w/ 6 (150 mm) Probe [WRNK-171] - $13.50 : Auber Instruments, Inc., Temperature control solutions for home and industry
Auber Instruments, Inc. K Type Thermocouple w/ 6 (150 mm) Probe [WRNK-171] - K type transition style thermocouple probe. The probe is 6" (150 mm) long and 5/32" (4.0 mm) in diameter. The transition section is 0.3" in diameter and 1" long. Both tip and transition section are made of 302...
www.auberins.com
This is the six inch, but the max working temp is 750.
There's a high temp version of the probe that applicable to kilns—is that what I should be looking at?
K type high temp thermocouple w/ mounting adapter [WRNK-193] - $30.00 : Auber Instruments, Inc., Temperature control solutions for home and industry
Auber Instruments, Inc. K type high temp thermocouple w/ mounting adapter [WRNK-193] - This K type transition style high temperature thermocouple probe can be used for glass kilns and heat treatment ovens. The maximum working temperature is 1100°C (2000°F). The maximum insertion length is 3"...
www.auberins.com
RandyBoBandy
Minister of Fire
It’s about 2”. VC sells their own. You could also get a condar I believe. If you get a probe from Auber it will be 6” long. If a probe has never been installed in this stove you will have to hand drill your own hole in the refractory box. It’s super easy. Just get a 1/4” drill bit and with your fingers only gently drill a hole in the box. Did you find the button cap covering the hole in the casting?
RandyBoBandy
Minister of Fire
Wrnk -191 is what you are looking for. Along with the AT100 or At200. Most of us have the AT100
Great, thanks. I haven't checked for the probe hole yet. The stove's been running consistently, and I'll have to pull off the backplate to get in to take a look. It's supposed to warm up here over the next couple days, so I'll dig into it then.
RandyBoBandy
Minister of Fire
That's what I was thinking. Shouldn't be a problem—that's well within my ability.
Hello All and happy 2022.
I had an issue with the glass retainer screws rounding out (Philips drive) so I sourced a direct replacement with Torx drive so you can get a more positive grip in it. I find the screws closes to the center of the stove tend to loosen up every couple months or so.
Last week I had the left side glass panel pop out from underneath the bracket.... stove was running hot! I suspect I have an undersized piece of glass on the left side, there is a lot of gap around the perimeter and it should never be allowed to move so much that it pops out from under the bracket. But I digress.....
I bought these from Bolt depot, inexpensive ( shipping was more than the fasteners). You will need 8 of them, get a few spares.
Install was easy and seems to be performing just fine after a week of burning.
Now if I could figure out how to keep my cat temps below 1750-1800F.....
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/data/attachments/290/290154-87c44cfe4dfd1fe175e5049c2cd62b34.jpg?hash=o8WBxiTKET "[Hearth.com] 2021/22 VC Owner thread")
I had an issue with the glass retainer screws rounding out (Philips drive) so I sourced a direct replacement with Torx drive so you can get a more positive grip in it. I find the screws closes to the center of the stove tend to loosen up every couple months or so.
Last week I had the left side glass panel pop out from underneath the bracket.... stove was running hot! I suspect I have an undersized piece of glass on the left side, there is a lot of gap around the perimeter and it should never be allowed to move so much that it pops out from under the bracket. But I digress.....
I bought these from Bolt depot, inexpensive ( shipping was more than the fasteners). You will need 8 of them, get a few spares.
Install was easy and seems to be performing just fine after a week of burning.
Now if I could figure out how to keep my cat temps below 1750-1800F.....
You can always shim the brackets with stainless steel washers. Do not over tighten….you will crack the glass. Those bolts should be stainless steel as well. As for cat temps…..time to do a stove surgery on your secondary air flapper.
Woodsplitter67
Minister of Fire
half inch seems kinda long.. If your temps are that high I suspect over draft or a leak into the stove.. 17/1800 degrees the cats going to start to break up..
RandyBoBandy
Minister of Fire
All good questions / comments but I suspect you are all thinking of the older models...... I will address each comment as best as I know how....
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642476824308-webp.290146/ "[Hearth.com] 2021/22 VC Owner thread")
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642476697352-webp.290145/ "[Hearth.com] 2021/22 VC Owner thread")
Cat Temps:
This posting window is not nearly large enough for all the comments I have on this topic, I will try not to turn it into one massive raging rant..... To put it succinctly, I believe the secondary burn chamber design on these newer stoves is flawed, in particular the lack of an active secondary air control element. I have been working this problem since the stove was new and have yet to find a solution (very frustrating). I did notice the newer stoves have different refractory part numbers, I am wondering if they realized this design was not good and made some changes......
Sadly VC has been of no help to me and the dealer I bought it from has gone out of business, other dealers have not been helpful. I wish we had somebody in this forum that really knew the secondary burn design for the newer stoves. I have studied it quite a bit over the years and I believe this design is unreliable at best, it works under certain conditions but runs away without an active control element.
To answer you comments directly:
Draft: I thought so too, a few years back I installed a damper in the exhaust pipe and it has not effect, open or closed. Recently I welded up all the holes in the damper plate, so I can really shut it off.... still no effect.
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642478902769-webp.290149/ "[Hearth.com] 2021/22 VC Owner thread")
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642479459989-webp.290150/ "[Hearth.com] 2021/22 VC Owner thread")
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642479549067-webp.290152/ "[Hearth.com] 2021/22 VC Owner thread")
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/attachments/1642479830521-webp.290154/ "[Hearth.com] 2021/22 VC Owner thread")
Other thoughts:
I grew up burning wood, I love the whole process, felling, bucking, splitting, stacking, loading the stove, cooking on the stove, etc.... Wood is my primary source of heat, (the thermostats in my house are off) I burn 24/7 December through mid March, 4 cord per year, almost all ash and oak, big splits. I have a moisture meter, typically around 15%.
There are a lot of things I like about this stove, big firebox (I do 20-22" logs), long burn times (can do an honest 8-12 hours of heat on a full load, easily restarts from coals after 12-16 hours), top load, swing out ash pan, cook top, the stove looks great and of course the warming shelves with mitten warmers is a must have... haha I have thought about getting rid of this one and buying something else but I have yet to find one that has all these features. I thought about getting an older encore and rebuilding it but I have 20 cord of 20-22" logs (not interested in taking 2" off 20 cord of split wood)
I believe part of the issue is some of the secondary air comes in at the bottom/back of the firebox, so it also contributes to the primary burn, not just the secondary burn. If I recall correctly on the older models the secondary air comes directly into the primary exhaust stream, there is no way for it to reach the primary burn (unless it travels upstream, not very likely).
I also believe that the secondary burn does not get enough air with a large load, that's why the temps launch, not enough cool air to control the temp. Smaller loads do seem to be more controllable, but burn times are shorter, obviously. I have found forcing air with a fan into the secondary inlet drops the cat temps, unfortunately it also accelerates the primary burn so it is not sustainable but for short periods of time.
Question for you guys: Does the bimetal secondary air control on the older stoves increase the air flow or decrease it as it heats up? I believe it increases the secondary air flow, correct?
Another unresolved issue I have had since day one.... When I burn with the cat bypassed the griddle temp will continually climb, even with the air lever fully closed (I have checked / reset the primary air damper, it is closed) I have gotten north of 650-700F. The one time I heard from the factory (10 years ago) they said "yeah that's normal, don't leave it unattended with the secondary bypassed". I suspect what is happening is the air is coming in through the secondary passages and driving the primary burn when bypassed. If I am correct that the older models secondary air flapper would be closed (cat is cold) then all the air has to come through the primary flapper. Again seems like a questionable design on my stove with no secondary air flow control......
And I forgot to mention, I am on my third refractory set since new, all replaced under parts warranty, my stove has lifetime refractory warranty, thank God they have honored it every time. $1000+ for the parts. ~5 years ago I did a complete rebuild per factory instructions and re-gasketed everything, no obvious issues found and the problem was unresolved. Stove seemed a little tighter for a while but cat temp issue persisted. I keep hoping VC will be annoyed with my warranty claims and maybe reach out to try and assist me, still waiting.....
If you are still reading this I think you for your attention, I hope it has been at least interesting if not entertaining. I am open to any and all suggestions...... For now it seems I will be running in "non-cat mode", at least my cat temp alarm does not wake me (or the wife) up at 1 am now..... Small blessings.
This is a great forum and I find all the discussion here invaluable, sure wish VC would get involved though, so much I do not know about why they do things the way they do and what is "normal" and what is not. Some day I am going to cut my logs shorter and rebuild an old Encore..... sounds like a dream.![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/data/attachments/290/290178-34d26cf86b29fbdbc02e165041d9f1ad.jpg?hash=OXxuDGuVCH "[Hearth.com] 2021/22 VC Owner thread")
![[Hearth.com] 2021/22 VC Owner thread](https://www.hearth.com/talk/data/attachments/290/290180-99dfe89e7b42139e3929068bc8c42c65.jpg?hash=jWGvDaHOLO "[Hearth.com] 2021/22 VC Owner thread")
I do not think that works on my stove. The newer stoves do not use the flat tabs like the old ones, below are pics I found, notice the clips are shaped so it kind of spring loads the glass when you tighten up the screws.
- I do agree over-torqueing could break the glass. Need to be judicious when tightening.
- The bolts are stainless, 18-8
1/2" is long for the older stoves, but with this clip 1/2" works perfect and is in fact the same length as the factory installed screws. I should have been more clear, this is for my stove (VC Defiant Model 1975 (2n1, cat / non cat) purchased new in 2009). I tried to cross reference to a VC part number but alas they do not show the screws in the exploded parts view..... The key here is to use truss head screws, a regular pan head or cap is not large enough (I tried it.....does not work well)
Cat Temps:
This posting window is not nearly large enough for all the comments I have on this topic, I will try not to turn it into one massive raging rant..... To put it succinctly, I believe the secondary burn chamber design on these newer stoves is flawed, in particular the lack of an active secondary air control element. I have been working this problem since the stove was new and have yet to find a solution (very frustrating). I did notice the newer stoves have different refractory part numbers, I am wondering if they realized this design was not good and made some changes......
Sadly VC has been of no help to me and the dealer I bought it from has gone out of business, other dealers have not been helpful. I wish we had somebody in this forum that really knew the secondary burn design for the newer stoves. I have studied it quite a bit over the years and I believe this design is unreliable at best, it works under certain conditions but runs away without an active control element.
To answer you comments directly:
If I had one I would! But alas I do not have one...... I am a surgeon without a patient, hahaha
Checked it many times, no significant leaks, except last week when the glass popped out from under the bracket! I also can tell when I throttle the air all the way down there is almost zero flame in the firebox and the primary burn gets very smokey. I suspect this overloads the secondary burn (not enough dilution air) and cat temps go to 1800+.
Draft: I thought so too, a few years back I installed a damper in the exhaust pipe and it has not effect, open or closed. Recently I welded up all the holes in the damper plate, so I can really shut it off.... still no effect.
You are correct! I verified it several times unfortunately. This is my fourth cat since new.... I get maybe 2-2.5 seasons and then they look like this..... This one has been through ~2 seasons....
That is the right question. On the 2n1 there is just a series of holes / passages that bring the secondary air in in a couple different places. Very hard to explain in words..... Some of the air comes in around the cat, some comes in at the back of the primary burn area, near the inlet to the secondary burn chamber. You may recall folks plugging holes (8 of them) with screws. This helps calm things down a bit but is not a total solution (at least not for me). There is another path on the lower left and right of the removable access cover, blocking these slows down the stove too but gives incomplete secondary burn, not enough air. Images below show the areas I am referring to. Air comes in where I marked in red.
Other thoughts:
I grew up burning wood, I love the whole process, felling, bucking, splitting, stacking, loading the stove, cooking on the stove, etc.... Wood is my primary source of heat, (the thermostats in my house are off) I burn 24/7 December through mid March, 4 cord per year, almost all ash and oak, big splits. I have a moisture meter, typically around 15%.
There are a lot of things I like about this stove, big firebox (I do 20-22" logs), long burn times (can do an honest 8-12 hours of heat on a full load, easily restarts from coals after 12-16 hours), top load, swing out ash pan, cook top, the stove looks great and of course the warming shelves with mitten warmers is a must have... haha I have thought about getting rid of this one and buying something else but I have yet to find one that has all these features. I thought about getting an older encore and rebuilding it but I have 20 cord of 20-22" logs (not interested in taking 2" off 20 cord of split wood)
I believe part of the issue is some of the secondary air comes in at the bottom/back of the firebox, so it also contributes to the primary burn, not just the secondary burn. If I recall correctly on the older models the secondary air comes directly into the primary exhaust stream, there is no way for it to reach the primary burn (unless it travels upstream, not very likely).
I also believe that the secondary burn does not get enough air with a large load, that's why the temps launch, not enough cool air to control the temp. Smaller loads do seem to be more controllable, but burn times are shorter, obviously. I have found forcing air with a fan into the secondary inlet drops the cat temps, unfortunately it also accelerates the primary burn so it is not sustainable but for short periods of time.
Question for you guys: Does the bimetal secondary air control on the older stoves increase the air flow or decrease it as it heats up? I believe it increases the secondary air flow, correct?
Another unresolved issue I have had since day one.... When I burn with the cat bypassed the griddle temp will continually climb, even with the air lever fully closed (I have checked / reset the primary air damper, it is closed) I have gotten north of 650-700F. The one time I heard from the factory (10 years ago) they said "yeah that's normal, don't leave it unattended with the secondary bypassed". I suspect what is happening is the air is coming in through the secondary passages and driving the primary burn when bypassed. If I am correct that the older models secondary air flapper would be closed (cat is cold) then all the air has to come through the primary flapper. Again seems like a questionable design on my stove with no secondary air flow control......
And I forgot to mention, I am on my third refractory set since new, all replaced under parts warranty, my stove has lifetime refractory warranty, thank God they have honored it every time. $1000+ for the parts. ~5 years ago I did a complete rebuild per factory instructions and re-gasketed everything, no obvious issues found and the problem was unresolved. Stove seemed a little tighter for a while but cat temp issue persisted. I keep hoping VC will be annoyed with my warranty claims and maybe reach out to try and assist me, still waiting.....
If you are still reading this I think you for your attention, I hope it has been at least interesting if not entertaining. I am open to any and all suggestions...... For now it seems I will be running in "non-cat mode", at least my cat temp alarm does not wake me (or the wife) up at 1 am now..... Small blessings.
This is a great forum and I find all the discussion here invaluable, sure wish VC would get involved though, so much I do not know about why they do things the way they do and what is "normal" and what is not. Some day I am going to cut my logs shorter and rebuild an old Encore..... sounds like a dream.
On the older models the secondary air flapper closes as the cat temp rises. Not sure who thought that was a good idea but I've changed my Intrepid II 1990 to a fixed secondary intake and it made the stove much more controllable.
You good sir are a true testament to the following VC has developed over the years. The adversity you have encountered with that stove alone would have driven me away looooong ago! Your Cat damage looks like thermal shock? Possibly?
Apologize for not having any operational advice.
You would be underwhelmed with the operational requirements of many newer Cat equipped makes/models. Likely you would be bored actually! Best of luck.
That cat looks like it's had cold air blowing in the front of it.
In my opinion the design of that refractory box has one fatal flaw (I also have the Encore 2040). The cold secondary intake comes in right under the cat exhaust which designed to run at 1500+ degrees. Separated only by a 1/2" thick refractory cement piece. Where the two pieces of the refractory box meet there is a gasket, and if any air leaks around that gasket it will crumble your catalyst and refractory box in short time due to the large temp gradient. It happened to me recently and I just globbed the whole thing up with refractory cement to stop the air coming in directly under the cat. Hopefully it lasts
RandyBoBandy
Minister of Fire
As stated above the older stoves have a secondary air flapper that closes as it gets hot. Most of us have completely blocked the secondary air channel. When I put in a new refractory box and upper damper this last fall I didn’t even install the secondary probe that controlled the flapper. Have you tried blocking all 8 of the holes letting in air? And does your secondary air have its own supply or does it use the primary inlet as well? If it’s independent from the primary you can try plugging the secondary inlet. Trying to feed it more cool air I believe is the wrong direction. This is most likely contributing to your cat crumbling.
Well detailed.
It appears that you have become pretty efficient at fixing this stove over the years. Cannot really add much here but I would try to find where the secondary air inlets are (not outlets inside the box) and experiment with plugging them (magnets work well or steel wool and bolt).
I believe the old VC Defiant 1945 has the same firebox size as yours. I am sure you can find one on craigslist needing rebuild. Many of us here were able to overcome the uncontrollable characteristics of these VC cat stoves and we all have documented the process on this forum.
It appears that you have become pretty efficient at fixing this stove over the years. Cannot really add much here but I would try to find where the secondary air inlets are (not outlets inside the box) and experiment with plugging them (magnets work well or steel wool and bolt).
I believe the old VC Defiant 1945 has the same firebox size as yours. I am sure you can find one on craigslist needing rebuild. Many of us here were able to overcome the uncontrollable characteristics of these VC cat stoves and we all have documented the process on this forum.
RandyBoBandy
Minister of Fire
I think you just called me a zealot, in a nice way. I won't deny it.... I am not really married to VC, my issue is I have ~$4k invested in this stove and I am trying to make that payback..... If I could swap this stove out for one that works well at minimal cost, I would do it, of course that is not a reality.
Which brings me to another issue, how do you know which stoves work well? Really hard to know before you buy one. I wish they would let you rent one for a month before you buy.
I see you are a BK guy? I have looked at them and heard good things. A couple things I don't like about them, correct me where necessary:
- No swingout ashpan: With the ashpan cleaning out is a snap and can be done with a fire going.
- No top load: Top load is easier on my back and easier to stuff I think.
- No cooktop?: Does the top of a BK get hot enough to cook on?
- Do they BK's require an electric fan? Or is that an option....
- Not as good looking as the VC's (a minor negative for me)
I think more likely the cause is flame impingement, notice the new VC stoves the secondary smoke inlet is at the bottom of the stove where all the hot stuff is. In the older units and other cat stoves the smoke inlet is higher up in the firebox. I think this gives the primary burn more time to mix and burn off before heading to the cat. When my secondary burn goes nuclear I can hear a sucking sound (to quote Ross Perot) and I think this is caused by carryover / jetting of flame into the secondary burn chamber, possibly impinging on the cat.
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