2023/24 VC Temperature discussion thread

[arnermd]

Pretty sure I got a dead kitty.... or a very sick one. Plot below is back to back burns, 1/2 loads. First burn was with the metal cat, second was with a ceramic cat (Condar), it has about 3 months of 24/7 operation on it.

First burn could not get the cat temps up even after a hot reload with coals raked to back.

Second burn: Notice the light off..... the rest of the burn was pretty weak, suspect small load and weak draft are the cause. I should have left the air more open, longer.

 

[JohnDaileyNH]

Based on the data it looks dead. Guess cats don't have 9 lives after all

 

[gthomas785]

Pretty sure I got a dead kitty.... or a very sick one. Plot below is back to back burns, 1/2 loads. First burn was with the metal cat, second was with a ceramic cat (Condar), it has about 3 months of 24/7 operation on it.

First burn could not get the cat temps up even after a hot reload with coals raked to back.

Second burn: Notice the light off..... the rest of the burn was pretty weak, suspect small load and weak draft are the cause. I should have left the air more open, longer.

View attachment 317889

I assume you have pulled the cat out to check if it's clogged/dirty...

Very interested in this because I just installed my first metal cat as well.

 

[arnermd]

Yeah I checked.... really hard to get the ceramic cat in without removing the metal one.....

Structurally it is in great shape. Corrugations have definitely shifted around a bit but they are all there and not coming apart. This looks way better than I typically see on my ceramics.... just not very active.

Top side, little bit of fly ash on there but pretty clean.

Bottom side:

 

[AsylumResident]

Encore
6 in probably 22-23 ft but got a pretty good horizontal run straight out of back of stove

I'm running the larger Defiant with a 6" flue that comes off my stove up about 30" to an elbow, then the horizontal run through the wall is about 3' to the T and then straight up about 16' through the exterior soffit. The entire exterior run is exposed which could cause some issues when the weather really starts to get cold. I do plan on building around it next summer to enclose it so it will be interesting to see how the Defiant runs this winter this way. I believe I have some draft issues but I have three solutions available to help solve that; enclosing the chimney on the outside, adding length to my chimney and/or going to a 8" flue. Until I really start burning when it's colder I don't plan to change anything.

I have made a few changes with how I load the stove and I have already seen an improvement there but I want to keep replicating my results before I get too excited.

 

[AsylumResident]

Yeah I checked.... really hard to get the ceramic cat in without removing the metal one.....

Structurally it is in great shape. Corrugations have definitely shifted around a bit but they are all there and not coming apart. This looks way better than I typically see on my ceramics.... just not very active.

Top side, little bit of fly ash on there but pretty clean.
View attachment 317893

Bottom side:
View attachment 317894
View attachment 317895

Faulty cat?

 

[Anthony09]

I'm running the larger Defiant with a 6" flue that comes off my stove up about 30" to an elbow, then the horizontal run through the wall is about 3' to the T and then straight up about 16' through the exterior soffit. The entire exterior run is exposed which could cause some issues when the weather really starts to get cold. I do plan on building around it next summer to enclose it so it will be interesting to see how the Defiant runs this winter this way. I believe I have some draft issues but I have three solutions available to help solve that; enclosing the chimney on the outside, adding length to my chimney and/or going to a 8" flue. Until I really start burning when it's colder I don't plan to change anything.

I have made a few changes with how I load the stove and I have already seen an improvement there but I want to keep replicating my results before I get too excited.

I have close to three foot as well, I think 30 inches, insulated liner through masonry chimney. Did you have an installer? If so what did they think about that long of a horizontal run

 

[AsylumResident]

I have close to three foot as well, I think 30 inches, insulated liner through masonry chimney. Did you have an installer? If so what did they think about that long of a horizontal run

My insurance company required it be installed by certified installer…unfortunately. I’ve had a few issues with the install that I have had to rectify on my own. The horizontal run is not ideal but I didn’t want to run through the inside of the house to go straight up. The stove is installed in the basement

 

[Anthony09]

My insurance company required it be installed by certified installer…unfortunately. I’ve had a few issues with the install that I have had to rectify on my own. The horizontal run is not ideal but I didn’t want to run through the inside of the house to go straight up. The stove is installed in the basement

Gotcha, yeah that sucks unfortunately bein a certified professional of somethin don’t really mean much anymore

 

[Woodsplitter67]

Yeah I checked.... really hard to get the ceramic cat in without removing the metal one.....

Structurally it is in great shape. Corrugations have definitely shifted around a bit but they are all there and not coming apart. This looks way better than I typically see on my ceramics.... just not very active.

Top side, little bit of fly ash on there but pretty clean.
View attachment 317893

Bottom side:
View attachment 317894
View attachment 317895

Im pretty sure you can put this in a vinegar bath... boil it .. Someone did that to bring there cat back.. Im pretty sure it was posted 5 years ago.. I definitely cant remember who posted it

 

[arnermd]

Im pretty sure you can put this in a vinegar bath... boil it .. Someone did that to bring there cat back.. Im pretty sure it was posted 5 years ago.. I definitely cant remember who posted it

really? I will have to look for that.... I would be very surprised if that actually works but I have been surprised before....

 

[arnermd]

Burns from yesterday, mostly 40% air setting.

During the mid day burn I had a pretty full load, left the air too high for too long and then tried to throttle it back to 10%.... After about an hour it started back puffing so had to open the air up to 50%.... I was a little surprised how fast the cat fell off....

Third load I raked coals to back, added 1/2 a load, engaged the cat and let it sit at 50% air. Took a little longer but the cat lit off and temps looked good.

 

[Todd]

really? I will have to look for that.... I would be very surprised if that actually works but I have been surprised before....

Yes, you may be able to squeeze out a few more months with a vinegar bath. I use to fill a spray bottle with a 50/50 vinegar/distilled water, spray the cat, let it soak for an hour, repeat and then rinse off with distilled water. Woodstock recommended this over boiling if I recall.

 

[Woodsplitter67]

really? I will have to look for that.... I would be very surprised if that actually works but I have been surprised before....

the guy did a super indepth with pictures.. and got months I believe out of it..

 

[arnermd]

Yeah found it.... separate thread by @Highbeam. Pretty impressive.... amazing what you can find on here.

I looked it up and they offer a 5 year warranty, after 90 days it is pro-rated by 50% plus $15 shipping and you have to send the old one back.... by the time all is said and done it might save me $50.... that's kind of annoying...

 

[Highbeam]

Yeah found it.... separate thread by @Highbeam. Pretty impressive.... amazing what you can find on here.

I looked it up and they offer a 5 year warranty, after 90 days it is pro-rated by 50% plus $15 shipping and you have to send the old one back.... by the time all is said and done it might save me $50.... that's kind of annoying...

Yeah, I did a vinegar boil on a steel cat that had died with success. In my case it had lived a much longer life than yours, closer to 8000 hours as I recall, but had totally died. Seems catalysts stop working when the precious metals are masked by junk from the burn. Like a coating that prevents the smoke from contacting the catalyst. By definition, a catalyst is not "consumed" but is covered up or flattened out by thermal shock so that its surface area is too small.

It's easy to try, you've already got the cat out. Steal some white vinegar from the canning supplies. Boil it on a camp stove or a BBQ side burner outside to burn off the coating. Then rinse with distilled water to neutralize the acid. You can search for the thread under my username.

Honestly, if you're setup physically destroys ceramic cats then you have a massive air leak and are thermally shocking your catalyst hard. That abuse will kill a steel cat too it's just that you won't get a visible physical degradation. 95% of cats are eventually killed by thermal shock is what the manufacturer tells us. Metal cats are inferior. The only advantage is that they don't visibly break so less warranty calls to the manufacturer.

 

[arnermd]

Yeah, I did a vinegar boil on a steel cat that had died with success. In my case it had lived a much longer life than yours, closer to 8000 hours as I recall, but had totally died. Seems catalysts stop working when the precious metals are masked by junk from the burn. Like a coating that prevents the smoke from contacting the catalyst. By definition, a catalyst is not "consumed" but is covered up or flattened out by thermal shock so that its surface area is too small.

It's easy to try, you've already got the cat out. Steal some white vinegar from the canning supplies. Boil it on a camp stove or a BBQ side burner outside to burn off the coating. Then rinse with distilled water to neutralize the acid. You can search for the thread under my username.

Honestly, if you're setup physically destroys ceramic cats then you have a massive air leak and are thermally shocking your catalyst hard. That abuse will kill a steel cat too it's just that you won't get a visible physical degradation. 95% of cats are eventually killed by thermal shock is what the manufacturer tells us. Metal cats are inferior. The only advantage is that they don't visibly break so less warranty calls to the manufacturer.

Ah... the original source appears, thanks for your thoughts. I agree with everything you said above, almost...
Catalyst masking: Yep I agree, all makes sense and my wife makes pickles, so I got vinegar.

I typically go through a ceramic cat every 2-3 years. Failure mode is structural, it just falls apart. Interesting though that the frame on the metal cat is perfect, my ceramics usually get pretty warped and bowed.

I also see a fair bit of spalling in my refractory, I have replaced the "engine" twice in ten years, complete stove teardown and rebuild. (I burn 4 cord a year, primary heat Nov - March, 24/7, ~3500hrs/year)

Not sure how familiar you are with the VC design but I suspect there is a design issue resulting in flame impingement on the cat and mixing of secondary air with the primary burn causing over firing.

My best evidence for not having an air leak is: With the cat engaged I can close my air down all the way and the flames all but go out. If there is enough fuel/ heat in the primary burn the cat temps will rocket to 1400 - 1700 and hang there for hours. Occasionally the stove will start back puffing, because the primary burn is starved for air. Air builds up in the primary burn and then all at once the gas ignites and then goes out, this pushes a puff of smoke out the griddle gasket....

Second best evidence: This stove has always behaved this way since new, after two complete rebuilds (all new gasketing) its bad attitude has never changed, similar to the way my teenaged children were.... haha

And.... it does not do this all the time, in fact I would estimate less than 30% of my burns go badly. I would expect an air leak to be more consistent.

Still searching for the answer.....

Your comment about the metal cat failure mode matches my limited experience, it looks fine, but does not perform fine any more.

 

[Woodsplitter67]

Yeah, I did a vinegar boil on a steel cat that had died with success. In my case it had lived a much longer life than yours, closer to 8000 hours as I recall, but had totally died. Seems catalysts stop working when the precious metals are masked by junk from the burn. Like a coating that prevents the smoke from contacting the catalyst. By definition, a catalyst is not "consumed" but is covered up or flattened out by thermal shock so that its surface area is too small.

It's easy to try, you've already got the cat out. Steal some white vinegar from the canning supplies. Boil it on a camp stove or a BBQ side burner outside to burn off the coating. Then rinse with distilled water to neutralize the acid. You can search for the thread under my username.

Honestly, if you're setup physically destroys ceramic cats then you have a massive air leak and are thermally shocking your catalyst hard. That abuse will kill a steel cat too it's just that you won't get a visible physical degradation. 95% of cats are eventually killed by thermal shock is what the manufacturer tells us. Metal cats are inferior. The only advantage is that they don't visibly break so less warranty calls to the manufacturer.

Highbeam.. is in the house.. I couldn't for the life of me remember who did that thread about boiling the cat... but verry interesting.. how long ago did you put it together..

 

[Highbeam]

Highbeam.. is in the house.. I couldn't for the life of me remember who did that thread about boiling the cat... but verry interesting.. how long ago did you put it together..

Here's the thread for reference.

Cleaning a catalytic combustor with vinegar bath

So as mentioned above my 2 year old steel cat stopped working earlier this year. I tried to tell myself that the white smoke was just steam but 14%MC wood and the dripping tar on my chimney cap told me otherwise. So did the constant smoke, reduced burn times, stalling cat, and low output. My cat...

www.hearth.com

I honestly am not familiar with the VC combustion system but catalyst physical degradation is bad. If that is happening for any reason including the original design then you are surely going to be blowing through catalysts quickly.

I'm only getting 2-3 seasons out of my BK cats which exceeds the 10-12k hours of expected and rated life so I'm happy.

 

[Woodsplitter67]

Here's the thread for reference.

Cleaning a catalytic combustor with vinegar bath

So as mentioned above my 2 year old steel cat stopped working earlier this year. I tried to tell myself that the white smoke was just steam but 14%MC wood and the dripping tar on my chimney cap told me otherwise. So did the constant smoke, reduced burn times, stalling cat, and low output. My cat...

www.hearth.com

I honestly am not familiar with the VC combustion system but catalyst physical degradation is bad. If that is happening for any reason including the original design then you are surely going to be blowing through catalysts quickly.

I'm only getting 2-3 seasons out of my BK cats which exceeds the 10-12k hours of expected and rated life so I'm happy.

Just out of curiosity.. How did you come up with the idea of boiling the cat to extend life. Did you read this somewhere. Did this come up from another member or different forum..

 

[Woodsplitter67]

Got the stove going this morning.. got cold in the house no fire for like 36 hours hous dropped to 60 degrees..STT like 615.. cat in the 1400s.. I just dialed the air all the way back.. This small load will last to like 1pm today

 

[arnermd]

I honestly am not familiar with the VC combustion system but catalyst physical degradation is bad. If that is happening for any reason including the original design then you are surely going to be blowing through catalysts quickly.

I'm only getting 2-3 seasons out of my BK cats which exceeds the 10-12k hours of expected and rated life so I'm happy.

Yep I hear you.... I agree and appreciate the comments. I have gotten very comfortable with replacing cats every 2 years or so. It is not that expensive and super easy in the VC 2n1 so it is no big deal to me and just part of the deal. I find it very telling that Condar offers a warranty on all their ceramic cats, except for.... the 2n1 designs (last time I checked).

What concerns me much more is the stress it is putting on the refractory..... I am one of the few that have a lifetime warranty on the refractory, VC (to their credit) has honored this warranty twice already. I wonder how many claims I can make before they call me.... No communication from them whatsoever on the issue and I have tried several times in years past.

I love having a stove but when I finally have had enough of this my next one will likely be a BK, or I may rebuild an old Encore with secondary air control.

 

[arnermd]

Got the stove going this morning.. got cold in the house no fire for like 36 hours hous dropped to 60 degrees..STT like 615.. cat in the 1400s.. I just dialed the air all the way back.. This small load will last to like 1pm today

View attachment 318007 View attachment 318008 View attachment 318009

I don't know how you do it man..... its like magic to me. Can I rent your stove for a month?

Or maybe I should rent you for a month.... free room and board. hahaha

How long did the cat hang at 1463?

 

[Woodsplitter67]

I don't know how you do it man..... its like magic to me. Can I rent your stove for a month?

Or maybe I should rent you for a month.... free room and board. hahaha

How long did the cat hang at 1463?

LOL.. I may take you up on this if I get some free time and you have land to hunt..

It didn't hang there long.. I dropped the air all the way down for the long burn.. house is now 68..

Right now this is where I am with the air dialed all the way back for about an hour

 

[Woodsplitter67]

Yeah found it.... separate thread by @Highbeam. Pretty impressive.... amazing what you can find on here.

I looked it up and they offer a 5 year warranty, after 90 days it is pro-rated by 50% plus $15 shipping and you have to send the old one back.... by the time all is said and done it might save me $50.... that's kind of annoying...

It is amazing what you can fined here.. There is so much information.. Some of the ideas people get.. who would of thought of boiling it.. Im interested in how this idea came about