2022/23 VC Owner thread

[arnermd]

I completely agree. This is why I am thinking that I am having CAT issues. Other than the cat not going to temp the stove is running fine. On reload the cat will get up to 650-700 or so, but it will quickly fall down to within 50 degrees or so of STT. I have the Auber and walk by it and see the Auber at about 650 most of the time. At 700 degrees I'd think that the CAT should be lit enough to start generating its own heat and start making it's way to 1000+ degrees. Also on reloads I push all coals to the back of the stove. Even If I dont close my bypass I get a raise in CAT temp since I pushed all of coals to the back. As far as draft goes I haven't had it measured, but I have good draft. I go out the back of a stove to a T then straight up. My house is 2 floors with 10 ft ceilings and a very steep roof. The chimney is at the top of that so I figure 28-30ft once you include the attic.

Hmmm Ok. I misunderstood you. Seems like that stack should give you plenty of draft. Did it always run that cold? My next guess is the cat is shot.... but could also be a big secondary air leak into the cat. Weird....

I am using a perfectprime datalogger model TC0520 to collect the data. Then I export it to excel and make the plots. You can buy them on amazon, $180.

I also have 2 watlow temp controllers that I use for readouts. The data logger can handle 4 channels but it has an lcd screen that I can't read in the dark and can't see from my couch....

 

[Woodsplitter67]

I completely agree. This is why I am thinking that I am having CAT issues. Other than the cat not going to temp the stove is running fine. On reload the cat will get up to 650-700 or so, but it will quickly fall down to within 50 degrees or so of STT. I have the Auber and walk by it and see the Auber at about 650 most of the time. At 700 degrees I'd think that the CAT should be lit enough to start generating its own heat and start making it's way to 1000+ degrees. Also on reloads I push all coals to the back of the stove. Even If I dont close my bypass I get a raise in CAT temp since I pushed all of coals to the back. As far as draft goes I haven't had it measured, but I have good draft. I go out the back of a stove to a T then straight up. My house is 2 floors with 10 ft ceilings and a very steep roof. The chimney is at the top of that so I figure 28-30ft once you include the attic.

Do you have a magnetic thermometer on the stove pipe about 15 inches fron the stove top.. if so.. what is the temperature of the stove pipe when you think the cats stalling..

are you a 6 or 8 inch stove pipe

 

[Woodsplitter67]

Hmmm Ok. I misunderstood you. Seems like that stack should give you plenty of draft. Did it always run that cold? My next guess is the cat is shot.... but could also be a big secondary air leak into the cat. Weird....

I am using a perfectprime datalogger model TC0520 to collect the data. Then I export it to excel and make the plots. You can buy them on amazon, $180.

I also have 2 watlow temp controllers that I use for readouts. The data logger can handle 4 channels but it has an lcd screen that I can't read in the dark and can't see from my couch....

he has plenty of height.. but if the pips not hot enough.. it will still struggle

 

[Woodsplitter67]

Hmmm Ok. I misunderstood you. Seems like that stack should give you plenty of draft. Did it always run that cold? My next guess is the cat is shot.... but could also be a big secondary air leak into the cat. Weird....

I am using a perfectprime datalogger model TC0520 to collect the data. Then I export it to excel and make the plots. You can buy them on amazon, $180.

I also have 2 watlow temp controllers that I use for readouts. The data logger can handle 4 channels but it has an lcd screen that I can't read in the dark and can't see from my couch....

I haven't said this, but I do enjoy your graphs of your stove burn.. pretty enjoyable to see your burn.. not so much the high cat temps every so often..

 

[NewGuy132]

Hmmm Ok. I misunderstood you. Seems like that stack should give you plenty of draft. Did it always run that cold? My next guess is the cat is shot.... but could also be a big secondary air leak into the cat. Weird....

I am using a perfectprime datalogger model TC0520 to collect the data. Then I export it to excel and make the plots. You can buy them on amazon, $180.

I also have 2 watlow temp controllers that I use for readouts. The data logger can handle 4 channels but it has an lcd screen that I can't read in the dark and can't see from my couch....

Completely my fault. I have well thought out replies in my head then once it gets to my fingers to type its comes out diarrhea. Last year due to not wanting it to run away or get too hot I spent the year typing to keep it cooler. Now that I'm letting the thermostatic control do its thing I'm noticing that it isn't up to par. Last year I had the bimetal thermometer in the back and probably 90% of the time it would sit just below the active zone. I blame garbage wood and me trying to keep it from getting away from me on this.

Do you have a magnetic thermometer on the stove pipe about 15 inches fron the stove top.. if so.. what is the temperature of the stove pipe when you think the cats stalling..

are you a 6 or 8 inch stove pipe

We have a 6 inch pipe. I do not have a magnetic thermometer on it. I'll have to measure but I know I can't get 15 inches up before I hit my blockoff plate. I occasionally hit it with the IR thermometer, but I couldn't tell you what temp is/was. If I were to guess it would be in line with arnermd's 250-400 degrees. I've never seen it so low that I'm like wow thats low, or so high that I think i'm risking a chimney fire.

 

[U235]

FWIW @arnermd, if I could graph my data, I think it would look a lot like your new low draft setup. Especially if it’s 40-50 degrees outside.

I’m always starting from a cold stove, but after getting 1-2” of coals with bypass open, my first partial load will creep to 500 then stall at 650-700. Second (partial) load will go up to 900 or 1000 before coming back down.

With the Auber and more experience, I’m feeling brave enough to try a full load with hot coal bed, just need cold enough weather to make it worthwhile.

I have 6’ double wall black pipe indoors in an alcove, 15’ cl-A above that in enclosed wooden chase. 6 inches - Straight shot. No visible smoke above 700 or so.

I still have a suspicion that our 6” probes partially immersed in the cat exit flow (even if we’re all reading 1000 deg) represent a different temperature for me (encore) ~3” immersion, your defiant (possibly >3”) and @NewGuy132’s intrepid (possibly <3”). I got up to 1230 on a 75% full load just before Christmas when it was -10 outside and windy. I was concerned that my sensor set was reading too low. Can’t argue with the other facts though. New guy’s smoke and dirty chimney <700 and your third refractory and crumbling cats >1400. Probably the probes are accurate (and consistent across our installs) enough to be useful.

 

[Eman85]

As far as the Auber sensor it's just a standard K style thermocouple. I had my cat out so I set the probe right in the center of the flow. The first couple of inches is the only part of the thermocouple that senses temp, the rest is just along for the ride. Auber told me I could bend the part that stuck out to conform to the exit spot on the stove as long as it wasn't too tight of a radius.

 

[Woodsplitter67]

Completely my fault. I have well thought out replies in my head then once it gets to my fingers to type its comes out diarrhea. Last year due to not wanting it to run away or get too hot I spent the year typing to keep it cooler. Now that I'm letting the thermostatic control do its thing I'm noticing that it isn't up to par. Last year I had the bimetal thermometer in the back and probably 90% of the time it would sit just below the active zone. I blame garbage wood and me trying to keep it from getting away from me on this.

We have a 6 inch pipe. I do not have a magnetic thermometer on it. I'll have to measure but I know I can't get 15 inches up before I hit my blockoff plate. I occasionally hit it with the IR thermometer, but I couldn't tell you what temp is/was. If I were to guess it would be in line with arnermd's 250-400 degrees. I've never seen it so low that I'm like wow thats low, or so high that I think i'm risking a chimney fire.

Ok.. so your a 6 inch.. Im assuming you have some 90s or 45s.. your 25 or so ft up.. got that.. explain your stove pipe setup..

 

[arnermd]

FWIW @arnermd, if I could graph my data, I think it would look a lot like your new low draft setup. Especially if it’s 40-50 degrees outside.

I’m always starting from a cold stove, but after getting 1-2” of coals with bypass open, my first partial load will creep to 500 then stall at 650-700. Second (partial) load will go up to 900 or 1000 before coming back down.

Thanks, that is helpful to have a relative comparison. Do you ever get a whips of smoke out the top during a reload? With bypass open of course. I get just enough for my darling wife to say "I smell smoke"..... I know we are supposed to crack the griddle to establish airflow but with lots of draft it was never an issue for me before. Old habits die hard.

I still have a suspicion that our 6” probes partially immersed in the cat exit flow (even if we’re all reading 1000 deg) represent a different temperature for me (encore) ~3” immersion, your defiant (possibly >3”) and @NewGuy132’s intrepid (possibly <3”). I got up to 1230 on a 75% full load just before Christmas when it was -10 outside and windy. I was concerned that my sensor set was reading too low. Can’t argue with the other facts though. New guy’s smoke and dirty chimney <700 and your third refractory and crumbling cats >1400. Probably the probes are accurate (and consistent across our installs) enough to be useful.

I think the encore 2040 and my refractory are identical. I know the cats are the same. Which makes me wonder.... maybe my symptoms are exacerbated as I am trying to stuff more smoke though the same size cat / refractory engine..... Maybe? Maybe not....

I struggle to comprehend the massive temp difference between cat exit and flue exit too.... seems like an awful lot. It may be just a local max, like maybe the ends of the cat are running cooler, or maybe there is some secondary air mixing in after the cat? Another thought I had was could radiation be affecting the temp probe? The cat and refractory is likely glowing at our temps (I can see it sometimes in the crack in the cover plate) maybe the probe is picking up the radiation energy and the gas is not really that hot? Not sure.... needs more research.

1230 cat temp sounds perfect to me..... When my stove is running nice I see 1200 - 1300, maybe 1400 on a full load. @Woodsplitter67 is running 1400 too. If I could do 1200 -1300 consistently I would be thrilled.

Waiting on colder weather......

 

[NewGuy132]

Ok.. so your a 6 inch.. Im assuming you have some 90s or 45s.. your 25 or so ft up.. got that.. explain your stove pipe setup..

My stove goes out the back to a T then straight up.

Also attached is a picture of my CAT. While I was in there I moved the temp probe back a little bit. I had it pushed all of the way in pushed up against the wall. Although I don’t really expect to see a difference with it now.

 

[Woodsplitter67]

View attachment 306916


My stove goes out the back to a T then straight up.

Also attached is a picture of my CAT. While I was in there I moved the temp probe back a little bit. I had it pushed all of the way in pushed up against the wall. Although I don’t really expect to see a difference with it now.

that looks.like a metal cat.. it has LOTS of build up on it.. Id try to blow it with some compressed air... dont be to rough with it.. Whats the woods MC on fresh split face, Theres something wrong in the box for the cat to look like that.. Can you put a magnet on the stove pipe 12 inches above the T

 

[U235]

@arnermd - I definitely got some smoke smell on reloads today - mid 40s outside. I also didn’t crack it, just lifted it straight up - yes - just enough for the wife to mention the smoke smell. I’m really hopeful your draft adjustments were the cure. We’ll see if you need a little damper angle when it gets colder.

I’m not sure what to think about the same sized catalyst and same sized “engine”/burn chamber. I suppose as long as you can control the flow of fuel and air at the catalyst, the defiant could just act like a larger fuel tank. As long as you have a healthy primary flame, you’ll lose more heat to stove body radiation. Do the defiant and encore have the same sized air inlets? I wonder if the BK/other guys have the same size catalyst across their different sized products?

Delta T still puzzling to me. I can buy the low flow/low BTU hypothesis until you install a massive key damper, definitely reduce the flow, and the flue temps start tracking more with catalyst swings.

Not sure how to handle the radiation vs air temperature question. I do think if the probe is touching the brick, the conduction could affect the reading. I’m not a K-type TC expert by any means.

Lots of good thoughts/questions. Not sure I answered any of them…

 

[arnermd]

Also attached is a picture of my CAT. While I was in there I moved the temp probe back a little bit. I had it pushed all of the way in pushed up against the wall. Although I don’t really expect to see a difference with it now.

Need to get that sucker hot..... that will clean it up. I personally never vacuum or blow air through my cat. If it is loaded with black sticky stuff I run it hot (easy for me do....). If there is fly ash on it I will either flip it over and run it or gently blow on it, across the top. Most aggressive I will get with it is a soft brush across the face just to know the dust off.

Not that there is anything wrong with vacuum or compressed air, just need to be gentle. I just never had the need to resort to that .

If you got creosote on it, black gummy stuff, the only way I know of to clean that off is to burn it off. I have had cats that were way more loaded than yours and after one good hot burn they looked like brand new. Took a while to get the cat to light off though.

 

[Diabel]

I believe (and someone will correct me if wrong) all 30 box BKs use the same size cat, the King uses the same. My princess cat is more than twice the size of my VC encore 2550. I remember/saw VC reduced the width of its cats for 2” to 1” thickness. Surly, the fire boxes are smaller but those cats definitely must work hard. Someone posted a pic of a steel cat above, was that from Intrepid? It looked very small!

 

[JohnDaileyNH]

I believe (and someone will correct me if wrong) all 30 box BKs use the same size cat, the King uses the same. My princess cat is more than twice the size of my VC encore 2550. I remember/saw VC reduced the width of its cats for 2” to 1” thickness. Surly, the fire boxes are smaller but those cats definitely must work hard. Someone posted a pic of a steel cat above, was that from Intrepid? It looked very small!

Assuming it fit, what would happen if I ran my Encore 2040 with a 2 inch VC cat as opposed to the 1 inch it has now?

 

[Diabel]

Assuming it fit, what would happen if I ran my Encore 2040 with a 2 inch VC cat as opposed to the 1 inch it has now?

I do not believe it would slide in the slot.

 

[JohnDaileyNH]

I do not believe it would slide in the slot.

Gotcha. I am going to measure the slot next time I let the stove go cold to clean it and see. I know there is some extra room but not sure about an entire inch.

 

[NewGuy132]

that looks.like a metal cat.. it has LOTS of build up on it.. Id try to blow it with some compressed air... dont be to rough with it.. Whats the woods MC on fresh split face, Theres something wrong in the box for the cat to look like that.. Can you put a magnet on the stove pipe 12 inches above the T

The cat doesn’t have as much buildup on it as it does fly ash. At that angle for the picture you could only see through part of the grid, but as I moved it around I could see through the entire grid.

I think that I am getting excess fly ash due to pushing all of my coals to the back. While I was pulling the CAT out I noticed that there was a bunch back there. I think it’s about time for my monthly sweep. When I have the shop vac in for the sweep this weekend I’ll put it back and suck all of the fly ask out of the CAT area.

I did some looking and measuring and the highest I could get a temp probe would be 8 inches above the T but it would be impossible to read as it would be up the chimney. Unfortunately my little Interpid is about as tall as my fireplace opening. I wanted a larger stove, but the fireplace was too small.

 

[JohnDaileyNH]

The cat doesn’t have as much buildup on it as it does fly ash. At that angle for the picture you could only see through part of the grid, but as I moved it around I could see through the entire grid.

I think that I am getting excess fly ash due to pushing all of my coals to the back. While I was pulling the CAT out I noticed that there was a bunch back there. I think it’s about time for my monthly sweep. When I have the shop vac in for the sweep this weekend I’ll put it back and suck all of the fly ask out of the CAT area.

I did some looking and measuring and the highest I could get a temp probe would be 8 inches above the T but it would be impossible to read as it would be up the chimney. Unfortunately my little Interpid is about as tall as my fireplace opening. I wanted a larger stove, but the fireplace was too small.

View attachment 306950

Less than ideal, but you can get a telescoping mirror from Harbor Freight for a couple bucks. Doesn't have to be perfect but would be a way to see back there to collect some data points and not spend a ton of money

 

[NewGuy132]

Whats the woods MC on fresh split face

Last January it was high teens. I haven't checked lately as it was mid teens in Sept/October when I started the stove up. This is all Maple that was cut, split, stacked and covered Spring 2021. Once it isn't raining outside I'll grab a couple pieces and check.

Need to get that sucker hot..... that will clean it up. I personally never vacuum or blow air through my cat. If it is loaded with black sticky stuff I run it hot (easy for me do....). If there is fly ash on it I will either flip it over and run it or gently blow on it, across the top. Most aggressive I will get with it is a soft brush across the face just to know the dust off.

Not that there is anything wrong with vacuum or compressed air, just need to be gentle. I just never had the need to resort to that .

If you got creosote on it, black gummy stuff, the only way I know of to clean that off is to burn it off. I have had cats that were way more loaded than yours and after one good hot burn they looked like brand new. Took a while to get the cat to light off though.

All of that stuff is fly ash. Nothing black and sticky. I think that I am getting a bunch back there because I'm really loading up the coals in the back on reloads. I typically cover all of the holes with coals on a hot reload.

I believe (and someone will correct me if wrong) all 30 box BKs use the same size cat, the King uses the same. My princess cat is more than twice the size of my VC encore 2550. I remember/saw VC reduced the width of its cats for 2” to 1” thickness. Surly, the fire boxes are smaller but those cats definitely must work hard. Someone posted a pic of a steel cat above, was that from Intrepid? It looked very small!

Yep that tiny CAT was from my Intrepid. I went to the store looking for the Dauntless, but it was too tall to fit in my fireplace without removing a couple rows of brick. The Intrepid fits with less than an inch between the exhaust pipe and the fireplace opening.

 

[JohnDaileyNH]

Last January it was high teens. I haven't checked lately as it was mid teens in Sept/October when I started the stove up. This is all Maple that was cut, split, stacked and covered Spring 2021. Once it isn't raining outside I'll grab a couple pieces and check.


All of that stuff is fly ash. Nothing black and sticky. I think that I am getting a bunch back there because I'm really loading up the coals in the back on reloads. I typically cover all of the holes with coals on a hot reload.



Yep that tiny CAT was from my Intrepid. I went to the store looking for the Dauntless, but it was too tall to fit in my fireplace without removing a couple rows of brick. The Intrepid fits with less than an inch between the exhaust pipe and the fireplace opening.

Seems odd that with the coals pushed back that aggressively the CAT won't light off. If I push my coals back too much my CAT likes to go to the moon

 

[NewGuy132]

The other night I was reloading before I went to bed. I'm not sure what I managed to do but after a few minutes the CAT went up to 1000. This is the first time I ever saw it get that high. Within 10 minutes or so it was back down to 700 or so like normal. This was on a hot reload where I pushed all of the coals to the back and I had been burning the majority of the day so I had a bunch of coals to push back. I'd assume that at 1000 the CAT was well lit off even if it was only for a few minutes. It seems like the CAT just can't maintain the temps for some reason. Even at 700 or so I'd imagine its lit off a bit and would start creating its own heat, but it just doesn't ever take off for me.

Seems odd that with the coals pushed back that aggressively the CAT won't light off. If I push my coals back too much my CAT likes to go to the moon.

 

[arnermd]

@arnermd - I definitely got some smoke smell on reloads today - mid 40s outside. I also didn’t crack it, just lifted it straight up - yes - just enough for the wife to mention the smoke smell. I’m really hopeful your draft adjustments were the cure. We’ll see if you need a little damper angle when it gets colder.

That's good news. I tells me I am closer on my draft setting. Got a good burn going this morning, 1/2 load from stone cold, took the cat up to 1000 with 100% air, dialed it down to 75% cat went to 1300, reduced air again to 50% and cat slowly dropped to 1200 and has continued down to 800 now. My only concern at the moment is how the cat seems to fall off on the back end. Will post the data once the burn finishes.

Do the defiant and encore have the same sized air inlets?

That I do not know, I suspect the answer is yes. My suspicion is the Defiant and Encore were meant to have similar burn rates but with the bigger firebox the Defiant will burn longer and throw more primary heat due to increase surface area. But I am only guessing here...

I wonder if the BK/other guys have the same size catalyst across their different sized products?

That I do not know. I just took a quick look at aftermarket cats for BK models and there does not seem to be a correlation between cat area and BTU outputs. The "big" stoves seem to use cats the same size as the smaller stoves, just my initial observation.

Delta T still puzzling to me. I can buy the low flow/low BTU hypothesis until you install a massive key damper, definitely reduce the flow, and the flue temps start tracking more with catalyst swings.

Yeah I do not have a good answer yet either. One thing I would love to know is what is the velocity of the gas in the exhaust stack. Maybe this weekend I can make up a pitot to get some kind of reading. My guess is it is really slow.

Not sure how to handle the radiation vs air temperature question. I do think if the probe is touching the brick, the conduction could affect the reading. I’m not a K-type TC expert by any means.

For sure TC touching the brick will affect the reading, at least during transients. You have essentially increased the thermal mass of the sensor so it will read slower. If you ever achieve steady state it might be OK.

 

[arnermd]

Delta T still puzzling to me. I can buy the low flow/low BTU hypothesis until you install a massive key damper, definitely reduce the flow, and the flue temps start tracking more with catalyst swings.

You know..... I just remembered something. The back of my stove has some massive cast fins, and those fins are covered by the rear heat shield. So they created a nice heat exchanger where room air is forced through by natural convection. With those fins there and the heat shield I bet the back of the stove is pumping out a lot of heat.

And..... the back chamber for the exhaust gasses is pretty large cross-sectional area so velocities are probably really low back there, gives the combustion gasses lots of resonance time to exchange heat with the back wall.

I can't prove it but I think that's the answer.... Lots of surface area and good convective air flow.

And..... this would tend to dampen out the exhaust gas temp to cat temp dT correlation. They should trend with each other but the change in exhaust gas temp will be much less. As the cat temp goes up the exhaust gas will not go up as much for two reasons

1. The mass of the back casting is really big.
2. The fins will pump more room air through as they get hotter. This is increasing mass flow on the cold side so you can get a lot more heat with little change in exhaust temp.

You buy it?

P.S. I love kicking this stuff around with you guys but I have to go do my real job..... I love working from home....

 

[JAB]

Anyone had issues with the CAT cover being loose and falling out of position? This is just our 2nd season and we are in TX so we don't burn full-time in winter but have gone through 4-5 cords. Our Encore CAT cover was never very tight even brand new but I thought it was supposed to be that way. While I was out of town the CAT cover fell out after my wife had completed a hot reload which caused the CAT to spike (don't have a digital CAT thermometer). My wife got that fire under control and then when cool looked at options to keep the CAT cover held securely. Ended up putting some door gasket material between the catch area and that seems to be working just fine...but may not be a good long-term solution. Anyone else have issues with their CAT cover?

Our Encore works like a dream and we are thrilled to not be having any issues like others have posted...when the CAT cover stays on. We weren't burning it as hot last season and had issues with gumming up the glass....but after reading some posts here decided to try burning hotter and it has helped a lot with keeping the glass clean. I will probably get the digital readouts and data logger like others have...my wife likes the alarm at high temps...but since the stove has been running pretty much flawlessly I haven't bothered yet.