Encore 2040 cat C burns too fast

[hoosierhermit]

I have a VC Encore 2040 cat c that I purchased in January of 2023, so it's now in its 3rd season of use. IMO, it has never worked properly. It burns through wood so fast and hot, specifically three to four 4-6" thick pieces of hardwood with moisture content of 13-16% will last about 3 hours on the lowest airflow setting with an in-line flue damper nearly closed and the griddle will be 650-670 degrees. No matter what I do, there are always vigorous flames throughout. After visiting the dealer every year since I bought it, expressing my concern and frustration, I finally got them to listen to me and a guy came out. There are no air leaks, all gaskets are good, everything is tight. The flapper door on the bottom back (primary air intake), controlled by the lever on the right side, opens and closes properly. He said he couldn't find a problem. I have also put a screw in a hole that's adjacent to primary air intake, which I had read about in a thread on one of these forums. I am somewhat confused about the secondary air intake, which seems to have a thermostatic coil that expands with heat and reduces airflow in the secondary intake to maintain a somewhat constant temperature. Some threads on here make it sound like the thermostatic coil controls the primary air intake flap, but I don't believe that's the case on this model stove. I believe the secondary air intake is located above the primary air intake on the back of the stove (the owner's manual schematic is not clear IMO). If my understanding thus far is correct, I would wonder if this thermostatic coil, or some aspect of that mechanism, is broken or not working. I've also read that there are air vents in the ash tray, but I can't find those on my stove, if they exist. And I've read to just allow ash build-up to "block" air entry which I've tried and haven't noticed any observable difference.

I just can't believe that this is normal. Does anyone have insight or know of a possible solution to this problem?

 

[skb31]

Below is my understanding and if I make any mistakes smart people here will correct me:

The primary air lever controls air that comes down the front of the glass.

The secondary air intake is at the bottom middle on the back of the stove and is unregulated. It’s a roughly 3x6 inch rectangular opening on my Encore 2040 cat c which was made in the fall of 23. The 8 holes at the bottom of the ceramic in the back of the firebox are where the secondary air passes into the stove. When I installed my digital probe I accessed this chamber and was able to see how the stove works a bit better.

As I just posted in another thread I block two of these holes on my stove to give me more control with my primary air. My initial experience was a bit scary as I would be damper closed, primary air shut, with cat temps and STT temps moving into the nervous range as at that point I’m out of options to control the stove. I also had it checked for leaks.

This year I had a key damper installed but haven’t needed it. These stoves aren’t supposed to use them but my chimney is a bit of a longer run. My instructions clearly state you can run the stove without the catalyst. I’ve tried both ways and for now settled on blocking two of the holes and using smaller loads of wood. My instructions say to push the coals to the back wall and load the wood there when refueling.

The size, dryness, and amount of wood is the main contributor to high temps for me. I run a fan across the top of the stove but that has been less important as I worked out my process. Doesn’t seem to be a one size fits all for these stoves which can feel a bit daunting.

 

[gthomas785]

I have the same model stove and it is very sensitive to draft. Too short a chimney and it will struggle for air, too tall and it will be hard to control. Based on your description it definitely sounds like it's getting too much air. If the flames are truly "vigorous" I would be double checking that the ash door is sealing tight. There should be no air coming in under the grate and even a small leak can cause an overfire situation. The griddle gasket is also a common culprit for these symptoms.

This stove does have a bimetallic thermostat. The coil is attached to the air lever, inside the intake channel on the right side. A cable runs down from that thermostat through the air channel to the flapper arm. It's possible the cable is getting hung up on the casting, but if the tech said the flapper is closing properly then that's probably not the issue.

Your description of the secondary air intake is mostly correct, except not all of the secondary air comes in through those holes. A large portion (maybe half?) of the secondary air is routed directly into the catalyst without entering into the firebox.

 

[gthomas785]

Also, dumb question but... You are shutting the bypass damper, right? Even without the catalyst you need to cruise with that damper closed. When it's open the stove will rage out of control no matter what air setting you have since the unregulated secondary air backflows into the firebox.

 

[Mreif]

I have a VC Encore 2040 cat c that I purchased in January of 2023, so it's now in its 3rd season of use. IMO, it has never worked properly. It burns through wood so fast and hot, specifically three to four 4-6" thick pieces of hardwood with moisture content of 13-16% will last about 3 hours on the lowest airflow setting with an in-line flue damper nearly closed and the griddle will be 650-670 degrees. No matter what I do, there are always vigorous flames throughout. After visiting the dealer every year since I bought it, expressing my concern and frustration, I finally got them to listen to me and a guy came out. There are no air leaks, all gaskets are good, everything is tight. The flapper door on the bottom back (primary air intake), controlled by the lever on the right side, opens and closes properly. He said he couldn't find a problem. I have also put a screw in a hole that's adjacent to primary air intake, which I had read about in a thread on one of these forums. I am somewhat confused about the secondary air intake, which seems to have a thermostatic coil that expands with heat and reduces airflow in the secondary intake to maintain a somewhat constant temperature. Some threads on here make it sound like the thermostatic coil controls the primary air intake flap, but I don't believe that's the case on this model stove. I believe the secondary air intake is located above the primary air intake on the back of the stove (the owner's manual schematic is not clear IMO). If my understanding thus far is correct, I would wonder if this thermostatic coil, or some aspect of that mechanism, is broken or not working. I've also read that there are air vents in the ash tray, but I can't find those on my stove, if they exist. And I've read to just allow ash build-up to "block" air entry which I've tried and haven't noticed any observable difference.

I just can't believe that this is normal. Does anyone have insight or know of a possible solution to this problem?

I have the same model, and also had the same problem. I had single wall pipe that went in to the top of the stove. I eventually noticed there was a gap around the sw pipe where it went into the stove collar allowing it to intensify the draft with in turned pulled more air into the stove through primary and secondary inlets. I changed sw pipe out for double wall witch fits into and around the flue collar on the stove. After this it was a completely different stove more controlable longer burns. Went from 3-4 hour to 8-9 hour burns . Also I never empty my ash draw I keep it full. Just something to check for

 

[hoosierhermit]

Below is my understanding and if I make any mistakes smart people here will correct me:

The primary air lever controls air that comes down the front of the glass.

The secondary air intake is at the bottom middle on the back of the stove and is unregulated. It’s a roughly 3x6 inch rectangular opening on my Encore 2040 cat c which was made in the fall of 23. The 8 holes at the bottom of the ceramic in the back of the firebox are where the secondary air passes into the stove. When I installed my digital probe I accessed this chamber and was able to see how the stove works a bit better.

As I just posted in another thread I block two of these holes on my stove to give me more control with my primary air. My initial experience was a bit scary as I would be damper closed, primary air shut, with cat temps and STT temps moving into the nervous range as at that point I’m out of options to control the stove. I also had it checked for leaks.

This year I had a key damper installed but haven’t needed it. These stoves aren’t supposed to use them but my chimney is a bit of a longer run. My instructions clearly state you can run the stove without the catalyst. I’ve tried both ways and for now settled on blocking two of the holes and using smaller loads of wood. My instructions say to push the coals to the back wall and load the wood there when refueling.

The size, dryness, and amount of wood is the main contributor to high temps for me. I run a fan across the top of the stove but that has been less important as I worked out my process. Doesn’t seem to be a one size fits all for these stoves which can feel a bit daunting.

What are the steps to accessing the 8 holes at the bottom of the ceramic in the back of the firebox and what did you fill the holes with? I suspect what I referred to as an in-line flue damper is probably exactly what you described, a key damper. Thanks for you help!

 

[hoosierhermit]

Also, dumb question but... You are shutting the bypass damper, right? Even without the catalyst you need to cruise with that damper closed. When it's open the stove will rage out of control no matter what air setting you have since the unregulated secondary air backflows into the firebox.

Yes, I shut it when the thermometer sticking out the back gets into the temperature range for optimal catalytic function.

 

[hoosierhermit]

I have the same model, and also had the same problem. I had single wall pipe that went in to the top of the stove. I eventually noticed there was a gap around the sw pipe where it went into the stove collar allowing it to intensify the draft with in turned pulled more air into the stove through primary and secondary inlets. I changed sw pipe out for double wall witch fits into and around the flue collar on the stove. After this it was a completely different stove more controlable longer burns. Went from 3-4 hour to 8-9 hour burns . Also I never empty my ash draw I keep it full. Just something to check for

I really appreciate this response. It's totally possible that that is my problem, or at least a major contributing factor. I remember when the pipe was installed it was slightly too big and multiple cuts were made around the circumference so that it could be crimped in a little and forced into the collar. I will check for air entry there the next time I use the stove.

If a get a double wall pipe as you describe will I have to replace all of the pipe segments with double wall or just that initial one?

 

[skb31]

What are the steps to accessing the 8 holes at the bottom of the ceramic in the back of the firebox and what did you fill the holes with? I suspect what I referred to as an in-line flue damper is probably exactly what you described, a key damper. Thanks for you help!

You can access the holes when your stove is cold. They are just below the removable ceramic plate in the firebox that allows access to the cat chamber.

I use 1 inch #10 size stainless allen head/hex cap style bolts. They do not screw in but gently slide into place. I tried a regular #10 screw and didn’t like the effort to remove it. These hex heads allow for a better grip to remove them.

Yes, I shut it when the thermometer sticking out the back gets into the temperature range for optimal catalytic function.

If you have the same factory installed bimetal probe that mine came with I suspect the process you’re describing here may be part of the issue. The wording on the probe has been problematic for many people. You should be closing the damper earlier if I am understanding you correctly. It reads “operate catalyst” in the silver range and that means the cat has engaged.

Are you referring to the damper (back left big lever when facing the stove) or the primary air supply (front right little lever when facing the stove) in your comment?

My owners manual reads, “it will take several minutes after closing the bypass damper for the temperature probe to fully adjust to the new temperature.” I did not like this probe so I bought two digital meters from Auberins. One to replace the cat meter and another for stove top or pipe.

 

[Mreif]

I really appreciate this response. It's totally possible that that is my problem, or at least a major contributing factor. I remember when the pipe was installed it was slightly too big and multiple cuts were made around the circumference so that it could be crimped in a little and forced into the collar. I will check for air entry there the next time I use the stove.

If a get a double wall pipe as you describe will I have to replace all of the pipe segments with double wall or just that initial one?

Not sure, if you stick with the same manufacturer you maybe able to replace just the first section. You will need a

I really appreciate this response. It's totally possible that that is my problem, or at least a major contributing factor. I remember when the pipe was installed it was slightly too big and multiple cuts were made around the circumference so that it could be crimped in a little and forced into the collar. I will check for air entry there the next time I use the stove.

If a get a double wall pipe as you describe will I have to replace all of the pipe segments with double wall or just that initial one?

If you stick with the same manufacturer maybe. You will need a stove top adapter to go on the collar first then dw pipe from there. I replaced all the pipe it was only 4.5 feet for me before the ss liner fit in.

 

[hoosierhermit]

Also, dumb question but... You are shutting the bypass damper, right? Even without the catalyst you need to cruise with that damper closed. When it's open the stove will rage out of control no matter what air setting you have since the unregulated secondary air backflows into the firebox.

Yes.

 

[hoosierhermit]

You can access the holes when your stove is cold. They are just below the removable ceramic plate in the firebox that allows access to the cat chamber.

I use 1 inch #10 size stainless allen head/hex cap style bolts. They do not screw in but gently slide into place. I tried a regular #10 screw and didn’t like the effort to remove it. These hex heads allow for a better grip to remove them.


If you have the same factory installed bimetal probe that mine came with I suspect the process you’re describing here may be part of the issue. The wording on the probe has been problematic for many people. You should be closing the damper earlier if I am understanding you correctly. It reads “operate catalyst” in the silver range and that means the cat has engaged.

Are you referring to the damper (back left big lever when facing the stove) or the primary air supply (front right little lever when facing the stove) in your comment?

My owners manual reads, “it will take several minutes after closing the bypass damper for the temperature probe to fully adjust to the new temperature.” I did not like this probe so I bought two digital meters from Auberins. One to replace the cat meter and another for stove top or pipe.

I am referring to the damper, which is opened (updraft mode) and closed (high efficiency mode) with the handle on the left of the stove.

 

[skb31]

I am referring to the damper, which is opened (updraft mode) and closed (high efficiency mode) with the handle on the left of the stove.

That damper should be closed earlier in your process from the sounds of it. On a hot reload (couple inch layer of coals) I load the stove and close the damper immediately. I begin to cut the primary air as the temp nears 1k.

I’d consider buying a digital probe and meter.

 

[gthomas785]

That damper should be closed earlier in your process from the sounds of it

Yes I second this. Close the damper as soon as you can do so without snuffing the fire.

 

[skb31]

To clarify I begin to cut the primary air when my cat chamber, digital meter nears 1k. The temps in that chamber far exceed stove top temps. For me I try to keep the cat cruising between 1100 and 1300 F

 

[stoveliker]

I think that is far too late.

 

[gthomas785]

I think that is far too late.

On the Encore, that's a good point to start cutting back. skb31 has the right idea. Not sure if that's what OP is doing though, and it sounded like they were also waiting for the cat to become active before shutting the bypass which I think is a bigger problem.

 

[skb31]

Yeah, I think this is where a digital meter for the cat comes in so handy with the Encore. You can get instant feedback on your air adjustments.

On a hot reload (cold startups are different) my temps are around 350-450 STT and 550-600 cat temp. As soon as I load I close the bypass damper and it takes only minutes for the cat temp to near 1k. I start cutting back the primary air and aim for 1200 on the cat probe. This keeps my pipe meter north of 325.

The burn cycles tend to be the same for me. Higher cat temps early but lower later. Stove top is the opposite with lower temps early and higher later. Opening the bypass damper mid cycle is risky. Attempting to add fuel in a burn cycle is a recipe for disaster.

Not sure how to say this well but here goes. When running at optimal heat output and efficiency, the burn won’t always look pretty. The stove looks really nice at cold start up or with small updraft fires. On hot reloads/continuous heating you’re operating a furnace with the potential to run really hot, really fast.

The stove is less user friendly for me than I expected or hoped for but it’s way more efficient than my old one. I had to get a lot of feedback here last year because I’d always run my old stove with just a bimetal pipe meter and/or an STT meter. Much like pilots, I now trust my instruments.

 

[hoosierhermit]

That damper should be closed earlier in your process from the sounds of it. On a hot reload (couple inch layer of coals) I load the stove and close the damper immediately. I begin to cut the primary air as the temp nears 1k.

I’d consider buying a digital probe and meter.

I don't see how your comment relates to the problem I have, which is that the wood always burns fast, and the stove is very hot as measured on the top surface. I also close the damper immediately after adding wood to a hot stove. Since I don't have a digital probe I don't know what the temperature in the secondary combustion chamber is, but it doesn't matter because in my case the primary air is always completely closed (and despite this a load of wood won't last but a few hours).

 

[hoosierhermit]

Yeah, I think this is where a digital meter for the cat comes in so handy with the Encore. You can get instant feedback on your air adjustments.

On a hot reload (cold startups are different) my temps are around 350-450 STT and 550-600 cat temp. As soon as I load I close the bypass damper and it takes only minutes for the cat temp to near 1k. I start cutting back the primary air and aim for 1200 on the cat probe. This keeps my pipe meter north of 325.

The burn cycles tend to be the same for me. Higher cat temps early but lower later. Stove top is the opposite with lower temps early and higher later. Opening the bypass damper mid cycle is risky. Attempting to add fuel in a burn cycle is a recipe for disaster.

Not sure how to say this well but here goes. When running at optimal heat output and efficiency, the burn won’t always look pretty. The stove looks really nice at cold start up or with small updraft fires. On hot reloads/continuous heating you’re operating a furnace with the potential to run really hot, really fast.

The stove is less user friendly for me than I expected or hoped for but it’s way more efficient than my old one. I had to get a lot of feedback here last year because I’d always run my old stove with just a bimetal pipe meter and/or an STT meter. Much like pilots, I now trust my instruments.

I never make "air adjustments" because the primary air is always closed. I don't see any meaningful difference in the size or amount of flames between closed and open and I've confirmed that the lever is opening and closing the primary air intake.

 

[gthomas785]

I never make "air adjustments" because the primary air is always closed. I don't see any meaningful difference in the size or amount of flames between closed and open and I've confirmed that the lever is opening and closing the primary air intake.

Then you have massive air leak somewhere else.

 

[skb31]

Yes, I shut it when the thermometer sticking out the back gets into the temperature range for optimal catalytic function.

I am referring to the damper, which is opened (updraft mode) and closed (high efficiency mode) with the handle on the left of the stove.

I don't see how your comment relates to the problem I have, which is that the wood always burns fast, and the stove is very hot as measured on the top surface. I also close the damper immediately after adding wood to a hot stove. Since I don't have a digital probe I don't know what the temperature in the secondary combustion chamber is, but it doesn't matter because in my case the primary air is always completely closed (and despite this a load of wood won't last but a few hours).

The first two posts are what led me to suggest closing the bypass damper earlier. Might be a misunderstanding with these combinations of posts, I’m not sure.

If your primary air control has little effect, as did mine when I started, then perhaps a key damper or limiting the secondary air a bit would help. I would also making sure the primary air flapper closes properly.

If you are seeing significant yellow or orange flames with the damper closed and primary air cut then steps should be taken to limit air a bit. I don’t see almost any yellow or orange flames when running continuously. Mostly bluish flames with some sporadic orange flames dancing around the firebox is what happens for me when things are going well.

 

[arnermd]

Sure sounds like an air leak to me, or excessive draft.

• Air leaks can be really hard to find, I like to use one of those stick lighters and carefully run the flame up and down all the seams.
  • Common sources are: Door gaskets, griddle gaskets, door glass gaskets (check your glass screws for tightness)
  • With the stove hot and air full closed reach down behind the stove and pull the wire that controls the primary flapper, make sure it is really shut. You can also run a lighter around the flapper and see how much air is getting sucked in. If it is not fully closing you can adjust it.
  • Check your bypass damper gasket, I do it by feel when the stove is closed, but a mirror on a stick might work.
  • Let your ashpan fill up and see if that makes a difference. If so it may be leaking.
  • Check tightness on the ashpan and door latches. They are adjustable, if you did not know.
• Draft: Leaks in the seams of the exhaust pipe will decrease draft not increase it. It allows air in which reduces draft and dilutes the exhaust making it colder, also reducing draft.
  • If you have too much draft installing a key damper may help.

Hope this is helpfull....

 

[Eman85]

My stove is a lot older than yours, but it is the original design of what you have. I can burn my stove with the damper open and easily control the fire and get overnight burns and never engage the cat. I burned like that for quite a few years with no problems other than cleaning my chimney more often. point is the firebox should be completely controllable with the primary air flap. If your stove can't do that I'd look a lot harder at the stove not sealing and sucking combustion air from somewhere.

 

[hoosierhermit]

Not sure, if you stick with the same manufacturer you maybe able to replace just the first section. You will need a

If you stick with the same manufacturer maybe. You will need a stove top adapter to go on the collar first then dw pipe from there. I replaced all the pipe it was only 4.5 feet for me before the ss liner fit in.

I wrapped some gasket rope where the stove and first section of pipe meet to "seal" any potential openings where air could be entering and increasing the draft. It didn't make any difference in how vigorously the wood in the stove burned so I don't think that is the problem. It was a good idea though