VC Encore not drafting

[mtnbiker727]

My parents had a Carmor top loading wood stove for almost 40 years, which they used exclusively to heat their home. The stove was awesome, but all good things eventually come to an end when they wear out. A neighbor tried to weld the stove, but couldn't get all the cracks sealed up.

They bought a VC Encore 2040 CAT-C from a dealer and had the dealer install it. Now they can't seem to get the smoke out of their house. They are frustrated with how small the draft opening is, and are opening the ash pan to get the fire to start quicker. When the stove is running they smell smoke, and it's a pretty big deal if my dad can smell it. The dealer came back and installed a goofy looking hood on top of the chimney, but that hasn't helped. Their chimney is a 6 inch square terracotta pipe, in the middle of their single story house.

My dad took the catalytic converter (is that right?) out of the stove, but I don't see how that would cause a problem.

They think the main culprit is the top loading door, which is the whole reason they bought the stove. I told them to do the dollar bill test on it, but they haven't done that yet. They think their problem is the poor draft, because they can't open it wide enough to make it burn hot enough to keep it from smoking.

The condition of the wood is not likely the problem. All their wood is cut and stacked outside for at least a year, then as soon as the heating season is over, transferred to the wood shed that's attached to their house.

Myself, I have a wood pellet stove, and I question their stove pipe not being sealed with anything, and to me it looks like the pipe is put together backwards, but that's the way the dealer did it. They tried to use RTV Silicon to seal the pipe when they had their old stove, but the silicon melted away, and so did the stove cement stuff.

Any thoughts or comments? Once the Chinese virus goes away they are going to have the dealer to take the stove back and buy something else instead....

 

[gthomas785]

How tall is the chimney? I have a single story 6" insulated liner, and even with the insulation my draft is pretty marginal. Hate to say it but these newer stoves really need a good strong draft in order to work right.

However, I would double check to make sure the primary air flap (middle back of the stove, near the bottom) is opening all the way. Mine came slightly misadjusted from the factory.

Edit: forgot to mention, even if you think your wood is dry, get a moisture meter and test it. Having a poor draft will exacerbate any damp wood issues, and vice versa. Also, I don't think this is a gasket issue since a leaky gasket will allow more air into the stove, not less. If your fire is not getting hot enough / smoking into the house, then it's either wet wood or poor draft, or both.

 

[webby3650]

The old stove had cracks you say. Was it leaking smoke? You mentioned they sealed the old stove pipe. That isn’t necessary. If the chimney was functioning properly it would pull air in, not leak smoke out. The same goes for gaskets or cracks on the stove.
It sounds to me like the old stove had the same issues the new stove has.

 

[mtnbiker727]

How tall is the chimney? I have a single story 6" insulated liner, and even with the insulation my draft is pretty marginal. Hate to say it but these newer stoves really need a good strong draft in order to work right.

However, I would double check to make sure the primary air flap (middle back of the stove, near the bottom) is opening all the way. Mine came slightly misadjusted from the factory.

Edit: forgot to mention, even if you think your wood is dry, get a moisture meter and test it. Having a poor draft will exacerbate any damp wood issues, and vice versa. Also, I don't think this is a gasket issue since a leaky gasket will allow more air into the stove, not less. If your fire is not getting hot enough / smoking into the house, then it's either wet wood or poor draft, or both.

The chimney is at least 16' from the top of the stove.

When the air flap handle is wide open, the opening in the back is 3/8". What should the opening be? My dad wonders if you adjust it too far, then the stove won't be able to shut itself down if it gets too hot.

 

[mtnbiker727]

The old stove had cracks you say. Was it leaking smoke? You mentioned they sealed the old stove pipe. That isn’t necessary. If the chimney was functioning properly it would pull air in, not leak smoke out. The same goes for gaskets or cracks on the stove.
It sounds to me like the old stove had the same issues the new stove has.

The old stove only had issues when it was too warm outside for a good fire, but since it's their primary heat source, they would just keep a low fire on those days. Prior to the stove cracking, if the stove wasn't burning well, the smoke went up the chimney because it could not escape into the house.

 

[gthomas785]

When the air flap handle is wide open, the opening in the back is 3/8". What should the opening be? My dad wonders if you adjust it too far, then the stove won't be able to shut itself down if it gets too hot.

I think mine opens wider than that but I can't remember. A good way to tell is that the flap should just shut completely when the lever is all the way closed, while the stove is cold. There shouldn't be too much slack in the cable at that point. As for the stove getting too hot, well, you obviously don't have that problem. For me it is normal to run the air wide open with the front door cracked for a good 20-30 minutes at the beginning of a cold start, before I'd need to worry about overfiring. But it will all depend on the draft your chimney is pulling. And the thermostatic control isn't really that precise, you'll still have to turn the air down a bit manually once the fire gets going nice and hot.

By the way, as tempting as it is, I would not recommend opening the ash pan during a fire under any circumstances. Even if your fire doesn't look very hot it can warp the bottom of the stove and would probably void the warranty.

 

[webby3650]

The old stove only had issues when it was too warm outside for a good fire, but since it's their primary heat source, they would just keep a low fire on those days. Prior to the stove cracking, if the stove wasn't burning well, the smoke went up the chimney because it could not escape into the house.

Well, now you have a downdraft stove that’s plagued with drafting and durability issues. It’s nothing like the old leaky stove that once was...

 

[Corey]

...
Their chimney is a 6 inch square terracotta pipe, in the middle of their single story house....

This could be a big part of the problem right here. 6x6" isn't too bad area-wise and 'middle of a single story house' seems ok - presuming it goes up through some sort of attic / roof peak... so hopefully at least ~15+ feet. But you say they burned the old stove 40 years - so sounds like the chimney is at least 40 years old(?). If that is the case, it's likely there are a few cracks which could let air leak in. If so, that will bypass the stove and make draft worse. Also, make sure the stove pipe is sealed tight to the thimble / chimney and also double check any ash doors, clean-outs, T's or anywhere else air can leak into the flue.

 

[mtnbiker727]

This could be a big part of the problem right here. 6x6" isn't too bad area-wise and 'middle of a single story house' seems ok - presuming it goes up through some sort of attic / roof peak... so hopefully at least ~15+ feet. But you say they burned the old stove 40 years - so sounds like the chimney is at least 40 years old(?). If that is the case, it's likely there are a few cracks which could let air leak in. If so, that will bypass the stove and make draft worse. Also, make sure the stove pipe is sealed tight to the thimble / chimney and also double check any ash doors, clean-outs, T's or anywhere else air can leak into the flue.

My dad asked if anyone else responded, and I told him about your response. He said the chimney has three layers. Outer layer is brick, followed by concrete blocks, then the 6 x 6 tile. So he said it's possible the chimney is leaking, but not very likely. He said when the ash door is cracked open the fire burns super hot, so we think the real problem is the opening size for the primary air intake. Is there anyone that has information on how to adjust this? It's not in the manual, and I can't find it anywhere on the web.

 

[gthomas785]

What about if you open the front door? Does the fire take off if you do that? Opening the ash pan door is a known way to create an inferno and destroy your stove even with suboptimal wood or draft, so don't do that.

How long do you leave the (glass) door cracked on a cold start before shutting it? With a masonry chimney, I think you'd need to get a good strong fire going (20-30 mins at least) before shutting it. Have you done that or are you trying to close the door sooner than that? On mine, if I try to close the door too soon the fire will go out. Once the masonry heats up I think you'll find it draws much better, and the air intake will be adequate.

The primary air intake is in the middle of the back, at the bottom. It's a flap covered by a slotted cover about 6" wide. To adjust it you need to pry that cover off, get an allen wrench, and adjust the slack of the cable coming through the hole in the flap. However, from your description, I don't think this is the heart of your problem. You said there is smoke coming into the room. That is not an air intake problem, it's a draft problem and you should focus on addressing that.

 

[mtnbiker727]

What about if you open the front door? Does the fire take off if you do that? Opening the ash pan door is a known way to create an inferno and destroy your stove even with suboptimal wood or draft, so don't do that.

How long do you leave the (glass) door cracked on a cold start before shutting it? With a masonry chimney, I think you'd need to get a good strong fire going (20-30 mins at least) before shutting it. Have you done that or are you trying to close the door sooner than that? On mine, if I try to close the door too soon the fire will go out. Once the masonry heats up I think you'll find it draws much better, and the air intake will be adequate.

The primary air intake is in the middle of the back, at the bottom. It's a flap covered by a slotted cover about 6" wide. To adjust it you need to pry that cover off, get an allen wrench, and adjust the slack of the cable coming through the hole in the flap. However, from your description, I don't think this is the heart of your problem. You said there is smoke coming into the room. That is not an air intake problem, it's a draft problem and you should focus on addressing that.

I don't think they open the glass door when they fire it.... I will suggest that.

I don't understand the intake versus draft.... If everything else is sealed (chimney, stove pipe, etc.), then the only way air can get into the chimney is through the stove, and if the opening in the stove is too small to let enough air in, the fire won't burn well (making smoke) AND the smoke won't exit the stove through the pipe efficiently either. Air can't flow in a vaccum, which is essentially what we're creating by choking the stove without a large enough draft opening. Am I wrong in this way of thinking?

 

[gthomas785]

Definitely leave the door (not the ash pan) cracked for several minutes at the beginning of a cold start. I think that may resolve a lot of your frustrations.

As for draft - You're not wrong, but it's important to understand the difference between draft (how strong is the vacuum pulled by the chimney) and the intake opening size. These stoves are engineered to work with a certain strength of draft and it's a shame that most installers don't check the draft when they install.

Older stoves used to work fine with weak chimneys because they let a lot of air in. But the trade off is that they also waste more heat up the flue. New stoves are tighter by design, which makes them more efficient but they also will not behave the way you are used to with an older stove, and they need a stronger draft to pull air in through the smaller air intake.

When you have smoke leaking out, that's an indication that you have enough openings in the stove, but the smoke is going the wrong way because the draft (vacuum) is not strong enough. Does that make sense? If the fire dies, but you still aren't getting smoke coming out, then it'd be possible that your draft is ok but the air is restricted too much.

The strength of the draft depends on many things such as chimney height / diameter, flue temperature, etc. Since it is a masonry chimney, it will take a lot of heat to warm up the flue and establish a strong draft, compared to a metal chimney or liner.

So make use of the front door to let plenty of air in at the beginning, to get your system heated up. Once the fire is going and the chimney is warm, you can start to close things down. And don't even try engaging the catalyst until the stovetop is 500f or so, it will just choke the fire further.

 

[mtnbiker727]

Definitely leave the door (not the ash pan) cracked for several minutes at the beginning of a cold start. I think that may resolve a lot of your frustrations.

So make use of the front door to let plenty of air in at the beginning, to get your system heated up. Once the fire is going and the chimney is warm, you can start to close things down. And don't even try engaging the catalyst until the stovetop is 500f or so, it will just choke the fire further.

It just doesn't make sense to me that you should have to leave a door open to get a fire going.... I guess it's the tradeoff between getting a manual stove that is idiot proof, vs. a stove full of electronics that does everything for you.

Thanks for your responses. They have been very helpful, even if they aren't what we wanted to hear.

 

[Diabel]

As stated before, i believe the chimney is your potential problem. Plus, (i might’ve missed it) you did not mention anything about the fuel quality.

 

[gthomas785]

It just doesn't make sense to me that you should have to leave a door open to get a fire going.... I guess it's the tradeoff between getting a manual stove that is idiot proof, vs. a stove full of electronics that does everything for you.

Thanks for your responses. They have been very helpful, even if they aren't what we wanted to hear.

Well, if you had a taller chimney, you probably wouldn't have to leave it open as long. I'd say it's not a bad trade-off for hauling 1/3 less wood over the course of the winter, though...

 

[kennyp2339]

1 year seasoned wood? probably a lot of your problem, oak takes a minimum of 2 years around here to get it marginally dry enough to burn (20%) best bet is to buy a $30.00 moisture meter from home depot or Lowes, take a split from inside, resplit it and test the fresh face, if your above 20% your going to have issues with these new stoves.

 

[mtnbiker727]

1 year seasoned wood? probably a lot of your problem, oak takes a minimum of 2 years around here to get it marginally dry enough to burn (20%) best bet is to buy a $30.00 moisture meter from home depot or Lowes, take a split from inside, resplit it and test the fresh face, if your above 20% your going to have issues with these new stoves.

It's usually maple, beech, or ash.... and it's seasoned for a year stacked in the woods, and 6+ months in the woodshed...

I guess the main thing I've learned so far is that new stoves are complete garbage compared to old stoves...

 

[mtnbiker727]

Well, if you had a taller chimney, you probably wouldn't have to leave it open as long. I'd say it's not a bad trade-off for hauling 1/3 less wood over the course of the winter, though...

So my dad is determined to make the air intake work like a normal draft should. After messing with the cable adjustment, and realizing there was a spring in there to prevent a catastrophic fire, he decided to leave it alone. So for a little experiment he shoved a wedge of wood into the intake to hold it wide open, and then tried to light a fire. After not getting much, he put a hair dryer into the intake and blew air into the stove, and didn't see a difference in the fire. Then he cracked open the ash pan and said within 15 seconds the fire was roaring. He closed the ash pan then he waited until the stovetop was 350 degrees and closed the damper.

Despite having the fire continuously lit for over 24 hours now (chimney should be hot!), they are still getting a burning sensation in their throats and can smell smoke. They have suspected for a while that the smoke is leaking out from under the griddle, so my dad put a 17 pound lead weight on top of the griddle, but it's still not going away. He had just cleaned the chimney (which never has anything in it), so that's not the problem. The stove pipe was installed by the dealer, and my dad checked the installation instructions and said it was done correctly.

I don't remember if I mentioned this or not, but the dealer came back last week and put a goofy looking thing on top of the chimney that is supposed to make it draft better.

Is it possible there is something wrong with the stove, and not just him unable to learn how to use a modern stove?

 

[semipro]

The flue is the engine that drives the stove. The stove does not push smoke up the flue. It creates a vacuum that pulls air in.
Most stoves are not airtight. The reason most of them don't leak smoke, and the reason a top loader works without smoke pouring out is because the flue is pulling air through the stove.

Your description of the chimney makes it sound like there's a lot of masonry to heat up to get a warm, functioning flue, especially if its on the exterior of the house. If you had a larger flue an insulated liner would help.

While many modern stoves need some extra air during a cold start they are highly tuned to work well with the right flue and dry fuel once they get going. You risk messing up that tuning if you jack with the air inlet settings.
If you haven't checked your wood moisture level yet as advised here that should be your very next step.
Also, many stoves have multiple air inlets. Some are controlled, some not. Don't assume the one you're looking at is the only way inlet air can get into the stove.
Although its a blast, literally, you risk cracking your stove if you use the ash pan door for extra air. I've done it.

Again, check your wood with a meter as described above before you waste any more time looking at other potential problems. Many have come here for advice, certain they have good wood, only to eventually find out that wood moisture was the problem all along.

 

[semipro]

I guess the main thing I've learned so far is that new stoves are complete garbage compared to old stoves...

It's kind of like comparing an old diesel engine to a modern gas engine. You could toss just about any fuel into an old diesel and it would run, but it would run dirty and use a lot of fuel. Whereas, a modern gas engine requires good fuel but burns cleanly and efficiently.
As your folks get older they'll really appreciate that efficiency n their new stove; less cutting, hauling, cleanup, etc.

 

[webby3650]

Is it possible there is something wrong with the stove, and not just him unable to learn how to use a modern stove?

Flue height and the moisture content of the fuel are the issues here.

 

[mtnbiker727]

Flue height and the moisture content of the fuel are the issues here.

Highest moisture content of the several sticks of wood he split and tested was 13%. Top of chimney is exactly 16 feet above the top of the stove, plus the stupid turbo draft thing the dealer put on top of it,

Any other questions?

 

[mtnbiker727]

As your folks get older they'll really appreciate that efficiency n their new stove; less cutting, hauling, cleanup, etc.

They would appreciate it more if they could breath the air in the house while it is running.

 

[Diabel]

I suggest seeking professional help from a dealer or reputable chimney sweep. They should stop using the stove if they smell smoke in the house.

 

[Mech e]

@mtnbiker727 I do not have experience with the VC stove your parents are using, but I do want to comment about their draft. I changed out my 30 year old Osburn wood stove a little over a year ago (second season) for a new 2020 stove. The new stove was a direct replacement with no modification to my chimney setup required. The first time I tried to start a fire, I immediately noticed the new stove did not "seem" to draft as well. As it turns out, the new stove has a much more restrictive air flow path, thus reducing air flow through the system. A couple of things that I have to do differently with the new stove:

1. To start a fire, I have to leave the door cracked open to get the fire burning. I need to get the stove heated up and the fire burning more aggressively before I can close the door. I actually close the door in two stages. The stove manufacturer even recommends cracking the door to get the fire started. If I don't do this the fire is lazy and will not get going.

2. Because of the restricted flow bath, it is tricky to open the door once a fire is going without letting smoke into the room. It takes a bit to sort out how to do this on these new stoves.

I cannot comment on your parents stove leaking once it is going. Like Diabel said, get that checked out by your their dealer. But once that is sorted out, running the new stove is effectively will be different from their new one. All that said however, my new stove puts out more heat and is more efficient. Don't give up on the new VC yet.