We have a Vermont Castings Defiant Encore (Pre CFM) that is now vented into a 8" metal pipe which replaced the old masonry chimney. The pipe is new to us as the chimney was torn down over the summer. I've noticed that the automatic damper on the stove may not be operating correctly. It seems as though I'm having to monitor the stove more than I used to to maintain the disired level of fire. For example, the stove will start to burn to hot so it needs to be turned down, then it starts to burn too cold and needs to opened up. This stove has the thermostatic air control, so I shouldn't be needing to adjust it as much as I am. Last night we got a pretty good scare. We loaded the stove up for the night and turn the air control down so the lever was pointed straight down. This is about half throttle. Previously this would give us a 6 hour burn. About 1/2 an hour later the smoke detector went off. It wasn't anything alarming, just the fresh paint on the flue pipe. But the stove was way too hot. With that air setting, it should not have been nearly so hot. I'm pretty sure that something in the thermostatic air control is not working properly. It's sticking if you will (or maybe the bi-metal spring is broken). Before ordering a bunch of parts on a guess, I was hoping some board members might offer me some pointers as what to check first.
Trouble controlling the fire with a Vermont Castings Defiant Encore
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webbie
Seasoned Moderator
One thing you are learning quickly is how superior the draft of a metal chimney is (compared to most masonry chimneys).
The stove is likely to run vastly differently. Yes, there might be various things wrong, from the fit of the ashpan gasket to a stuck air control, but you have to keep in mind the vastly stronger chimney. Even then things are right, the stove will run differently.
If the stove burns too cold when turned down, then it is unlikely that your problem is the primary air damper - or, that it is leaks. After all, if the stove was leaking in too much air, this would happen especially when the air control was turned down!
So my first thought is that you have an over draft, and the cheapest part you can buy is a turn damper to be installed in the stove pipe 2 or 3 feet away from the stove. Use this to choke down the chimney to some degree. Note that a turn damper in such an installation should not be constantly fiddled with, just set at a level that slightly spoils the chimney draft.
That would be my first step based on your symptoms. When operating properly, that stove should give you an 8-10 hour burn easily on an overnight fueling (full of hardwood).
The stove is likely to run vastly differently. Yes, there might be various things wrong, from the fit of the ashpan gasket to a stuck air control, but you have to keep in mind the vastly stronger chimney. Even then things are right, the stove will run differently.
If the stove burns too cold when turned down, then it is unlikely that your problem is the primary air damper - or, that it is leaks. After all, if the stove was leaking in too much air, this would happen especially when the air control was turned down!
So my first thought is that you have an over draft, and the cheapest part you can buy is a turn damper to be installed in the stove pipe 2 or 3 feet away from the stove. Use this to choke down the chimney to some degree. Note that a turn damper in such an installation should not be constantly fiddled with, just set at a level that slightly spoils the chimney draft.
That would be my first step based on your symptoms. When operating properly, that stove should give you an 8-10 hour burn easily on an overnight fueling (full of hardwood).
How would I have an over draft? The pipe is correctly sized for the stove (8") and extends slightly over the correct height above the ridge line. The pipe is a straight shot with no bends. The total height is 18'. The fuel is seasoned black oak. Later I'll be switching to mixed seasoned hardwoods (red oak, birch, hickory, beech).
webbie
Seasoned Moderator
That stove is approved with a 6" chimney......which shows that it needs less draft than the 8" provides.
My point is that, compared to BEFORE, you have a vastly stronger chimney (most likely), so that the stove ends up responding differently. A straight up chimney which is interior and round is much stronger than a masonry one (which probably had one or two turns).....
My guess would be that you have doubled your draft - again, does not mean that there may not be something wrong with the stove, but if it turns down well when you change the control, then it cannot be stuck open - nor can be be leaking a lot of air in the gaskets, so I am simply drawing a conclusion based on your post.
I think you can actually see the action of the air inlet damper in the rear- so you should be able to confirm that it responds to your control and does not stick. This is best done when the stove is out (cold).
One of our moderators operates the same stove and just rebuilt it, so perhaps he will chime in with more.
check this thread also:
https://www.hearth.com/econtent/index.php/forums/viewthread/11594/
Service manual PDF is here:
https://www.hearth.com/econtent/index.php/wiki/Defiant_Encore/
My point is that, compared to BEFORE, you have a vastly stronger chimney (most likely), so that the stove ends up responding differently. A straight up chimney which is interior and round is much stronger than a masonry one (which probably had one or two turns).....
My guess would be that you have doubled your draft - again, does not mean that there may not be something wrong with the stove, but if it turns down well when you change the control, then it cannot be stuck open - nor can be be leaking a lot of air in the gaskets, so I am simply drawing a conclusion based on your post.
I think you can actually see the action of the air inlet damper in the rear- so you should be able to confirm that it responds to your control and does not stick. This is best done when the stove is out (cold).
One of our moderators operates the same stove and just rebuilt it, so perhaps he will chime in with more.
check this thread also:
https://www.hearth.com/econtent/index.php/forums/viewthread/11594/
Service manual PDF is here:
https://www.hearth.com/econtent/index.php/wiki/Defiant_Encore/
swestall
Minister of Fire
Perhaps overdraft is confusing. You have a stronger draft than you use to. And, how hot, is too hot? If I recall that stove is a CAT stove and can easily run hot for efficient operation. Hot as in 500-700 degrees stack temp is not a problem at all. (on a single wall connector into the flu). Stove top temp can also run 500-700 without overfiring. The thermostatically controlled damper can become sticky and can be cleaned pretty easily if you can access it. If you go to the CFM site, you can look at the parts breakdown. I would agree with Craig that it must be working to some extent if you can shut it down. Try operating in the first 1/4 of the range instead of the 1 st half and see what that nets you. As Craig points out, you have alternatives, much better than not enough draft. Finally, you might want to check the ash pan gasket as it gets most use. The "dollar bill" test will show any loose gasket there.
The early Encore is a great stove and throws off a ton of heat with the CAT engaged. It is possible you are getting the most of it with the new Chimney.
If you want, post back your operating temps. They may actually be OK. I had my Encore operate at 800 degrees for short times and no problem; but lots of heat.
The early Encore is a great stove and throws off a ton of heat with the CAT engaged. It is possible you are getting the most of it with the new Chimney.
If you want, post back your operating temps. They may actually be OK. I had my Encore operate at 800 degrees for short times and no problem; but lots of heat.
gasavage
Member
My 2003 Defiant would run 450 - 600 degrees stovetop @ 1/4 - 1/3 throttle. 1/2 or more & you were going to see 700 +. Fully closed yielded 350 with 12 hrs burn time. (love them cats) I had 14' of Excel double wall 8" pipe with 2 30 degree elbows inside, and 6' of class A outside. Sounds like you have a totally different stove now & are having to adjust to a "new stove".
Right now I'm burning the stove wide open with the converter off. I have 600 degrees of griddle temp and 250 degrees of flue temp. That's all she'll give me. I don't know why it won't burn hotter, I've certainly had it hotter with less throttle. (before I posted this message, I threw in another piece of wood. That's what she wanted. Right away the temps shot up)
The other night when she started to get away from me I had 800 degrees of griddle temp and 500 degrees of flue temp. Now that's not terribly hot, but remember, we had already gone to bed and the temps were still climbing with 1/2 throttle. Damage would have resulted if I hadn't turned it down. That worries me a bit...
Once I get things warmed up in here, I'll try throttling it back down to 1/4 to see what happens.
The other night when she started to get away from me I had 800 degrees of griddle temp and 500 degrees of flue temp. Now that's not terribly hot, but remember, we had already gone to bed and the temps were still climbing with 1/2 throttle. Damage would have resulted if I hadn't turned it down. That worries me a bit...
Once I get things warmed up in here, I'll try throttling it back down to 1/4 to see what happens.
webbie
Seasoned Moderator
There is no reference as to how it should burn without the converter, as it is not designed or meant to burn that way. That is only for starting and loading. The rest of the time, the cat should be engaged.
The best I can tell that appears to be the trick. Some time ago I was told to not bother burning with the cat so I got into the habit of not using it. With this new flue, things have changed enough that apparently need to go back to using it.
swestall
Minister of Fire
Craig is POSITIVELY correct. That stove is not meant to be run at operating temps without the converter engaged. You have been wasting so much wood and most likely producing much more smoke than you needed to; not to mention losing a great amount of heat. Once the griddle gets up to 550 or so, engage that CAT. Whatever stack temp you get should be fine as long as you do not have a lot of air leaks. Check the site for air leak checking methods. A stack temp of 550-650 is fine on that stove. You have just had an AH HA moment!
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