Defiant Encore damper hard to close

[Ladd]

I have a VC Defiant Encore purchased new in March 1991, which I assume is a model 2140. Over the last year, the damper has become increasingly difficult to close; I start moving the lever and it jams before moving very far. If I jiggle the handle back and forth, eventually the jam releases and the damper can be fully closed and locked. Lately the jam seems more difficult to clear and extends through a wider range of handle motion.

The damper opens up just fine.

The damper gasket looks fine and does not appear to be getting in the way. After removing the flue collar, visual inspection of the two side damper tabs shows them to be unbroken and straight. The damper tab over the torsion rod also appears to be unbroken and straight, but the end of the torsion rod that goes under the tab has a linear area that is scraped clean with contact with the underside of the damper tab.

I don't know if the "scraped clean" area is indicative of too much friction or how I would remedy it if it was.

What else can I check to try and find what is causing this issue?

FWIW: I have removed and replaced all easily accessible gaskets at least twice over the period of ownership, the catalytic converter multiple times, and replaced the inside cast iron fireback about 15 years ago that warped due to (I assume) over-firing by a first-time woodstove owner (me).

Thanks.

 

[defiant3]

So the culprit is likely the torsion bar clip, which holds the torsion bar securely down against the upper fireback.. Over time, it bends upwards allowing the torsion bar to flop around a little often creating the symptoms you describe.

Remove the pipe and flue collar, and you should see the clip. It's like a half-round steel piece which goes over the rod and is bolted to the upper fireback casting. I use a hammer and long screwdriver to bang it back down so that it's tight to the rod. It may or may not appear to be out of shape, but give it a few whacks and see if it helps. You'll know right away if it worked.

It might be just that easy...

 

[Ladd]

So the culprit is likely the torsion bar clip, which holds the torsion bar securely down against the upper fireback.. Over time, it bends upwards allowing the torsion bar to flop around a little often creating the symptoms you describe.

I'll triple check it, but it looked pretty flat the first two times I looked at it. Can't see any harm in hitting it a few times though.

Any advantage to taking the clip off and reversing it? I'ld squirt some penetrating oil on the bolt first.

 

[defiant3]

No need for all that. If tapping the clip doesn't do it, next most likely possibility might be the upper fireback. Once it gets warped enough it can get the damper to misbehave. The fix is to replace that assembly. Kind of kills the fly with the shotgun. BTW, is catalyst access through the back or through the firebox?

 

[Ladd]

No need for all that. If tapping the clip doesn't do it, next most likely possibility might be the upper fireback. Once it gets warped enough it can get the damper to misbehave. The fix is to replace that assembly. Kind of kills the fly with the shotgun. BTW, is catalyst access through the back or through the firebox?

Catalyst access is through the back; it is pre-through-the-inside. Is the upper fireback accessed through the inside or the outside?

 

[defiant3]

Start by removing the cover plate on the left (inside the stove) . it has 2 allen head screws holding it in. Then there are 4 7/16 head bolts 1 in each corner of the upper fireback/damper assy. It's sort of a pain getting to the upper ones, but not too bad. Spray liberally with PB blaster or penetrating oil of choice the day before. Big pain if they break.

 

[Ladd]

I may have solved the problem, mostly due to your advice.

Spending a minute behind the stove and opening and closing the damper while watching the action of the torsion rod moving under the holding clip, I was struck by the sharp angle the rod was when in contact with the clip (hence the 1-inch rub mark on the rod). Looking down I noticed that the rod was coming out from the holder down at the bottom!

I propped the damper halfway open with a piece of wood and a bit of refractory foam (left over from replacing the broken long piece that is immediately under the removable cat cover) and with a few wacks with the chisel and hammer, the holder was bent down. The rod no longer comes out and the damper opens, closes and locks as it used to.

Yay!

Photo of bracket below (lower right of photo). Oil stain is Kroil penetrating oil sprayed on damper tab bolt in case I decided to remove it the next day.

Of course, with the good, comes the bad. I accidentally knocked the 2" square piece of refractory foam down the air channel on the left side of the refractory box. Doh!

I can't imagine that this will improve the performance of the stove, so I guess I need to get it out of there. Short of taking off the entire back, any other ways of getting down in there?

 

[defiant3]

Well I wouldn't sweat it, but folx have tackled stuff like this by duct taping garden hose to the end of a shop-vac hose somehow, and feeding it carefully down the side. Fortunately the 2140 has that steel cover on the refractoryso it's not quite as delicate as later models, but b e careful! Leaving that piece of material;l in there isn't the end of the world, but damaging the refractory sure is.

 

[defiant3]

Good work, btw.

 

[Ladd]

Well I wouldn't sweat it, but folx have tackled stuff like this by duct taping garden hose to the end of a shop-vac hose somehow, and feeding it carefully down the side. Fortunately the 2140 has that steel cover on the refractoryso it's not quite as delicate as later models, but b e careful! Leaving that piece of material;l in there isn't the end of the world, but damaging the refractory sure is.

A hose at the end of a shop vac hose; an interesting idea. Can't say I had thought of that one. Might be worth a try, given all the cleaning of cement and re-gasketing that would need to be done in taking the back off.

 

[Ladd]

I spent some time this morning attempting to get the foam piece out with no luck. First tried with a four foot section of garden hose taped to the hose of a large shop vac. Then tried some larger tubing, about 1.24 in diameter and no luck there either. As the metal shield on top of the refractory foam does NOT cover the sides of the box, I was very careful and don't think I caused any damage to the side. I'm going to leave the piece of foam at the bottom of the cavity.

I don't think there is any air flow being blocked, is there?