Older Encore secondary air flap??

[Eman85]

Vermont Castings Encore Model 0028 in cleaning and regasketing I removed the cover over the secondary air flap. The flap is closed with the stove cold. I find conflicting info on this site when I do a search found one old post one says open cold one says open hot. I would like to know for sure.

 

[Defiant 3]

Should be OPEN when stove is cold. Not all the way open, the gate should rest at like the "2 o' clock" position roughly. Your probe should be replaced, and in fact they should really be replaced whenever the catalytic combustor is replaced.

 

[Eman85]

Thanks for the reply. I'll order a new thermostat coil for it.

 

[Eman85]

Exactly how does it control the burn? It appears to under the cat what does it control the air for?

 

[Defiant 3]

It gives the cat a bit of extra air while it's initially firing, then the gate closed as the probe heats up. I don't know why the cat needs this secondary air but I do know that as the probe wears it allows the gate to stay open longer and eventually may not close it at all. The cat then overfires. You likely won't be aware as the griddle temp may appear normal, but it can destroy the cat and possibly other expensive internal stuff.

Having it always closed may or may NOT affect performance but I kinda feel like it's best not to second guess the engineering.

 

[Eman85]

Stove seems to be working fine, new cat heats up and I have a probe on it so I can see temps. I should have left the flap uncovered so I could see what it does if anything.

 

[Malarky112]

Stove seems to be working fine, new cat heats up and I have a probe on it so I can see temps. I should have left the flap uncovered so I could see what it does if anything.

Be sure to keep an eye on it. I replaced secondary air probe on my encore and I believe it’s the same part. I am having an issue that sometimes (not always) when it gets hot, that cool will spin all the way around from 4 o’clock position and keep going to the 9 o’clock position, which in turn opens that cat air flap back up. This results in my stove cranking, even when it’s turned down.
I am on my second one after having the first part replaced under warranty.
I even had a buddy who works at a stove shop contact VC. They said that shouldn’t happen (no kidding) and make sure the nut is tight.
My replacement seemed to be working well until tonight out of the blue my stove starts getting hot while I have it turned down. Sure enough the price was doing it again. I think I’m going to leave it disconnected, the part is obviously not working like it should and it’s a real hazard if you ask me. I never had this issue with my original probe. I’ll attach a pic of the probe in the position where it opened it back up.

 

[Eman85]

My stove is really acting up which it didn't do in the past. When I bought the stove years ago it was simple, STT was high enough flip the damper wait and then turn the primary air down. No cat temp probe and no problems. If you turned the primary down too far sometimes it would puff when the gases ignited. When the cat wore out I burned it like a conventional stove and never flipped the damper and it worked fine. This time when replacing gaskets and stove pipe I decided to replace the cat and go back to using the cat. Now if I load the stove it will over fire when I close the damper to the point of it sounding like a chimney fire inside the stove.
I'm using the stove without engaging the cat and it does fine and will give me 8+ hour burns like it always has. I'll just have to pay attention and clean the chimney more often. I don't know if the new cat is more active than my old cats or what the deal is. I know I could have saved $200+ and not replaced the cat, secondary coil and installed a temp probe.

 

[Eman85]

New secondary coil installed, cold the secondary air flap is open about 1/4" My wife had the stove lit when I came in and without the cat engaged the secondary was closed already. Still don't understand the engineering of it. I left the cover off so I could observe it to be sure it doesn't do what @Malarky112 stove is doing. So far with the cat engaged and at 900 it stayed closed.

 

[Eman85]

Started off at 4 O'Clock and all was good, cat got to 1400 and if it gets any hotter I'd bet the secondary air will open.

 

[Eman85]

No doubt these secondary thermostats are a problem. After burning for a few days then letting the stove go cold because it warmed up outside the coil didn't relax and the flap remains closed.

 

[fbelec]

probably from the corrosion. or the screw is to tight. i run a defiant 1 with the automatic air control spring and it's the original spring. from what the woman i bought the house from said she didn't use the stove for 6 years before i bought this house and i have owned it 22 years. i know that she didn't use it because she told me to clean the chimneys before i use the stove or the fireplace and the clay liners looked new they were so clean. so my vote is with the screw and the corrosion. if the spring is bad you might be able to adjust it and put the cover back over it so it feels the stove heat.

 

[Eman85]

The secondary air wouldn't reopen after it got hot because the S bend in the rod was binding on the coil. The bend in the coil is too short and the tip of the rod would catch it. I trimmed the tip of the rod and it's free now.
No corrosion on anything, it was all disassembled and cleaned before new probe/coil was installed. As far as the old probe/coil the end of the probe was burned off about 1" from use. this whole secondary air thing is a mystery and evidently many have had problems with it over the years.