VC Older Encore 0028 Secondary Air Control??

[TheElementalCashew]

That is the primary air control

That is actually the internal side of the primary air control.
It has a coil as well that closes the primary air door a bit as the stove heats up.
He is talking about the secondary air control, different part.

Ah I see. Good catch on that, and sorry for the misdirection.

 

[Eman85]

I've never gotten any definitive answer on secondary air control of my stove. I've emailed VC, I've gone through Amazon and they refereed the message to VC and both attempts get me an email and a case # and all they say is contact a dealer. I've called dealers in a few different states and no answer. My local dealer attempted to help, took the case # but didn't have any more info than I had. I've even been referred to a stove repair but he didn't have any more info. No one had any clue or answer about the coil going past 6 o'clock and reopening the secondary shutter.
What I find interesting is it has happened to me twice so far that I have seen. Both times I found the shutter reopened by the spring going to the other side the cat temps were dropping with the shutter reopened. Last night the cat was at 1500+ and the shutter had opened and I did nothing and the cat temp was dropping.
I would love to find the correct info about this control, it's designed operation and what position it should be in at certain temps.

 

[DGL]

I might do as you say and just disable and keep the shutter closed. I am getting tired of the anxiety of watching it and concern that the coil will open the shutter when the cat is at 1600 and it overfire. I still have my old probe that I can install to plug the hole.
Tell me what different technique you've used in running the stove? Does the secondary being open when cold really make any difference in any operation of the stove?
It sounds like there were a lot of people that had problems with the secondary on these stoves. I searched and didn't really find much about the secondary on an Encore.

OK, here are the results of my experiments on the secondary air flap mechanism on an older model 0028 Defiant Encore. The secondary air probe setup description in the maintenance manual is exactly correct. Adjust the hole on the bimetallic strip to 4:00 o’clock from the mounting bar. Flapper will be slightly open (1/4 inch gap) when the stove is cold. As the stove heats up, the bimetallic strip expands and drops the flapper closed. When the catalytic chamber starts reaching 1200-1300 degF, the bimetallic strip continues to expand and gradually pulls the flapper back open. The effect is to introduce fresh air to the catalyst which dilutes the combustion air and cools down the catalytic chamber. The flapper mechanism will then cycle as necessary to maintain the catalyst chamber temperature by introducing as much fresh air as is necessary to compensate for whatever is going on in the main firebox.
I’ve had a camera monitoring both the catalytic chamber and the secondary air flap position for several burn cycles which confirms this operation. So, several conclusions:
1) adjust the secondary probe per the maintenance manual
2) replace any worn gaskets that can allow unmetered air into the stove (my ash drop gaskets were allowing firebox air to flood the catalyst causing rapid overheating [1600+ degF] even while the stove surface and pipe were relatively cool
3) do NOT block the secondary air, it is necessary to maintain safe catalyst temperatures!!