wood king stove

[birdseye view]

I have just installed a wood king wood burner that I rebuilt. There is an air control/damper on the top of the stove as well as the one in the ash door. The one on top is close to the opening for the stove pipe. Can anyone tell me the purpose of the one on top. How should it be used. All the wood stoves I have seen only had an air control on the bottom. Thanks

 

[begreen]

Can you move the upper control while looking down the flue pipe? I'm wondering if it is a flue bypass control.

 

[birdseye view]

 

[begreen]

Ah, ok, pictures help. That looks like a basic secondary combustion port. Open it up after startup, when the wood is outgassing strongly during the early burn. You can close it once the fire is in the coaling stage with little or no flame.