badlegdave wrote:I asked barnstablestove about this vent just above the oval exhause outlet and they said to keep it closed.
When and how is this check damper used?
Like a barometric damper it will check or reduce high draft. It was a way to better control the fire during high draft conditions, especially in a stove that was not very well sealed in the ash door area. Because it will remain open if the draft condition changes to low draft it can be very dangerous under those conditions being prone to leak carbon monoxide into the house. It's just too potentially dangerous to use. The barometric damper will automatically close under low draft conditions and open with high draft providing the chimney draft is capable of it. Much safer and more uniform draft.