If there is a metal chain in or besides your fireplace it means that your chimney has a top mounted damper.
Fireplace damper handle which way is open.
A flue damper should be opened all of the way when opening a stove door to add further fuel to the fire to help prevent any smoke from pouring out of the stove and into the room.
A handle beside or just inside the fireplace operates the damper.
Modern fireplaces often have a handle installed above or inside the opening.
Damper controls are usually located near the top of the firebox.
If your fireplace has a knob you ll twist the knob to open the damper.
Worse yet if you have a gas fireplace burned gas can escape the fireplace and create the conditions for carbon monoxide poisoning.
If the chain is tightly attached to a hook the damper is closed.
A fireplace damper should always be open all of the way when starting a fire and usually always open throughout the length of the fire.
Some handles push in and pull out others turn clockwise or counter clockwise and some slide.
The method of opening and closing the flue depends on the type of fireplace and how it was constructed and installed in the room.
If you start a fire before opening the throat damper smoke will flow out of the fireplace instead of going up the chimney.
These dampers are open by lifting the handle up pushing the damper upwards and pinning the damper in the upward position by setting one of the notches on the handle onto the mounted ratchet on the frame of the fireplace.
To close it you simply lift the handle up again pull the damper shut and set the handle back into position on the ratchet.
To open it take the chain off the hook and let it go.
You turn the handle to a vertical position to open the flue damper and back to a horizontal position to close it.
Move the lever to open or close the damper.