How Open Should A Fireplace Flue Be. Our research shows that the flue on a gas fireplace should remain open during use or when the pilot light is lit. Once the flue is open, place.
An open damper also invites outside air that assists in keeping the fire alive. The damper should always be fully open before lighting a fire and when the fireplace is in use. The flue should only be open during the heating season when you need to expel combustion gases.
If the chain is tightly attached to a hook, the damper is closed.
Either seal up the fireplace and never use it (they have magnetic covers which will work nicely) or climb in there (clean out fireplace first, but it will still be quite sooty) and figure out how to open/close the flue yourself. There are a number of different things you can do to your new open fireplace, such as the below. For more information on glass doors for fireplaces, check out my article explaining whether wood burning fireplaces need. If a fire is lit and the damper is closed, the gas and debris have nowhere to go but into the house, causing a smoky situation.