What Are Fireplace Flue Dampers?
A fireplace flue damper (or chimney damper) is a small device that sits inside or on top of the flue and serves to regulate airflow. While several different types of flue dampers exist, the most modern version is the rooftop flue damper, which doubles as a chimney cap and secures to your flue tile that sticks up above your chimney crown. A stainless steel cable is then dropped down your chimney and connects to a bracket on either the right or left-side wall of your firebox. This allows you to open and close the damper from inside.
Opening this metal plate reduces the pull of upward drafts that become too strong, which can limit your control over the fire, cause excessive fuel consumption, and carry heat out the chimney instead of into your home. You must open the flue damper whenever you start a fire so the smoke can exit through the chimney.
Rooftop dampers, when closed, also help the chimney cap protect against rain, pests, and animals that might otherwise enter your flue.
Is a Fireplace Flue Damper Right for Me?
If you are missing a flue damper or your current flue damper is rusted down inside your fireplace, a new rooftop damper is a great choice. We find that chimneys that do not have a chimney cap tend to have issues with water getting inside the chimney and then damaging the interior, along with rusting out the original chimney flue damper.
Fireplace flue dampers — especially older “throat” dampers — require regular cleaning to prevent them from becoming clogged, which could restrict airflow to a dangerous level. If you have a flue damper, you still need a chimney cap to keep out rainwater.