Top-Sealing Damper

The damper unit is fastened to the top of the flue tile. A spring holds the lid open. To close it, you pull the cable down and hook it to the bracket in the firebox, which pulls the lid tight against its gasket. To open it, you release the cable and the spring lifts the lid. Because the seal is at the top, the whole flue is closed off from outside air when the damper is shut.

Compared with an old throat damper, a top-sealing damper usually seals much more tightly. It also keeps rain, cold air, and outdoor smells out of the flue when the fireplace isn’t in use.

• Your throat damper is rusted, warped, stuck, or broken
• You feel a cold draft from the fireplace even with the damper closed
• The damper won’t close all the way or won’t stay closed
• The fireplace smells musty or smoky in hot or humid weather
• Rain gets into the firebox
• You don’t have a chimney cap and want one combined with a damper
• A liner was installed and the old damper had to be removed

Learn more about the original style of damper on our fireplace damper page.

1. Inspect and measure. We inspect the chimney, check the top flue tile for cracks or damage, and measure the flue so the damper fits correctly. If the chimney needs sweeping, we do that first.

2. Choose the right model. Top-sealing dampers come in different sizes and styles, including models with a built-in cap and screen. We pick one that fits your flue and chimney top.

3. Install. The damper is secured to the flue tile, the cable is run down the flue, and the handle bracket is mounted inside the firebox where it’s easy to reach.

4. Deal with the old throat damper. If the old damper is stuck or broken, we may secure it in the open position or remove it so it doesn’t block the flue.

5. Test. We open and close the damper several times to make sure it seals and opens fully, and show you how to use it.

A fireplace with a poorly sealing damper is like an open window. A top-sealing damper helps keep conditioned air in the house and keeps rain and animals out of the flue, which helps protect the flue liner and smoke chamber.

One safety rule matters more than anything else: the damper must be fully open before you light a fire, and it must stay open until the fire is completely out and the ashes are cold. Closing a damper on smoldering embers can push smoke and carbon monoxide into the house. If you’re ever unsure, leave it open and call us.