If you look at the anatomy of a fireplace, note that the damper is found at the top of the firebox. It’s the metal (normally cast iron) that you lift up and down with the lever found in the top front of the firebox.The purpose of the damper is to open the fireplace up to the outside to let smoke, gases and debris go up the chimney flue and out into the atmosphere. It is closed when the fireplace is not in use to keep the inside air from escaping up the chimney flue to the outside and to keep air from coming down the flue and coming into the house.





What Can Go Wrong with Dampers

While dampers are made of hearty material like cast iron, they can warp from the heat and can also jump the track they ride on when used a lot over time. Both of these repairs often require replacement. When that happens, we recommend a different type of damper that can actually save as much as 10% on your energy bills! It’s called a top-sealing damper.

The Advantages of a Top-Sealing Damper

The top-sealing damper actually sits on top of the flue and, when shut tight, seals the flue off with a rubber-tight fit. When released, the damper springs up to let the air needed to start a great fire in and all the waste materials out. The spring also acts like a screen, keeping critters out and flying embers in, which are all great; but how does this damper save on energy costs?


The part of your chimney from the top of the firebox to the top of the flue on a normal throat damper is heated and cooled by the weather. That means it’s freezing when you are trying to heat your home and hot when you are cooling your home. When sealed at the top, the air in the flue is the same as the air in your home and doesn’t fight against the heat or air conditioner.