How Do Fireplace Dampers Work

Fireplace Damper: Understanding How They Work and Why They're Essential for Optimal Efficiency

How do fireplace dampers work? Do all chimneys have dampers and how can you tell if it’s open or closed? Understanding the components of your fireplace and how they operate will help you get the most out of your fires and keep your space warm all winter long. Here are just a few frequently asked questions about how to operate fireplace dampers.


How do fireplace dampers work?

If you take a peek inside of your fireplace and look up, you should see something resembling metal flaps. These flaps work as doors, to release oxygen that helps get your fire started. This oxygen, however, is provided from outside air, meaning that you might be letting cold air in, or some of your warm heat out.

Is the damper the same as the flue?

While the damper is connected to the flue, it is not the same thing as the flue. If you think of the dampers as the doors to open or close off outside air, the flue is the passageway through which that air travels. The flue also draws the exhaust gas produced by the fire and releases it outside. Interestingly enough, in older times the flue referred to the chimney itself, but this is no longer the case.


How do I open the damper?

There are three different types of dampers. First, you should figure out what type of damper you have in your fireplace.

Poker Damper

Open arch-shaped (like a banana) poker dampers by lifting up on the handle. Typically, the arch of the handle runs through a metal slit and you’ll find at least a couple of notches on the arch. These notches allow you to mount the arch on the slit in several positions to provide varying degrees of airflow. To close it, you simply release the handle from the notch. 

Rotary Damper

A rotary damper is screw-shaped and requires a twist of the handle to the left or right to open. Occasionally, these types of openers can become rusted or stuck in place. Oiling them or applying some WD-40 can help release them again for use. 

Double Pivot

The double pivot open has a long handle with notches at the head. Moving the handle up and over to the right or left, into a new notch, will open or close it.


How can I tell if the damper is open or closed?

Looking at the metal door or flap inside your fireplace, you should be able to tell if it is flattened. This would indicate a closed position. An open damper will have some kind of space or gap, allowing for airflow. If you have a poker or double pivot damper, you can also check the notches. On a rotary damper, turning your damper counterclockwise should ensure it is closed.


Do all chimneys have dampers?

While all fireplaces that produce exhaust should have a damper, not all of them do. If your fireplace doesn’t have a damper, there are a few things you can do. Top dampers are available. This is an ideal solution for warmer months when you have no plans of using your fireplace.


When should you close the damper?

Fireplaces with gas logs require the damper to remain open at all times. But if you’re using a wood-burning fireplace, there’s definitely an optimal setting for your damper. Keeping the damper partially closed while you have a fire going will help keep your fire burning longer while allowing just enough room for the exhaust to escape. It’s important to remember that the damper should remain at least partially open while you have a fire burning. Not doing so is a fire hazard. You can learn more about safely operating your fireplace from the Chimney Safety Institute of America.


Can you leave the damper open overnight?

It’s good to leave your fireplace damper open until all of the embers have burned away, but leaving it open overnight will reduce the energy efficiency of your room. It might also let in cold air from outside.

Knowing how fireplace dampers work will help you keep your space warm. And best of all, it will keep your fires burning safely and efficiently.

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.

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