How to Use a Fireplace Damper

8/30/2021

Dampers are among the important components of chimney and fireplace systems and knowing how to use a fireplace damper is essential knowledge. Yet, how to use a fireplace damper is a common question--as is what is a damper? Less frequently, homeowners seek information on how to replace a fireplace damper. Answers to these questions and more follow.

What is a Damper?

A fireplace damper is a metal vent above the firebox that should always be fully opened before getting a fire started. There have been countless times when fires have been started without first opening the damper, and the resulting problem can become serious. Instead of going up the chimney to the out-of-doors, the toxic combustion gases vent into the home. Thus, it is crucial that anyone who operates a masonry fireplace knows to open the damper first in preparing to get warm next to a cozy blaze.

After fires have gone out and any remaining hot embers have sufficiently cooled to the point no smoke is visible in the firebox, then the damper should be closed. An open damper in a cold fireplace is like keeping a window open that sucks the heated air out of the home. Heating costs always spike when a damper is inadvertently left open.

How to Use a Fireplace Damper

Have you ever wondered, “Is my fireplace damper open or closed?” If so, you are not alone. It’s understandable for a person who is unfamiliar with dampers to need some instruction. Therefore, tips on how to open and close a fireplace damper follows, and the information covers a variety of styles of dampers:

• A common mechanism for opening and closing fireplace dampers is a rotary style that uses a knob or key. The knob or key should be turned clockwise all the way. To close it, turn the mechanism in the opposite direction.
• If a banana-shaped metal rod is used, you have a poker-styled damper. Push the rod up all the way to open the damper. Grooves will hold the damper in place. To close it, jimmy the rod out of the groove and back to the closed position.
• For top-mounted chimney dampers, a stainless-steel chain that is tightly affixed to a hook tells you that the damper is closed. Remove the chain from the hook, let it go, and the chain should spring up, which means the top-mounted damper is open. The chain should be in reach for closing the damper after the fire has gone cold.

If none of these descriptions apply to your damper and you don’t have any literature to refer to, a local professional chimney sweep can help.

If you have a prefabricated metal fireplace with a chimney pipe that came with it, the damper is used differently. For prefab fireplaces only, follow the steps below:

When starting the fire, open the damper all the way. After the fire has been burning for a few minutes, partially close the damper and check to see how the fire is affected. If it is still blazing hot, close the damper a bit more, to about two-thirds closed. This adjustment should reduce the intensity of the flames and increase heating efficiency.

When to Repair and How to Replace a Fireplace Damper

Dampers become damaged due to heat that causes warping, and rusting caused by a chimney leak is also common. Repair or damper replacement is needed if the damper won’t create a virtually airtight seal. To test your damper, close it and light a match. If air goes upward instead of into the room, the damper isn’t working properly. To repair or replace your fireplace damper, contact a trusted chimney services company.

Contact Clean Sweep Chimney Service

Clean Sweep Chimney Service is a family-owned chimney sweep company serving the St. Louis metro area since 1977. Our chimney sweeps are CSIA-certified and have the experience to provide all chimney services you may need and answer questions you may have. Call Clean Sweep Chimney Service at 636-477-9966 today for help understanding how to use a fireplace damper plus any of your chimney and fireplace needs.