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Should fireplace damper be open or closed?

Author

Emily Ross

Published Jan 24, 2026

The fireplace damper should always be in the open position whenever you have a fire in the fireplace. Never close the damper or leave the fireplace unattended while there is a fire in the fireplace. This is not only a fire hazard, it can also cause deadly carbon monoxide poisoning.

When should I close the damper on my fireplace?

You should close the damper on your fireplace once the fire and embers have all burned out. This prevents warm air in your house from escaping out the chimney. You should open the damper before lighting a fire and close it once the fire is done burning.

Is the damper supposed to be open or closed?

You need to open the damper when you start a fire to allow for proper airflow and let the smoke out. A closed damper can restrict airflow and become a safety issue since smoke would fill your house.

Can you leave damper open overnight?

Leave the damper open overnight. Yes, you will lose some heat up the flue, but you will save the occupants of the home from poisoning by colorless, odorless carbon monoxide. In the morning, stir the embers and check them for any hot spots.

What happens if you leave fireplace damper open?

By leaving the damper open, heat is lost. Essentially, warm air is pulled through a large hole in your living room ceiling. It's called a chimney!

33 related questions found

Should fireplace damper be open in summer?

Even if you have a chimney cap, it is a good idea to keep the damper closed in the summer. Chimney caps can become damaged creating a pathway for rainwater or pests to get into your chimney. Closing the damper will ensure that they can't get into your home through the fireplace.

Should damper be open or closed in winter?

In most homes, dampers going to the upstairs are open in the summer and closed in the winter. By closing the dampers to the upstairs in the winter, it allows for the heat to rise naturally after first being introduced into the lower levels of the home.

How do I get more heat from my fireplace?

Fortunately, there are several things homeowners can do to maximize fireplace heating efficiency:

  1. Install a Glass Fireplace Door. Installing a fireplace door is an effective and inexpensive solution to get more heat out of your fireplace. ...
  2. Use a Fireback. ...
  3. Upgrade Your Fireplace. ...
  4. Use the Damper to Turn Up the Heat.

What is the difference between a damper and a flue?

A damper is located in the flue of your chimney. The flue is where the smoke escapes when the fire is going. Dampers are placed inside of the flue to help control ventilation. Your damper should have a chain or handle that you can access in order to open and close it.

Does damper need to be open for gas fireplace?

Because gas-log fires produce copious amounts of carbon monoxide, they have to vent outside in a fail-safe manner. That's why there is, or should be, a keep-open device attached to the damper in gas-log fireplaces.

Which way does fireplace damper open?

You should turn the knob clockwise, as far as it can go, or push the rod all the way up to open the damper. If there is a metal chain in or besides your fireplace, it means that your chimney has a top-mounted damper. If the chain is tightly attached to a hook, the damper is closed.

How do you know if your fireplace damper is open?

Lean in under your chimney just outside of your wood burning stove. You should find a metal device just within the chimney or flue opening. The damper is open if you can see through the damper up to your chimney. If you only see a metal plate, the damper is in a closed position.

How do you know if the flue is open?

Feeling the breeze is another method you can use to know whether you have an open or closed flue. Locate your hand inside the fireplace and wait to notice if you can feel the air flowing. When the flue is open, air will flow down the chimney.

Should damper be open or closed with gas logs?

If you're burning wood, keep it fully open until all the burning embers are completely burned out. If it's a gas log set, turn off the flames before the closing the damper as far as possible. If there is no fire, always keep the damper closed to prevent air infiltration and heat from being lost up the chimney.

Should flue be fully open?

The damper should always be fully open before lighting a fire and when the fireplace is in use. Close it when it's not it use. Operating the fireplace with the damper partially closed will not generate more heat. Instead, blocking the passage through the flue will result in smoke entering the home.

How do you close a fireplace damper?

To open or close the damper, lift the handle and push or pull to move the damper to the desired position. Replace the handle when the damper is in place. Rotary dampers. As the name implies, rotary damper work on a rotating system, with long, screw-like rods that move the damper.

What is the lever on the side of my fireplace?

in your home are turned off when burning your fire. Also, some wood burning fireplaces have a lever to open or close the outside air vent to the fireplace. If your fireplace has this lever (usually located on the left inside panel) make sure the outside air vent is in the open (or up) position.

Should I close the glass doors on my fireplace?

The doors should always be fully open or fully closed. Glass doors should be fully open when starting a fire and when the fire is burning strongly. The glass doors should be closed as the fire dies down to minimize the amount of room air going up the fireplace chimney.

What type of fireplace gives the most heat?

In this regard, the gas fireplace clearly comes out on top.

Does a fireplace actually heat a room?

Fireplaces won't be able to heat a room as well as a wood stove is able to, but you'll still feel warmth sitting nearer to an open fire. Wood burning fireplaces aren't known for their ability to generate large amounts of heat for a room.

How do I increase the airflow in a room?

Homeowners that want to get more air in the individual room have probably already checked if the filters are dirty:

  1. If you want to increase airflow to one room, the first thing to do is to check if the air filters are clean.
  2. If you want to increase airflow, you usually have to install larger vents.

Should I close the damper on my wood stove?

You don't want to leave your wood stove damper fully open, though, because then the heated air will continue to escape, and your room won't get warm. By closing the damper, it will reduce the oxygen levels in the chimney, and you'll have a longer fire. According to Northeastern Chimney, this also creates a downdraft.