Yes, gas fireplaces are one potential cause of carbon monoxide poisoning. While there are many potential sources of such exposure, including certain appliances and devices, motor vehicles and wood stoves, gas fireplaces are a common culprit.

What happens if you don’t open the flue on a gas fireplace?

Our research shows that the flue on a gas fireplace should remain open during use or when the pilot light is lit. If the flue is closed in either instance, you risk a greater chance of carbon monoxide poisoning or a spark induced structure fire due to a buildup of toxins emitted by propane or natural gas burners.

What happens if flue is closed?

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. The damper should be kept open until all embers are finished burning to prevent smoke from escaping into the home.

Can gas fires make you ill?

Health effects

While exposure to low levels of natural gas is not harmful, long-term exposure can affect your health. Burning natural gas produces nitrogen oxide, carbon monoxide, and methane. These chemicals can trigger respiratory problems, depression, and decrease the quality of your health.

Do gas fireplaces give off fumes?

Ventless gas fireplaces may produce a faint gas smell during use, but any strong rotten egg gas smells associated with any form of gas fireplace should be considered as a gas leak and you should leave the house immediately and get professional advice.

What happens if fireplace damper is closed?

A closed throat damper will cause smoke to fill your house immediately when you start a fire. If you have a chimney with a closed top-mount damper It might take a few minutes for smoke to start filling the house, but you will eventually notice that there isn’t enough airflow.

Should you close the flue on a 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. Why is the damper so important?

Can gas logs cause carbon monoxide poisoning?

Just like real burning logs, both types of gas logs produce carbon monoxide — a toxic gas that can be lethal — when they burn. Venting and proper use of a gas fireplace can help keep CO at a safe level.

Do gas fireplaces create carbon monoxide?

Gas fireplaces are safe. But as with all gas appliances, they do produce carbon monoxide. If something goes wrong, carbon monoxide put the home’s occupants at risk. It’s not always easy to tell when theres a carbon monoxide leak.

Can gas fireplace cause headaches?

The smell of burning gas can cause sensitivity, headaches, and other issues in some people. This can especially be the case with vent-free gas logs. These types of logs don’t have a chimney or vent to remove the fumes produced by the fire, so the smell is typically stronger.

Should I close the damper on my gas fireplace?

Those gases contain carbon monoxide. Therefore, while it’s great to save energy by closing off the damper inside a fireplace, be sure to do so in a safe manner. Do not close a fireplace damper until the fire is completely out.

Do you need to open chimney for gas fireplace?

You need to leave your chimney’s damper partially open to vent the carbon monoxide that the gas fire produces, so much of the heat generated by a vented gas log set goes up the chimney.

Is a damper and flue the same thing?

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.

Should fireplace damper be open or closed?


A fireplace damper should always be kept open while the fire is burning. Furthermore, keep the damper open until all the embers are completely out; since smoke and dangerous carbon monoxide can enter the house. Once the ember bed is entirely out, close the damper.

How do you block a flue on a gas fire?

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Do gas fireplaces have dampers?

Traditional wood or gas fireplaces have one of two types of dampers. Throat dampers are installed at the base of the chimney, over the firebox — the main chamber where the fire burns. They’re usually opened by a handle, a crank or a chain located inside the fireplace.

Does a gas fireplace have a flu?

Do Gas Fireplaces Need A Flue? Natural vent gas fireplaces may not have a flue but will use the existing chimney flue to vent waste air from a home. Direct vent gas fireplaces will need a flue that vents air directly out of a home, and ventless gas fireplaces won’t need any form of flue.

How can I tell if my fireplace is safe to use?

5 Easy Steps to Make Sure Your Fireplace Is Safe

  1. #1 Examine the Firebox. Look for any cracks, gaps, or signs of wear in the lining of the firebox (the interior of the fireplace). …
  2. #2 Look for Telltale Smoke Stains. …
  3. #3 Make Sure Your Grate Is the Right Size. …
  4. #4 Check the Chimney. …
  5. #5 Double-Check Your Fire Extinguisher.