How To Open A Fireplace Flue

An adequately operated fireplace can make a difference not only in the health and safety of those living in your home but it also helps keep energy bills low. Before you light a fire, you'll want to know how to open the fireplace flue. We have thoroughly looked into this topic and have found a good answer to this question.

A fireplace flue that has a damper installed will typically have a knob, lever, or chain and hook control. Here are some ways to open a flue by damper type:

  • Turn a knob damper control to the right
  • The lever inside a fireplace should be raised
  • Release a hanging chain control from the hook

Though these are some of the common ways to open a flue, not all dampers are alike. We'll discuss how to operate different dampers and whether the damper is the same as the flue. Keep reading as we cover what you can do if your damper won't open and when you should keep it closed.

Wood burning stove, with blazing log fire - CHIMNEY FLUE - FIREPLACE FLUE - How To Open A Fireplace Flue

Is A Damper The Same As A Flue?


The flue of the chimney is the part of the chimney that reaches up to the sky from the fireplace or firebox. The damper is located inside the flue, usually at the base of the throat or up near the top of the chimney opening. It may also be on the chimney in the form of a cap.

It is made of metal or another fire-resistant material, and its controls are located on the outside or just inside the fireplace mouth. The damper is a vent-like or cap-like structure meant to control the airflow in the flue from the outside to the inside of the home.

Read more about dampers and flues in this article: Fireplace Flue vs. Fireplace Damper: What Homeowners need to know

Can You Have A Chimney Flue With No Damper?

If your chimney is an older style open fireplace, it may not have a damper. If you have no controls outside of the fireplace or if you cannot find any controls just inside the mouth, there may not be a damper.

You can also tell if you have a damper by looking inside the chimney from the bottom. A bottom damper or throat damper is easily visible. Observing from the outside, a chimney cap or upper damper may be visible if it's open.

To learn about how to install a cap-style damper on your chimney, read this article: How To Install A Chimney Cap Without A Flue

How Can You Tell If A Damper Is Open Or Closed?

There are a few ways to tell if the damper in your chimney flue is open. One way is to see if you can feel a draft. In cooler months, place your hand in the mouth of the dormant chimney. If there is a draft, your damper may be open. 

The positions of the controls may also tell you if the damper is open. There are a wide variety of controls. Here is how to ensure some of the most common ones are in the open position. Do not experiment with the damper controls after lighting a fire or while a fire is burning.

Turn A Knob Damper Control To The Right

A knob damper control is a metal or cast-iron control that usually sticks out of the outside of the fireplace. Sometimes called poker dampers, they can be pushed or pulled or turned from right to left.

Knob dampers are usually in the open position when turned to the right. If the knob is one that you push or pull, pushing the damper will open it.

The Lever Inside A Fireplace Should Be Raised

Some fireplaces have a lever that is just inside the mouth of the firebox. This lever can have a circle (or any number of designs) at the end. The open position for this type of damper handle is raised. Some levers will go left to right. Dampers usually open by sliding the lever to the right.

Release A Hanging Chain Control From The Hook

Top dampers that are located near the top or on the outside of the chimney are controlled by a chain or levy-style control. These dampers are in the open position when released or pushed in. To close, pull the chain tight or pull it towards you.

What Are The Two Levers On The Fireplace?

If your fireplace has an air vent, it may have two levers. One will control the damper inside, while the other leads to the vent. The vent lever may be located on the left side of your fireplace. This lever should be in the upwards position for the vent to be open. This is also referred to as the outside air kit.

When Should You Close The Flue?

Image of square cast iron woodburner contemporary log wood burning stove fireplace mantle with orange fire flames burning and generating heat to warm up room instead of gas boiler central heating, modern multifuel stove wood burner stand chimney flue

The damper in your flue should be in the closed position when you are not using your fireplace. Open fireplaces can cause higher energy bills in both cooler and warmer months. An open flue without a fire is tantamount to a hole in the roof.

Should Damper Be Open Or Closed In Summer?

Some homeowners may have been advised to keep the damper open in the summer to encourage hot air to leave the home. According to many experts, this is a common but false assumption. In the summer months, it's important to keep the damper closed.

Dampers control thermal transfer and airflow. When the damper is open, it allows the smoke and debris from the fire to flow up and out of your home. A closed damper protects your home from animals, insects, leaves, and other debris. 

How Long Should You Leave The Flue Open After A Fire?

Never close the dampers while the embers are still glowing. When the ember bed is completely dormant or cold, then it's safe to close the flue. Even with the fire out, the damper control may still be hot to the touch. Exercise caution and use gloves or another tool to work the damper within hours of a fire.

Should The Flue Be Open Or Closed On A Gas Fireplace?

A gas fireplace is operated differently in the summer. Many fireplaces have a pilot light that burns year around.

If this is the case, never close your flue. If you decide to close the damper on a gas-operated fireplace, turn off the gas leading to the fireplace first. For more on gas fireplace flues, read this article: Should You Open the Flue on a Gas Fireplace?

Chimney Flue Won't Open—What To Do?

Mage of square cast iron woodburner contemporary log wood burning stove fireplace mantle with orange fire flames burning and generating heat to warm up room instead of gas boiler central heating, modern multifuel stove wood burner stand chimney flue stock

If your controls aren't working on your chimney damper, you want to first make sure they are still connected. In most fireplaces, you may be able to visually confirm that the pieces are still connected to the main pull of the damper. Consult a professional if you suspect you need an internal repair or replacement.

If the damper control won't move, rust could be the problem. You may be able to lubricate the hinges using a high-temperature lubricant. Consult a professional or the manufacturer of the lubricant for safety advice if the place where you want to apply the lubricant is close to the fire.

WD-40 mentions that you can use their lubricant to ensure that dampers stay in good condition. This Spray and Stay Gel lubricant performs well at high temperatures.

Click here to see it on Amazon.

Another culprit of an underperforming damper could be debris. Before starting a fire, always make sure the damper and controls are free of any foreign material. Soot buildup can also cause serious problems in the damper and flue. Remove creosote buildup regularly with a professional-grade chimney cleaner.

Click here to see the chimney cleaner on Amazon.

Click here to see a kit for cleaning your chimney on Amazon.

In Closing

A cast iron wood burner, with a flue alight giving out a warm glow in a living room

Now that you know how to open your fireplace flue and when it's best to leave it closed, keep it in good condition. Regular maintenance of this often overlooked part of your chimney will ensure that you can safely operate your fireplace for years to come.

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