How To Open Fireplace Flue
A warm and cozy fire can be just the thing you need on cold winter days.
However, before you can light your fireplace, you need to ensure that the damper is open.
If the damper isn’t opened, the flue will be blocked, allowing smoke to enter your home instead of moving up through the chimney and out into the air.
Once the fire is out, you’ll also need to close the damper again, so the heat remains in your room.
You’ll learn more about what a flue does in a fireplace, including what the flue and damper do, and how to open the damper to prevent combustion gasses from entering your room.
What Does A Flue Do?
A flue is the vertical passage within your chimney. It’s necessary as it moves waste gas from your fireplace back out in the air.
This makes warm gasses move upwards and out of the chimney’s flue cap.
The exhaust will move past your fireplace damper, into the flue, and out into the air.
Are A Flue And A Damper The Same Thing?
The flue is the channel inside your chimney that draws smoke and gases from your fireplace back out into the air.
The damper is different. This is a metal panel located at the top or bottom of the flue.
It works like a valve to control the air within the flue, but it also stops debris and water from affecting the fireplace.
Dampers should always be open when using your fireplace. If they aren’t smoke can start to accumulate and enter your room.
It should also stay open until all of the embers are extinguished, as there’s still a risk of carbon monoxide and smoke entering your home.
Some people mistake opening and closing the flue with the damper. Technically, the flue is always open, unless the flow of air is blocked with a damper.
Not all fireplaces have a damper, as you might find some older ones which work fine without one.
However, it’s always a good idea to install one if your fireplace doesn’t have one.
Dampers can help you look after your fireplace, control the air within the flue, and let you seal off the chimney when it’s not needed.
Different Kinds Of Chimney Dampers
Dampers are available in two main kinds. Older fireplaces usually have throat dampers.
These are usually made from cast iron or steel and are found slightly above the fireplace. They have a plate with hinges that resemble a trap door
Top-mount dampers, also known as top-sealing dampers, are found inside the chimney or on top of it.
These look like chimney caps, but they have other purposes.
Top-mount chimney dampers will keep precipitation, debris, and small animals out of the chimney, but they also have a gasket that acts as an airtight seal.
This works well to stop air from leaking and prevents smoke from escaping into your home.
How To Know If Your Fireplace Damper Is Open
Figuring out if a fireplace damper is open will depend on the type of damper in your chimney.
You'll know if it is closed, as smoke will start to fill your home.
This is very dangerous, so it’s important to check that your damper is open before you start a fire.
There are three ways you can check if your fireplace damper is open or closed.
Feel For A Draft
If your damper is open, air will circulate through the flue and enter the fireplace.
If you put your hand into the fireplace, you should notice a cold draft.
However, this isn’t the best method to use if you have a top-mount damper, as there will already be cold air inside the chimney.
The best and simplest way to check if your damper is open is to use your eyes.
Position your head into your fireplace and look into the chimney. You can try using a flashlight if it’s too dark.
If your chimney has a throat damper, you’ll either be unable to see past it when it's closed, or able to see into the flue when it is open.
If you prefer, you can double-check by reaching upwards and touching the damper to see if it is closed.
If your damper is a top-mount model, you should notice the light at the top, as long as you check during the day.
If the damper is closed, there will be no light, just darkness.
Looking At The Damper Control
You can look at your damper controls to see if it is closed or not. Check your rod, handle, or cable’s position to see whether the damper is open or closed.
How To Open A Throat Damper
Look inside the flue to find the throat damper control.
This might be a screw-like handle that you turn to open and close, or a lever that you operate by moving forward or to the side.
It might also use a latch handle that you lift and push to open, then place into a latch to leave the damper open.
If you want to close it again, lift the handle again, then pull it towards you.
Keep in mind that some dampers use the opposite movement, so you’ll need to pull forward to open it and backward to close it.
How To Open A Top-Mounted Damper
Top-mounted dampers are controlled with a chain. If these are closed, the chain will be attached to your fireplace’s wall surround.
The damper is opened by taking the chain off its hook and letting it hang. If you want to close the damper again, just place the chain back on its hook.
The Bottom Line
Some people confuse a fireplace’s flue and damper for each other, but they are different things.
The flue is the tall passage within your chimney. This remains open unless you have a damper installed.
A damper can be opened to let smoke and gasses from your fireplace back out into the air, or closed so that heat doesn’t escape from your room.
Throat dampers can be opened or closed by operating their handle, latch, or lever.
Top-mounted dampers can be opened by simply unhooking a chain, then rehooking if you want to close it again.
If you want to light a fire, always make sure that your damper is open. Don’t close it again until all of your fire’s embers have been extinguished.
This will prevent smoke and carbon monoxide from entering your home.