Fireplace Flue vs Fireplace Damper: What’s the Difference?

Fireplace Flue Vs Damper

Do you know the difference between a flue and a damper? If you are like most people, you most likely don’t know the difference. That notwithstanding here is a breakdown of the chimney ventilation basics. Read on to learn the difference between the two, how to open fireplace flue, and much more.

What Is a Fireplace Flue?

If you have a wood-burning fire, your system will require a flue. Ideally, a flue is a duct through which smoke and other waste gases exit your home. Either the flue could be inside the chimney, or it could be a simple flue pipe. Notably, flues come in different sizes, and the one you get depends on the capacity of your fire system. Keep in mind that there are around six different types of flues, and it’s important to know which one your home has, especially when picking the ideal fireplace for your home. Here are the most popular flue types:

1. Brick Chimney

This is a classic flue and quite common. Rightfully so since they are suitable for most solid fuel appliances. You will have a chimney breast inside the room, or on the outside wall for this type of flue. Usually, this type of flue will have a minimum diameter of 175mm.

2. Pre-Fabricated

Similar to brick chimneys, pre-fabricated flues are suitable for most gas fires and gas stoves. Since they have a good depth, you can choose from a wide range of fires. However, you will notice that pre-fabricated flues are more common in older houses.

3. Balanced Flue

Unlike a conventional flue, the balanced flue vents directly through an outside wall. If you have a gas-condensing boiler, your balanced flue will have two tubes: one to let oxygen in and the other to let waste gases out.

Notably, obstructions could find their way into your flue, which in turn hinders the free flow of gases. For instance, small animals and debris from nearby trees could fall into the flue. A blocked flue will also mean a harder time starting the fire. To prevent such scenarios, you might consider getting a chimney cap.

What Is a Fireplace Damper?

In a nutshell, a fireplace damper is a device you can manually open or close, whose purpose is to let gases and other byproducts vent out of your home. When you are not using the fireplace, you can close the damper to prevent air from escaping. Typically, chimney dampers are at the base of your chimney, at the top of the chimney, or the base of your flue. Given the direct contact with heat, dampers need to be made from strong materials to withstand. They are typically made out of metal or ceramic. Besides letting gases out of the fireplace, an open damper also allows air from outside to keep the fire going.

By closing the damper when using the fireplace, the smoke and harmful gases will enter the room, which poses a serious health hazard. Similarly, keeping the damper open when the fireplace is not in use will only lead to air loss. There are three main types of dampers, as we have outlined below:

1. Throat Dampers

With a traditional damper, you can grab it from the lower part of your fireplace. For that reason, most people often confuse throat dampers for flues.

2. Top-Sealing Dampers

Top sealing dampers sit on top of the terra cotta flue.

3. Woodstove Dampers

A woodstove damper lets the exhaust out while adjusting the fresh air intake.

Regardless of the type of chimney damper you have, it’s important to ensure that it’s in good shape. Otherwise, it will not be as efficient. For instance, if your damper is rusted or broken, it might not open fully, limiting its functionality.

What Is the Difference Between a Fireplace Flue and Damper?

Understandably, the terminology around chimneys and fireplaces can get quite confusing. Therefore, you might not distinguish between fireplace flues and chimney dampers. Although the two work together, they also have important differences.

One notable difference is their location. While a damper will be just above the firebox, the flue is right at the center of the chimney. Additionally, the damper is the actual device that seals a chimney and controls airflow while the fireplace flue is the structure that the air and smoke pass through. Besides, you can manually open or close the damper, while that is not true for a flue.

How to Open a Fireplace Damper

Every time you want to light a fire, you need first to open the damper. Otherwise, the room will fill up with smoke. Therefore, it’s essential to understand how to open up a fireplace damper. The first step involves finding out if the damper is closed in the first place. You can do so by placing your hand into the fireplace. If you don’t feel any cold air, then your damper is closed. You can also check the controls. Alternatively, shine a flashlight up your chimney and see if you can see through to the sky.

If a knob controls your damper, you can turn it clockwise to open. In other cases, your chimney will have a top-mounted damper, it will have a chain to open and close it. You just have to take the chain off the hook and let it go. Since it is just a tube, you don’t need to learn how to open fireplace flue. All you have to do is ensure that it’s not clogged before lighting the fire.


Now that you know how to open up a fireplace dumper be keen to notice any difficulties. If you notice any, don’t light the fire until the problem is fixed.

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