Parts of a Fireplace & Chimney Explained (with Diagram)

Fireplaces come in different designs, shapes, sizes, and types. They are made up of numerous components both seen and unseen. Whether your model is operated by gas, by burning wood, or just for looks, it is helpful to understand the basic parts of a fireplace.

No matter how complex the parts may seem, most fireplace models share similar pieces and additional accessory options. For your unit to perform as expected, all of these pieces must be in proper working order. Developing an understanding of all the various components can help you diagnose potential problems and stay safe when you build a fire. You will also be better equipped to communicate with a fireplace specialist and discuss any problems with your unit.

While many believe that the fireplace and chimney are one and the same, they are actually separate pieces that work together to bring warmth to your home. The fireplace is made up of many parts including the hearth, firebox, mantel, and face. This is where you build your fire. Then, the chimney is the vent that safely exhausts heat from your home.

Read on to learn more about the different parts that make up the fireplace and chimney. We’ve also included some helpful photos and diagrams for a clear picture of what goes where.

Fortunately, a fireplace solves both of these potential issues. Fireplaces are traditionally made of stone, brick, metal, tile, or a combination. These are materials that are fire-proof and will direct smoke out the chimney.

The most important mechanical purpose of a fireplace is to produce a draft. Your fireplace creates a column of heated gas inside of the chimney. As the air rises, more heated air is pulled from the fire after it. This process results in a draft, or a balanced flow of hot gases and smoke, up and out of the fireplace’s chimney.

As far as heating goes, a traditional fireplace uses radiation to produce heat. This is when warm electromagnetic waves carry heat to cooler objects, warm them, and cause their molecules to speed up. In this case, the heat from the fireplace send out waves that hit people and objects in a particular room. This speeds up their molecules, causing them to warm.

When you first observe a fireplace, your eye is often typically drawn to the firebox where the physical flames exist. However, this component works directly with another important piece known as the hearth. Unless you have a zero-clearance fireplace, both gas fireplaces and traditional wood-burning fireplaces are generally outfitted with a protective hearth.

In masonry fireplaces, you’ll generally have a hearth that is constructed out of bricks extending from the fireplace. In this installation, the hearth can be either flat or raised. While raised hearths rest on a platform that is a couple of inches off the ground, flat hearths sit flush with the floor. A flat hearth offers much more space for additional furniture and is cheaper to construct than their raised counterparts.

On the other hand, for prefabricated models, the hearth is typically metal and includes a decorative cover. The cover may be a porcelain-coated liner, cement liner with a brick pattern, or any other type of decorative material.

Often referred to as a fireplace front or overlay, the surround is the outer component of the fireplace that “surrounds” the fireplace and visually ties it into the room – hence the name. They cover any gaps between the fireplace and the wall giving your fireplace a tidy appearance. Fireplace surrounds are mainly decorative accessories and are not always made out of fireproof material.

Both prefabricated fireplaces and traditional masonry fireplaces have a number of decorative options to help the surround fit with the rest of the décor in the room. Prefabricated models are outfitted with a metal weldment, or front, that may be covered up directly with metal, stone, or brick.

When finished with brick, the fireplace’s facing can make it especially difficult to determine the difference between a prefabricated and masonry model.

Atop the surround, or on the top of the face of an open fireplace, is where the mantel sits. It offers a shelf for decorative items can be placed and Christmas stockings can be hung. In some cases, the mantel helps to prevent the smoke from the fire from entering the surrounding area.

The mantel design can be a relatively simple shelf or feature elaborate designs that extend all the way to the ceiling. Mantels also come in a variety of materials such as wood, stone, concrete, and more. Whether you prefer a modern, classic, Colonial, or Victorian style mantel, chances are you’ll find one that matches your design preferences.

Moving to the inside of the fireplace, the firebox is the term used to describe the enclosed component where the fire is built and actually burns. This designation is used regardless of the type of fireplace you have. The firebox is usually square or rectangular in shape.

As far as gas fireplaces go, the firebox is just a combustion chamber where the fire ignites. It consists of a floor, sides, and the top is lined with ceramic or firebrick liner for enclosing the flames.

To put things into perspective, the hearth is at the base of the firebox and the front of the firebox is often called the opening where you’ll usually find fireplace doors. Whereas, at the top of the firebox you have the damper, smoke shelf, and smoke chamber.

Both gas and prefabricated wood-burning fireplaces have liners. Gas and ethanol fireplaces use either porcelain-coated reflective liners or ceramic liners. They not only protect the firebox from flames, but they also help to radiate heat back into your home. Also, they make the fire look lovely!

While masonry models tend to rely on firebrick to protect the fireplace, prefab fireplaces rely on an inner wrapper. This wrapper is typically hidden behind liners and is either a heavy gauge sheet metal or plate steel assembly/ This piece links the firebox together, giving it strength and shape.

Many fireplaces won’t have an ash pit. However, if you do have an ash pit, it can your fire-building life a bit easier. The ash pit usually has fire-resistant metal doors that are under your fireplace grate. When the fire is done, opening the doors will drop the ashes into a pit below. Many ash pits will hold a season’s worth of ashes. This means you don’t have to spend time and energy cleaning out your ashes each time you want to build a new fire.

Many fireplaces have glass doors on the front of the fireplace. While these look mostly decorative, they help keep the cold out when your fireplace is not in use. However, when the fireplace is in use, should these doors stay open or closed? The US Fire Administration (USFA) resolves this question for us. They recommend you always leave the glass doors open when you have a fire going. If you are worried about sparks flying out, many fireplaces have a chain curtain you can pull across the opening. Or, you can also add a freestanding fireplace guard in front of your fire.

Chase covers, or “top pans” are similar to chimney caps, however, as you can see there are a few differences. While a chimney cap covers a masonry chimney, a chase cover is used for the top of prefabricated chimneys. The chase cover shields the chimney opening and comes in a variety of materials such as aluminum, copper, stainless steel, and galvanized steel. Ideally, the cover will deflect rain and snow so moisture doesn’t enter your prefabricated chimney.

Due to their durability, copper and stainless steel tend to be the most popular options. Although, aluminum is also common since these come in more colors and are generally cheaper.

Dampers, sometimes called throat dampers, are in the “throat” of the chimney, just above the firebox. It is a valve or door that controls the draft in an open fireplace.

When not in use, the damper helps to seal off the fireplace so that drafts don’t enter through the chimney. However, while you’re using the fireplace, you want to make sure that the damper is open. This allows the smoke to exit out the flue.

Maintaining the damper is crucial to the safe operation of your fireplace. If your damper is broken, smoke cannot escape out of your home. Or, if the damper becomes stuck in the closed or open position, you may get drafts.

Nearly every type of fireplace uses a blower to circulate heated air from the fireplace itself throughout your home. While a lot of heat from the fireplace could escape out of the vent system, blowers and fans prevent this.

Although masonry fireplaces rarely have blowers, some still use fans. Older models usually used ductwork embedded into the stone or brick with outputs in the ceiling and intake ducts near the floor. Whereas, direct vent gas, prefab wood burning, electric, and vent-free gas fireplaces will typically use a rotary style blower.

The most traditional way to ignite a fireplace is by lighting the flames manually with a matchstick or long lighter. A match lit ignition system requires holding one of the aforementioned near the burner prior to opening the gas valve.

The valve controls the amount of gas you use, which changes the height of the fire. With this system, there are little to no moving parts so it is very low-maintenance. A match lit system is only available for indoor natural gas fireplaces. It does not have a standing pilot, and you won’t be able to use a remote control with this system.

A standing pilot, or safety pilot, is another way to manually ignite a fireplace. However, it is slightly more advanced than a match-lit ignition system. Instead of using a long lighter or match, you can ignite the flame by simply turning the control knob inside the fireplace.

A small flame is constantly lit, even when you are not using your fireplace. If the pilot light ever goes out, the flow of gas automatically shuts off to avoid gas leaks. Unlike match-lit ignition systems, a standing pilot works with both natural gas and propane.

The final type of ignition system is an electronic, or non-standing pilot, system. This option eliminates the hassle of manually lighting your fireplace with a match, lighter, or control knob. It is incredibly convenient and requires a battery-operated connection or power-line connection to function.

A battery-operated connection is usually cheaper than wiring your fireplace to an electrical system, at least up front. However, with a battery-operated system, you will need to keep replacing the batteries.

The electronic ignition system is much safer and is also easy to use. It has a flame-sensing pilot feature that activates whenever the fireplace is not in use. This means that if your system detects the absence of flame, it will shut off the gas flow or try to re-ignite the flames.