FIREPLACE DAMPER: THE ULTIMATE GUIDE TO SAFE & EFFICIENT USE

 

Your fireplace damper is a critical component that must be operated correctly to protect your family and your property. We’ll answer your questions and help you understand how to operate your fireplace damper safely.

WHAT IS A FIREPLACE DAMPER?

Chimney Sweep Masonry Diagram from Ash Away

A fireplace damper is designed into your fireplace to open or close the chimney flue. Think of a chimney damper as a small mini door that, when closed, stops any airflow through the firebox. When opened, the damper establishes the draft, and smoke is pulled up the chimney.

An effective damper can be compared to your front door. Left open, you’ll lose lots of heat. Do some of those long ‘goodbyes’ with friends and family at the front door come to mind?

Since warm air rises, heat will not be lost up the chimney without a fire in the fireplace. Conversely, because cold air is heavier, closing the damper when the fireplace is not in use will prevent cold air from spilling down the chimney and cooling the living room.

WHY IS A FIREPLACE DAMPER IMPORTANT FOR SAFETY AND EFFICIENCY

The fireplace damper is crucial for a couple of reasons.

  1. When a fire is going, the damper MUST be fully opened. If not completely open, we guarantee that smoke will quickly return to the room, creating a potentially hazardous situation. Therefore, always check to make sure the chimney damper is completely open before starting a fire.
  2. You should close the chimney damper when the fire and coals are out and the fireplace is not in use. This will prevent the house’s heated air from being pulled through the fireplace and lost up the chimney and will also stop cold air from coming back into the house.

Each year, retail fireplace dealers get phone calls from customers asking why their furnace cycles on or why the living room cools down when they have a fire. Nine times out of ten, the fire has gone out, and the damper has been left open.

With an 8” or 10” hole through your living room ceiling and depending on the weather conditions, you can almost picture that column of warm air being drawn out of the house or cold air spilling into the living room!

HOW TO USE A FIREPLACE DAMPER: A STEP-BY-STEP GUIDE

Correctly using a fireplace damper is easy.

  1. The time to fully open the damper is before you strike a match to the newspaper and kindling. If you’re unsure if it’s open, bend down and look inside the fireplace at the top of the firebox. You may need a flashlight, but once you know what you’re looking for, it will be evident if the chimney damper is open.
  2. Keep it fully open until all embers and coals have burned out. This will allow smoke and other combustion by-products to exit the fireplace safely and up the chimney.
  3. Close the damper after the fire, and the coals have completely burned out. After some practice, you’ll get a sense of how many logs to add in the evening and how long burning coals and embers will last before retiring for the night. Then, by fully closing the damper, you can prevent the loss of warm air from your home up the chimney when the fireplace is not in use. And again, if you’re not sure if the damper is fully closed, bend over and look at the inside top of the firebox.

DIFFERENT TYPES OF FIREPLACE DAMPERS

There is a diverse range of damper styles, each suited to different fireplaces. Understanding these options will help you to make informed decisions about your fireplace.

Cast Iron or Steel Dampers: If yours is a masonry fireplace, your chimney damper will likely be one of these two types. The first is made of cast iron or heavy steel. It often spans the full width at the top of the firebox.

This type of fireplace damper is usually opened and closed with a worm gear mechanism. A key will normally be seen from the front of the fireplace. By continually turning this key to the left, the damper will open. Conversely, turning the key clockwise to the right, the damper will close.

Lever-Operated Dampers: The second type of masonry fireplace damper is operated by a simple lever that’s normally mounted on the right inside wall of the fireplace. By pulling the lever toward you, the damper opens. By pushing it away from you, the damper is closed.

ZC Pivoting Dampers: The damper on some factory-built zero clearance (ZC) fireplaces differs from those mentioned above. In many ZC fireplaces, the damper is a simple metal plate that pivots open when a lever is pushed or pulled.

Incidentally, the efficiencies for this type of equipment are not rated. Still, they are very low compared to an EPA-certified model. The doors on ZC fireplaces are not gasketed or sealed, and the control over the burn rate is not precise.

Lock-Top Damper: The cap on the top of the chimney is replaced with a spring-loaded damper or lid, so to speak. The chimney is effectively sealed at its top, not at the top of the firebox. These lock-top sealing dampers come in different sizes and shapes, but their function is the same as that of other dampers: They seal up the chimney.

Lock-top dampers are designed to prevent cold outside air from spilling down the chimney or transferring warm, heated air from the house up the chimney.

How does a lock-top damper work? A heavy-duty cable is installed down the chimney and through or around the old damper. Often, a damaged damper is completely removed. This cable is mounted to a handle and bolted to the inside wall of the fireplace. The cable is pulled to spring the damper up or to open it. Or, it can be pushed to seal it back up.

The installation of this device can be tricky and is best left to a professional.

EPA-Certified Fireplaces: Generally speaking, if your fireplace is an EPA-certified unit, it will be designed with gasketed, ceramic glass doors; it will not have a damper. EPA-certified fireplaces and stoves are designed to be burned with the doors closed tight.

FIREPLACE DAMPER VS. AIR CONTROL

EPA-certified fireplaces have primary air controls that allow a specific air volume into the firebox for efficient combustion. In essence, the chimney is always “open” and cannot be closed off with a damper. However, the sealed, gasketed doors prevent air leakage and smoke from entering the room. That’s why it’s always essential to keep the doors closed whether you have a fire going on or not.

The primary air control on an EPA unit controls the burn rate. More air to the fire means more heat in the room and shorter burn times for the wood. Reducing the amount of combustion air results in longer burn times and less heat.

Make sure to tell apart the primary air control ‘ON’ on an EPA-certified fireplace from the damper on older fireplaces. They function differently.

  • The primary air control on an EPA-certified fireplace controls the burn rate of the fire. It determines how hot or lively the flames are and how much heat is produced.
  • On the other hand, a damper opens and closes the chimney flue to control the draft.

TROUBLESHOOTING FIREPLACE DAMPER ISSUES

If you’re noticing a damper that does not seal tightly, is cracked, warped, or is missing altogether, it’s probably time to call in the ‘A’ team.  WE LOVE FIRE®, as well as national fireplace and safety codes, recommends that chimneys be cleaned and inspected annually by a certified chimney professional.  They will inspect your entire fireplace system, including the damper and chimney.  So, if there’s a problem with a damaged or missing damper, it will be obvious to the inspector, and options to repair or replace will be discussed.

Another frequently asked question is, “What can be done with my fireplace that is missing the damper?”   Many years of heating up to high temperatures and cooling down will take a toll on any damper. They can warp, twist, rust, and begin to deteriorate. A “lock-top sealing damper” device might be the answer in cases like these.

FIREPLACE DAMPER SAFETY TIPS:

  • Remember, never close a fireplace damper while a fire is burning.  Smoke will quickly back up and fill the room, posing severe health risks and potential property damage.  Always ensure the damper is completely open before starting a fire to avoid these dangers.
  • But can I close my damper just a little so I lose less heat on my chimney?  No, never do this.  The damper to your fireplace must be completely open when a fire is burning.  If you close the damper even slightly, you risk allowing smoke and other dangerous contaminants from the combustion process into the house.  And remember, the most dangerous by-product of combustion is carbon monoxide.  Always keep the damper fully open until the fire and all coals have entirely burned out.

What about gas logs?

There are circumstances where a damper must be left open all the time.  Decorative gas logs in fireplaces are very popular.

Does the damper need to be opened for safety?  The answer depends on local codes in your area and the type of gas logs.

Vented Gas Logs: Many gas log sets are vented, meaning the damper must be wide open to operate safely. Since the pilot light runs continuously and there’s a risk of forgetting to open the damper before the gas logs are ignited, a small C-clamp keeps the damper slightly ajar.

Unvented Gas Logs: Other gas logs are unvented and can be operated with the damper closed.  Unvented logs may add a little heat to the room but are also likely to add considerable moisture.  Some unvented equipment may cause odors in the home, too.  Because of the moisture and odors, many dealers and manufacturers recommend operating unvented gas logs for only a few hours.

SAFETY TIPS!

  • Before you go the unvented gas log route, be sure to check your local codes.  Some areas do not allow them.
  • One last fireplace safety tip: if possible, try to visually inspect the damper and check to see if it’s sealing tight.  Can it be easily opened and closed?  It may be a bit stiff, but it should not take leaning into it with both hands and using all your weight to make it move!

LET’S SUMMARIZE THE FIREPLACE DAMPER GUIDE:

Before you start a wood fire, always fully open the damper.

Keep the damper fully open until all the embers are completely burned out.

  • If you have a vented gas log set in your fireplace, turn off the flames before closing the damper as far as the safety C-clamp allows.
  • If yours is an unvented gas log, the damper can be fully closed, but again, be aware of the moisture and odors concerns with unvented equipment.
  • If there is no fire in your fireplace, keeping the damper closed is always good practice to prevent air infiltration and heat from being lost up the chimney.
  • Using a damper is a simple concept.  However, not using it correctly or forgetting about it can have serious consequences, putting your loved ones and property at risk.

WE LOVE FIRE® is your trusted partner for everything about your hearth and home.  We have a network of experts, all independent, family-owned, local businesses across the USA and Canada that offer:

  • Premium and affordable wood-burning and gas fireplaces, stoves, and inserts.
  • Assistance in planning and designing the hearth portion of your building or remodeling project.
  • Personalized guidance on selecting and operating your equipment safely and efficiently.
  • Meeting customer expectations by providing a thorough understanding of hearth products.
  • Professional installation and maintenance services.

Do you want to create and enjoy a warm, inviting space for your loved ones?  We’re here to help you make unforgettable memories.  Please visit our website to find a dealer near you.

 

Below is a list of fireplace and grill stores that service ()

Auburn, AL

Top Hat Chimney Sweeps
1280 Financial Ct.
Auburn, AL 36830

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Elk Grove, CA

Custom Fireside Shops
9097 Elk Grove Blvd.
Elk Grove, CA 95624

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Sacramento, CA

Custom Fireside Shops
5455 Auburn Blvd.
Sacramento, CA 95841

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Durango, CO

Durango Outdoor Living
140 Rock Point Drive
Durango, CO 81301

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Durango, CO

Four Corner Stoves & Spas
3001 Main Avenue
Durango, CO 81301

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Grand Junction, CO

Stove Depot and Chimney Works
330 North Ave.
Grand Junction, CO 81501

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New London, CT

Family Hearth and Patio LLC
571 Broad Street
New London, CT 06320

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Ridgefield, CT

Yankee Doodle, Inc.
71 Ethan Allen Highway
Ridgefield, CT 06877

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Dover, DE

Byler's Stove Shoppe Inc.
1368b Rose Valley School Rd.
Dover, DE 19904

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Destin, FL

Doodlebuggers Service Network
36054 Emerald Coast Parkway
Destin, FL 32541

Bettendorf, IA

Fireplaces Plus, Inc.
1745 State Street
Bettendorf, IA 52722

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Post Falls, ID

Quality Stoves & Home Furnishings
569 N Syringa St
Post Falls, ID 83854

Rockford, IL

Advanced Chimney Systems, Inc.
3486 Lonergan Drive
Rockford, IL 61109

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Wauconda, IL

Grass Roots Energy, Inc.
28751 N Route 12
Wauconda, IL 60084

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Evansville, IN

Firemaster, Inc.
5300 E Morgan Avenue
Evansville, IN 47715

Jeffersonville, IN

Olde Towne Chimney & Fireplace Sales
915 Nachand Ln
Jeffersonville, IN 47130

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Overland Park, KS

Kansas City Fireplace Center
10470 Metcalf Avenue
Overland Park, KS 66212

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Erlanger, KY

TateBuilder's Supply, LLC
3511 Dixie Highway
Erlanger, KY 41018

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Littleton, MA

Woodstove, Fireplace and Patio Shop, Inc.
60 White Street
Littleton, MA 01460

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Seekonk, MA

The Fireplace Showcase
775 Fall River Ave
Seekonk, MA 02771

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Sudbury, MA

Woodstove, Fireplace and Patio Shop, Inc.
348 Boston Post Road
Sudbury, MA 01776

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Duluth, MN

Duluth Stove & Fireplace
2431 W Superior Street
Duluth, MN 55806

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Minneapolis, MN

Woodland Stoves & Fireplaces
2901 Franklin Ave. South
Minneapolis, MN 55406

Oakdale, MN

Energy Savers of Minnesota
6298 Highway 36 Blvd N
Oakdale, MN 55128

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Rochester, MN

Brekke Fireplace Shoppe
1904 S. Broadway
Rochester, MN 55904

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Walker, MN

Wilkening Fireplace Company
9608 State 371 NW
Walker, MN 56484

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Fargo, ND

Home Heating, Plumbing & A/C Inc.
701 28th Street South
Fargo, ND 58103

Omaha, NE

Fireplace By Design
13913 R Plaza
Omaha, NE 68137

Epping, NH

The Stove Shoppe
285, Calef Highway Rte. 125
Epping, NH 03042

Windham, NH

The Stove Shoppe
25 Indian Rock Road
Windham, NH 03087

Hamilton, NJ

Bowden's Fireside - Hearth & Home
1731 Nottingham Way
Hamilton, NJ 08619

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Voorhees, NJ

Rettinger Fireplace Systems, Inc.
476 Centennial Blvd
Voorhees, NJ 08043

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St. Henry, OH

Buschur's Refrigeration, Inc.
541 N Eastern Avenue
St. Henry, OH 45883

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Media, PA

Chimney Cricket
101 State Road
Media, PA 19063

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Rapid City, SD

Hebron Brick Company
1543 Deadwood Ave
Rapid City, SD 57709

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Sioux Falls, SD

Hebron Brick Company
2211 W. 50th Street
Sioux Falls, SD 57105-6525

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Vermillion, SD

Kalin's Indoor Comfort Inc.
710 Cottage Avenue
Vermillion, SD 57069

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Manassas, VA

Winston's Chimney Service
11301 Industrial Road
Manassas, VA 20109

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Barre, VT

Chimney Sweep Fireplace Shop
1284 US Rte, 302 Ste 10
Barre, VT 05641-2317

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Bennington, VT

Friends of The Sun
126 Hicks Avenue
Bennington, VT 05201

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Manchester, VT

Friends of The Sun
159 Depot Street
Manchester, VT 05255

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Shelburne, VT

Chimney Sweep Fireplace Shop
3113 Shelburne Road
Shelburne, VT 05482

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White River Jnct, VT

Home Comfort of New England
1255 VA Cut Off Road
White River Jnct, VT 05001

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Burlington, WI

Burlington Fireplace & Heating LLC
857 Milwaukee Ave.
Burlington, WI 53105

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Madison, WI

Top Hat
5117 Verona Rd
Madison, WI 53711

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Morgantown, WV

Rustic By Design
709 Beechurst Ave. Suite 15
Morgantown, WV 26505

Laramie, WY

High Country Stoves & Fireplaces
860 N. 3rd Street
Laramie, WY 82072


For more information, contact your local fireplace and grill store.

5 Responses

  1. Tips to Keep Your Home Energy Efficient This Winter
    […] fireplace damper is a mechanism that keeps your fireplace sealed when not in use. Keeping your damper open during […]
  2. Amy Saunders
    OMG! I never realize that closing our chimney damper can help maintain the warmth of our indoor space as well. As winter approaches, I plan to spend more time just relaxing in front of my fireplace. I'll keep this tip in mind so I'll be as comfortable as possible.
  3. How to burn less firewood and reduce emissions - Going green time
    […] flue damper should be kept open when the fire is burning. This helps the fire burn hot, reduces emissions and […]
  4. M Cooper
    Not all gas logs have a pilot light. Some a manually lit by turning the gas key slightly and then lighting the logs with a standard long-stem type lighter - then turning the gas key to increase or decrease the flames. Since I have no pilot light, when I turn off the gas (using the key) and the fire goes out, I can close my damper since nothing is burning (no pilot light) to require the damper to remain open.
    • Joseph Bodden
      You make a good point that's true. However, it's older technology you're describing and many people are quite uncomfortable with this type of equipment. The vast majority of customers want the convienience of a remote control or a wall switch to turn the gas log set on & off.
  5. Max
    Just had a gas log set installed last week in an existing fireplace and they installed the damper block full open. Is that truly necessary? I have 2 other fireplaces with gas logs and they have simple c claps to keep them from totally closing keep it w 5-10% open always. Fireplace guy says it is required by law/manuf (realfyre) to have blocked fully open.. I can’t find anything to this and internet searches seem convoluted.. given the 32 yr old house it seems unnecessary to permanently block full open your flue in MN.. should I conseder swapping to a c claps? they also completely closed my air intake in the fireplace saying the fireplace should draw from inside the house least resistance..which also doesn’t make sense to me since it is air and there is no blockage on the built in cold air duct in the fireplace.. my other fireplaces draw from these vents fine.. thoughts?
    • Joseph Bodden
      Max, thank you for your question. Gas log manufacturers include a clamp that is to be installed on the damper. This is a safety requirement. If someone not familiar with the gas logs would turn them on and not realize the damper must be fully open during operation, the results could be very serious. Local building codes can override those requirements from the manufacturer. Some state the damper must be blocked fully open. The installer must follow the manufacturer's requirements as well as any local requirements from the Building Inspector's office. There would be a significant liability issue if this procedure is not followed and something would happen. Hope this helps.

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