Should I keep damper open or closed?

Author: Ora Boyle  |  Last update: Sunday, June 7, 2026

OPEN OR CLOSED? The damper should be kept closed when there is no fire or coals burning. Warm air from your home will not be lost up the chimney when the fireplace is not being used. Fully open the damper before your start a fire and keep it fully open until all embers and coals have burned out.

Should my damper be open or closed?

No you would never burn with the top mount damper closed. The damper should be fully open when burning. The top Mount damper is more to keep warm air in and cold air out when your not using the fireplace. You should be able to adjust the handle on the cable coming down the chimney so it closes all the way.

Does a fire burn hotter with the damper open or closed?

To create fires that produce more heat, open the damper as wide as possible when lighting a fire. A wide-open damper will increase the amount of air reaching the fire and improve combustion. As a result, the fire will burn hotter.

What happens when you close the damper?

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.

What does the lever on my fireplace do?

Also, some wood burning fireplaces have a lever to open or close the outside air vent to the fireplace. If your fireplace has this lever (usually located on the left inside panel) make sure the outside air vent is in the open (or up) position. The outside air kit is designed to provide additional air for combustion.

Chimneys Explained #16 - Chimney Dampers

Should I leave the fireplace damper open?

OPEN OR CLOSED? The damper should be kept closed when there is no fire or coals burning. Warm air from your home will not be lost up the chimney when the fireplace is not being used. Fully open the damper before your start a fire and keep it fully open until all embers and coals have burned out.

Should the damper lever be up or down on a fireplace?

Well, an open damper will allow the smoke from the fire along with other harmful combustion byproducts to escape through the chimney and be channeled safely to the outside. An open damper also invites outside air that assists in keeping the fire alive.

Are dampers normally open or closed?

Outside and exhaust dampers will generally revert to a normally-closed (NC) position, while return air dampers will revert to their normally-open (NO) position to ensure that any supply fans are not deprived of fresh air.

Does a damper help keep heat in?

After the fire burns out, the damper prevents the heated indoor air from escaping through the chimney. Without an operational chimney damper, the cold outside air will keep your home drafty and allow most of the heat generated in the fireplace to escape up the chimney increasing energy costs.

How to make a fireplace more efficient?

6 Tips to Make Your Fireplace Super-Efficient
  1. Burn Seasoned wood. Dry wood burns hotter and more efficiently than damp (unseasoned) wood. ...
  2. Chimney cleaning. ...
  3. Make sure your damper works correctly. ...
  4. Fix excess drafts inside your home. ...
  5. Convert an inefficient masonry fireplace.

Does closing the damper make the fire last longer?

However, partially closing the damper will reduce the oxygen level in the chimney. This will reduce the burn rate resulting in a longer fire. It will also create a downdraft that will force the heated air back into the fireplace, thus increasing its efficiency.

How to maximize heat from a fireplace?

Evenly distributing small pieces of wood throughout the fireplace will increase air circulation and speed up the burning of the wood. This creates a sustainable fire, but the wood burns faster. Placing large logs closer to the fireplace will keep the fire burning longer between refills, maximizing heat output per log.

Can you go to bed with embers in the fireplace?

No, you should never leave a fireplace burning overnight or unattended during the day.

What position should my damper be in?

HVAC Damper Open Or Closed In Summer/Winter

In most homes, dampers going to the upstairs are open in the summer and closed in the winter. By closing the dampers to the upstairs in the winter, it allows for the heat to rise naturally after first being introduced into the lower levels of the home.

How much heat is lost through an open chimney?

Warm air from your home naturally rises, and an open chimney provides an easy escape route. In fact, it's estimated that up to 30% of your home's heated air can be lost through an open chimney when the fire isn't in use.

What is the best damper setting?

You could row every workout at the recommended damper setting of 3-5, no matter how short or long the workout, and no matter the intensity. But if you like to experiment, you can try lower or higher drag factors and see how it affects your performance and feel.

Is it OK to leave damper open?

One common myth about chimneys is that leaving the damper open during the summer helps “air out” the chimney. However, the opposite of true. Leaving the damper open just fouls up the rest of your home, and does nothing to clean your chimney.

Does closing a damper increase heat?

By not creating an airtight seal, these dampers minimize the strain on the system. In summer, you can close the dampers downstairs so cooler air reaches upstairs rooms. But in winter, closing upstairs vents halfway allows heat to rise.

Should damper be open or closed in summer?

Closing your fireplace keeps your space cool.

If you keep your damper open, your air conditioner will have to work much harder to keep your space at a comfortable temperature. This can result in higher energy bills, and warm, humid air from outside can still make its way into your space.

When should you close your damper?

The damper is designed to be shut when the fireplace is not in use and can be easily opened when it is. It's common to forget to close the damper after a fire goes out, however, and that leaves a big hole through which heated or cooled air can escape the house.

What happens if damper is closed?

A closed throat damper will cause smoke to fill your house immediately when you start a fire. If you have a chimney with a closed top-mount damper It might take a few minutes for smoke to start filling the house, but you will eventually notice that there isn't enough airflow.

When should I close my HVAC damper?

In most houses, dampers on the upper level are opened in the summer and shut in the winter. In the winter, closing the dampers on your HVAC system to the upstairs allows for heat to rise naturally as it is distributed throughout the home.

How to properly use a fireplace damper?

First, ALWAYS ensure the damper is fully open BEFORE lighting the fireplace. Otherwise, you and your home may be covered in soot and ash if the chimney back puffs. The damper has notches, so you can partially close it (throttling), like a manual stick shift in a car.

How to close off a chimney permanently?

This can be done by installing a chimney cap or cowl at the top of the chimney. This method of blocking off a chimney is considered one of the most secure.

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