What’s the Difference between Chimney Flues & Dampers?

There’s a lot of terminology surrounding fireplace and chimney systems, and often it’s hard to know the real difference between one component and another. Chimney flues and fireplaces dampers are both involved in drafting and regulating the air that helps fires burn, but there are key differences between the two.

chimney flue inspection, concord nh Chimney flues

Your chimney flue is the passageway inside your chimney that carries smoke out of and away from your home. When built correctly, the size of the flue is perfect to draft its connected fireplace.

Most flues in modern homes have flue liners (chimney liners) that run throughout the passageway and provide a smooth path for smoke. Liners can be made of stainless steel, clay tiles or a cast-in-place compound.

Fireplace dampers

Your fireplace damper is a plate device that sits above the firebox and opens and closes with the aid of a convenient handle or other apparatus. The function of the damper is to remain wide open during a fire to assist in drafting, and to be closed tightly when the fireplace isn’t being used.

Damaged or severely rusted dampers often neither open nor close completely. Partially open, a damper can cause smoke to back up into your home. Partially closed, a

damper will cause conditioned air inside your home to escape while letting in “unconditioned” outside air.

Common problems with chimney flues

Over the years, especially if the fireplace is used regularly, chimney liners can become compromised and allow acidic smoke and materials such as creosote to affect the interior masonry of the flue. This can result in brick damage, smoke damage, fire damage and dangerous gases seeping into living areas of the home.

Another serious issue with flues is creosote buildup. Creosote forms when fires are burned and is highly flammable. Most chimney fires in the U.S. each year are caused by creosote accumulating in chimney flues.

Along with creosote, outside debris can build up inside a flue and lead to smoke-drafting issues. Falling leaves and twigs from nearby trees as well as nests of small animals such as squirrels, rodents and birds can obstruct the flue.

Obstructions can be prevented by having a secure full-width chimney cap installed at the top of your chimney. Creosote and obstructions should be removed by a CSIA-certified chimney sweep, who has the equipment and training to do the job safely and correctly.

Common problems with fireplace dampers

fireplace damper, henniker nhRust, intense heat and old age all can cause your fireplace damper to no longer work properly. When a faulty damper sends smoke from the fireplace into your home, the biggest concern is not the smoke but rather the carbon monoxide that’s present in smoke. Carbon monoxide can’t be smelled or seen, but it is known to be potentially fatal to humans and animals.

The damper and all other components of your chimney and fireplace should be inspected once a year by a licensed chimney professional. This is the best way for you to keep on top of needed repairs and ensure that your entire chimney and fireplace system is working safely and efficiently.

A damaged damper can sometimes be repaired; in other cases, it’s best to replace an old damper with a new one that will serve you well for many years.

Black Moose Chimney & Stove of Antrim, NH, provides expert chimney flue and component repairs and replacements, annual chimney inspections and certified chimney sweeping. Get your questions answered or speak with a chimney professional at (603) 525-7905.


First Thing

John RantaJohn Ranta
17:01 22 Mar 24
They arrived on time, worked quickly and showed me the results. Prfessional throughout. jr
william greenwilliam green
23:21 14 Mar 24
Really helped me out can't say enough good things highly recommend!!!! The young man that came to my home was very knowledgeable and friendly great attitude all around answered all my questions and left me stress free best of all left no mess.🤙🏻🤙🏻
Michael Dell'OrtoMichael Dell'Orto
18:39 14 Mar 24
Jaime ConleyJaime Conley
17:13 14 Mar 24
Sarah GilliattSarah Gilliatt
01:46 13 Mar 24
A very thorough and careful job done! Thank you.
Larry CookLarry Cook
15:11 07 Mar 24
I wanted to give 5 stars but they are very busy which meant I had a good wait for both the inspection/cleaning, then for a quote on repairs and then for the repairs. Their prices seemed a little high to me but I have nothing to compare with as they were highly recommended by someone I trust and other companies had plenty of negatives reviews which kept me from getting additional quotes. I am happy with the work and they promptly returned to fix a mistake that had been made. Chris the inspector, Jennifer in the office, and Alex and his repair crew were all pleasant and took the time to answer all of my questions. Alex and his crew even took their shoes off (it was winter) before entering my house without even being asked! So if you are not in a rush and want to ensure you chimney is as safe as possible then I think you'll be happy with Black Moose.
Rebecca DeFuscoRebecca DeFusco
22:35 21 Feb 24
After a recent sweep of our chimney, it was discovered that our flue tiles were cracked. Black Moose techs were hard working, detail oriented and professional! Nice jobs guys! See you next year for my cleaning!
Karen CKaren C
14:52 14 Feb 24
Excellent I highly recommend Black Moose Chimney and Stove; Kelly and Liam are awesome, they did a great job. Extremely professional, arrived early, went through everything with a fine tooth comb ensuring pellet stove was thoroughly cleaned. They also were respectful of my home, conscientious and cleaned up after themselves. Made sure stove worked prior to leaving and told me to call promptly if anything came up afterward. Will definitely use them again.
Denise ClarkDenise Clark
16:32 31 Jan 24
We've had Black Moose clean our chimney for a number of years.But recently, we had an emergency situation at our home involving our chimney & oil furnace flue, which was caked full of soot from a malfunctioning furnace. They came & cleaned out both flues in no time, even going up on the roof with snow on it! They cleaned up after their work in the interior rooms where the oil furnace and the woodstove are located. Great work. Reasonable prices. Very nice people. You can't go wrong with Black Moose.
Joe GJoe G
18:30 24 Jan 24
Goods: The technicians know their business, very efficient in cleaning/inspection along with cleaning up after the 'dirty work'.Others: Communications could be more effective. Despite early coordination about scope of work (multiple flues within same chimney) the estimate provided did not reflect this and the final invoice was significantly more than the estimate provided.Quote for follow-on chimney relining was significantly more than that offered by other companies in the area (and far more than neighbors experienced for similar work accomplished by other companies)