Chimney Dampers and Cap Dampers in New Jersey
A damper opens the chimney when you use the fireplace and closes it when you do not. A damper that is rusted, warped or leaking lets heated and cooled air go up the flue.
What a damper does
The damper is a movable plate that opens and closes the flue. It needs to be fully open whenever there is a fire, so smoke can leave, and closed the rest of the time to cut off air movement between the house and the outdoors.
Two kinds
| Throat damper | Top-sealing (cap) damper | |
|---|---|---|
| Location | At the throat of the fireplace, just above the firebox | At the top of the chimney, on the flue |
| Operation | A handle or lever inside the fireplace | A cable or chain that runs down to the firebox |
| Seal | Metal on metal, which often leaks air as it ages | A gasket seals against the flue, which usually seals tighter |
| Other benefits | None beyond control of the flue | Also acts as a cap, keeping rain, debris and animals out |
| Things to know | Can rust, warp, or fail to open or close fully | The cable must stay in good order, and the lid has to be opened before every fire |
Signs of a damper problem
- A cold draft or a noticeable airflow from the fireplace
- Rust, flaking metal or a damper that is stuck
- A handle that does not move, or a plate that will not seat
- Water or debris coming down the flue
- Smoke coming into the room because the damper does not open fully
- Animals or noise from the chimney
Repair or replace
A damper that is stuck from soot can sometimes be freed during cleaning. If the plate is warped or the metal is rusted through, replacement is the fix. A top-sealing damper is a common upgrade when a throat damper no longer seals, since it replaces the cap and the damper in a single part.
If you use gas logs
With a gas log set, the damper may be required to stay open or partly open, according to the log manufacturer or local requirements. Check before closing it, and ask us if you are not sure what applies to your setup.
Always open the damper completely before lighting a fire.
Our work
Recent chimney dampers projects
Damper Cap Installation and Two Fireplace Cleanings in Wanaque, NJ
Wanaque, NJ · Damper cap installation, fireplace cleaning
A damper cap installed and two fireplaces cleaned in Wanaque.
Read the project
HeatShield, Cap Damper, Smoke Chamber and Fireplace Repair in North Bergen, NJ
North Bergen, NJ · HeatShield flue repair, cap damper, smoke chamber repair, fireplace crack repair
Several chimney and fireplace repairs completed together in North Bergen.
Read the projectRelated services
Chimney Caps
A top-sealing damper doubles as a cap.
Learn moreSmoke Chamber Parging
The smoke chamber sits right above the throat damper.
Learn moreChimney Sweep & Cleaning
Cleaning can free a damper stuck with soot.
Learn moreWe work throughout New Jersey. See our service areas, or browse all services.
Questions
Frequently asked questions
What is a cap damper?
It is a damper at the top of the chimney, operated by a cable from inside the fireplace. It seals the top of the flue and also works as a cap.
Should I close the damper when the fireplace is not in use?
Yes, when there is no fire and no embers or smoldering. Closing it limits air moving between the house and outside. If you use gas logs, check what the manufacturer or local rules require first.
Why is there a draft coming down my chimney?
An open damper, or one that no longer seals, is the usual cause. A top-sealing damper is often a good fix.
Can I replace a damper myself?
The damper has to fit and operate properly. Installing it correctly is why many homeowners ask for help.
Ready to have your chimney looked at?
Call us, or send a scheduling request. We will contact you to confirm a time. Your appointment is not confirmed until we do.