A chimney smells when creosote, moisture or debris sits in the flue and warm, humid air pulls the odor down into the house. Connecticut summers and early falls make it worse, and the smell often intensifies when the air conditioner or a bathroom fan runs.
Common Causes
- Creosote deposits that give off a campfire or tar smell
- Water entering through a missing cap or cracked crown
- Animal nests or a dead animal in the flue
- Mold or mildew growing in damp masonry
- Downdraft from a pressure imbalance in the house
Fixes That Work
- Professional sweep and deodorizing treatment
- Chimney cap to keep out water and animals
- Waterproofing and crown repair
- Sealing the damper or installing a top-sealing damper
- Opening a window slightly when exhaust fans run
What Does Not Work
Candles, sprays and baking soda treat symptoms only. The source has to be removed, which usually requires cleaning and a camera inspection.
When to Call
If the odor is strong, comes with water stains or gets worse after rain, schedule an inspection right away.
Where the Smell Comes From
Warm air rises in winter but sinks in summer. When air conditioning cools the house, air can move down the chimney and carry odors into rooms. Humidity activates creosote odor. A clean, capped and sealed chimney reduces the problem.
Odor Source Checklist
- Open the damper and look for debris
- Check the cap for damage
- Look for stains showing water entry
- Listen for animals at dusk
Frequently Asked Questions
Can odors be dangerous
Strong odors can indicate carbon monoxide risk or dead animals.
Do deodorizers work
Chimney deodorizers help after cleaning but do not remove the source.
How do I stop smells in summer
Install a top sealing damper and keep the chimney clean.
Local Help and Related Reading
Our crews handle chimney sweeps in Norwalk, chimney repair in Fairfield, chimney caps in New Canaan and chimney cleaning in Greenwich. Browse every town on our service areas page or our services.
More to read: How to Choose a Chimney Sweep in Connecticut, Chimney Flashing Repair in Connecticut: Signs, Causes and Cost, Chimney Relining in Connecticut: Options, Costs and Timing.
For wider guidance, see the EPA Burn Wise program, the U.S. Department of Energy and CT DEEP.
