Skip Navigation

What Causes Strange Chimney Smells?

What Causes Strange Chimney Smells? champion chimneys

Have you ever noticed a strange, unpleasant smell coming from your fireplace?

Have you ever noticed a strange, unpleasant smell coming from your fireplace? Chimney odors become more common during the summertime when the moisture inside a chimney heats up on hot and humid days. Bad chimney smells are often the result of some sort of blockage in your chimney. This blockage can be caused by many factors and can be resolved by having your chimney professionally cleaned. Here are some common causes of bad smells in your chimney.

Creosote Can Cause Chimney Smells

Creosote build-up inside a chimney is relatively common and can have a strong, acrid smell similar to asphalt or tar. Even a tiny amount can have a strong odor and, depending on your fireplace, can be smelled throughout the home. Smelling creosote is usually the first sign of a bigger issue. Creosote build-up can add extra stress to your chimney flue, which serves as a layer to protect the inside of the chimney. Excess creosote can make existing problems much worse as this substance can block and mix to create an even more toxic substance.


If there is water in your chimney, it can lead to an unpleasant musty smell.   The best way to eliminate moisture in your chimney is to install a chimney cap.  Without a cap, rainwater can quickly accumulate in your chimney. In addition, water can cause the chimney damper to rust and fail to function correctly.  If the moisture mixes with the creosote in the chimney, it can harm the chimney lining, resulting in expensive chimney repairs.

Negative Air Pressure

One of the main reasons odors enter the home through a fireplace is the negative air pressure in the house. This problem occurs most frequently during the summer, after improvements have been made, or installing new additions to the home. Negative air pressure occurs when there is slightly less air inside the house than outside of it, resulting in the air going down the chimney rather than up it. You can solve this by opening a few windows to even out the air pressure. For a more long term solution, make sure to have the fire damper closed when the fireplace isn’t in use.

Debris in the Chimney

Branches, sticks, leaves, and other debris can easily fall into your chimney and create a blockage, especially if you do not have a chimney cap. When debris begins to accumulate in your chimney system and remains there for too long, it can form a dangerous chimney clog and also can cause an odor as it decays in your chimney.

Call the Experts at Champion Chimneys for Chimney Cleaning Today!

Champion Chimneys, Inc. is a fully licensed, bonded, and insured chimney service company that has served customers in Baltimore County, Howard County, and Anne Arundel County, Maryland since 2001. Our team is trained and certified by Certified Chimney Professionals, Inc. (CCP, Inc.). Courteous service is our trademark, and our crews arrive on time in uniform, driving fully equipped trucks. We specialize in all aspects of your chimney system. Whether you need chimney and flue cleaning service or a full chimney rebuild or inspection, contact us at 443-Chimney today and let us fix all your chimney problems. Also, follow us on Facebook, Twitter, LinkedIn, and Pinterest.

This entry was posted on Friday, August 6th, 2021 at 11:11 am. Both comments and pings are currently closed.