Lifestyle

6 Signs Your Chimney Needs Attention Before You Light the First Fire of the Season

By Erica Coleman · November 2, 2026

The first cold snap of the year can mean the first fire in months for a fireplace or wood stove. Fire safety groups say the chimney above it deserves a look first.

The National Fire Protection Association says chimneys and heating systems should be inspected and cleaned each year before they are fired up for the season. By the NFPA’s count, fires involving fireplaces or chimneys made up 6% of home heating equipment fires from 2020 to 2024, but caused nearly one-fifth of the direct property damage. Nearly half of all heating equipment fires happened from December through February.

The Chimney Safety Institute of America follows NFPA Standard 211, which says chimneys, fireplaces and vents shall be inspected at least once a year for soundness, freedom from deposits and correct clearances. The institute says that applies even to a chimney that rarely gets used, because animals may build nests in the flue or the chimney may deteriorate.

These are signs drawn from the CSIA, the NFPA, the U.S. Fire Administration and the Environmental Protection Agency that a chimney needs a professional’s attention.

Black or brown buildup inside. The residue that sticks to the inner walls of a chimney is called creosote, and the CSIA says creosote is highly combustible. It can be crusty and flaky, tar-like and sticky, or shiny and hardened. The institute recommends that masonry fireplaces be swept at 1/8 inch of sooty buildup, and sooner if any glaze is present.

A smoky smell that lingers. The CSIA says a fireplace odor, often worse in humid weather, comes from creosote deposits in the chimney. It says the real problem is air being drawn down the chimney because of pressure problems in the house.

Smoke that drifts into the room. A damper that is closed or not working right can mean a smoky room at best and a fire hazard at worst, according to the CSIA. It advises looking up into the fireplace with a flashlight to make sure the damper is fully open before lighting a fire.

Smoke pouring from the top of the chimney. The EPA suggests going outside after a fire has burned for 20 minutes and looking up at the chimney. If there is smoke, the agency says, the wood may be too wet, the fire may need more air, or the stove and chimney may need maintenance.

Nests or debris blocking the flue. The CSIA lists animal or bird nests, debris-clogged passageways and damaged flue liners among chimney problems that can let toxic gases into the house. Gas heating chimneys can be blocked by nests too, it says, so they also need annual inspections.

Clues of a past chimney fire. The CSIA says the majority of chimney fires go undetected. Signs a sweep looks for include cracked or collapsed flue tiles, a warped damper, a discolored or distorted rain cap, creosote flakes on the roof or ground, cracks in exterior masonry, and smoke escaping through mortar joints.

Carbon monoxide is the other concern. The CSIA says the elderly are more susceptible to its effects and that symptoms of low-level poisoning are easily mistaken for a cold, flu or exhaustion. The EPA recommends smoke and carbon monoxide detectors on every floor and outside each bedroom.

A few habits help between inspections. The EPA says to burn only dry, seasoned wood, and never garbage, plastics or pressure treated wood. The U.S. Fire Administration advises keeping anything that can burn at least 3 feet from heat sources, including fireplaces and wood stoves, and having chimneys cleaned and inspected by a professional each year.

This article is for general information. Have a qualified chimney professional inspect your chimney, and call 911 if you suspect a chimney fire. This article was produced with the assistance of AI and fact-checked against the sources cited by LightWave Reports.