How Often and How to Clean a Chimney

Determining how frequently and when to clean a chimney depends on several factors. The degree of soot buildup in flue channels is influenced by the type and quality of fuel burned; for instance, using a wood or coal boiler versus a gas boiler yields different results

However, a golden rule applies universally: chimney inspection and, if necessary, cleaning should occur at least once a year, typically at the end of the heating season. Experts agree that cleaning at the end of the heating season is preferable to doing so at the start, as it’s easier to remove deposits then.

Furthermore, cleaning both the boiler and chimney at the season’s end prevents soot and resin buildup from remaining within the system for months, combining with moisture to create aggressive compounds that can damage surfaces.

Chimneys in gas boilers generally require less maintenance, while those connected to older wood or coal boilers and stoves are more prone to dirt accumulation. Resin, particularly difficult to clean, forms due to low flue gas temperatures. Another concern is damp wood, so purchasing well-seasoned fuel and storing it in a well-ventilated area sheltered from rain and snow is advised, as it can alleviate this issue. The same applies to coal.

Inadequate combustion often necessitates chimney cleaning during the heating season, even if it was thoroughly cleaned beforehand. These periodic cleanings involve removing larger deposits of soot with a wire brush to ensure unobstructed flue gas flow. While major cleanings are typically left to professionals, minor maintenance tasks, especially for smaller chimneys, can be tackled independently.

For safety reasons, use caution when cleaning with a wire brush, preferably through the chimney’s access door rather than from the roof. Attempting a chimney burn—where leftover resin deposits are incinerated—should strictly be avoided without proper precautions, as it carries a risk of damaging the chimney or, worse, causing a fire.

However, if chimney issues persist despite previous cleaning, consult a professional. Accumulated resin and soot could indicate combustion problems stemming from fuel quality, boiler or stove malfunctions, or improper settings, particularly with modern devices like gas or pellet boilers and stoves. In such cases, seeking advice from the device manufacturer or an authorized technician is advisable.

Foto: Pixabay