Q: How Often Should I Have My Chimney Cleaned?
A: The answer to this question depends on what fuel you use. It also depends on the age of your home, the condition of your chimney, and the weather (mild winters cause more problems than cold ones!). Generally, if you use wood, it’s good to have the chimney cleaned at least every 6-12 months (more often if you burn two or more cords of wood, or if you burn green wood). Oil flues -especially if there’s a ventilation problem- need to be inspected and cleaned each year in order to avoid chimney blockage. Problems in the furnace or boiler can cause highly sooty conditions in the chimney.
Even though natural gas is a clean-burning fuel, today’s high-efficiency gas furnaces create special problems. The fumes they produce are cooler and produce higher levels of water vapor than previous models, and this vapor in turn produces more water condensation.
These vapors also contain chlorides from house-supplied combustion air which combine to form hydrochloric acid. The acid-water condensates from these latest natural gas furnaces cause more flue deterioration than previous models. It’s important to check the chimneys that vent these systems at least once each year.