What is one sign of chimney blockage?

One sign of chimney blockage is the presence of excess smoke in the home. When a chimney is obstructed, it prevents the proper venting of smoke and gases produced by the combustion process. This blockage can lead to smoke backing up into the living space rather than being expelled outside, creating dangerous conditions for inhabitants, including exposure to carbon monoxide. Homeowners should be vigilant for this sign, as it indicates a serious issue that can not only affect air quality but also pose significant safety risks.

Other options like increased heat production, increased clearance, and reduced maintenance needs do not typically signify a blockage. Increased heat may actually occur due to improved combustion rather than blockage, and an increase in clearance usually points to proper installation rather than indicating any issues with blockage. Similarly, reduced maintenance needs suggest that a chimney is in good condition, which does not align with the problems associated with a blocked chimney.