What is a common cause of a gas furnace malfunction?

A dirty air filter is indeed a common cause of a gas furnace malfunction. The filter's primary function is to trap dust, dirt, and other airborne particles to ensure that only clean air circulates through the heating system. Over time, if the air filter becomes clogged, it restricts airflow, leading to several issues.

When airflow is impeded, the furnace has to work harder to circulate air, which can cause it to overheat and shut down as a safety precaution. Additionally, reduced airflow can lead to uneven heating in the home since hot air doesn't distribute properly. A dirty filter may also cause the blower motor to strain and eventually fail, leading to costly repairs or replacements. Regularly changing or cleaning the air filter is a crucial maintenance step that helps prevent such malfunctions and promotes the efficient operation of the furnace.