Which maintenance task is critical for maintaining proper airflow in a gas furnace?

Regularly cleaning or replacing air filters is critical for maintaining proper airflow in a gas furnace because air filters play a direct role in how efficiently the furnace operates. Dirty or clogged filters can restrict airflow, making it difficult for the furnace to take in and circulate air. This decreased airflow not only hinders the heating efficiency but can also lead to overheating of the system, increasing the risk of damage and reducing overall lifespan.

Proper airflow is essential for the furnace to operate safely and effectively, ensuring that heated air can be distributed evenly throughout the space. Neglecting to maintain clean air filters can result in poor indoor air quality and increased energy consumption, as the furnace has to work harder to achieve the set temperature.

While cleaning ducts and sealing leaks also contribute to optimal airflow, these tasks are typically less frequent and may not provide immediate relief from airflow issues caused by dirty filters. Inspecting the heat exchanger is important for safety and efficiency, but it does not directly impact airflow in the same way that maintaining air filters does. Therefore, prioritizing air filter maintenance is vital for sustaining the overall performance of a gas furnace.