What might be a sign of insufficient airflow in a gas furnace?

Insufficient airflow in a gas furnace can lead to a variety of operational issues, and unusual blower operation is a notable indicator of this condition. When the airflow is restricted, the blower may struggle to push air through the ducts effectively. This can manifest as erratic or inconsistent blower speeds, an unusually loud operation, or the blower running continuously without adequately warming the air.

The blower's primary role is to circulate air through the furnace and into your home. If it is not operating correctly due to low airflow, it may fail to distribute heat efficiently, causing discomfort. In some cases, the blower may even shut down unexpectedly as a protective measure against overheating.

The other signs mentioned correlate with various inefficiencies or problems but are not as direct indicators of airflow issues specifically. For instance, increased gas bills could suggest any number of efficiency problems or increased usage, but they do not point to airflow alone. Similarly, warm air from the vents may still occur despite airflow problems if the furnace is still firing correctly. Higher indoor humidity levels, while possibly influenced by airflow, usually relate more directly to the furnace's ability to properly cycle air and humidity control, rather than indicating immediate airflow problems.