HVAC Fan Problems and How to Solve Them

HVAC fan problems usually aren’t something you can put up with for long. Once a fan begins to malfunction, household comfort is the first casualty. As system airflow declines—or abruptly stops entirely—due to HVAC fan problems, normal indoor temperatures can’t be sustained. Fortunately, problems with the typical blower fan aren’t hard to diagnose and resolve for a qualified professional service technician.

To get an idea of what may be the cause of HVAC fan issues, here are some likely suspects:

The drive belt is slipping.

Belt-driven blower fans rely on an intact, properly-tensioned drive belt to deliver specified speed and air volume. After years of operation, the belt may stretch and slip on the motor pulley, decreasing blower rpm’s. The result is lower airflow throughout the house or—when the worn belt finally breaks—no airflow at all.  Fan belt inspection, adjustment (and replacement, if needed) are a critical part of regular annual preventive maintenance provided by a professional HVAC service technician.

Dirt and dust are building up. 

Dust particulates in the air can eventually cause a heavy coating on blower fan surfaces. This reduces fan efficiency and diminishes airflow. Dirt and dust accumulation occur silently and, since the fan sounds like it’s running at full speed, the problem may not be noted for some time. Cleaning these components to restore full fan function is a job for a qualified service tech. To help prevent recurrence, make sure you change the system air filter regularly—every month during the cooling season and at least every other month during the heating season.

The motor is defective.

HVAC fan motors typically last from 10 years up to 20 years on average before replacement is required. Service life varies according to total seasonal hours of operation as well as other factors such as dust and dirt contamination due to infrequent air filter changes.  A worn-out fan motor is generally non-repairable and replacement with a new unit is neccessary in order to restore proper airflow.

If you suspect HVAC fan problems, contact CCAC for an inspection and professional repair or replacement.