What Causes a Refrigerator to Howl?

The Damper

• If the howling noise is ongoing and incessant, you probably have a real problem -- but if it just occurs briefly and periodically, you probably have nothing to worry about. For example, when the damper door opens and closes, it sometimes produces a brief howling sound. The damper regulates airflow and temperature inside of a refrigeration unit. It contains a door that opens and closes, and if it sticks open, the howling noise may persist. You can find the damper between the freezer and fridge compartments, usually appearing as a small, white rectangular box with a flap. In some cases, you must disassemble an ice maker or other component to reach the damper.

The Defrost System

• An incessant squealing or howling noise may indicate a problem with your defrost system, particularly on self-defrost models. When water drips onto defrost heaters, it can produce a loud noise -- but if the noise continues, it may indicate excess frost or a problem with the timer, forcing the mechanism to work overtime. Check for a coating of frost along the rear of the freezer to determine if you might have a problem with the defrost system.

The Evaporator Fan Motor

• The evaporator fan motor maintains the airflow through the freezing and refrigeration compartments. In most models, you can find this small oscillating fan along the back of the freezer. Open the freezer door and examine the fan to see if it produces the unwanted noise. If it gets louder when you open the freezer, you have pinpointed the problem. You must replace the mechanism, as you cannot repair a faulty evaporator fan motor.

Other Causes

• If the noise does not present an apparent source within the refrigerator, try moving it away from the wall and examining the back. Certain mechanisms along the back of the unit may produce a loud, persistent noise when not working properly. First, look at the compressor, a black, football-sized case near the bottom. If it seems responsible for the noise, it will likely require replacement. Next, check the condenser fan, sometimes hidden behind a thin panel on the back of the unit. Remove any lint or dust from the blades and see if that solves the problem. If the noise continues, and seems to originate from the fan, replace the motor.