Refrigerators are common household appliances designed to prolong the life of fresh and frozen foods. While the bulk of refrigerators are manufactured to last you and your household years, like any other appliance, certain malfunctions can occur. If you notice your refrigerator making a howling sound, you may have defective or improperly working parts.
A refrigerator evaporator fan, typically located behind the freezer, is responsible for blowing air across evaporator coils to help distribute cool air throughout the refrigerator. If the fan motor is clogged with dirt, lint or other debris the sound of air passing through the fan motor simulates that of howling wind. To determine if this is the cause of the howling, open the freezer door for 30 seconds. If the howling noise becomes louder, this is the cause of the sound. To clean, move the refrigerator away from the wall and disconnect the power. Use a damp cloth to clean the fan, which is accessible on the backside of the refrigerator. Use a soft brush to clean deeper into the fan, and if ice accumulation is found dip a cloth into warm water and apply it directly to the fan blades. After cleaning, return the refrigerator to its original position and reconnect the power. If the howling does not stop, the problem may be with the fan motor.
Like the evaporator fan, the condenser fan is responsible for blowing air over condenser coils to push cool air throughout the lower portion of the refrigerator. The condenser fan is located on the lower backside of the refrigerator, and because it's close to the ground dirt and debris can clog the fan, resulting in a howling-wind sound. Turn off the refrigerator and move it away from the wall. Take a damp cloth and wipe down the condenser fan blades. Spray past the blades with a can of condensed air to ensure all dust is removed from the motor. If this procedure does not eliminate the howling sound, the condenser fan motor may be damaged.
A refrigerator defrost system is responsible for preventing ice accumulation along evaporator and condenser coils, which is caused by warmer air moisture entering the freezer when the freezer door is opened. If excessive frost develops on these coils, the entire refrigerator is affected, as the defrost system is a vital component of any refrigerator. If this system is malfunctioning a high-pitched howl may be heard coming from the rear of the unit followed by a "pinging" sound. Resetting the defrost system can typically remedy this sound. Reset by turning the freezer temperature control dial to the "off" or "0" position for 15 minutes. Activate the freezer once more by setting the temperature control dial back to its previous temperature point. If you begin to hear a howling sound or a "pinging" sound, the defrost thermostat may be damaged.
When Consult a Professional
If the howling noise does not disappear after cleaning the evaporator and condenser fan as well as resetting the defrost system you should contact a professional as one of these systems may need to be replaced. If your refrigerator is under warranty, contact the warranty company to have the refrigerator serviced. If not, contact an appliance repairman and discuss the symptoms of the refrigerator to determine what steps should be taken to repair this appliance.