Thumping Sound When the Refrigerator Turns Off
Refrigerators don't go about their jobs silently. They make a number of strange noises, from groaning to sighing and squealing to knocking. Most of these noises are a normal part of the cooling or ice-making process. One common complaint is a knocking or thumping noise. Although the cause may be benign -- depending on where or when it occurs -- it may also signify a serious problem with your refrigerator.
Your refrigerator may make a thumping sound as water flows through the pipes to fill your icemaker. This is normal and to be expected, according to Whirlpool's customer help website. On the other hand, a thumping noise that occurs at the moment your fridge shuts off is a clear sign there is something wrong with the compressor.
Compressors are the heart of a refrigerator. A compressor unit consists of a fan and motor with pump, which work together to circulate coolant through the coils and remove heat from the fridge. The compressor is housed in a compartment about the size of a football that sits toward the bottom of the back of the refrigerator. Inside the compartment, the compressor rests on three springs. These springs absorb the movement of the compressor. Over time the springs wear out, and the compressor or compressor fan may hit the walls of the compartment as the motor shuts down, causing the thumping noise.
In most cases, the noise is annoying but does not signify an immediate problem with the operation of the compressor. If you notice the compressor making the thumping sound while it is running, or if it shuts on and off at random intervals, call an appliance-repair professional to come take a look at your refrigerator and diagnose the problem. Although refrigerator compressors are made to run for several years, it is possible yours might be broken and may need to be replaced.
Other less common circumstances may be causing a thumping noise in your refrigerator. Tubes that rub or touch each other can sometimes make a knocking or thumping noise. You may be able to verify this by inspecting the back or bottom of the appliance. The condenser fan, which is located behind or under the refrigerator, may be hitting a foreign object as it rotates. Alternately, the condenser tray, which is located under the fridge, may become loose and thump as it hits the floor. Finally, if an object of some sort is trapped behind the refrigerator, it may make a noise when the appliance powers down.