Why Does My Refrigerator Start & Stop?
A refrigerator that operates normally tends to start and stop as needed to maintain a target temperature. There are a few exceptions: when it is first plugged in after a long period of time, it will require several hours (or even days) to reach the target temperature, and when it is loaded from empty with room temperature food, it will run constantly for a long time.
Just like an air conditioner, refrigerators do not operate continuously; doing so would not only waste electricity, but would also freeze food that doesn't need to be frozen. Instead, refrigerators contain at least one thermostat that runs the refrigerator only until a target temperature is reached, and then shuts it off until the temperature rises again. This is part of the normal operation of the refrigerator, and shouldn't cause concern. On the contrary, a refrigerator that runs constantly is a sign that something is wrong.
Another common function is the defrost cycle that many refrigerators perform. As the freezer runs, ice inevitably builds up on the walls. This ice actually interferes with the operation of the freezer and has to be removed. To do so, the freezer will shut off occasionally for just long enough to let the ice thaw. Like the thermostat, this is a normal part of your refrigerator's operation.
If you believe the refrigerator is more erratic than it should be, electrical problems may be the cause. Most refrigerators require a lot of electricity, and if the line is overloaded, the circuit breaker could be flipped.
Generally, the functioning of your refrigerator should be close to silent. You should only be able to tell that the refrigerator is alternatively cooling and not cooling by close examination. However, if your refrigerator, while cooling, has a loud buzz or hum, this is a sign of some issue that requires repair. The most common cause, and the easiest to fix, is dirty condenser coils. These black metal coils on the back or bottom of the refrigerator help the fridge dissipate heat that it removes from its contents. To function effectively, they need to be cleaned. To do so, simply unplug the refrigerator (the coils have an electric current while plugged in) and vacuum them. Any coils you cannot reach can be cleaned with a brush that can be bought in any hardware store. Be careful while doing this, as the coils may be hot.