Almost every home in America has a refrigerator that runs continuously to keep food and drinks cold. The basic design of a refrigerator isn't overly complicated, but if something goes wrong it can cause you to lose hundreds of dollars worth of food, as well as cause a significant amount of frustration. A small, but integral, component in your refrigerator is the start relay. Without a properly functioning start relay, your refrigerator would not work.
The compressor in your refrigerator is an essential component of the cooling system. You refrigerator operates by a liquid coolant that is pushed through sets of condenser and evaporator coils by the compressor. If the compressor does not function properly, the coolant does not circulate and the refrigerator cannot reach the required temperature.
Start and Run Relay
Many appliances, including refrigerators, use start relays to start a compressor. As the name implies, the start relay "relays" electricity directly to the compressor. Often, the start relay's job is simply to start up the compressor. Once the start relay gets the compressor running, a run relay takes over to keep the compressor operating properly. The start relay is always attached directly to the compressor. It is typically small with two or three wires attached to it.
Signs of a Bad Start Relay
If the start relay fails to operate properly, it will not engage the run relay. This, in turn, will cause the compressor not to operate. When the compressor does not circulate the coolant, the refrigerator will not cool. Signs that the start relay may not be operating properly include the refrigerator not reaching optimum temperature, a clicking noise when it starts up or the overload tripping causing the refrigerator to shut off. The refrigerator often sounds as though it is operating properly because the fan motor may continue to run; however, if it fails to cool down then either the start relay or the compressor may not be operating properly.
Without a professional opinion, it is often difficult to tell whether the start relay or the compressor is the problem; however, replacing the start relay is generally easy and inexpensive so you may wish to try this first. Remove the refrigerator from the power source before checking or removing the start relay. If your refrigerator compressor uses a capacitor, you will also need to safely discharge the capacitor, or empty the electricity out, before proceeding.