The first self-contained home refrigerator, with a compressor located at the bottom of appliance, was invented in 1916. Within two years, this product was being mass produced by the Frigidaire company and has remained an indispensable part of our kitchens ever since. Being able to preserve our food and keep our beverages cold with such ease now seems like a constitutional right, but regular maintenance and the occasional repair will always be necessary to keep a refrigerator cooling as expected. To properly troubleshoot the causes for why a refrigerator would stop cooling, it’s a good idea to understand how a refrigerator works.
How a refrigerator keeps things cool
A refrigerator doesn’t actually create coldness per se, but, instead, removes the heat from the air traveling through the refrigerator and freezer compartments. To accomplish this, a refrigerator uses a compressor to pump refrigerant through a set of coils, and fan motors to circulate the air. The compressor compresses the refrigerant in gas form into the condenser coils (often located at the bottom of the appliance) where the gas is then condensed into a hot liquid. The condenser coils dissipate the heat as the liquid travels through them. When the refrigerant reaches the evaporator coils (usually located behind a rear panel in the freezer compartment), it expands back into a gas which makes the coils cold. The gas continues to flow through a suction line attached to the compressor which converts the gas back into a liquid and the cycle continues. A condenser fan motor assists the condenser coils in dissipating the heat while an evaporator fan motor draws air over the cold evaporator coils then circulates that air through the refrigerator and freezer compartments.
Top reasons why a refrigerator doesn’t cool
When everything is working properly, your refrigerator should maintain a consistently cool temperature around 40° Fahrenheit (4° Celsius) in the refrigerator compartment and 0° Fahrenheit (-18° Celsius) in the freezer compartment. If your appliance is having trouble staying cool, here are the six most common reasons, presented from most likely to least likely:
- Dirty condenser coils – Over time, the condenser coils can collect dirt, dust, and hair which hinder the coils’ ability to dissipate the heat from the refrigerant passing through the coils. This can cause the refrigerator to stop cooling. You should use a dedicated condenser coil cleaner brush to periodically clean the debris off the coils to keep the refrigeration system in good condition.
- Malfunctioning condenser fan motor – The condenser coils may also have trouble dissipating the heat if a malfunctioning condenser fan motor is unable to draw air past the coils. The fan motor can either fail mechanically or electrically. A broken fan blade or a blade that does not rotate freely is indicative of a mechanical failure; if the motor is receiving power, but doesn’t run, then the motor has probably failed electrically.
- Defective evaporator fan motor – If the evaporator fan motor is defective, the cold air will not be circulated into the refrigerator compartment. If the motor is unusually noisy when the refrigerator is running, or the fan blade does not rotate freely, you should replace the motor with a new one. You can also use a multimeter to test the motor for continuity – a continuous electrical path present in the part. If the motor tests negative for continuity, you know that it has failed electrically.
- Faulty start relay or capacitor – The start relay or capacitor works in conjunction with the start winding to cycle the compressor on-and-off. If the relay or capacitor are malfunctioning, the compressor may fail to cycle properly or may not work at all. You can test a start relay for electrical continuity using a multimeter to determine if it has failed. An analog-style Ohm meter can be used to test a capacitor’s ability to release its charge while a capacitor meter (or a multimeter with a capacitor testing function) can determine if the component has a strong enough capacitance rating to start the compressor.
- Evaporator frosted over – While the evaporator coils will collect frost during normal operation, excessive frost build-up can cause the refrigerator to stop cooling. To avoid becoming frosted-over, evaporator coils require periodic defrosting. If you own an older model, you may have to do this manually, but most modern refrigerators use an automatic defrost system consisting of a defrost heater, defrost thermostat, and defrost control (which may be a defrost timer or a defrost control board depending on the refrigerator model). You can use a multimeter to test the heater and thermostat for electrical continuity, although the thermostat will need to be tested at a temperature of 15° Fahrenheit or lower for a proper reading. If both the heater and thermostat test positive for continuity, then it’s likely the defrost control is defective.
- Malfunctioning temperature control board – While it’s not a common problem, the refrigerator’s temperature control board could be malfunctioning and unable to direct voltage to the compressor and/or the two fan motors. Since the board can not be easily tested, you should confirm the other components are working properly before you consider replacing this part.
Find the right refrigerator parts with Repair Clinic
To find a complete list of replacement appliance parts that fit your refrigerator, enter the full model number of the appliance in the Repair Clinic website search bar. You can then use the part category and part title filters to narrow that list down to the specific part you need, from condenser and evaporator fan motors and blades to start relays, capacitors, and defrost system components. You can even get a dedicated condenser coil cleaning brush to keep up with your maintenance. While Repair Clinic stocks parts for all the top brands in refrigeration, including KitchenAid, GE, Kenmore, LG, Samsung, and Frigidaire, you’ll want to make sure you’re purchasing the exact part that matches your model.