Setting a Refrigerator Thermostat

 Refrigerator CatThe invention of refrigeration changed our lives dramatically. Before refrigeration we had to throw out any leftovers. We couldn’t store meat unless it was salted and cured. Refrigeration gave us a way to preserve our food supply. This made us more efficient and in doing so improved the quality of our lives.

The purpose of a refrigerator is to chill our food to temperatures that will slow down bacteria growth in the refrigerator and to stop bacteria growth in the freezer. The safest temperature for a refrigerator is 35-38 degrees F. It should never be higher than 40 degrees F to insure food safety. Anything higher will promote food spoilage, including food borne illnesses.

Anything lower will result in unintentional freezing of things like milk and eggs. Freezer temperatures should be set to 0 degrees. At this temperature food can be safely stored indefinitely. When in a frozen state there is no bacteria growth although it doesn’t kill any bacteria present at the time of freezing. Over time frozen food will lose its quality and taste.

True Temperature

The refrigerator thermostat does not set the temperature to the exact setting. Instead it gets slightly warmer or cooler when turned up or down. The only way to get a true temperature reading is to use a refrigerator/freezer thermometer.

There are several types of refrigerator/ freezer thermometers available. Liquid filled thermometers use the expansion of a colored liquid, usually alcohol, to indicate the temperature. Bimetallic-coil thermometers use a metal coil made of two different metals that have two different expansion rates. These two metals are bonded together. As the temperature increases the coil expands to indicate the true temperature.

When you use refrigerator/freezer thermometers place them in an area where they can be easily read and check them often.

How Refrigerators Work

Refrigeration uses a liquid coolant contained within an evaporation coil and a condenser coil. This liquid is circulated by a compressor and a motor. The liquid coolant is cooled in the condenser coil. Then it passes through the evaporation coil where it absorbs the heat from the air in the evaporation coil resulting in cooler air.

Frost-free refrigerators have a timer that automatically turns on a heater to melt any frost that has formed. It automatically turns off and returns to the normal cooling cycle.

Refrigerator Problems

You will know that your refrigerator is not working properly if these symptoms are present. Many problems can be fixed with a minor adjustment that you can do by yourself. Some will require the use of a professional who is HVAC certified.

The most common malfunction in refrigerators is the formation of frost too quickly or it doesn’t defrost at all. This can be caused by the improper setting of the temperature. It may need raised slightly. Other causes include a broken defrost heater, faulty defrost switch, the door being opened to often or too long, the door sagging or the drain could be clogged.

The improper setting of the temperature controls can cause many problems. If your refrigerator runs continuously, if it does not cool or condensation appears this may indicate that you need to adjust the temperature setting. These symptoms may also be caused by other factors including faulty gaskets, improper location, doors opened to frequently or too long, etc.

Other Symptoms

Some other signs that your refrigerator is not functioning correctly are water leakage, cycling to frequently or running noisily. Some of these you can fix yourself. For water leakage you may need to clean the hoses or replace them if cracked. Check the drip pan for cracks. If it cycles to often the compressor may be broken. If it is loud the refrigerator may not be level or the drip pan may be vibrating.

Refrigerators are running in our homes continuously. It is somewhat rare that they break down. If your refrigerator is broken you may end up with a large repair bill and the replacement of your food. Correct temperature maintenance can prevent many of these problems.

Photo by meggito, Creative Commons Attribution License