Causes of Frost in a Commercial Refrigerator

frosted refrigerator inside

When frost develops in a commercial refrigeration system, food safety can be compromised. Each type of food is meant to be kept at a certain temperature. Any number of factors can cause frost to develop and accumulate, freezing food not meant to be frozen. Here are some of the most common causes of frost in a commercial refrigerator:


One of the most important parts of a refrigerator is the thermostat. This part helps keep the temperature under control and allows power to flow through the condenser fan, evaporator fan and compressor. To test your thermostat, rotate the temperature control knob all the way, and listen for clicks. If you don’t hear a click, remove it, and check it for signs of obvious damage.


The thermistor is a sensor connected to the control board that monitors air temperature. If this part is faulty, your refrigerator may cool continuously, causing food to freeze. After being overworked by cooling your refrigerator constantly, the part may stop working to cool it at all.

Damper Control

Air damper controls open and close to allow the correct amount of air to get into the refrigerator. If this part is stuck open, it can cause the refrigerator to freeze the food inside. When it’s broken and won’t open, this can also let too much cold air in, which causes frost.

Maintenance Needed

The most common causes of frost are due to the above electrical issues, but a lack of proper maintenance can also lead to frost. Here are a few examples:

  • Dirty or dusty coils cause the compressor to work harder. These coils can easily be cleaned using a hose-type vacuum cleaner.
  • Leaking door seals can also cause frost. If the door seals have damage, you may be able to replace them yourself. However, professional installation is a safer bet.
  • Badly positioned air ducts can cause issues, as well. If your air duct seems to be facing the wrong direction, call a professional company to inspect your refrigerator.

Frost in a commercial refrigerator can come from many places, and a professional refrigeration company can help you diagnose the issue. All Temp is here to help with commercial St. Cloud refrigeration maintenance. We also offer 24/7 emergency repair. Contact us online or give us a call at (407) 857-7800 to schedule an appointment.

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