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Why Does A Refrigerator Freeze Up?

You’re late for work and head for the kitchen planning on a quick cup of coffee before you rush the kids off to school but instead walk into a cacophony of complaints. The kids’ lunch-boxes are incomplete because the lettuce and tomato salad has frozen solid in the refrigerator, there are icicles in the milk, so they can’t have cereal, and Mom’s yogurt will need chiseling or a long soak in a hot pot. Why is this happening?!

A refrigerator is usually split into two parts, the freezer and the fridge. Cold air is produced and distributed around the refrigerator/freezer, cooling the air and the contents. This air movement is regulated, but the food and drink inside the fridge may begin to freeze when an imbalance occurs.

What Causes the Imbalance of Air Temperature in A Refrigerator?

Some fridges have only one cooler located in the freezer. When the refrigerator requires more cold air, a Damper Control port opens between the fridge and freezer, and cold air is drawn into the refrigerator. This action creates a surplus of air, which escapes back into the freezer via a vent.

Fine in theory, but the flap that opens and closes between the two units can ice up. This icing-up action will result in a fridge that gets too cold and freezes when the flap ices up in the open position or gets too warm when the flap ices up in the closed position.

Incorrect placement of items inside the freezer or fridge can also ensure that this flap is prevented from opening correctly. In a refrigerator with the freezer situated above or below the cold section, a vent may be used for the passage of cold air, which is often blocked by plastic bags containing food, etc.

Mono Cooling vs. Twin Cooling

Mono Cooling

  • Has one evaporator situated in the freezer
  • Keeps a level of around 30% humidity in the cold section (the central part of the fridge)
  • Carries any smells like fish, garlic, etc. from the cold section into the freezer, possibly tainting food that has not yet frozen

Twin Cooling

  • Has one evaporator in the freezer and another in the cold section
  • It offers a level of around 70% humidity in the main compartment, and the freshness means healthy greens stay healthy for longer

Other Issues That Can Cause A Fridge To Freeze Up

  1.  Thermostat Malfunction

The thermostat is often the guilty party with a fridge that is iced up, so you might want to start here, and that’s why I have noted it in first place on our list.

It controls the refrigerator’s cooling system – including the freezer – and regulates the compressor, the evaporator, and the condenser.

The thermostat directs voltage to the compressor and the condenser and evaporator fan motors to cool the air as needed. If it malfunctions, it might run too often, resulting in the freezing we notice in the fridge compartment.

Steps to follow to Check The Thermostat

  • Confirm whether or not your fridge has power. As you might do with your automobile, check for lights first.
  • If your thermostat has a power indicator, check this is lit.
  • Turn the thermostat right down and ensure that you hear an audible click when you get to zero. No click means you have probably solved the problem. The thermostat is no longer able to turn on and off and remains on, with no automatic temperature regulation: The thermostat is guilty.
  1. Faulty Door Seal

This issue doesn’t seem important at first sight because we all imagine that if there’s a faulty door seal, we’ll notice it immediately. Not so. This component’s efficiency will have a considerable impact on your refrigerator’s smooth running, but in the event of a leak, don’t go expecting to see torn seals or a massive gap between the door and the fridge when the door is closed.

Take a paper sheet; A4 is fine, and close the door with the paper between the door and the fridge. Tug gently on the paper. If you can easily remove it, that seal is probably shot and needs replacing.

  1. Temperature Sensor Failing

The temperature sensor is the component that measures – not controls – the air temperature in the fridge and the freezer. This information is relayed to the electronics to monitor. If the sensor is faulty, you will have inaccurate readings sent to the electronics, which will act on this information, resulting in either too high or too low temperatures.

  1. Defrost Heater

If your refrigerator is equipped with a defrost heater, you have a component that defrosts the ice from the evaporator coil unit. Usually, a wire filament is encapsulated in a glass tube. This heater can fail over time and will then allow a build-up of ice on the evaporator coil.

Does My Refrigerator Require Regular Defrosting?

Modern refrigerators do not require manual defrosting, as freezing up of the fridge is, in theory at least, controlled by the technology placed within the unit. Older fridges say pre-2000 may well need manual defrosting, but check on the manufacturer’s website to be sure.

Does It Matter If My Fridge Freezes On Occasion?

Yes, it sure does. Occasionally, anything can become a permanent problem, and a freezing fridge is rarely an occasional issue.

When a fridge freezes up, food gets freezer-burn, a state created by dryness and a loss of moisture. This freezer burn might cause the meat to discolor and cause fresh produce to dry out, so it becomes limp and lifeless in appearance. Freezer-burnt food can still be eaten but will not be very appetizing.

NB This freezer-burn can also occur in the freezer section, so make sure all containers are airtight in there. I suggest that any fresh fish be wrapped in newspaper or similar in addition to the fishmonger, or supermarket, even when vacuum-sealed.

How Can I Prevent My Fridge Freezing?

  1. Temperature Settings

Fresh food and produce should be stored close to 39 degrees Fahrenheit / 4 degrees Centigrade (Celsius). Before you become alarmed that your fridge is freezing, remember to set the temperature correctly. 

Many fridges do not show the actual temperature, but numbers (from one upwards, usually to six or ten), or just a series of dashes on the dial. You will require a portable thermometer to test the temperature change as you change the control dial in the latter two cases.

Caveat: Do not expect an instant change. Take a measurement and note the reading, returning in four to six hours to do the next. This checking may seem like a meticulous job, and it is, but there is no way to rush this task.

  1. Food Arrangement

As discussed earlier in this article, we have learned that air cooling is caused by cooling by one or two evaporators. 

If one evaporator is used, it will be located in the freezer section, and air will then circulate between the freezer and the fridge. 

If the fridge contents are packed correctly, leaving these vents or ports open to the flow of air, your fridge will be able to operate smoothly.

  1. Door Seals

Check your fridge door seals regularly. There is no reason to forget to check this with today’s plethora of smart-watches/phones/tablets. Just set a reminder for every three months or so, and you’re good to go.

NB. If you have stepped up your game and have an inner and an outer door, make sure both are closing correctly.


A freezer is designed to freeze food, but a fridge is not. Set the temperature correctly and leave it alone after that. Pack your food and other items in the refrigerator/freezer sensibly. (It’s generally the freezer that gets over-packed as if we’re expecting Covid 20-30 to arrive all at once) Finally, check those door seals, and you should have many years of happiness with your refrigerator.

If you require far more control over what happens in your unit, it might just be time to upgrade to a smart refrigerator, where Wifi can help you in more ways than you can imagine.