How to Defrost a Freezer

Prevent freezer burn by learning this essential appliance maintenance.

how to defrost a freezer

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Each time you open your freezer, water vapor can enter, where it's quickly frozen. Over time, this can cause a layer of ice or frost to build up on the inside of the freezer. If the issue isn't resolved, it can spread over the temperature sensors or cover the air vents, causing the freezer to work overtime, which in turn can increase the frost buildup.

This situation can occur with refrigerator freezers, upright freezers, and chest-style freezers. To handle the problem, all you need to do is defrost the freezer. This easy maintenance project melts the ice and allows it to drain out of the freezer. It also gives you an opportunity to clean the inside of the freezer before plugging it back in or turning it on. Use this guide to learn how to defrost a freezer.

Common Causes of Frost Buildup

The main reason for defrosting a freezer is to prevent frost and ice buildup from blocking important components inside the appliance. When the door is opened, water vapor in the air enters the freezer. The water vapor then freezes to the sides of the appliance and, over time, it can build up inside the freezer. However, this isn't the only way frost forms inside a freezer.

When you put hot food directly into a freezer, the steam from the food rapidly cools until it freezes to the inside of the freezer. This can be mitigated by allowing your food to cool before putting it into the freezer.

Another issue that can cause frost buildup is a dirty or damaged door seal. If the door doesn't seal properly, air continues to enter the freezer, carrying water vapor through the faulty seal. The water vapor then freezes, leading to a buildup of frost and ice.

It's recommended to defrost a freezer at least once a year to remove any ice that has built up. If your appliance is prone to frost buildup, you may need to defrost it more than once a year. Check the thickness of the ice buildup; if it is more than 1/4 inch, the freezer should be defrosted.

a close up of a stainless steel refrigerator

James Schroder

How to Defrost a Freezer

The process of defrosting a freezer is relatively simple, but it can take several hours for the ice and frost to fully melt. During this time, be prepared with plastic liners, towels, and a mop to ensure that the melting ice doesn't create a mess or damage floors.

What You Need

  • Cooler
  • Ice
  • Towels
  • Plastic liners
  • Mop
  • Baking soda
  • Cloth
  • Bucket

Step 1: Turn Off Freezer

Ice takes a long time to melt, so before doing anything else, unplug or turn off the freezer. This will start the defrosting process. As you wait for the ice to melt, take out any food items that are still in the freezer and put them in a small, portable freezer to ensure they remain frozen while you work. If you don't have a portable freezer, you will need to find a suitable place to keep the food cold, like a cooler filled with ice.

Step 2: Prepare the Area

The ice and frost will gradually melt as the inside of the freezer warms up. Avoid soaking the floor and the surrounding area. Not only can it create a mess to clean up, but it can also cause water damage and may lead to mold growth. Lay down towels or plastic liners on the floor in front of the freezer.

You can also put towels or rags inside the freezer on the lower shelves to help absorb the water. In some cases, a freezer might have a drainage hose that can be placed into a bucket to help collect the draining water. Just keep in mind that the drainage hose might not be able to collect all the water, so it's still recommended to have towels and a mop at the ready.

Step 3: Wait for Ice to Melt

With the freezer unplugged and the door to the freezer open, you can expect to wait between two to 24 hours for the ice to melt on its own, depending on the thickness of the frost buildup. To help speed up the melting process, set up a fan near the freezer. This will force warm air into the freezer and push cold air out, ensuring the ice is exposed to room-temperature air throughout the defrosting process. Use your towels and a mop to clean up any water that isn't captured by a drainage hose or plastic liner. 

Step 4: Clean the Freezer

After the frost has melted, wipe down the inside of the freezer to remove any excess water. Take this opportunity to clean the inside of the freezer with a solution made up of 1 Tbsp. baking soda and 4 cups warm water. Apply the solution to a rag or cloth, then wipe down the racks, inner walls, and the door of the freezer. Once the inside of the freezer is clean, use a towel or cloth to dry the inside of the freezer.

Step 5: Test the Freezer

The final step in the process is to plug the freezer back in or turn the freezer back on, then wait for it to reach the set temperature. Check the freezer after about 15 minutes to ensure that it is working properly, then put your food items back into the freezer and close the door or lid.

How to Prevent Frost Buildup

While you can't do a lot about water vapor that enters a freezer when you open the door to retrieve items, there are steps you can take to reduce the buildup of frost and ice. The most straightforward step is to limit the amount of time you spend with the door open. When putting items into the freezer, don't leave it open while you grab other grocery items to put away. Similarly, when taking items out of the freezer, try to have an idea of what you want to retrieve before opening the door so that you aren't standing with it open for too long.

Hot food can also cause a buildup of ice and frost, so make sure your food has had time to cool before you place it in the freezer. It's also important to store food in a properly sealed freezer-safe container or bag. Remove as much air as possible from the containers before putting them into the freezer.

Keep the freezer set to 0 degrees Fahrenheit and check the seal surrounding the freezer door or lid. If you feel any cold air flowing out of the freezer when the door or lid is closed, then the door or lid is not sealed. In this case, the rubber seal either needs to be thoroughly cleaned or it may need to be replaced.

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