How Long Does a Freezer Defrost Cycle Last?

Defrosting a freezer is essential to enhance its lifetime. But most people are unaware of how long it lasts or how frequently they should defrost the freezer.

Typically, it takes 10-60 minutes to defrost a freezer. The time depends on the temperature and how full the freezer is.

If it is full, the temperature will have to drop first to defrost it.

This blog discusses how long a freezer defrosts cycle lasts. This includes the duration between defrosting cycles and when they should be replaced.

Why Should You Worry About Defrosting a Freezer?

When ice builds up on the coils of a freezer, it decreases the appliance’s efficiency and makes it work harder to maintain a consistent temperature.

In addition, ice can damage the coils, potentially causing a leak. As a result, it is essential to defrost a freezer regularly.

The best way to defrost a freezer is to unplug it and remove all of the food. Once the freezer is empty, prop open the door and let it thaw for several hours.

After the ice has melted, wipe down the interior and coils with a cloth dampened with warm water.

Once the freezer is clean and dry, you can plug it back in and restock it with food. By taking these steps, you can help increase the life of your freezer.

Freezer Defrost

What Processes Take Place During a Defrost Cycle?

When you set your freezer to the “defrost” setting, a few different things happen. First, the compressor turns off.

The compressor is responsible for creating the cold air that circulates through your freezer, so turning it off allows the temperature inside to rise.

Next, a small fan starts circulating the warmer air around the freezer. This helps to speed up the defrosting process.

Finally, the heat from the coils helps melt any ice built up on the walls or ceiling of the freezer.

Once the defrost cycle is complete, the compressor turns back on, and the temperature drops back down to its average level.

What are the Different Types of Defrost Systems?

There are four main types of freezer defrost systems: manual defrost, automatic defrost, frost-free, and adaptive defrost. Let’s understand each one of them.

Manual Freezer Defrost Cycle

In a manual freezer defrost cycle, the freezer must be defrosted manually with a thermometer.

The defrost cycle begins when the temperature reaches about 40 degrees Fahrenheit (4 degrees Celsius).

After the freezer has defrosted for about 10 to 15 minutes, the defrost cycle ends, and the compressor can start cooling the freezer.

In this defrost cycle, you must use a timer to turn on and off the power switch. This helps keep the food inside your freezer fresh by keeping it at a lower temperature during the off hours.

Automatic Freezer Defrost Cycle

This is a special type of defrost cycle. It has an automatic defrost cycle. When it detects frost build up on the unit, it will automatically start a defrost cycle.

During defrost, water droplets are evaporated off the ice, leaving behind small air pockets that prevent frost from forming again.

The defrost cycle occurs whenever the temperature of the freezer drops below freezing. It will take about an hour before the food is fully thawed. The defrost cycle can be turned off in the control panel if desired.

Defrosting the freezer is a routine task that should be done every time. The automatic defrost cycle helps in minimizing the manual effort required to defrost the freezer.

Moreover, it also helps save energy and helps the freezer maintain its temperature more efficiently.


Frost-Free Freezer Defrost Cycle

A frost-free freezer is an appliance used to freeze, store food items, and defrost food items. It does not involve any direct contact with ice.

It uses a refrigerant gas that circulates between freezer coils to maintain the temperature.

The defrost cycle occurs when the gas is turned off, allowing the air in the freezer coil to cool down and condense on the evaporator coil.

The condensed water flows down to drain holes and is removed by the drain hose.

This process removes heat from the freezer’s interior and lowers the temperature inside the freezer so that food can be defrosted without damage.

Adaptive Freezer Defrost Cycle

The adaptive freezer defrosts cycle works by using a timer to turn on and off the freezer compressor automatically.

When the compressor is turned off for more than 4 minutes, the motor spins at a slower speed to allow the freezer compartment to cool down.

After the compressor turns on again, it runs at the higher speed it was operating at before the defrost cycle kicked in.

How Long Does Freezer Coil Defrosting Take?

This is a tough question because there are too many variables. First, let’s look at what we have to work with. In the United States, most freezers have 4 coils inside them.

Each coil is approximately 4 feet long, 2 feet wide, and 1/2 inch thick. Next, let’s look at some basic freezer physics.

The first thing to realize is that most freezers are double-walled. On the inside of the freezer, there is an insulating layer of ice. This layer is about 1/2 to 2 inches thick.

Under the ice is another layer of water. This layer is usually about 1/4 inch thick. In between the two layers is a layer of air. This layer is usually about 2 inches wide.

I’m not sure why this is so. I think it has something to do with the way that water freezes. When water freezes, it forms hexagonal crystals. These crystals are like little bricks.

They have flat sides and rounded corners. The water molecules line up in a nice orderly fashion. The ice is made up of these little bricks.

So now, coming back to the question, for small Freezers (e.g., 2.5 cu ft), it takes 2-3 days for Freezer coils to defrost completely.

For big Freezers (e.g., 8 cu ft or more), defrost time is reduced to 1-2 hours.

If you can leave the freezer door open for a while, you can speed up defrosting. Note that defrosting may not be needed in some cases.

If the freezer door is open, Freezer will defrost itself and cool down without any human intervention.


How Warm Does a Freezer Get on a Defrost Cycle?

This is a common misconception. The temperature inside a freezer does not actually change at all.

Instead, the temperature of the freezer itself changes as the door to the freezer is opened and closed. On the “defrost” cycle, the temperature inside the freezer rises until the ice melts away.

During a defrost cycle, it usually gets to between 40 and 45 degrees Fahrenheit.

The room remains cold while the door is open because cold air is being pumped in, and warmed air is being pumped out.

What Happens When a Defrost Timer Goes Bad?

Usually, when a defrost timer goes bad, it will automatically reset to zero at the end of the timer. If you know how to reset the defrost timer, you can use the following procedure to reset it to zero.

Make sure you have a piece of paper or a credit card handy. If you have a piece of paper, you can write down the date you put the food in the freezer.

If you don’t have a piece of paper, write down the date on the paper on your debit card.

Then, write your last 4 numbers on the paper or your card. Now, write “reset” and the 4 numbers from the back of your card.


As mentioned earlier, how long a freezer defrosts cycle last depends on many variables, from size to the amount of food stored in the refrigerator. However, the average time is around 30-45 minutes.

Regardless of the time, it is important to defrost your refrigerator at regular intervals. Follow the steps mentioned in this article to defrost the freezer and increase its life.

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