All You Need To Know About Auto Defrost In Refrigerators

Freezers and refrigerators are designed to provide a cool environment for the safe storage of food items. They save the food from getting rot and are also helpful in making the various food items and beverages cold for their consumption. An essential feature that one needs to put a focus on while buying a refrigerator is the auto-defrost function that ensures the optimal working of the refrigerator.

As we open and close the refrigerator door multiple times, ice starts building up in its system. This is because moisture introduced inside comes in contact with the coils inside the appliance and start freezing. This ice on the shelves of the refrigerator hampers its working. Hence, the auto-defrost feature plays a crucial role in the smooth working of the refrigerator, and you must look out for this feature while purchasing a new single door refrigerator. Fortunately, all double door refrigerators in India come with Frost Free Technology about which we talk later in the article.

This article will provide you with insights on the auto-defrost feature and all you need to know about it. Let us start by first understanding what auto-defrost means.

auto defrost

What is Auto Defrost?

Automatic defrost or the auto defrost is a feature of the refrigerator that prevents the ice from building up in the system by performing an automatic evaporation process. To put it simply, the refrigerator has the functionality to periodically run warmer temperature cycles so that any build-up ice can be melted.

This prevents the system from turning into an ice cave and make sure the fridge keeps working fine. Refrigerators usually come in two variations, auto defrost refrigerators and manual defrost refrigerators.

Working of Auto Defrost

The auto defrost unit has a fan installed on their compressor along with an electric timer that helps in maintaining the running of the temperature cycles. The timer attached in the unit is pre-programmed to run after a specific period of time. It makes the fan blow out cold air and also controls the heating elements for melting any built-up frost.

The process involves heating the evaporator coil by the heating element, which is present at the back of the refrigerator. This results in the melting down of the accumulated ice at the back of the fridge, and the water runs down to the evaporator tray that is located at the top of the compressor. Further, the heat generated by the compressor evaporates the water into air particles.

Mainly there are three components in an auto-defrost refrigerator:

ADC Board or Defrost Timer

Defrost timer works similarly like a clock. The timer keeps moving, and every eight to ten hours (depending upon the fridge), it hits the defrost spot and starts the process. Refrigerators that have Adaptive Defrost Control are smarter as they calculate various factors such as opening and closing of the door and the time duration for the running of the compressor to determine when the defrosting is required. Accordingly, it starts the defrosting process.

Defrost Thermostat

This component is responsible for controlling the time duration for the heater to stay on during the defrosting process. For instance, in a defrost cycle of thirty minutes, the heater only stays on for a period of ten minutes. When all the ice melts down, the temperature of the back panel of the fridge starts rising. When it reaches a certain point, the thermostat breaks and cuts of the electric supply. Hence, it saves the machine from overheating.

Defrost Heater

This is the main part of the defrost system, which heats up and melts the ice and frost. Most of the refrigerators have a coil of wire enclosed in a glass tube below the evaporator coils. The working of a defrost heater is quite similar to that of a light bulb. When the process starts, the coil starts heating up, raising the temperature of the whole unit and thereby meting the frost and ice.

Is Auto Defrost the Same as Frost-Free?

Most people confuse these two terms, auto defrost and frost-free and treat them as a single entity. However, it is not true. They both are two different terms.

Auto defrost is a function of the refrigerator that automatically melts down the built-up frost from the fridge by running the defrosting process. A heating element present in the fridge gets heated and melts down the ice and frost and evaporates it into the air.

On the contrary, frost-free is a specific feature of the refrigerator in which the air consistently circulates between a pre-decided circuit and does not let the frost accumulate at all in the appliance.

Refrigerators that have frost-free functionality are usually more expensive than that of the fridges having the auto-defrost feature.

Manual Vs. Automatic Defrost Refrigerators

The refrigerators that do not have an auto-defrost system present in their structure requires manual defrosting. Manual defrosting is done by removing all the food items from the fridge and then shutting off the refrigerator unit that makes the built-up ice to meltdown. Fortunately, refrigerators that require manual defrosting are no longer manufactured.

The defrosting of any refrigerators is extremely crucial as, over time, the frost keeps accumulating itself on the doors and shelves of the fridge, which results in poor functioning on the fridge.

Automatic Defrost

The automatic defrost refrigerators have electric heating elements embedded in their evaporator coils. The timer placed in the system automatically turns on the automatic defrost cycle. As the auto defrost process starts to implement its functionality, the temperature inside the freezer starts rising and hence melting down the built-up ice. As opposed to manual systems, refrigerators having automatic defrost function consume more amount of energy.

Steps to Implement Auto Defrost

Usually, a button or a defrost timer is present on the freezer that initiates the auto defrost process. If your model of the fridge does not have an integrated automatic feature for the defrosting process, then you might need to push the defrost button to start the process.

You can press the defrost button whenever you feel the ice is being built inside the refrigerator. The best way is to conduct the process once in three months for the efficient working of the fridge.

Manual Defrost

On the contrary, the manual defrosts refrigerators lack the functionality of automatic defrosting and require the process to be done manually. Whenever the ice builds up in large quantities inside the refrigerator and the freezer, you need to shut down the entire system and let the ice meltdown naturally so that the working does not get affected.

Steps to Implement Manual Defrost

To conduct the process of manual defrosting, the primary step is to turn off and unplug the refrigerator. You can then use a hairdryer or gently pour hot water over the ice to melt it down. Clean the fridge efficiently and ensure that it is entirely dried before moving back the stuff inside the refrigerator.

Pros and Cons of Auto Defrost 


  • They have easy maintenance.
  • It saves your time and energy by reducing the efforts of manual defrosting.
  • Only occasional cleaning of fridge required.


  • These are more expensive.
  • The temperature fluctuations are more.
  • They consume higher energy

Pros and Cons of Manual Defrost


  • These are more energy-efficient.
  • They have a low-cost price.
  • They maintain a consistent temperature for storing large quantities of food.


  • Frost build-up is more.
  • Defrosting takes time and effort.
  • The cleaning process is more complex.

Benefits of Auto Defrost Function in a Refrigerator

Auto defrost is a wonderful feature that highly enhances the functioning of a refrigerator. There are many benefits linked to this feature. Let us explore some of them:

No Heavy Frost Build-Up

One of the best advantages of having an auto defrost system is that it prevents building up a heavy amount of ice in the freezer and the refrigerator.

No Alternatives Required

The most significant benefit that the auto-defrost feature offers is that the defrosting process occurs naturally, and you do not have the need to turn off the entire unit. This saves you from the process of storing the food into another freezer or refrigerator until the defrosting is happening.

Easy to Maintain

Refrigerators having the auto defrost feature have low maintenance as opposed to the ones that do not have this functionality. As the frosting process itself initiates whenever it is required, the refrigerator does not have compromise on its working and eventually produce better and efficient results.

No Need of Manual Defrosting

Unlike the manual defrost refrigerators, one big perk of an auto defrost process is that you do not have to waste your time and effort in defrosting the fridge manually. You only need to press the defrost button to initiate the process.

Moreover, in modern refrigerators, you do not even need to press the button, the unit automatically senses the need for defrosting and starts the process.

More Storage Space

In the case of a manual defrost system, the refrigerator collects a large amount of ice, and therefore, the space inside the fridge gets reduced. While in the auto defrost system, the process is fixed, and the ice built-up is much low. Hence, you always have more storage space available in the refrigerator.

How Often Does a Freezer Need Auto Defrost?

The defrosting process happens when the cooling system of the fridge completely shuts down, and the heating coil inside the system gets activated. The frequency of fridge defrosting may depend on a few factors. One of the primary factors is the climate and indoor environment.

It will be surprising for many people to know that the regional climate and the indoor activities in the kitchen can highly influence the number of defrost cycles the fridge needs.

Refrigerators that are present in regions with humid climates build more frost opposed to others. Also, if your daily cooking involves a lot of steam, the moisture enters the freezer and accumulates more frost, and the defrosting cycle also increases.

The fridges that use the basic defrosting technology and have a timer included let the compressor run for a period of eight to twelve hours. Once the cooling system hibernates, the defrost system starts working, and the heating coil turns on. It then runs for 20 to 40 minutes depending upon the model and size of the freezer compartment. Overall, the defrosting occurs twice or thrice in a day.

In the case of the ADC Board, the refrigerator itself decides the frequency of the defrosting cycle. The frequency depends upon the external weather, how often the door of the fridge is opening and closing, how much frost is accumulating, and accordingly, the refrigerator runs the defrosting cycle.

What are the Potential Problems of Not Defrosting Refrigerators?

Many times, problems may arise with the fridge’s defrosting process. The most usual symptom of the defrosting process is the uniformly frosted evaporator coil. However, there may be other problems too that may hamper the optimal working of the defrosting process. Check out the potential problems that may have occurred:

Faulty Defrost Timer

As the defrost timer is responsible for controlling the cooling and defrost cycle. Its job is to consistently switch between the defrost and the cooling mode. In case it goes bad and gets stuck on the cooling mode, the system starts building excessive frost and eventually reduces the airflow disrupting the defrosting process.

Defrost Sensor Issues

The defrosting process may get hampered if the sensor that monitors the temperature of the evaporator gets faulty, leading to the forceful shut down of the defrost heater.

Defective Thermostat

When the cooling coil present inside the refrigerator panel becomes extremely cold, a signal is sent by the thermostat to turn on the heater. Likewise, on extreme heating of the coil, it sends a signal to shut off the heating elements. In case the thermostat stops working, it won’t send the signal leading to malfunctioning of the refrigerator.

Not Working of Defrost Heater

In case the defrost heater that melts the frost stops its working due to some error, the airflow inside the refrigerator will be affected, and the fridge will not work ideally.


Auto defrost is a great technology that saves you from the efforts of manually defrosting the refrigerator. It not only saves you time but also ensures smooth and efficient working of your fridge. A refrigerator that has an auto defrost technology is a great option to buy, and this amazing technology surely makes life simpler.


Smart Home Guide Team

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