How Much Frost Should Be On The Freezer Coils?

Refrigerator Evaporator Coils

Frost build-up inside your freezer is common and is usually nothing to worry about. However, frost build-up in certain areas can signal that a part is malfunctioning. So, how much frost should be on the freezer coils?

If you’ve noticed that your freezer is cold, but your refrigerator is warm. It can result from a number of parts not functioning as they should, including the defrost timer, heater and thermostat.

In this article, we’ve provided further details on the potential causes and fixes.

frozen freezer coils

How Much Frost Should Be On The Freezer Coils?

So, how much frost on the freezer evaporator coils is normal? A small accumulation of frost on the freezer coils is normal. But coils full of frost and ice means you have a defrost problem.

Common Causes Of Frosted Freezer Coils

Therefore, each component must function correctly for the defrost process to work. Otherwise, frost will continue to build. We’ve listed the most common causes leading to frosted freezer coils below. So you can quickly diagnose and fix the problem.

Malfunctioning Freezer Defrost Heater

The freezer defrost heater is responsible for melting any ice that builds up on the freezer coils several times throughout the day. Therefore, should the defrost heater malfunction, no heat is produced, and frost continues to build.

To test whether the defrost heater is to blame, you can perform a continuity test.

A continuity test will determine if an electrical path is present in the component. A failed continuity test will tell us that the electrical path is broken and the defrost heater is no longer functioning as it should.

Malfunctioning Freezer Defrost Thermostat

The freezer defrost thermostat is responsible for tracking the temperature in the freezer and activating the defrost heater once it senses that the freezer coils are too cold. The defrost heater will turn on once the temperature drops below 30.

Therefore, if the thermostat isn’t functioning as it should, it can’t signal the heater to turn on, thus causing the evaporator coils to frost.

Using a multimeter to test for continuity, you can test whether the thermostat is broken. Should the test fail, you’ll need to replace the defrost thermostat.

Damaged Freezer Door Seals

If the door seals on the freezer are damaged in some way, resulting in a gap in the door seal, it can allow warm air to enter the appliance, causing the coils to freeze. 

It’s important to inspect the door seals regularly and replace them if you find them not sitting flush with the refrigerator. 

Some common symptoms of damaged freezer door seals include the formation of ice on the coils, the freezer not reaching the correct temperature, and the door not sealing properly.

How Much Frost Should Be On The Freezer Coils? 1

Malfunctioning Freezer Defrost Timer

The freezer defrost timer is responsible for controlling the defrost cycle of the appliance. Therefore, if the timer is not functioning correctly, the defrost heater won’t turn on when required and thus cause a build-up of frost on your freezer coils.

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