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Refrigerator Evaporator Coil Partially Frosted

The refrigerator evaporator coil cools refrigerant for better absorption of heat. Sometimes, you will notice that there is a bit if frost on your coils. It’s not a big deal, and you don’t have to replace them right away.

The only time you should worry about your refrigerator evaporator coil is when there is too much frost on it. Frost levels higher than 1/8 inch can cause problems with how well your fridge functions, and may even cause it to stop working altogether.

The cause of a partially frosted evaporator coil is the passage of humid air over the coils. Usually, this happens when you leave the door open while running the refrigerator or freezer. What this does is that it causes condensation to form on the inside walls and ceilings of your refrigerator, which then freezes onto your evaporator coil.

Reasons why your Evaporator Coils Freeze Up

If you are wondering why there’s frost on your evaporator coil, here are some possible reasons.

Worn or damaged door gaskets

If your refrigerator has a frosted or partially-frosted evaporator coil, it is usually due to a faulty door gasket. Door gaskets work by preventing air from getting into your fridge and ultimately forming moisture. As you can imagine, a worn or damaged door gasket will allow air to seep through.

This air will then condense once it gets to the evaporator coils and inadvertently causes them to freeze up, and that is when you will notice the frosting. This consequently renders the defrost cycle of your fridge useless leading to the accumulation of frost and a malfunctioning appliance.

Faulty defrost thermostat 

A faulty defrost thermostat can cause your evaporator coils to freeze up. The thermostat’s work is to detect frost and send signals to the heater regularly throughout the day to melt any frost that may have formed on your coils.

A common problem is that the thermostat’s oil level is too low. This can cause the interlock system to not work properly and prevent the heater from coming on properly when needed. 

You should check your thermostat for proper operation, including making sure that it’s properly affixed, and that it has proper heat-sensing functionality.

Malfunctioning default timers

Another common reason behind the freezing up of evaporator coils is malfunctioning default timers. Default timers work by automatically turning on the heater to melt any frosting on your coils at set intervals.

Now, think of what would happen if the timer was not working. Of course, your refrigerator, wouldn’t get the signal to turn on the heater and there would be an accumulation of frost.  

Broken defrost heater

The defrost heater functions by melting any frost that forms on your evaporator coils. This is because it produces heat just as the name implies. The heating occurs severally throughout the day when the thermostat perceives low temperatures.

With a damaged defrost heater, there will be no melting of frost, so you can expect a buildup.

How Much Frost Is Safe On Evaporator Coils?

There is no definitive answer to that question because there are different refrigerator sizes. That said, you want to keep in mind that the less frost in an evaporator coil, the more efficient your refrigerator will be at cooling food and drinks. 

With less frost, you also get to save on electricity costs and increase the lifespan or extend the useful life of your refrigerator.

Locate your refrigerator’s coil

The refrigerator evaporator coil is a copper component usually found at the back of your freezer section and it looks like a radiator. In order to repair or clean this part, you will have to detach the back panel of your fridge. You can do this by taking off the two screws on each side of the back cover.

As you begin to do this, you want to make sure that your refrigerator is disconnected from its power source. You also need to have a flashlight or some other source of light. Use it to illuminate any obstructions inside your fridge as well as any other parts that might be in the way. 

It’s important not to hurt yourself when removing these obstacles because some parts are fragile and can easily break if you drop them.

Once you have your light source, use it to find where your refrigerator’s evaporator coil is located behind your fridge’s freezer compartment. This is where the fan is located as well, so you may want to clean it up if it has buildup.

How to prevent your refrigerator coils from freezing

When your refrigerator coils freeze, the problem often begins with a buildup of frost around the evaporator coils. This can reduce the cooling power of your refrigerator and cause it to operate less efficiently. 

When this happens, you may want to check for signs of abnormality and make sure that it does not cause any damage or safety concerns.

Want to get rid of the frosting? Here’s what you can do.

Defrost manually

To do this, you want to turn off your fridge, empty it, and place paper towels below or anything absorbent to hold the frost when it melts.

Use a thermostat

Here, you need to set your thermostat to a preferred temperature. You then want to place a container behind your fridge where water running through the exit pipe will be collected.

Use a heater

This method requires you to empty the fridge and then set the thermostat to zero. After that, you need to switch on the heater to facilitate the movement of warm air into the compartments and evaporator coil.

The frosting will melt and collect in a water tray at the bottom of the refrigerator.

What is the Cost of Replacing a Refrigerator’s Evaporator Coil?

It’s no secret that evaporator coil replacement is costly. However, you want to keep in mind that different sizes and brands cost differently. On average, you can get one for $200 – $1,500. Installation costs up to $1,200.

That means that it would cost you roughly $700 to $2,700 for a complete replacement.