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Refrigerator Evaporator Coil Partially Frosted: What to Do?

Although frost isn’t an unusual thing with refrigerators, it should concern you when the evaporator coil becomes partially frosted or accumulates a lot of frost. When this happens, your fridge’s cooling capacity decreases, translating to heftier energy bills.

Perhaps you’ve just noticed that your fridge is partially frosted over or has a lot of frost build-up. Don’t worry; in this article, we’ll explain everything you need to know about a partially frosted refrigerator evaporator coil, what causes it, and how you can fix it. So, what does it mean when your fridge’s evaporator coil is partially frosted?

When your fridge’s evaporator coil starts to frost over, it’s a sign that the unit is not working as efficiently as it should. It results from the failure of any of the components of the fridge. It could be the door gaskets or the individual elements of the defrost system. Examine the distinct parts of your fridge to see which one needs to be replaced or fixed.

What Causes Refrigerator Evaporator Coils To Freeze Up?

The causes of refrigerator evaporator coil freezing up can be anything really from faulty door gaskets to defective defrost heater, damaged defrost thermostat, or even faulty defrost timer. Even so, the solution is often simple, so you won’t need to replace your refrigerator.

Before I proceed, let me pick it up from the beginning. The evaporator coil is the part of your fridge that’s responsible for cooling. Located behind the back wall of your fridge, this component consists of a set of coils through which refrigerant circulates.

As the refrigerant passes through the coils, it draws heat from the air inside the fridge, making it cold. This cooled air is then blown into the fridge by a fan, keeping the food inside at a constant temperature.

Now, for the evaporator coils to work properly, they need to be free of frost. And that’s where the defrost system comes in. The defrost system is responsible for removing frost from the evaporator coils. It consists of a defrost heater, a thermostat, and a timer.

When you notice that your fridge is partially frosted over, the defrost system is likely not working as it should. It could be a faulty heater, a defective thermostat, or a broken defrost timer. Let’s take a look at each possibility.

1. Faulty Defrost Heater

The defrost heater melts the frost on the evaporator coils. The component turns on multiple times a day to prevent frost build-up. If the heater is not working correctly, frost will start to accumulate on the coils and could be why you’re seeing a lot of frost on your fridge.

To check if the heater is working, use a multimeter. Set the multimeter to the ohmmeter function and touch the probes to the heater’s terminals. If there’s no continuity, the heater is faulty and needs replacement.

2. Damaged Defrost Thermostat

The defrost thermostat works by sensing whether the evaporator coil is cold enough. If it’s cold enough, it triggers the heater to radiate heat and melt any frost. Usually, the coil’s temperature must be below 30 degrees Fahrenheit for the heater to be activated.

If the defrost thermostat is not working properly, it won’t sense when the evaporator coil reaches the activation temperature. As a result, the heater won’t turn on and frost will accumulate on the coil.

To check if the defrost thermostat is working, it’s much similar to the heater. You only need a multimeter to check for continuity. If the outcome suggests no continuity, the defrost thermostat is damaged and needs replacement. Otherwise, it’s probably not the thermostat that’s causing the issue.

3. Broken Defrost Timer

The defrost timer is responsible for turning on the defrost heater regularly. It’s usually located behind the control panel of your fridge. Setting the timer triggers the heater to radiate heat and melt any frost on the evaporator coil.

A broken defrost timer won’t enter the defrost cycle. That causes frost to pile up on the evaporator coil. So, if you’ve checked the heater and thermostat and they are all working fine, probably the problem is with the defrost timer.

Now, checking whether the defrost timer is working is quite different from the previous two. Even so, it’s pretty simple; 

Using your hand or screwdriver, turn the defrost timer clockwise until it clicks. The compressors and the fans should cease. If the heater and the thermostat are in good condition, heat will radiate and melt the frost on the evaporator coil. And if that’s so, the defrost timer is broken and needs replacement. Otherwise, the problem is likely not with the defrost timer.

4. Faulty Door Gaskets

Door gaskets create a tight seal that keeps air from getting in and out of the door. By sealing the door, gaskets maintain the internal temperature of the fridge. So, when they aren’t working properly, humid air might find its way in.

When that happens, the humid air will pass over the colder evaporator coils, condense and freeze faster than the defrost cycle can keep up. That explains why you see a lot of frost on your fridge.

Conduct a dollar bill test to check if the door gaskets are up to par. Close the fridge door on a dollar bill. If you can easily slide the bill out, there’s enough space for air to pass through. In that case, you need to replace the door gaskets.

However, if the bill doesn’t slide out, the door gaskets are still in good shape and not the reason you’re seeing frost on your evaporator coils.

Should Refrigerator Evaporator Coil Have Frost?

Yes, the refrigerator evaporator coil having frost is normal. Actually, that’s why it comes with a defrosting system in the first place. But again, the frost shouldn’t be too much. Otherwise, it will affect the efficiency of your appliance, something you don’t want.

Since refrigerators produce a chilling effect, you could be tempted to think that a lot of frost is normal. But that’s not the case. If there’s too much frost on your evaporator coils, your fridge works harder than usual.

That frost acts as an insulator, making heat escape difficult. As a result, your fridge has to work overtime to maintain the internal temperature, which is unsuitable for the appliance. Not to mention, it will also increase your energy bill.

So, if you see too much frost on your evaporator coils, it’s time to take action. The good news is it’s not that difficult to fix the issue. In most cases, it’s probably because of a broken component that you can easily replace.

How Much Should Frost Be On Evaporator Coils?

Ideally, there should be as little frost as possible on the evaporator coils. That way, your fridge can work more efficiently without using too much energy. As said, much frost compromises the appliance’s performance and could lead to more significant problems down the road.

As such, always try to inspect your fridge regularly. If you see frost accumulating on the coils, take action immediately to prevent further damage. The seemingly small step of defrosting the coils could save you a lot of money in the long run.

How Do I Keep My Refrigerator Coils From Freezing?

The obvious way of keeping your refrigerator coils from freezing is finding out what’s causing them to freeze in the first place and then fixing that problem. You may have to replace a faulty component, change the coils, or do a few operations.

Defrosting is an automatic process if you have one of the latest refrigerators. You won’t need to tire yourself with anything to keep the refrigerator coils from freezing. As long as the defrosting system is up to par, the rest of the things will fall into place naturally.

But again, remember that you still have to maintain the defrost system. Occasionally check the defrost heaters, timers, thermostats, and other essentials to ensure they are working as they should. Otherwise, you’ll still end up with frozen coils.

How Do Defrost Refrigerator Evaporator Coils?

Some refrigerators have an automated process for defrosting the coils. So, if that’s the kind of appliance that you have, you really don’t need to do anything. But if you’ve got one of the old models, you’ll have to do the defrosting manually.

Now, there are several ways of defrosting your evaporator coils. You can do the thermostat defrosting or the heater defrosting. It all depends on what you’re comfortable with.

1. Thermostat Defrosting

This process involves manipulating the thermostat to help activate the melting process. You’ll have to set the thermostat temp a few degrees higher than usual so that the coils can start to thaw. Just ensure that you use a pan to catch the water that will drip from the coils. You can place the pan underneath the exit tube.

2. Heater Defrosting

This is probably the most common method of defrosting coils. With this approach, you’ll need to remove all the foods from the fridge first. Then, turn the thermostat to zero to activate the heater. 

The heat will help melt the frost on the coils. You can use a pot of boiling water at the bottom of the fridge to hasten the defrosting process.Once the coils are defrosted, turn the thermostat back to its standard setting. 

And that’s pretty much all you need to do to defrost your evaporator coils. Just remember always to keep an eye on the condition of the coil so that you can take action right away when necessary.

How To Fix Frozen Freezer Coils?

You can fix frozen freezer coils by replacing any damaged parts. You may need to change the heater, thermostat, timer, or even gaskets if they’re the problem. Sometimes, the coils can be the problem, so you’ll need to change them.

You can try to fix the coils by yourself if you have some knowledge about refrigerator repair. But if you’re not confident about your skills, it’s best to call a professional. Refrigerator repair can be tricky, and you don’t want to worsen things.

But again, the best way is always to prevent the problem from occurring in the first place. As much as it may seem unnecessary, occasional maintenance can save you money and headaches.

So, don’t be too complacent with your appliances. Take good care of them, and they’ll take good care of you.

How Much Does It Cost To Replace An Evaporator Coil In A Refrigerator?

The cost of replacing an evaporator coil in a refrigerator differs depending on the coil size and the brand. However, you can expect to pay between $200 and $500 for the component and almost the same for installation.

So, replacing an evaporator coil can sometimes be more expensive than you’d think. But again, refrigerator repairs are often less costly than buying a new appliance. That said, you’d rather replace the coil if it’s the only problem and you’re satisfied with the overall performance of your fridge.

Final Verdict

While frost is an inevitable part of having a refrigerator, too much of it on the coils can be a problem. It can cause your fridge to work less efficiently and, in some cases, break down completely.

That’s why it’s essential to know how to deal with frosted coils. The good news is, it’s not that difficult to defrost them. You can do it manually or let the fridge do it for you. But with good maintenance, you can prevent the coils from frosting over in the first place.