A refrigerator evaporator plays a vital role in how well a refrigerator works. But it can develop problems that need immediate attention and solutions.
Table of Contents
How Does a Refrigerator Evaporator Work?
Here is how a refrigerator evaporator works in the refrigeration cycle:
Once you add a refrigerant to the compressor, the motor constricts it and raises its pressure. Then, it pushes the gas out of the refrigerator and into the condenser coils. When the refrigerant, which is now in the form of hot gas, reaches the coils, the cooler ambient temperature cools and turns the gas into a liquid.
While still at high pressure, the liquefied refrigerant flows from the condenser coils to the evaporator, and it cools while doing so. When it gets inside the refrigerator and into the evaporator, the refrigerant in its liquid form absorbs the heat. That process removes the warm air from the refrigerator, thereby creating cold air.
The evaporator evaporates the refrigerant and turns it back to gaseous form. It is in that form that it returns to the compressor. And the cycle repeats itself.
What Does a Refrigerator Evaporator Fan Do?
A refrigerator evaporator fan spreads cold air inside the refrigerator after drawing it and passing it over the evaporator coils. The refrigerant turns from gas to liquid and flows to the evaporator coils. The liquid is cold when it gets to the evaporator coils, so when the evaporator fan draws the air over the coils, the air becomes chilly. That is because the refrigerant absorbs all the heat from the warm air and leaves it cold.
The evaporator fan takes the now-cold air and spreads it throughout the freezer. From the freezer, the cold air moves through the damper into the refrigerator. So, both compartments have cold air.
Refrigerator Evaporator Fan Always Running – What to Do
The evaporator fan should run whenever the compressor runs. It should turn off when the compressor turns off for the defrost cycle. In other words, it should not run all the time. So, if you find that the evaporator fan in your refrigerator runs all the time, here is what to do:
1. Check the Defrost System
If the defrost system is malfunctioning, the evaporator fan will keep running to generate and spread cold air in the refrigerator. One of the first things to do is to check the evaporator coils. An ice buildup on them confirms the defrost problem. And one of the main reasons why the system malfunctions is a faulty defrost timer.
To test the timer, locate it in your refrigerator. Consult your user manual for its exact location, though most refrigerators have them either at the back, behind the base grille, or inside the temperature control housing. When you find it, turn the timer to advance it manually; it goes in just one direction.
The defrost heater should turn on as the compressor goes off to start the defrost cycle. Wait about thirty minutes and check whether or not the timer advances out of the cycle automatically. If it does not advance out, it is faulty and should be replaced.
But if the defrost timer is the electrical type, check it by running a continuity test using a multimeter. If there isn’t any continuity, replace the defrost timer.
The defrost cycle runs on how well the timer functions. It times the cycle and determines when to shut off the compressor and other cooling system components so the cycle can run. If it develops a fault, the cycle won’t run, and the evaporator coils freeze. As a result, the fan runs non-stop as it tries to keep the refrigerator cold.
But if the timer is in good working condition, check the defrost thermostat. The thermostat is typically on the evaporator coils. In some cases, it comes with the defrost heater as one assembly. When you find it, test it using a multimeter to check for continuity. If the thermostat shows no continuity, it means it is defective, so it needs a replacement.
The defrost thermostat has the job of sensing the temperature needs of the evaporator coils. When the coils get too cold, the thermostat senses it, closes its contacts, and allows the heater to turn on. That way, the heater warms the coils and prevents freezing.
However, if the thermostat fails, it cannot sense how cold or warm the coils are. Therefore, it won’t close contacts. Consequently, the defrost heater cannot run on when necessary, and the coils freeze. That keeps the refrigerator from getting cold, and the fan runs to maintain a cool temperature.
In the event of finding the thermostat working well, check the heater. It is right under the evaporator coils, where it turns hot and warms them. Take a multimeter and test the heater for continuity. Replace the heater if you find no continuity.
If all else fails, check the defrost control board. While control boards hardly fail, it is necessary to check them if nothing else seems to be the problem. The board governs the system’s functions, so if no component is faulty, consider replacing the control board.
2. Check the Cold Control Thermostat
Turn the thermostat to its warmest setting and wait for the compressor and fan to turn off. The warm setting alerts the cooling system to the need to keep the refrigerator warm. So, the system should automatically go off. But if the fan and other cooling system components keep running even with the thermostat set to warm, you have a faulty part.
The cold control thermostat closes contacts and powers the cooling system when the refrigerator’s internal temperature is not cold enough. When the need arises, it turns off the cooling system to prevent freezing. But if any part of the cooling system continues to run without shutting off intermittently, the thermostat may have failed.
3. Check the Door Gasket
Age can cause the door gasket to stop sealing tightly, leading to the escape of cold air. Poor usage can have the same result. Take a look at the gasket, which is the rubber part running around the door, to see if it is loose. Sometimes, it comes loose through the handling of the door.
If the gasket is loose, simply push it into place using a small screwdriver. Ensure it fits behind the gasket retainer before closing the door. But if the gasket appears weak, test it to verify. Place a thin paper between the door and the cabinet, and close the door. Make sure a part of the paper is sticking out.
Next, pull the paper as if you want to remove it from between the refrigerator cabinet and door without opening the door. The gasket is weak if the paper comes out; a working gasket will hold the paper tightly. Replace the refrigerator door gasket.
Dirt on the gasket can also cause poor sealing. Inspecting it will let you know whether or not you need to clean it. If it is dirty, use warm water and soap to clean it. Scrub hard-to-reach crevices with an old toothbrush, but don’t scrub too hard.
The door gasket seals cold air inside the ref4igerator and keeps warm air out. That way, the internal temperature is not compromised. But if the evaporator fan starts running without stopping, it may be that the gasket is leaky, letting cold air escape and increasing the need for more cold air.
4. Check the Fan Motor
The fan’s motor may be defective, stemming from an electrical short causing the fan to run without stopping. Test the motor windings with a multimeter to check for continuity. If the motor shows a short or a faulty terminal, replace it.
Replacing a Refrigerator Evaporator Fan
The following are steps to replace the evaporator fan in a refrigerator:
Step 1
Disconnect the refrigerator from electric power. If you cannot reach the wall outlet, flip the switch of the circuit breaker. Empty freezer section by removing the food items and the shelves, rack, and bins. Store perishable foods in a well-insulated cooler or another refrigerator.
Step 2
Unmount the screws that secure the rear panel of the freezer section. Carefully lift off the panel to see the evaporator fan attached to it by wire harnesses. Disconnect the harnesses and separate the fan from the panel.
Step 3
Pull the blades of the fan from the motor shaft. Set them aside, turn the fan over, and separate the motor from the fan’s shroud.
Step 4
Put a new fan motor in the place of the old one, turn it over, and put a new fan on the shaft in the position of the old one. Discard the old fan and motor. Now, set the new fan in place on the panel and reconnect the wire harnesses.
Step 5
Sometimes, you may find that the wire connectors from the old fan don’t match the new one. If that is the case, remove the fan and shroud. Pull the motor out and cut the harnesses from the wires’ ends. Also, cut the harnesses from the wires in the freezer.
Step 6
Peel a third of an inch of insulating material away from the cut fan wires and the cut freezer wires. Next, make a connection between the two sets of wires, making sure to match the colors. You will find a crimp connector with the new fan; place it over the connected sets of wires. Then, crimp the attached connectors to the wires.
Step 7
Replace the fan and shroud in place inside the freezer. Position the rear panel and mount the screws to secure it. Finally, put back the shelves, racks, bins, and food items into the freezer, and reconnect the refrigerator to power. If you turned off the circuit breaker instead of unplugging, turn it back on.
Here is a video showing how to replace the evaporator fan in a refrigerator…
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Refrigerator Compressor Is Cold [How to Fix]
Refrigerator Compressor Shuts Off [How to Fix]
Refrigerator Evaporator Coils Are Frosted Up – How to Fix
If you find that the evaporator coils in a refrigerator are frosted up, check the following:
1. Defrost Heater
Find the defrost heater under the evaporator coils. The coils are behind the interior back panel in the freezer. After disconnecting the refrigerator from electric power, pull the heater out and run a continuity test on it. If the heater has no continuity, replace it.
It is the job of the defrost heater to warm the coils when they get too cold. The defrost timer turns the heater on a few times every day when the temperature of the evaporator coils drops lower than the preset point. So, if the heater fails to work, the temperature will keep falling, and the coils will frost up.
2. Defrost Timer
Find the timer in your refrigerator. Some timers are mechanical, while others are electrical. Therefore, determine what type of timer your refrigerator has. If it is the mechanical type, turn the timer using a screwdriver or with your hand.
If the timer clicks, the cooling system should turn off, and the defrost heater should turn on. This should be the case as long as the heater and defrost thermostat are in good working condition. If the heater turns on and the defrost cycle starts, you know the timer is faulty and should be replaced.
But if the timer is the electrical type, run a continuity test on it using a multimeter. If you find no continuity in the timer, replace it.
The defrost timer controls the timing of the defrost cycle, ensuring the thermostat closes contacts, and the heater turns on. It shuts down the compressor and fans so that the cycle can work. But if the timer becomes defective, the defrost heater won’t turn on, and the evaporator coils will keep getting cold. Eventually, they will frost over.
3. Defrost Thermostat
Most refrigerators have their defrost thermostats on the top of the evaporator coils. But check the user manual of your refrigerator to find it in yours. Take a multimeter and test the thermostat for continuity. If the thermostat shows no continuity, replace it.
The timer must turn the heater on, but before the heater turns on, the thermostat must close its contacts when it detects the temperature of the coils is too cold. Then, it allows power flow to the heater. However, if the thermostat fails to work, the heater won’t come on. Consequently, there will be an accumulation of frost on the evaporator coils, and they will freeze.
4. Door
First, open the door of the refrigerator. Then, check the gasket for looseness, weakness, and dirt. If the gasket is loose, you can repair it by pushing it into place with a small screwdriver. Close the door and check the effectiveness of the gasket over time.
If the gasket is not loose or repairing it does not fix the problem, it may be weak. When it is weak, it lets humid air into the refrigerator. The moisture in the air may settle on the coils and freeze over time. Therefore, use the dollar bill or paper trick to check the gasket.
Close the door on a dollar bill of your choice or a thin paper. Pull the dollar bill to remove it; if you can, it indicates the gasket does not seal tightly anymore. It is compromising the cold air in the refrigerator. Not only will it cause the coils to freeze, but it will reduce cooling in the refrigerator. So, replace the gasket.
If the gasket has dirt on it, it won’t seal tightly. Therefore, clean the gasket, ensuring you reach the crevices to remove every trace of dirt. Wipe it dry afterward so the moisture does not freeze over time.
Opening the refrigerator door too often or not tightly shutting it has the same effect on the coils as a leaky gasket. The same applies when you hold it open for too long. So, reduce the number of times you open the refrigerator door a day. And when you do, ensure you shut it tightly and entirely.
It also helps to decide what you want before opening the door. That way, you don’t hold it open while deciding. It reduces the length of time you keep it open and eliminates the quick escape of cold air and entrance of warm air.
Refrigerator Evaporator Fan Starts and Stops – Quick Fix
There may be a loose wire, or the fan motor may be faulty if the evaporator fan in a refrigerator starts and stops. Typically, an evaporator fan should run when the compressor runs. Once the defrost timer shuts the compressor down for the defrost cycle, the fan shuts down, too. And when you open the freezer door, the fan stops.
If none of the above is what you are experiencing, check the blades to ensure nothing is obstructing them. You may have to clean them and oil the shaft for better functionality. But if the blades are not jammed, check the fan’s motor for continuity with a multimeter. Replace the motor if there is no continuity.
Benefits of Dual Refrigerator Evaporator
Here are some of the benefits of a dual evaporator refrigerator:
1. Different Cooling Capacities
The refrigerating section does not have to get as cold as the freezer section. And it does not have to wait for the cold air in the freezer before it cools. Many refrigerators share one evaporator system. The evaporator coils cool the freezer first before the cold air gets to the refrigerator.
However, if there is a problem with the evaporator, both sections stop cooling. The refrigerator is affected because it is usually not as cold as the freezer. And if the air vents are blocked, or the damper control stops working, the refrigerator stops cooling. A dual evaporator system eliminates some of these issues.
2. Humidity Control
The two compartments in a refrigerator need differing humidity levels. The temperature in the freezer means the section needs lower humidity. Frozen food does not need humidity because it does not need to stay fresh – humidity in cold temperatures leads to a frost buildup.
On the other hand, the fresh food compartment needs a slightly higher humidity level than that in the freezer. It helps to keep the food fresh for a longer time. However, it should not be excessive.
What a dual evaporator system does is regulate the humidity in both compartments. That way, each compartment has the right level of humidity.
3. Smell Control
Sharing the same cooling system means sharing the same air, good or bad. If there is any bad odor coming from the freezer, it will travel to the refrigerator, and you cannot control it. The only way to fix it in such a situation is to keep both compartments clean.
It does not cost as much to run a dual evaporator refrigerator as it does to run a dual compressor evaporator.
Refrigerator Evaporator Leak – Solved
To solve the problem of a leaking evaporator in a refrigerator, do the following:
Disconnect the refrigerator from electric power or trip the circuit breaker. Next, empty the freezer section and store perishable foods in another refrigerator or a cooler with ice packs. Unmount the screws holding the interior back panel in place and remove the panel.
Find the clamps holding down the evaporator. Then, remove them using a quarter-inch nut driver or a Phillips screwdriver. Lift the evaporator out of the compartment and locate the leak. Typically, it is challenging to find such a leak with the naked eye. So, try using a bubble solution or a freon sniffer to locate it.
When you locate the point on the coil with the leak, it is crucial to close it. You can use a special patch to repair the leak. Otherwise, go to a hardware store close to you and find a suitable replacement.
If you are not sure how to fix a sealed system leak, hire a professional to check the refrigerator. The professional will find the leak and fix it permanently. It is the best solution.
Refrigerator Evaporator Drain Clip – What It Does
The drain clip on a refrigerator evaporator conducts heat from the defrost heater. When it is warm, it prevents the drain from freezing up. Not all refrigerators come equipped with a drain clip, but you can purchase one and attach it to the evaporator.
Refrigerator Evaporator Drain Clogged – What to Do
If the drain under the evaporator in the freezer is clogged, find out what is obstructing it. If there is ice over it, pour hot water over it to melt the ice. Once the top of the drain opens, fill a turkey baster with warm water and squirt it down the hole in a forceful manner.
Clean the drain hole once the water runs clear and free. Mix equal parts water and bleach or a quarter measure of baking soda and a three-quarter measure of water. Pour the mixture down the hole to clean it. You can also push stubborn debris out with a stiff wire before cleaning it.
More times than not, ice covers the drain and keeps water from flowing out. As a result, you will have a leaking refrigerator.
However, before ice covers the drain, there must be debris inside the drain. The debris prevents the free flow of water out of the freezer. Over time, the water backs up and freezes in the freezer and over the drain.
Refrigerator Evaporator Drain Pan – What It Does
The drain pan into which defrost water flows from the freezer is usually under the refrigerator. You will find it beside the compressor or through the front grille. Consult the user manual for the refrigerator to locate the drain pan.
Some refrigerators have drain pans you cannot remove, but most have removable drain pans. Ensure it is empty and clean; if you cleaned the drain recently, it is important to empty the pan, wash, and sanitize it.
If you can remove it, pull it out from under the refrigerator. Empty it and put it under running water. Pour some soap into the pan and scrub it using a brush with soft bristles. Rinse it thoroughly afterward and add some bleach to sanitize it. Note that the bleach may change its color if the pan is not originally white. White vinegar also does the same job as bleach if you would rather use it.
Wash off the bleach or vinegar, dry the drain pan, and put it back under the refrigerator. Ensure you set it correctly, so that defrost water does not spill under the appliance.
Refrigerator Evaporator Fan Making Noise – How to Fix
Ensure nothing is in the way of the fan blades. If there is an ice buildup around the fan, the blades may hit it and create noise. Use a dryer or steamer to melt the ice. You will need to troubleshoot your defrost system after fixing the fan.
Then, check the shaft; it should turn freely. Otherwise, it is a pointer that the motor is faulty and you need to purchase a new one. The same solution applies if the motor appears to be generating the noise or is not running.
Check the grommets on which the fan sits. Unplug the refrigerator from power, remove the inside back panel, and inspect the grommets. You will be able to tell whether or not they are loose or worn by looking at them or touching them. Replace the grommets if they appear loose or worn.
Over time, the grommets may become loose or wear out. And when either happens, the fan will become unstable and generate noise when it moves.
Refrigerator Evaporator Fan Not Getting Power – Quick Fix
Disconnect the refrigerator from electric power, take a multimeter, and set it to AC voltage. Attach the probes of the multimeter with clips and place them in such a way that they don’t touch the refrigerator’s body or each other.
Reconnect the refrigerator to electric power and check the reading on the multimeter. You should see 120V, but if you see 0 on the meter, the motor is indeed not getting power. Disconnect the refrigerator from electric power again, and check the thermostatic control.
Pull out the control and check for continuity between the wires’ ends. Replace the control if the wires are working well.
Refrigerator Evaporator Fan Not Running – Solution
Unplug the refrigerator from the wall outlet and check for any physical obstruction to the movement of the fan. There may be an ice buildup around the blades. And constantly hitting the ice destroys them. Replace the blades alone if they are bent.
Sometimes, the bearings of the motor need oiling. Applying a little oil will fix the problem and get the fan running again. However, if none of these apply, you may need to replace the motor if it has no continuity.
The fan motor may not be receiving enough voltage to run. Therefore, check the voltage, and if there is none, check the thermostatic control. Replace the control if it has no continuity.
Refrigerator Evaporator Partially Frozen – Solved
If you find that only one part of the evaporator coil is frozen, it means there is a leak in the sealed system. Take a look inside the freezer; if only one shelf is freezing, it is a confirmation.
Hire an appliance technician to check the sealed system and find the leak. Adding more refrigerant won’t solve the problem; it will only leak out. According to EPA laws, it is illegal to do that.
With older refrigerators, repairing the leak may not be cost-effective. Replacing the refrigerator is usually better. But for newer and high-end refrigerators, repair the leak, even though it is unlikely to happen.
What Is the Difference Between Evaporator and Condenser?
An evaporator in a refrigerator is where the refrigerant goes to absorb the heat in the refrigerator. As it absorbs the heat, the refrigerator’s internal temperature cools. Then, the fan blows the cold air around.
A condenser in a refrigerator, on the other hand, holds the hot refrigerant when it flows out of the evaporator. It is there that the heat in the refrigerant dissipates. Then, the refrigerant flows back to the evaporator to absorb more heat and returns to the condenser.
The evaporator coil is usually located within the walls of the refrigerator. In most refrigerators, you will find it in the freezer compartment, behind the inside back wall. From there, it cools the refrigerator.
The condenser coil is typically on the outside, at the bottom back, near the compressor. Its location makes it easy to release heat into the atmosphere, so it does not adversely affect the refrigerator.
Recap
A refrigerator evaporator is a vital part of the cooling system. Without it, the refrigerator won’t function correctly. And if it freezes, there will be no cold air for the refrigerator. Therefore, if you notice any problem with it, find a solution immediately. We have discussed issues that can occur with a refrigerator evaporator, and it is a guide for solving such problems.
Remember to disconnect the refrigerator from electric power before repairing or replacing any refrigerator part. And if any repair proves difficult, hire a professional to do the job.
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