Refrigerator Not Defrosting: Top 6 Reasons & How to Fix (With Video!)

Is your refrigerator transforming into an igloo instead of keeping your food cool and fresh? It’s time to tackle that pesky defrosting issue head-on before frost takes over your fridge. Dive into our easy-to-follow guide and discover how you can bring your appliance back to its prime; don’t miss the helpful how-to video just below to walk you through the process!

If your refrigerator has a problem with the ability to defrost, you may notice an ice buildup and assorted issues with cooling the rest of the refrigerator. Before you get underway with an inspection of any of the refrigerator parts, it’s essential to make sure the work area is safe. The circuit breaker should be turned off or the refrigerator should be unplugged. The water supply under the kitchen sink should also be turned off. Follow this easy guide to diagnose which refrigerator part failure may be the problem.

How do you force a refrigerator to defrost?

Many newer refrigerator models can be forced into a defrost cycle, though how you start this cycle depends on the brand and model of your fridge. For some, it involves pressing the refrigerator light switch a certain number of times, for others, you can activate forced defrost from the front control panel by going into debug mode. Consult your appliance’s manual for specific instructions, or pack up all that frozen food in a cooler and do a manual defrost.

What to do if a fridge is not defrosting?

If you’re finding frequent frosty build-up in your fridge, you’re going to want to diagnose the source of the problem. You won’t be able to properly troubleshoot if there’s ice in the way, though, so get rid of that ice by either manual or forced defrost. Once your freezer’s cleared out, you can start checking parts. Continue with this guide to figure out what’s keeping your fridge from defrosting.

Once you have identified the part needed to repair your refrigerator, search below using your specific refrigerator model number to identify the exact part needed:

1. Defrost Timer

There are a few things that can cause a refrigerator to stop defrosting and troubleshooting the issue can give you insight into any repairs or replacements that need to be made. The first thing to look at when a refrigerator isn’t defrosting is the defrost timer. This is the part that turns on and off the defrost cycle on the refrigerator and it may no longer be working properly. This component is made up of a motor along with contacts and gears. It moves the refrigerator from cooling cycles to defrost cycles and prevents ice from building up on the evaporator. The defrost timer is made to cool the refrigerator for several hours and then defrost for a certain number of minutes.

You’ll typically find the defrost timer in the control panel on the refrigerator but sometimes it may be found behind the kick panel at the bottom of the appliance. If the defrost timer is no longer working the way it should be, it can cause the refrigerator to stop defrosting. It can also lead to large amounts of ice on the evaporator which can make it hard for the refrigerator to cycle cold air around.

There are two ways to test whether the defrost timer is working. One way involves making a mark on the timer shaft and paying attention to where you place it. Take a break for a few minutes and come back to see if the location of the mark has changed. If the mark hasn’t moved, the motor or gears of the defrost timer may be bad and the component will need replacement.

The other testing method is quicker and involves using a screwdriver to move the timer shaft manually. As soon as it reaches defrost mode, there should be a sound when the heater activates. However, the refrigerator will need to be plugged in for this to occur. Next, find the heater behind the refrigerator and wait a few minutes before checking for heat. If there is none, a replacement will be needed.

2. Defrost Thermostat

If the first component is working well, the next thing to inspect is the defrost thermostat. This can go bad and cause the refrigerator to stop defrosting. The defrost thermostat is a safety part that turns the defrost cycle off if the refrigerator gets overly warm. It also makes the defrost come on when it is needed. In most cases, the thermostat will have writing on it that tells you when the cycle should turn on and off.

Most of the time, the defrost thermostat is found behind the back wall of the fridge on the evaporator. If there is ice building up in this area, it can indicate that the part has gone bad. Sometimes when it goes bad, the full evaporator will become encased in ice. Before moving to other testing, first, check whether the thermostat is hotter or colder than the reset temperature. If it’s warmer, the thermostat may not be working.

A multimeter set to the continuity setting should be used for testing. First, make sure the unit is working by placing the probes against each other. If everything is working well, the probes can be placed on the bare wires or the terminals on the defrost thermostat. When the part is cold, continuity should be shown. If this isn’t the case, it will need to be replaced.

3. Defrost Heater

If all the components are working so far, the next thing to look at is the defrost heater if the defrost isn’t working in the refrigerator. This is a part that helps melt ice when it starts to build up on the evaporator. There are many different styles of defrost heaters but they are all tasked with doing the same thing. A defrost heat will melt ice to keep the refrigerator cooling and defrosting the appropriate amount.

Typically, the defrost heater will be found behind the freezer wall and at the sides and bottom of the evaporator. If the part fails, it can prevent the refrigerator from defrosting. It can also make it harder for moisture in the air to circulate through the machine so a continuity test needs to be done. First, take a multimeter set on continuity and put the probes together to test it. Then take the probes and place them on the wires to see if continuity is present. If there is not, this component needs to be replaced.

4. Defrost Temperature Sensor

Assuming the components above are in good shape, the next place to look is the defrost temperature sensor on your refrigerator. This part is designed to determine the temperature by the evaporator and provide it to the control board. It has a bulb shape and is made out of white plastic. It can provide an indication of what the temperature is when the defrost cycle is one. If the temperature is too warm, it also turns off the heater, but it can’t do that if it isn’t working.

Many temperature sensors are found in a refrigerator, but the defrost sensor is most likely in the freezer area behind the back wall near the evaporator. If it isn’t working, it can stop defrosting and make the refrigerator too cold. This part needs to be removed from the appliance before it is tested.Similar to other components, the defrost sensor has wires that connect somewhere nearby. If they can be unplugged, that’s the first thing that should be done. If they can’t, the wires need to be cut out of the refrigerator. After this has been done, the next step is to take the ambient air temperature. Take a look at the refrigerator user manual to find the temperature and its corresponding ohms for testing.

How do I know if my defrost sensor is bad?

Set the multimeter to ohms in order to read the defrost temperature sensor. Place the probes on the bare wires or the wiring harness pins to get a reading. Make sure the number that is shown is close to the one mentioned in the user manual. If the number is off or there is no reading, the defrost temperature sensor needs to be replaced.

5. Defrost Thermal Fuse

The next part to look at is the defrost thermal fuse, which shuts off the defrost cycle any time it gets too warm inside of the freezer. This fuse cannot be rest, and if the temperature rises too high during defrosting, the fuse will blow and shut off the power to the defrost heater. Sometimes the defrost thermal fuse can be bought by itself, and other times it will come bundled with a defrost temperature sensor. In most cases, this component is going to be mounted behind the back wall of the freezer on the evaporator. If the fuse has failed, it can cause the freezer to stop defrosting. Most times, the defrost thermal fuse will include a wire harness that can be unplugged so you can test them. After you have access to it, it will need to be tested for continuity.

Put your multimeter on continuity mode. If your defrost thermal fuse comes with a temperature sensor, follow the wires to the wiring harness connector so you can be sure you’re testing the fuse. Touch one probe to each terminal and check for continuity. If it doesn’t, it will need to be replaced.

6. Defrost Control Board

Finally, the defrost control board can sometimes result in a refrigerator that isn’t defrosting. It’s responsible for controlling the refrigerator’s defrost cycle. This is done to ensure the evaporator coil doesn’t become covered in ice build up. In some cases, the defrost control board is built into the main control board, but in others, it comes as an individual component.

Sometimes the control board will be mounted behind the refrigerator controls, and other times it will be behind the back access panel. If the refrigerator isn’t defrosting, it could be due to a problem with the defrost control board working properly. However, many boards have been used over the years, so you will need to look at your user manual for specifics. Run the diagnostics to see if the part is no longer working and will need to be replaced.

Where To Find Us

Have you gone through diagnosing this problem and still haven’t fixed the problem or found the solution? Please reach out to us at AppliancePartsPros.com, we are always happy to help. Since 1999, AppliancePartsPros.com has helped millions of people repair their broken appliances by providing high-quality original parts at well below retail prices, free tech support and troubleshooting, and award-winning customer service! We’re open 7 days a week. Visit our site at https://www.appliancepartspros.com or call us at 877-477-7278. Over 90% of orders delivered in 1-2 days with guaranteed overnight shipping available! 365 days to return any part.