How To Test The Whirlpool Adaptive Defrost Control Board

How To Test The Whirlpool Adaptive Defrost Control Board

As technology develops, appliances are becoming smarter. Refrigerators in particular have come a long way from being a cold box. They are capable of doing so much more than your father’s refrigerator thanks to smart technology.

That includes the adaptive frost controls. These controls help to make refrigerators more energy-efficient than ever before. They also break down from time to time. If you want to test your Whirlpool refrigerator’s adaptive defrost control board, there are two methods. You can try turning the thermostat on and off again to see if the control board kicks on. You can also try pulling the power to the refrigerator entirely and then plugging it back in, effectively “resetting” the device.

What Does the Adaptive Defrost Control Do?

The adaptive defrost controls shut down the cooling devices within the refrigerator, redirecting power to the defrost heater during a defrost cycle. When the cycle has ended, the adaptive frost controls then redirect the necessary power back to the fans and the compressor.

This is different than a defrost timer. The adaptive frost controller only defrosts when the freezer or refrigerator actually need to. When the freezer or refrigerator are not in use, defrosting will not happen nearly as often.

How Does the Adaptive Defrost Control Work?

The adaptive defrost controls work to constantly adjust the defrost intervals in your refrigerator and freezer. The defrost intervals are based on the compressor run time as well as the number of door openings that the refrigerator and freezer have.

The defrost control has a microprocessor in it which gathers up the necessary information about the system defrost requirements. It then processes that information, using it to create more energy-efficient defrost cycles.

During a defrost cycle, the board watches the refrigeration system, analyzing the total run time of the compressor. That information, in tandem with the previous defrost cycle, provides the determination for the length of the next defrost cycle.

Non-Volatile Memory Technology

The key behind these adaptive controls is the non-volatile memory technology that the control board employs. That memory leads to the storing of fault conditions coming through power outages. The most common faults found will be in the compressor, thermostat, and failures in the defrost heater.

The fault codes are then displayed through a circuit board LED which flashes in specific patterns to discern each type of problem. When repairs have been made and normal operations restored, the LED light is cleared and stops flashing or blinking.

Testing the Adaptive Defrost Control Board

On your Whirlpool refrigerator, there are two different methods for testing the adaptive defrost control board. The most common way to test it is through the manual initiation of the defrost cycle. Here are the two different ways to run a test on your adaptive defrost control board.

Method 1: Turn Thermostate Off

This one is relatively straightforward and involves turning the thermostat on and off again. Turn off the thermostat for 15 seconds before turning it back on again for 5 seconds. In these same intervals, repeat the process three times before finally turning the thermostat off once again.

After turning off the adaptive defrost control board for the fourth time, you should see it turn on the defrost heater, provided the bimetal is closed, after anywhere from 3-8 seconds.

The test mode terminates when that bimetal opens, so make sure that it stays closed. Should the freezer or refrigerator already be in defrost, the test mode can be stopped by simply unplugging the entire unit from the outlet. Wait 30 seconds before you plug it back in.

If it fails to initiate a defrost cycle, then you can try the second procedure instead.

Method 2: Unplug the Unit

The second method is much quicker than the first and is a little easier, too. Simply pull the plug from the wall outlet for about 30 seconds. The thermostat (and the rest of the components) will turn off. Give it about 30 seconds before plugging the unit back into the outlet again.

Wait 3-8 seconds for the adaptive defrost control board to turn the defrost heater on. Again, the bimetal has to be closed for this to work. Should the unit not go into defrost mode, then the adaptive control board is likely not the culprit here.

The more likely cause of the issue here is a defective bimetal. The adaptive defrost control board will only go into Test Mode when the bimetal is closed. If it senses that the bimetal is open, then it will go back into cooling mode after somewhere between 4 and 8 seconds.

A Helpful Hint

There is one little helpful hint that can tell you if your adaptive defrost control board is working properly. When it enters Test Mode, the relay that is mounted to the adaptive defrost control board should turn the defrost heater on and the compressor off.

You will hear a click when that change happens. Should the relay click once when it goes into Test Mode, then check the defrost heater for continuity. Should you hear two clicks, then check to ensure that the bimetal is closed.

How to Manually Initiate/Terminate the Defrost Cycle

When the adaptive defrost control board is out of commission, you may have to execute or terminate the defrost cycle manually. Doing so is a temporary measure until you can have the refrigerator serviced and the part replaced.

Forced Defrost Cycle

In order to initiate a forced defrost cycle, start by cycling the cold control off and on. You will have to cycle it three times within a six-second span. It is important to remember that the cold control has to be left on the closed position in order for the defrost system to properly energize across all platforms.

Cycling the cold control knob is not enough. You must also open and close the contacts manually. You can open the doors for a short period of time if need be to force the control to call up the cooling command. Most of the time, you should be able to hear the contacts close and open when they are working properly.

Terminating the Force Defrost

When you are done running the forced defrost cycle, it comes time to end that cycle. The process is simple: just disconnect the power to the entire unit for five seconds. It should “reset” the fridge, terminating the forced defrost as well.

Related Questions

What are the Signs of a Bad Defrost Thermostat?

When you have a faulty defrost thermostat, it may result in the defrost heater failing to turn on. When the heater fails to turn on, then there may be a buildup of frost on the evaporator coil. If the evaporator coil can’t do its job, then the temperatures start to rise and can defrost the items within your freezer.

Another telltale sign is the positioning of the defrost thermostat. When your refrigerator or freezer is cold, the defrost thermostat should be set to the closed position. Check to make sure the thermostat is working properly by making sure that the thermostat opens at the right temperature.

You can test this by putting it in water and then slowly heating that water. Most defrost thermostats have been designed to open at temperatures ranging from 40F to 90F.

Can You Bypass a Defrost Thermostat?

If you have been experiencing issues with your defrost thermostat, you may be wondering if you can simply bypass the thing entirely. The short answer is that you should absolutely not, under any circumstances, bypass the defrost thermostat.

Bypassing the defrost thermostat is a major fire hazard and should never be done. Should the timer get hung up in defrost, then you would have a heater that could just keep running. Eventually, the temperature would get hot enough that it would cause a meltdown within the appliance, leading to a fire.

When the defrost thermostat is malfunctioning and all troubleshooting has led to nowhere, call in a professional. Never bypass the defrost thermostat as it poses a serious risk.

How Do You Replace a Whirlpool Refrigerator’s Defrost Thermostat?

The process of removing a faulty defrost thermostat can be relatively simple. Start by unplugging the refrigerator. Whenever working with a major appliance, you want to keep safe from potential electrocution.

Go to the back of the fridge and look for a panel located near the freezer. You need to take off the side door and may even have to take the ice bucket off to gain access to the defrost thermostat. When you have the outside panel off, you can now find the old thermostat.

The defrost thermostat is near the evaporator and is held by just a single metal clip. There are black and red wires to be cut and prepared for the new thermostat. When you have removed the old thermostat, simply install the new one and close everything up.

Ryan Womeldorf

Ryan Womeldorf has more than a decade of experience writing. He loves to blog about construction, plumbing, and other home topics. Ryan also loves hockey and a lifelong Buffalo sports fan.

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