How to Fix Whirlpool F21 Error Code

Appliance Express
October 4, 2021
Washer Repair

If your Whirlpool washer has an F21 error code, it indicates that your washer has a drainage problem. The good news is the issue can usually be resolved by simply clearing the drain filter or drain hose. However, if the error persists, the drain pump and pressure switch will likely need to be tested with a multimeter to determine if the part is defective and needs to be replaced. If you need to resolve the error code quickly, performing a reset should provide a temporary fix.

The following guide applies to most Whirlpool washers, including the following models:






















What Causes the F21 Error Code?

The most common causes of the F21 error code are:

  • The drain pump has a blockage or is faulty and needs to be replaced.
  • The drain filter on the drain pump is blocked or clogged.
  • The drain hose is blocked or bent.

Other less common causes include:

  • The pressure switch is faulty and causing a communication error between the drain pump and the main control board.
  • The drain pump wiring harness is damaged, or the harness has a communication problem with the main control board.
  • The pipe the drain hose drains into is blocked or clogged.

How to Fix the F21 Error Code

Perform a Reset

If you want to clear the error code quickly, you can either try pressing Pause/Cancel two times or perform a reset. To reset the washer, disconnect the power to the washer for 1 minute. When you reconnect the power, the error code should have cleared.

Sometimes, an error code is caused by a glitch. If the power is disconnected, the glitch will be fixed, and the washer should work normally again. However, if it is not a glitch, disconnecting the power may clear the error, but the problem will remain. Therefore, even if you resolve the error code, you should still check for drainage problems and fix the issue to avoid causing more serious damage to the washer or your laundry.

Check the Drain Hose

If the washer will not drain, the drain hose may be kinked, pinched, or obstructed by a small object. It is also possible that the drain hose outlet has been submerged in water, which would restrict the washer’s draining ability. Another thing to check is that the drain hose is installed correctly.

The drain hose may be connected to a spigot on the waste pipe or a waste trap or to a standpipe. How the drain hose should be installed can depend on the model and type of connection you have. Check the washer’s manual for the specifications needed for your hose to work correctly.

If the drain hose cannot be unclogged or connected properly, it will need to be replaced.

Check the drain hose:

  • If the washer has recently been installed and is connected to a spigot, make sure the blanking cap has been removed from where the hose connects to the spigot.
  • Check the hose is connected properly.
  • Check there are no bends or kinks in the hose.
  • Check that the expelled water from the drain hose can drain sufficiently.
  • Check the drain hose outlet is not submerged in water.

To remove and unclog the drain hose:

  1. Disconnect the power to the washer.
  2. Turn off the water supply to the washer.
  3. Disconnect the drain hose from the washer. On most models, pliers will be needed to release the clamps securing the drain hose to the washer.
  4. Unblock the drain hose with a drain snake tool, or wash the hose with a mixture of hot water, white vinegar, and baking soda.
  5. If the drain hose is defective and the issue cannot be fixed, replace the drain hose. If the drain hose has holes or is worn, it is best to replace it rather than try to patch it up.

Check the Drain Pump and Drain Filter

If the drain hose is not blocked, a defective drain pump or a clogged drain filter may be causing the issue. The drain pump and drain filter usually become clogged due to small foreign objects, like an article of clothing, coins, or bobby pins. The pump’s impeller can also wear out or break and obstruct or damage the pump. If an impeller is broken, the pump should be replaced to ensure it works correctly. If the impeller is not damaged and the pump is not blocked or being obstructed, it may have failed electrically. To determine if the pump is defective, the pump’s motor will need to be tested for continuity (a continuous electrical path) with a multimeter.

Many Whirlpool washers have a drain filter connected to the drain pump. Like the drain pump, small items can end up in the drain filter and restrict the washer’s ability to drain. Once you remove the access panel, the drain filter should be easy to locate and clear. After clearing the drain filter, check the pump as well for obstructions or damage.

Access to the drain pump and filter will depend on your model. If you have a top-loader washer, you will likely need to place the washer on its back so that you can access the drain pump and filter underneath the washer. If you have a front-loader washer, you will likely need to remove an access panel at the back or front of the washer. Check the washer’s manual for the location of the drain pump and filter for your specific washer.

To check the drain pump and filter:

  1. Disconnect the power to the washer.
  2. Turn off the water to the washer. Depending on the model, you may need to disconnect the water hoses to move the washer and gain access to the drain pump and filter.
  3. Unscrew the access panel and remove it from the washer.
  4. Put a container down to catch any water that may leak out (there may be 2-3 gallons of water).
  5. Unscrew the knob on the drain pump by turning it counterclockwise.
  6. Turn the knob over, and the filter should be on the back of it.
  7. Remove any debris or lint in the filter.
  8. Check the drain pump for a damaged impeller or an obstruction.
  9. Check the wiring harness on the drain pump. Make sure it is secure with no visible damage to the wiring.
  10. Check that the water drain lines are not blocked or kinked and are attached correctly.

If clearing the filter and drain pump fails to fix the error code, you may need to check the drain pump motor with a multimeter to determine if it is faulty and needs to be replaced. With the multimeter probes touched to the terminals on the pump, the pump should read 5-10 ohms, depending on the model. If the reading is zero or infinity, the pump will need to be replaced.

While you have the access panel removed, check that the pressure switch is not causing the issue.

Check the Pressure Switch

The pressure switch or water level control determines how much water is in the tub to tell the control panel whether the tub needs to be filled or emptied. The location of the pressure switch can vary depending on your model. Check the washer’s manual for the location of the switch. The pressure switch is usually round with a wiring harness connected to the back of the switch.

To check the pressure switch with a multimeter:

  1. Set the multimeter to RX1 or X1 scale.
  2. Looking at the pressure switch, place one probe into the far left hole and the other probe into the third hole from the left. The reading should be zero.
  3. Test the pressure switch’s “suds detect” function. Stick one probe into the far right hole and another probe into the hole next to that one. The ohmmeter should read zero.
  4. Place a probe into the second hole from the left and the other probe in the third hole from the left to test the rinse. The reading should be zero.
  5. Leave the probe in the third hole from the left and place the other probe into the fourth hole from the left to test the overflow pressure. Again, the reading should be zero.

If the pressure switch fails any of these tests, it will need to be replaced.

Hopefully, these instructions have fixed the drainage issue and the error code has been resolved. If the error code persists, you may need to get a trained professional to check that the control board is not defective and causing the issue.


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