Whirlpool Error Code F21: What It Is and How to Fix It

The washer code F21 appears on a Whirlpool washing machine when the water in your washer’s drum drains too slowly. This issue usually stems from a defect in your drain pump or drain hose. However, other malfunctioning washing machine parts can also cause slow drainage.

Maybe your control board sends or receives incorrect signals. Or perhaps your water level pressure switch is the culprit for sending the wrong indicators. To solve the mystery of why exactly your washing machine isn’t draining, you’ll need to keep in mind that your appliance has a myriad of moving parts that could malfunction at any time.

So, what do you do if you get this cryptic error code? Try the solutions that we’ve provided below. And if all else fails, call an appliance professional. Your local professional at Mr. Appliance can repair your Whirlpool washing machine so that it drains normally.

Whirlpool Washer Code F21 Error: Six Causes and Fixes

If your appliance does happen to display washer code F21, fret not. These common causes for slow machine drainage (aka the F21 code) all have solutions.

1. Obstructed Drain Pump

The drain pump removes the water from your machine’s tub through the drain hose. If your drain pump is clogged with debris such as lint or foreign objects, it can’t properly remove the water — leaving you with a washer full of soiled water.

Unclogging your drain pump involves disassembling it and manually removing any visual blockage. The pump should then be flushed with hot water to remove any leftover debris. If you’ve never dismantled parts of your washing machine before, we recommend calling in an appliance professional for help with this one.

After reassembly, you can test your machine by putting it through a full cycle. Your water should drain normally since the drain pump is now clear.

2. Blockage in the Drain Hose

Drain hoses dispose of your dirty laundry water by sending it through the drain hose and into your home's drain lines. When the hose fills with debris, the water from your washer’s tub cannot empty down your drain. Because the water has nowhere to go, it will stay in your appliance, causing an excess of dirty water to sit in the tub of your machine. One way to resolve this issue is to clear the drain line of any debris. However, if you attempt this yourself, there are a few things you should know.

If you run the snake through the hose while it’s still attached to the washer, you may end up packing the debris into the pump, which will cause a bigger problem. If you want to clear the drain line yourself, here are the steps you should follow:

  1. To drain the hose line properly, you’ll have to remove the hose from the washer. Before you do this, have a basin and towels ready to catch any water that comes out when you remove the hose.
  2. Once the hose is off the washer, you can run a snake through it to dislodge any debris.
  3. Once the line is clear, you can reattach the hose to the washer. Make sure it is attached securely to avoid any leaks.
  4. To see if your washer drains properly, cancel the current wash cycle and hit the ‘drain’ option. If the line is clear, any water in your washer should drain within a few minutes.

If following these steps does not resolve your issue, it’s time to connect with a Mr. Appliance pro near you for help.

3. Malfunction with the Control Board

Your washer’s control board displays error codes and manages your machine’s wash settings. A vital part of your appliance’s operation, the control board governs settings such as your machine’s temperature, spin speed, and cycle transitions. If you’re receiving the F21 error code, your control board’s input or output signals could be glitching.

Control board issues can be complex to repair and are best handled by an appliance professional.

4. Faulty Water Level Pressure Switch

The water level pressure switch signals to your washer’s control board whether the drum is empty or full. A faulty switch can give the control board an incorrect reading by signaling that the machine is empty instead of full.

Since this is such a vital part, it will likely need to be replaced. Call your local appliance professional for part replacement.

5. Twisted Drain Hose

In many cases, your drain hose may be pinched instead of clogged. When this happens, the water is never pumped out of your washer.

You can attempt to remove any bends in the hose by straightening it out, but if you notice that this part looks beyond repair, have it replaced. Even if you remove the bends, a damaged drain hose will continue to stop your dirty laundry water from draining.

6. General Plumbing Issues

If you notice that the other drains in your home seem to back up or not drain properly, it may be time to call a plumber to make sure that the problem isn’t just limited to your appliance.

Need Help Figuring Out the F21 Error Code on Your Whirlpool Washer?

If your laundry days are filled with frustrating error codes and drainage issues, your local Mr. Appliance can help. Our team of experienced pros are washing machine service experts. They will diagnose your washing machine’s specific part malfunction and repair it quickly. Schedule an appointment online or call to take care of your Whirlpool washer repairs today!