Fixing the F21 Error Code in Your Whirlpool Washer [PRO ADVICE] -
Appliance Troubleshooting

Expert Technician: Whirlpool Washer’s Frustrating F21 Error Code Solved!

Written by

Jason Carter

Expert Technician: Whirlpool Washer’s Frustrating F21 Error Code Solved!

Here’s the thing:

There’s nothing quite like that sinking feeling when you spot the F21 error code flashing on your Whirlpool washer. Believe me, I’ve been there more times than I can count. But over the years, I’ve cracked the code on this pesky problem.

Here’s some good news:

I’ve not only faced and tackled the F21 error myself but also helped countless customers do the same. And today, I’m here to guide you through it.

For a deeper dive, I’ve also brought on board Dylan Bennett, a seasoned appliance technician hailing from Columbia, South Carolina, to share his invaluable insights.

Ready to tackle that error? Let’s get started!

Whirlpool Washer Error Code F21

Explaining the Whirlpool Washer Error Code F21

Whirlpool states that the F21 error code signifies a drain issue, usually leading to slow and poor drainage. As such, you must look out for a faulty drain pump, a clogged pump filter, a kinked drain hose, or a defective pressure switch as likely causes. If these parts function properly, you might be doing something wrong with your laundry detergent.

Moving forward:

I will expand on these likely causes of the F21 error code and provide clear troubleshooting guidelines to repair them.

First, you need to reset your Whirlpool washer by stopping the cycle. Unplug it, wait a few minutes, and then plug it back in.

What next?

Now that the unnerving display is gone, unplug your washer, turn off the water supply, grab your tools, and let’s get cracking.

5 Reasons & Troubleshooting Steps for the F21 Error Code on a Whirlpool Washer

Commonly Affected PartsEstimated Cost
Drain pump$15 – $60
Drain pump filter$10 – $30
Drain hose$14 – $40
Pressure switch$13 – $95

1. Clogged or Failed Drain Pump

Whirlpool Washer Clogged or Failed Drain Pump
PartDrain pump
LocationIt is located behind the front access panel, at the bottom of the washer.
Ease of troubleshootingModerate
Cost$15 – $60
RepairableYes – if it is clogged
No – if it is damaged


Because the F21 error code denotes a draining problem, the first component to inspect is the drain pump. This is because the drain pump is the heart of your Whirlpool washer’s drainage system.

So, what could be the problem?

Dylan asserts:

“Small objects could find their way into the drain pump, obstructing the drainage. Also, a failed drain pump could be culpable.”

Whirlpool Washer Debris Cloggin the Drain Pump

You see:

This Reddit user’s Whirlpool Duet WFW9200SQA12 washer displayed the F21 error and wouldn’t spin or drain. And true to Dylan’s position, he discovered a sock in the pump’s motor impeller.


Another Reddit user got the occasional F21 error on his 8-year-old Whirlpool Duet washer. However, what stood out this time was the absence of the drain pump’s functional sounds.


It led him to believe the drain pump had failed. And several other users affirmed his belief, urging him to make the replacement.


Usually, you’ll be able to tell when your drain pump is faulty by listening for squealing noises and looking out for standing water in the tub. Other times, you’ll know when your Whirlpool washer refuses to spin.


To this end, I will show you how to examine and unclog or replace your drain pump to resolve the F21 error.

Here’s what to do:

Detach the access panel, locate the drain pump, disconnect it from the wiring, and inspect it for any lodged debris or clothing items. If you detect any, dislodge them and clean the pump thoroughly.

In addition:

You must inspect the drain pump for visible signs of damage. To confirm its functionality, you should also test its motor for electrical continuity with a multimeter.

Replace the pump if it fails this test or is physically damaged.

2. Blocked Drain Pump Filter

PartDrain pump filter
LocationIt is situated at the front bottom of the washer and is attached to the drain pump.
Ease of troubleshootingEasy
Cost$10 – $30
RepairableYes – if it is clogged


You already know the drain pump could set off the F21 error code if it is clogged or faulty. But what about the drain pump filter?

You see:

This filter restricts debris like coins, cloth fiber, and other small objects from entering the drain pump.

And while that is great, it becomes a problem when it starts restricting much more than debris.


The thing is:

Over time, the drain pump filter will accumulate debris, causing the flow of wastewater out of the machine to be rather slow.

So, if your Whirlpool washer is not draining and is displaying the F21 code, it is time to inspect the pump filter.


This Reddit user posted about their Whirlpool WFW9300VU02 Duet washer/dryer set that displayed the F21 error code.

They figured out that the drain pump filter needed a new filter seal and advised other users to clean their drain filters regularly.

Dylan comments:

“After inspecting the drain pump for defects, you must ensure not to neglect the pump filter. Cleaning the drain filter at intervals will prevent the build-up of debris as well as damage to your pump filter seal.”

To remedy this:

Place a towel on the floor and position a bowl underneath the pump filter compartment to catch the spilled water.

Next, unscrew the drain pump knob carefully to reveal the filter and check for any visible damage to the seal.


Clean the pump filter meticulously until no collected debris is left, and then screw it back in.

3. Kinked or Clogged Drain Hose

PartDrain hose
LocationIt is located behind the washer at the bottom and tethered to the drain pump.
Ease of troubleshootingEasy
Cost$14 – $40


Hear me out!

Imagine folding a juice straw and then attempting to drink through it. Your attempt will be futile because the crease will make it incredibly difficult for fluid to pass through.


That’s exactly what happens when your drain hose is kinked, pinched, or clogged—wastewater from the tub will be unable to drain effectively.

Take it from Joe, a SimplySwider reader who reached out about his 12-year-old Whirlpool CHW9060AW0 Commercial washer.

You see:

Joe complained that his washer was draining very slowly, even after testing and replacing his faulty drain pump.

What’s more? It kept displaying the F21 error code.


So, I asked him to check for kinks or clogs in his hose, and he discovered a stunning amount of accumulated debris.

This was a 12-year pile-up because he admitted that he had never cleaned his drain hose since he purchased his washer.

Dylan weighs in:

“Joe’s case is very interesting because he is a real-life testimony to why regular maintenance and cleaning is essential to your washer’s health.”


If you’re in the same boat, you’d want to unclog your drain hose immediately. First off, check for kinks and straighten out the hose.


Disconnect the hose from the pump and the standpipe and use a flexible brush to clear out all the lodged debris.

You can flush a mixture of vinegar and water through the hose to break down the mineral build-up.

Once you’re satisfied:

Reconnect the hose, ensuring it’s properly connected and aligned. Then, run a test cycle to be sure you got all the gunk out.

4. Defective Pressure Switch

PartPressure switch
LocationIt is usually located behind the control panel and is connected to a small tube.
Ease of troubleshootingModerate
Cost$16 – $95
RepairableNo – if it is damaged
Yes – if the tube is blocked



We must inspect our next suspect, the pressure switch. This washer part is also called the water level switch, and by its name, you can tell that it regulates the water level in the washer.

So, how does it trigger the F21 error code?

Here’s the thing:

The pressure switch sends a signal to the control board indicating when the washer needs to be filled or drained.

If the pressure sensor is faulty, the signal will not be sent out, and the washer will not be emptied.



James, our Facebook community member, made a post concerning this issue.

He claims his Whirlpool WFW9200SQ00 Duet HT washer displayed an F21 code, and the washer would not drain.

He also noticed that the pump would come on but shut off after a few minutes. 


I advised him to examine his washer’s pressure switch. To do this, unscrew the control panel and identify the pressure switch, as shown above.


Inspect it for visible signs of damage and test for electrical continuity with a multimeter. If it fails this test or is physically damaged, you will have to replace it.

Dylan adds:

“Also, check the tube attached to the pressure switch for any blockages preventing air from activating the switch. Then, blow through it firmly to clear it out.”

Note that:

The Whirlpool online parts store stocks authentic replacement parts.

5. Excess Laundry Detergent

Whirlpool Washer Excess Laundry Detergent


Let’s get straight to the point.

Using excess laundry detergent during a wash cycle will cause oversudsing, which in turn leads to drainage complications.


If you’ve tried all the other component repairs to no avail, then the F21 error code is likely prompted by this usage mistake.


Dylan adds, “In most cases I’ve resolved, the F21 error code is usually followed by the SUD or SD error code.”

This code directly indicates the presence of excess detergent suds preventing the washer from draining.


Whirlpool has guidelines for the use of detergent in their washers.

They recommend High-Efficiency (HE) detergent for HE washers to prevent the excessive suds that non-HE detergent produces.


Even HE detergent will lead to oversudsing when used in surplus.

So, be guided by the manufacturer’s quantity recommendations while factoring in your load size and the degree of blemishes.


If you’ve accidentally been too generous with your laundry detergent, you can reduce the suds by adding a bit of fabric softener to your load.

In this Reddit discussion, I discovered that certain appliance technicians swear by cooking oil as an effective agent to eliminate suds.


Dylan recommends using white vinegar instead. In his words, “Sure, cooking oil will help eliminate suds. But it is better for use with a dishwasher.”

Models Most Affected

Here’s the thing:

Certain Whirlpool washer models have garnered a reputation for having drain problems that trigger the F21 error code.

I have listed these models along with their respective model-specific reasons for the defect.

Here you go!

Model NumberModel NameReason
WFW9200SQA12Whirlpool DuetFailed drain pump
W10918732BWhirlpool CommercialKinked drain hose
CHW9060AW0Whirlpool CommercialClogged drain hose
WFW86HEBW0Whirlpool Duet SteamExcess laundry detergent
WFW8300SW00Whirlpool Duet SportClogged drain pump
WFW9200SQ00Whirlpool Duet HTDefective pressure switch
WFW9300VU02Whirlpool Duet Washer/ Dryer SetBlocked drain pump filter


There you have it!

Now you know that the F21 error code denotes a draining complication. What’s more, you’ve also surveyed the potential reasons for this complication.


We’ve explored ways of troubleshooting these defects, including:

  • Clogged or failed drain pump
  • Blocked drain pump filter
  • Kinked or clogged drain hose
  • Defective pressure switch
  • Excess laundry detergent


If any of these repairs prove difficult, don’t hesitate to use our Ask the Expert feature for bespoke guidance.

Note that:

Adopting appropriate maintenance habits will help you avoid issues that could trigger Whirlpool error codes.

To corroborate this point, Dylan advises that you regularly clean and service your Whirlpool washer.

All in all:

I encourage you to share your troubleshooting experience, additions, or questions in the comment section below. I will be looking out for them.

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