F21 Code on Whirlpool Duet Washer

Whirlpool washers are sturdy appliances that’ll last you for many years as long as you follow the manufacturer’s instructions. However, some problems will crop up with time, and your whirlpool duet washer will throw out an error code to alert you.

That’s why it’s imperative to understand those error codes to know your next course of action. Today, we’ll tackle the F21 error and explain its causes and how to fix it so that your washer works properly once again.

Meaning of the F21 Error Code on Your Washing Machine

The F21 error code will pop up on your display when your Whirlpool washer is unable to drain the water. No drainage means your laundry will come out soaking wet; that’s if your whole floor doesn’t get drenched in water first.

Typically, you’ll find that your washer can work pretty well until it nears the end of the wash cycle. Once the drain cycle begins, this code will then be displayed, telling you there’s something wrong with your washer’s drainage.

Causes of an F21 Error Code

Since the F21 error code means a drainage problem, the Whirlpool washing machine parts responsible for pushing away the water are the most common culprits. However, occasionally, the reason for the drainage error is electrical and has to do with the washer’s wiring or central control unit.

We’ll break down the possible causes so that you can find the problem with your machine to get it working properly again.

Fault in the Drainage System

Drain Hose

The drain hose located at the back of your Whirlpool washer may be responsible for the F21 error code if it’s bent, twisted, or clogged. Small items like socks, coins, paper, buttons, or even lint can plug the hose, and when it’s blocked, the water in the washer will have no place to go.

The same will happen if your drain hose isn’t installed according to the manufacturer’s instructions. For example, it should never be inserted more than 4.5 inches (11.4 cm). Also, there should be a gap between it and the drain pipe for ventilation purposes. If you fail to comply with those instructions, the F21 error will appear.

Drainpipe and Main Drain

Speaking of the drainpipe, you shouldn’t place it at a height over 96 inches or below 30 inches. If you overstep these two limits, your drain pumps won’t be able to push the water out of the washer, and the F21 error code will emerge.

Moreover, since the drain hose drains out the water into your wall/floor drain, the water won’t reach the sewers if the main drain is also clogged with debris or many foreign objects. So, always make sure your main drain is unclogged.

Drain Pump and Drain Filter

The washer drain pump is the part responsible for flushing out the water from the washer into the drain hose and pipe. If something is blocking the pump or hoses, or more commonly, its filter, it won’t be able to suck out the water, and your washer won’t run properly when the drain cycle starts.

Consequently, once you clear the drain pump filter and the pump from all obstructions, your washer should drain properly once more. However, if the error code persists or the washer is noisy or pumping during the drain cycle, the drain pump is damaged.

The damage could be because of a defective engine or an open circuit in the pump’s wiring. The pump can be repaired in some cases, but you’ll most probably need a replacement.

Fault Outside the Drainage System

Main Control Board

out of order

The control board is in charge of telling the pump that the time has come for it to drain. If it’s out of order, the pump can’t begin to drain the water, and the F21 error will be displayed when the washer refuses to execute the action.

The error code f21 could be due to a short circuit, or the control board could be faulty. Some damages are repairable while others aren’t, so you may end up needing a new control unit.

Pressure Switch

The pressure stitch reports to the control unit the amount of water in the washer. If it doesn’t work properly, then the control unit won’t know about the water that needs to be drained, so it won’t tell the drain pump to start its job.

Usually, the pressure switch malfunctions because the pressure hose connecting it to the washer’s tub is twisted or pinched. It could also be due to an electrical issue.

Loss of Communication

If the wiring harness of the drain pump has come loose from its connection with the control unit or has been damaged, the washer fails to pump out the water because it’s not receiving power. So, ensure that the wires are in good condition and well-connected from the pump and water lines to the control unit.

How to Repair the Water Drainage Issue

repair the water drainage issue

To repair the water drainage issue, you should check the door of your Whirlpool washer. If the door has come open for some reason, the washer won’t drain, and the error code F21 will appear.

Occasionally, this code appears by accident due to an error in your washer’s software. A simple resetting can eliminate this error.

To reset your washer, simply press “Pause” once and the “Cancel” button twice and hold it until the display is clear of any codes. If the code is still there after the reset, restart your washer and see if it’s finally gone. If not, then there’s a faulty component in your washer somewhere.

Unplugging your washer from the power source and examining the drain system is the next step. Check the drainpipe and pressure hose for kinks or blockages of any sort. A powerful stream of water or air can help dislodge and remove most items, leaving your washer ready to drain.

If nothing happens, then the next step is to clear the drain pump filter from any debris. Run it underwater and clean it with a brush.

Also, check the drain pump for any dirty obstructions, other foreign debris, and loose or damaged wiring. Also, inspect the water drain lines from the pump for a total or partial blockage. Once you’re done, run a test wash and see if the F21 error clears.

If the error persists, get out your multimeter and test the control unit, pressure switch, and remaining wires. You’ll find the accepted values in your washer’s manual. If any part doesn’t conform to the correct values, then you need to repair or replace the drain pump.

Other Whirlpool Duet Washer Error Codes


To put it plainly, the F21 error code stands for a water draining problem caused by various reasons for this code to appear. Fortunately, most are easy to fix on your own.

If you feel you’re unable to handle it, don’t hesitate to call an appliance repair service to spare you the trouble of having to fix the washing machine yourself.

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