How To Fix Whirlpool Washer Error Code F21?

If you see error code F21 on your Whirlpool washing machine, this refers to a water drain problem. The washer won’t be able to finish the cycle and your laundry will be wet.

Whirlpool Washer Error Code F21 Fix

This error code means draining is taking too long, and something is wrong with the water pumping. An issue with any of these parts can cause a Whirlpool washer F21 error code:

  • Filters
  • Pump
  • Hoses
  • Nozzle
  • Sewage
  • Motor

There are also other reasons that could result in such an error. The pressure switch might have an issue. There could be broken pump wiring or a loose or damaged contact. Maybe the pump and control board have lost their connection.

How To Diagnose the Issue?

The first thing you should do is ensure it isn’t a software fault, by trying to reset the error:

  1. Plug the washer into a wall outlet.
  2. Press the button that says Pause/Cancel twice.
  3. Now hold the button for a few seconds, until the display is blank.
  4. If the F21 error continues to flash on your display, switch the washer off and unplug it.
  5. Then plug it back in and switch it on.
  6. See whether the issue has been fixed.

If that didn’t solve the problem, that means it wasn’t a software malfunction causing the error.

At this point you can either call a washing machine technician (if your washer is still under the warranty) or attempt some DIY.

8 Causes and Solutions of Whirlpool Washer F21 Error Code

If you want to try to fix the F21 error yourself, here are some problems that might be causing it, and what to do about each one.

Some of these solutions are relatively easy to implement (and free or inexpensive to fix). Sadly some are not!

#1 Clogged Drain Hose

The F21 error code refers to something wrong with the drain system, but there are various components involved.

Sometimes the drain hose can get blocked up with buttons, coins, flash drives, and anything else that comes off of clothes or is left in pockets. It might also have a kink in it.

  • Disconnect the washing machine from the power by removing the plug from the outlet
  • Move the washing machine away from the wall so you can get to the back of it.
  • Disconnect the washer hose and see whether it is bent, kinked or clogged up.
  • You can try to run water through it or blow air through it, to check for a blockage.
  • If water won’t go through, push the blockage through using a long-handled hook.
  • When you have cleared the blockage, reconnect it to the machine and make sure it isn’t kinked or bent.

Important: Make sure you don’t accidentally pull on the sewer connection when moving the machine. If you do, you’ll have to change the whole drain hose, which will cost between $19 and $35.

#2 Dirty Filter

You can access to pump, mesh hair catcher and wiring by removing the front bottom panel.

You need to remove the screws holding it in place first.

Remove the filter and brush the gunk off. Rinse under running water and replace.

#3 Clogged Pump

You might get an F21 Whirlpool washer error if the actual pump is clogged, or if there is a blockage in the corrugated tube connected to the pump.

You will find the pump behind the front bar at the bottom of the washing machine:

  1. Disconnect the machine by unplugging it from the wall.
  2. Remove the bottom panel by removing the screws and pulling it off.
  3. At this point it’s a good idea to put towels or a container down, to catch the water coming out.
  4. Unscrew the washer drain filter.
  5. See whether there are foreign objects causing a clog, then remove them.
  6. Clean out the filter and other washing machine parts.
  7. Put everything back as it was.
  8. Plug the machine back in and see if it works now.

If the pump has failed, you’ll need to buy a new one. Expect to pay between $30 and $160 depending on model and store.

#4 Damaged Cable Loop

A cable loop should have loose contacts or breaks in it. If you can see a problem, you can twist or solder the ends and fit the plug properly in the groove.

If there is such a problem, it means the machine won’t be able to pump water. This can result in the F21 error.

If you can’t see any obvious damage, try using a multimeter (multitester) to check each wire individually.

#5 Broken Pump Motor

If you are sure that the wires aren’t damaged, and the drain hose and filter aren’t clogged up, the pump motor might have failed.

You can use a multimeter to check. The pump has to be at exactly 120V to run properly, not above or below that figure.

If the reading is lower, you will have to replace the pump, which is found behind the front panel and the bottom of the machine.

#6 Defective Pressure Switch

The pressure switch keeps the main control board communicating with the drain pump. A problem with this connection can result in an F21 error code.

Use a multimeter to check the pressure switch, in case it needs to be replaced or fixed. It isn’t difficult to access this pressure switch:

  • Turn the machine off and unplug it from the wall outlet.
  • Take the top panel off.
  • Undo the 3 screws securing the rear panel, then remove the bar.

The pressure switch is found at the top right of the washer. It is a small disk connecting to the hose with a rubber tube.

Expect to pay around $70 for a replacement.

#7 Defective Control Board

A Whirlpool washer F21 error code can also be caused by a fault in the control board.

This can happen when there is no signal to begin the drain cycle. It means drainage times are longer than usual, triggering a flashing F21 error code.

De-soldered wires and short circuits can mean severe damage to the control board.

If this has happened, you should replace the burned board (expect to pay between $200 and $450 for this).

If not, you should be able to fix it by soldering.

#8 Sewer Blockage

If you have water pumping out of the machine but spilling from the drain tube, you might have a sewer blockage.

Things like coins, socks and bits of paper can clog these plumbing pipes.

In this case, you should disconnect the nozzle and then clean any debris from out of the pipe.

If dirt or dust from out-flowing water make the adaptor clearance too narrow, you should replace it.