Whirlpool Washer Error F21: Long Drain Fix

The Logic Verdict

My Take: In this Duet/HE front-load demo, the tech shows that F21 is almost always a clogged drain filter. He removes the lower kick panel, drains the captured water, pulls the trap, and only replaces the pump if the impeller is damaged. Start with a thorough clean-out, then ohm the pump before buying parts.

What It Means

F21 = Long Drain. The control gave the drain pump 8 minutes to empty the tub but the pressure sensor still detected water, so it stopped the cycle and flashed F21/F9E1.

Common Causes

1. Clogged pump filter: Coins, hairpins, or lint jam the clean-out and stall the impeller.
2. Kinked or frozen drain hose: The hose can’t move water fast enough, so the tub never clears.
3. Improper standpipe height: A hose jammed too deep or routed too low causes siphoning that confuses the pressure system.
4. Failed drain pump: A seized impeller or an open winding (should read ~16 Ω) prevents flow.
5. Pressure hose blockage: Soap residue in the clear tube leading to the control tricks it into thinking water is still present.

Step-by-Step Fix

1. Unplug and prep for water. Kill power, put towels under the front edge, and lean the washer back on blocks for easier access.
2. Remove the lower access panel. Three Torx screws hold the kick plate; pull it off to expose the drain pump assembly.
3. Drain the sump. Loosen the clean-out cap slowly and capture the water in a shallow pan so you don’t flood the floor.
4. Clear the trap and impeller. Remove coins, rubber bands, or lint cakes from the filter body and ensure the impeller blades spin freely.
5. Inspect hoses and wiring. Check the tub-to-pump hose for debris, make sure hose clamps are tight, and confirm the harness is seated on the pump terminals.
6. Test the pump motor. Disconnect the wires and measure resistance; anything far outside 14–18 Ω or a grinding noise during drain tests means the pump should be replaced.
7. Reassemble and run a drain/spin. Reinstall the cap, panel, and plug the washer back in. Run a drain & spin cycle to confirm the error clears.

Resources

• Drain Pump Assembly (Amazon)
• Washer Drain Hose Kit (Amazon)
• Pump Clean-Out Cap & Seal (Amazon)