Washer displays F21, long drain, water remains in tub, sometimes with a humming noise from the bottom front.

Safety first: Unplug the washer. Expect water to spill when opening the pump filter; use towels and a shallow pan.

Step-by-step:

• Access pump filter: Remove the lower front access panel. Locate the drain pump clean-out cap.
• Drain water: Place a pan under the cap and slowly loosen it to control water flow. Allow all water to drain.
• Clean filter and housing: Remove lint, coins, buttons, and other debris from the filter and pump housing. Check the impeller for damage and ensure it spins freely.
• Inspect drain hose: Check the hose from the pump to the standpipe for kinks or clogs. Detach and flush if necessary.
• Test pump: With power off, disconnect the pump wiring and measure resistance across the terminals. Replace the pump if readings are open or shorted, or if it is noisy and weak under load.
• Reassemble: Reinstall the filter cap securely, reattach the access panel, restore power, and run a drain/spin cycle.

When to call a technician: If the pump receives power but does not run, or if you are uncomfortable working with water and electrical components, contact a professional.