Washer attempts to drain but stops with E21, often with a humming noise from the bottom front.

Safety: Disconnect power and prepare for water spillage.

• Access and clear pump: Open the pump filter cover, drain residual water, and remove the filter. Reach into the pump cavity and rotate the impeller by hand. Remove any objects (coins, hairpins, bra wires) that prevent free movement.
• Inspect impeller: If the impeller is loose on the shaft, broken, or wobbly, the pump assembly should be replaced.
• Check for leaks: While the filter is out, inspect the pump seal area for signs of leakage or corrosion, which indicate pump wear.
• Test pump electrically: With the machine unplugged, remove the lower front or rear panel to access the pump. Check coil resistance with a multimeter. Replace the pump if open circuit or shorted.

If the pump and wiring test good but E21 remains, the main control board may not be driving the pump correctly and requires professional service.