Diagnosis
Error F21 means a 'drain time-out'—the machine is taking too long to empty, usually due to a clog, a kinked drain hose, or a failing drain pump.
How to Fix It
Clear the drain path obstruction. This is almost always a physical blockage.
1. Unplug the washer.
2. Pull it away from the wall and disconnect the drain hose from the standpipe or sink.
3. Check the hose for kinks and straighten it. Inspect the end for lint clogs.
4. Tip the machine back (get help, it's heavy) and locate the drain pump on the bottom. Remove the small service panel (often held by quarter-turn fasteners).
5. Check the pump filter (if accessible) and the pump impeller for obstructions like coins, hair ties, or socks. Remove any debris.
6. Reconnect everything, ensure the drain hose isn't pushed too far into the standpipe (should only be 6-8 inches), and run a drain/spin cycle to test.
If That Didn't Work
If the path is clear, the drain pump itself may have failed. You'll hear no humming from the pump area when it tries to drain. The pump motor is replaceable.
Heads Up
Never use drain cleaners or chemicals in your washer to clear a clog. They can damage seals and plastic components. Always do the physical check first.