F21 on a Whirlpool washer means the drain took too long — more than 8 minutes. The machine stopped to avoid pumping indefinitely. Clean the pump filter first; it fixes F21 in the majority of cases.
What This Error Means
F21 is a long-drain timeout. The drain pump ran but couldn’t move water fast enough through a clog or restriction.
Common Causes
- Clogged pump filter — Coins, hair ties, lint blocking the filter
- Kinked drain hose — Sharp bend restricting flow
- Drain hose inserted too deep — More than 6 inches into the standpipe creates a siphon
- Failing drain pump — Motor wearing out, reduced flow
- Slow household drain — Sluggish standpipe backs up
Step-by-Step Fix
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Open the pump filter access panel at the bottom front of the machine (small door, right side).
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Drain standing water first. Pull the small emergency drain hose and remove the cap into a pan. Drain water slowly before opening the main filter.
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Remove and clean the pump filter. Unscrew counterclockwise. Remove coins, hair ties, debris. Rinse and scrub the mesh. Check the impeller behind the filter — it should spin freely.
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Reinstall the filter and close the access door.
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Check the drain hose routing. No kinks. No more than 6 inches into the standpipe. Not routed higher than 96 inches from the floor.
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Run a Drain+Spin cycle to test.
Parts You May Need
When to Call a Technician
If the filter is clean and hose routing is correct but F21 persists, the drain pump has failed. Front-panel removal required on most Whirlpool front-loaders to replace the pump.