Whirlpool F21

Long Drain Time

Medium severityVerified Diagnostic Guide

What Your Machine Is Actually Telling You

F21 means the drain pump couldn't remove water within 8 minutes. The CCU monitors the pressure sensor during drain — if the level doesn't drop fast enough, F21 triggers.

Common causes:
1. Clogged debris filter/coin trap (40%) — coins, buttons, lint.
2. Kinked drain hose (15%) — bent behind machine.
3. Clogged standpipe (10%) — plumbing blockage.
4. Drain pump failure (10%) — motor dead or jammed.
5. Pump impeller broken (10%) — blades cracked.
6. Excessive suds (10%) — foam blocking drain.
7. Pressure sensor (5%) — false high reading.

What You're Probably Seeing Right Now

  • Drum is full of water — clothes soaking.
  • Pump is humming but water stays.
  • Or pump is completely silent.
  • F21 happens every few washes — partial clog.

DIY Fix — From Easiest to Hardest

1

Emergency Drain (5 minutes)

1. Find filter access panel (bottom-front).
2. Place baking dish and towels.
3. Open emergency drain hose.
4. Remove cap — drain slowly.
5. Empty pan as needed.
2

Clean Debris Filter (5 minutes — Fixes 40%)

1. Twist filter cap counterclockwise.
2. Pull out.
3. Remove all debris.
4. Check pump impeller behind filter — spin with finger.
5. Reinstall filter.

**Clean monthly.**
3

Check Drain Hose (5 minutes)

1. Pull machine from wall.
2. Straighten any kinks.
3. Check standpipe connection:
- 6-8 inches insertion.
- 24-36 inches height.
4

Test Drain Pump (3 minutes)

1. Select Drain Only cycle.
2. Listen: humming, silent, or grinding?
3. If dead: test with multimeter 5-30Ω.
4. Replace if failed ($25-60).
5

Replace Drain Pump (30 minutes)

1. Unplug.
2. Access pump (bottom or front).
3. Disconnect hoses and wiring.
4. Remove mounting screws.
5. Install new pump.
6. Test.

When to Call a Pro

  • Drain pump — $100-$250 installed.
  • Standpipe clog — plumber: $100-$250.
  • CCU pump relay — $200-$500.

What It'll Cost You

Repair / PartDIY CostWith a Technician
Clean filter (40%)Free$80 – $120
Fix drain hose (15%)Free$80 – $120
Drain pump (10%)$25 – $60$100 – $250
Snake standpipe (10%)$15 – $25$100 – $250
Swipe left to see full table

Frequently Asked Questions: Error F21

What does error code F21 mean on a Whirlpool washing machine?

Washer is not draining fast enough.

What usually causes the Whirlpool F21 error?

The primary cause is: Filter clogged with debris (coins, socks) or drain pump failure.. It may also be caused by temporary sensor misreadings or wiring connection issues.

How do I reset and clear error F21?

Clean the debris filter. Test drain pump for continuity. If the error persists, unplug the washer from electrical power for 10 minutes to perform a complete logic board reset.

Is it safe to continue using the machine with error F21?

This code has a Medium severity level. While the machine might run, resolving the issue early prevents long-term wear on internal parts.