Common causes of error F21:

• Clogged drain filter: 
  • This is the most common culprit. The filter traps debris like coins, socks, and lint, and if it's full, it can prevent water from flowing out.
• Blocked drain hose: 
  • Check for kinks, clogs, or objects stuck in the hose that could be blocking the water flow.
• Faulty drain pump: 
  • If the pump itself is malfunctioning, it won't be able to push the water out effectively.
• Drain hose elevation: 
  • The drain hose shouldn't be higher than 96 inches (2.4 meters) above the floor, as it can create gravity issues with drainage.

Troubleshooting the F21 error code in Whirlpool Washing Machine

1. Clear the drain filter: 
   • Locate the filter (usually at the bottom front of the washer) and follow the instructions in your user manual to remove and clean it.
2. Check the drain hose: 
   • Inspect the hose for visible blockages or kinks. Straighten out any kinks and remove any debris you find.
3. Reset the washer: 
   • Sometimes, a simple reset can clear minor glitches. Unplug the washer for a few minutes, then plug it back in and restart the cycle.
4. Consult your user manual: 
   • Refer to your specific model's manual for detailed troubleshooting steps or a diagnostic guide. It might suggest additional checks or procedures.

Additional notes:

• F21 code might appear with other error codes: This could provide further clues about the issue. Consult your manual to understand the meaning of combined codes.
• Specific troubleshooting and parts might vary: It depends on your washer model and age.
• Seek professional help if the issue persists: If you've tried these steps and the F21 error remains, it's best to contact a qualified appliance repair technician. They can accurately diagnose the problem and recommend the necessary repairs.

Remember, safety is paramount. If you're not comfortable with any troubleshooting steps, particularly involving water or electrical components, always seek professional help.