An improperly installed drain hose can prevent the washer from draining properly.
F21 error code kenmore washer.
I was so sick of my washer i always got the f20 and f22 message.
Followed the troubleshooting guide above.
The f21 code on many kenmore elite front load washers indicates a long drain problem.
Oh man this is a great fix.
I had the same problem still getting f21 sud codes even after changing the pressure switch and the drain pump.
Check for excessive suds in the washer tub.
Had sporadic f21 code approx every 3 4 washes.
No hose kinks or anything wrong with the drain lines.
I finally took the drain lines all off from the drain pump up to the plastic elbow near the top where it exited the washer as well as the next line from that same elbow to.
Found lint debris in the filter.
Check the tub for excessive suds.
If you see this condition then i recommend that you drastically cut back on the amount of he high efficiency detergent that you are using in the washer.
Excessive suds can prevent the washer from draining properly and will result in the f21 code.
Check the drain hose for kinks and clogs.
The causes of the error tips on how to fix the breakage of the washer.
This can be caused by excessive suds or a restriction in the drain system.
I would clean the hose and it may work for a bit.