Chosen Solution
I don’t know if that makes any difference. I have replaced the analog water sensor. I have cleaned out the drain in the bottom of the washer. Neither is working still getting F 21. What do I do now? Call the appliance man?
F12 isn’t an easy code to diagnose see this post https://www.fixya.com/support/t4184073-f… find more by searching “Kenmore Elite HE3 F12 error”