Whirlpool duet 4.5 cubic foot model wfw9470ww01 F21 error.
Whirlpool duet 4.5 cubic foot model wfw9470ww01 F21 error.
The F21 error can be erratic on different cycles like that sometimes it still means the same thing the drain pump is not working properly. Replace the drain pump if it's not stopped up with trash. The part you need for that model can be ordered from the link below:
https://prismparts.com/products/for-whirlpool-washer-washing-machine-water-drain-pump-pp0463693