What does F21 mean on Whirlpool Washer? I have a Whirlpool Duet front loading washer that keeps flashing the F21 code. When this code appears, the washer. Learn how to diagnose and repair the F21 error code on your Whirlpool Duet Washer (Model WFW9400SU00) with our detailed DIY guide. This video walks you throu.
An F21 error on your Whirlpool washer means there's a draining problem. The problem is likely related to the drain hose, so remove any kinks or knots and check the hose for blockages.. Is your Whirlpool washer displaying error code F02 or F21? Use this page to troubleshoot the error.