What Does F28 error code on whirlpool duet steam washer mean?

F28 means that your main central control board (CCU) and the motor control board (MCU) are not communicating with one another properly.

You will need to check all the connections at both boards, the mcu is in the bottom of the washer and the ccu is mounted at the top inside of the washer on the right side. Unplug the connections and plug them back on in on both boards. Then try a new cycle if the problem persists you will need to replace one or both boards. Replace the mcu first if that does not correct the problem replace the ccu next.