I had F02/F06 fault codes and I replaced the MCU board when I restart the machine, I hear like a buzzing noise at door latch, it does not display door lock.

what could be the problem?

My Duet washer stops in the wash cycle and gives an F8E1 code when I select Warm Water Wash. However, if I select Hot Water Wash, it completes the cycle. Since the machine says cold water is used for all rinses, I am confused about how it can complete the wash cycle at all. Is there a part that is important only when cold water is used during the wash not the rinse? I have cleaned both water inlet filters, and cleaned out the pan underneath the tub.