What should I do when the 'Sud' error code appears on the display?

The 'Sud' error means there are excessive suds in the washer and it is running a suds reduction routine — allow the washer to continue. You should use only HE detergent, always measure detergent, and base detergent quantity on load size following the manufacturer's instructions. You can also touch WATER HARDNESS to change the water hardness setting to 'soft' to help reduce suds.