I believe that those are error codes....isn't it great to have a washer that checks itself :) anyhow some of the codes are
“F20” (Water Inlet Problem—no water or insufficient water supply)
Select STOP twice to cancel the cycle. Unplug washer or disconnect power.
“F21” (Drain Problem)Select STOP twice to cancel disconnect power.
“SUD” (Suds Routine)When excessive suds are detected, a suds routine
automatically starts. This routine removes extra suds and assures proper rinsing of your garments. “SUD” is displayed during rinsing to inform you that Suds Routine was activated.
“F22” (Front door lock)Select STOP twice to cancel the cycle.
“F” Codes other than F20, F21 and F22
Select STOP twice to cancel the cycle. Select if there is excessive water in the washer.
I believe that the HF is the error code for a water inlet issue. You need to ensure that the unit is getting both hot and cold water if so the pressure switch will need to be replaced. The switch is located on the top right of the unit.
These should be in your user manual. Hope this explains a little bit about your display. Good luck