If there is F1 on the display, there is likely to be a problem in the main control board. Also, a hose may have gotten clogged.
Unplug/disconnect the washer and wait for 5-7 minutes.
Undo the three screws at the back of the control board and raise it. Remove the rubber hose, which is located on the right of the control module and blow it. If there are no blockages, clogs or kinks, replace the control module.