Check tap is fully turned on. 4E means no water coming in. If tap open then turn it off and remove hose from back of machine, point end into bucket or sink & open tap again slowly to make sure water flows from tap. If ok, check filter in inlet valve where the hose connects. Look for blockage. If all okay then probably the inlet valve is not opening. You will need a multimeter to find out why.
Lincoln Appliance NZ, October 2019