DIAGNOSIS E1 is a water shortage error. The sensor detects insufficient water in the reservoir to begin a freeze cycle, even if the tank appears full.
FIX Check the actual water level. The minimum required line is marked. Add water to just below the 'Max' line. Remove and reseat the water reservoir firmly. Ensure the float switch inside the reservoir moves freely up and down. Manually move it a few times to clear any mineral buildup.
IF THAT DIDN'T WORK The water level sensor contacts inside the machine base may be oxidized. Unplug the unit. Use a cotton swab dipped in white vinegar to gently clean the two metal contact pins where the reservoir sits.
HEADS UP Using hard water accelerates sensor failure. Use filtered or distilled water to prevent mineral scale on all internal sensors.