DeLonghi · ESAM4200 Espresso Machine
If the machine cannot make coffee and makes excessive noise while the water tank light flashes, it means the steam knob is open.
Click steps to track your progress.
Turn the steam knob clockwise all the way until it stops (closed position).
Check that the steam knob is completely closed before attempting to make coffee.
If the light continues to flash, turn the machine off, close the knob, and restart.