The E4 error code means your machine’s water temperature sensor is malfunctioning. You can try to resolve this by pressing the button on the far right of the Control Panel for 10 seconds to reset the sensor.
Then make another bottle and see what happens. If the E4 error code doesn’t return, then the issue is resolved. If the E4 error code does return, unfortunately, then your Formula Pro has a more serious issue that will need to be addressed. Please contact us, you can do so here.
