..-..4 years ago0+1-1What happens when the water tank gets empty? Is it safe to leave it operating during night when water can run out unattended?Anno.Nym4 years ago0+1-1 Helpful answerHi - when the water runs out, the unit stops (and as far as i know) a red LED shows that, the unit stops. As soon as you put water back in, it resumes... BrComment