It is possible that the shut-off valve was blocked by the cumulated white stuff. As a result, water supply can not be stopped even when water level is high. 8 y7 {$ Y# G9 r6 _6 p/ J) r' u6 R9 e3 s$ V
Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking.# H a, Q; q! V( D' b9 m. z# v
5 q( ^: x5 l; P7 B$ i8 r ' y3 Y& W j: f1 yOtherwise, find a professional or change a new set.