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. ! E [. q# d+ C( q& R' ~0 {) n! `6 Q, y1 }+ D& {( R
Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking.% J6 J4 Y7 ~ ^% X6 D2 A) b
) C0 u; ] g2 I+ C. F6 S + p+ n9 r: _$ U5 dOtherwise, find a professional or change a new set.