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 ?2 z) H, t# C0 j2 n
/ B* @! O# M8 rSolution: turn off water supply and take the humidifier apart and clean it will stop the leaking. ! F A+ g2 Y' @! d' k8 G " R% W% \" \9 n( C' b3 T) Q- H6 r + a* @, |; g4 B4 s+ z7 x* I% _Otherwise, find a professional or change a new set.