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. / @1 d. U: n' a) d& [, T9 o
) W k5 O. d: S7 T- wSolution: turn off water supply and take the humidifier apart and clean it will stop the leaking. 1 v9 n$ }* P+ d0 W, b: T- I1 L ; N2 X* M7 M$ p" J! s8 V+ z9 \6 T& M8 v" u* Z
Otherwise, find a professional or change a new set.