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 Z. H3 O: P9 u, b" `" q
! d6 @& `1 G+ l- l7 YSolution: turn off water supply and take the humidifier apart and clean it will stop the leaking.. {1 N' _* [ L7 o4 u& _
* W+ |7 g* S. B3 V% ` Q3 ]$ d7 x) ~' `& ^2 ?( A
Otherwise, find a professional or change a new set.