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. + s* e( \( ~- t3 l ~) _3 B/ z2 U5 e* ?/ i. b
Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking./ l8 C: A- s8 b( H' e! v! g8 b4 P
, \; e7 l( x/ ^6 q' L: Z R ) w- @) F; P- T) P2 ~) H" w( E9 JOtherwise, find a professional or change a new set.