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. ' G1 ]4 A' ]( T+ A
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Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking. / U" K; U1 R4 S$ ~ - v, I( D- |5 n! s# W$ h" t4 M- S8 Q+ L5 h' r* I l0 Y) v
Otherwise, find a professional or change a new set.