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. 4 l+ Y: M$ ]$ r- G& f5 h; D6 i0 |$ | X3 N i0 H4 |& z
Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking." y. ?/ n2 w' u3 c5 N
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) N$ R# D( x/ S5 FOtherwise, find a professional or change a new set.