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. 2 d6 b9 T x1 X1 I- R+ j* l
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Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking.7 ]* U" X7 o \4 L
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Otherwise, find a professional or change a new set.