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 M7 i$ V* H; Z$ ]1 `) }
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Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking. 5 ~0 [3 f @8 X! h6 W4 W! G9 A3 Z1 v. S
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Otherwise, find a professional or change a new set.