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. 8 W/ e2 y1 [) p v o0 _! R " _$ {8 I) g- l$ Q. `6 }% f' \Solution: turn off water supply and take the humidifier apart and clean it will stop the leaking. 0 ]. l/ r0 y( _- M& g 9 N& i2 I- K+ \ , ]- \$ R" {3 B, N. T+ iOtherwise, find a professional or change a new set.