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. 9 _& {" O- G, {( n3 | s- m: u$ @: S* aSolution: turn off water supply and take the humidifier apart and clean it will stop the leaking.' o7 F3 ?" c8 e0 L$ e/ o+ X; l% p
v4 o# w0 z2 L* T: n % u1 N Z5 \: W7 `2 xOtherwise, find a professional or change a new set.