How do you de-set value in blueprint my dudes ?

So basicly my problem is that:I’m making a game where one of the enemies has ability to heal units that overlaps his special sphere. When other Capsule overlaps sphere it sets Value as Bool. It allows them to heal themselves. But after leving this sphere they should stop healing themselves. But they don’t. Here how it look’s . What I want is for bots to de-set so they won’t keep heal after leaveing sphere. Also this heal unit usses different tree than other units. How can I do this ?