My teenage son called me this morning at work and said that the plastic thing that rises with the water (tank bulb) or whatever you call it on the Fluidmaster 400 to cut off the water supply to the tank had gotten stuck in a position that allowed water to keep going into the tank. He said that there was something in the toilet part clogging it and therefore when he woke up the bathroom was flooded and the kitchen which is below the bathroom also had a good amount of water that came through the ceiling. I check the tank once a week for any signs of leakage and never noticed the plastic thing sticking. He said after he shutoff the water and cleared the clog that the thing wasn't sticking anymore and still isn't now that I am home. My question is, can this happen, a seemingly good fluidmaster that is only a few years old getting stuck one second and being fine the next? My son doesn't usually lie to me (that I know of), but this sounds awfully fishy to me. Also, from the time I left for work & the time my son woke up was only a matter of 3 hours. Can that much water come out of the toilet in that little time?