I've never seen this happen. When I turn on the water in the tub upstairs makes the water in the toilet tank where the ball is over flow which causes water to exit the top of the tank. The toilet hasent even been flushed, it just starts to activate on its on. What kind of problem do I have and what should I do?

I'd say faulty fill valve in the tank, replace with a Fluidmaster 400A.

Ok thanks, I wil try that.

Your real problem is that the overflow tube is too high. It should be lower than the opening for the flush lever so the wate could NOT overflow the top of the tank.

I tryed that but when u run water in the tub it makes the tank overflow on its own, "weird" the water is licking threw the sealing down into the living room.

You have a weird, almost incomprehensible, problem that we might have to be there to diagnose, since it should NOT be able to happen the way you describe it.

Im going to try to turn the pressure down and change the float. Hope it works for me thanks.

When you open the tub faucet, THAT reduces the pressure so that may not help the situation.

Ok, I have changed to the fluid master and im hearing a small hiss after the tank is full. The water slowly risese. What could b my problem?

That would most likely be debris trapped under the seal. Turn the water off, remove the black plastic cap and turn the top of the fill valve 1/4 turn and lift up. Ease the water back on to clear any debris.

Thanks! So I would need to take the fluid master out to do this? Also, it fills up great but the problem is once its done thats when it starts to hiss, then it fills the entire tank over night and it will overflow onto the floor. Would that still b the same problem? I may have not explained it correctly the first time
I do have the valve turned off for now until I hear from u, THANKS



Edited 1 times.

One more thing, the fluid master 400a is brand new. It was doing it b for I installed and after.

When the fill valve is hissing like that, it is something preventing the gasket from seating and it is leaking water past. It can happen on a brand new valve when little pieces of rubber from the stop dislodge and get wedged in the fill valve. you can turn the water off, disassemble and flush the valve, then reassemble in about 2 minutes for a pro, or probably 4 minutes for a layman.

Ok thank u so much



Edited 1 times.

Can you post a pic of the inside of the tank?