QUESTION FROM pateo331

The toilet in my guest bath on the 2nd floor, spontaneously flushes. Turning off the water supply solves the problem but that's inconvenient. Why does it do that? I've had the "guts" fixed but that didn't solve the problem.

ANSWER FROM HOME-WIZARD

pateo331:

A toilet which spontaneously flushes on its own is doing what is sometimes called a "phantom flush." Almost always this is caused by water slowly leaking from the tank side to the bowl side.

There is an easy way to test for this. Just place a few drops of kitchen food coloring into the tank of your toilet. If after a few minutes you start seeing the color begin to show up in the bowl of your toilet, then the flapper valve is not sealing properly, which is allowing water to leak past it.

The flapper valve is the rubber flap or plug that lifts up when you use the handle to flush the toilet. If this becomes warped, or the wrong piece is installed, or if it gets coated with slime . . . then it prevents that flapper valve from sealing properly, and therefore water will be able to continually run from the tank to the bowl, and as it fills up over time, it causes your toilet to flush on its own.

It sounds like you already had this replaced, but there are a couple of reasons why you may still be having a problem:

1) the flapper valve may not have been installed properly, and so it is not sealing tightly.

2) there may have been slime or deposits on the seat where the flapper valve goes, and this is preventing it from sealing properly.

3) the flapper valve may be warped or distored.

4) if the flapper valve uses a chain, it may not be long enough to allow the valve to close tightly.


Hope this is helpful
Home Wizard