There is a simple test you can perform to determine if you might have a flush valve that is not seated correctly in your toilet. The flush valve controls the flow of water from the tank into the bowl of the toilet. There is an easy way to tell if your flush valve is not seated or aligned correctly by using colored dye.
Step 1 – Fill Tank
Make sure the toilet reservoir or tank is full of water. Flush the toilet and allow the tank to fill completely.
Step 2 – Add Color
With the toilet reservoir full of water, drop 4 to 5 drops of colored dye (food coloring) into the toilet tank. It is best to use a dark color such as a green, blue or red.
Step 3 – Watch Bowl
For the next few minutes, watch the toilet bowl to see if any of the colored dye is leaking into the bowl. If you see the coloring in the bowl, you know that the flush valve is not properly aligned and is leaking water from the tank into the toilet bowl. This is an indication that you need to replace the flush valve in your toilet.