Replacing the flush valve is an easy, efficient way to stop leaking and save thousands of gallons of water per year.
Step 7: Open the shut-off and test the new valve Turn on the water supply from underneath the toilet and let the tank fill. Once the water completely covers the flapper, water should stop filling the bowl. Test the new valve by flushing the toilet and watching the bowl fill. Once the flapper closes, all water to the bowl should stop as the tank refills.
The flapper will seal tight when covered with water and all water going into the bowl should stop.
