Here's a question we received a while back from a prospective plumbing customer in Orlando: "My toilet slowly overflows from the flush handle opening over night, but during the day and evening this does not happen. Can you please explain why this is happening and help me solve my plumbing problems?" Here's something to try. Take a little blue food coloring and put it into the toilet tank until the color of the water is blue. If the color of the water in the bowl turns blue after about five minutes, then your flapper valve is leaking. If there is no blue food coloring visible in the bowl, then the water is running into the overflow tube in the center of the toilet tank from the fill valve. After the water shuts off, remove the 1/4 inch tube from the center fill tube and see if the water continues to drip from the fill tube. If it does, then the fill valve needs to be replaced. In either case, your toilet is partially clogged or the vent pipe is clogged because the toilet bowl should not fill up and overflow even if the flapper and fill valve are leaking. You may want to call a respected Orlando plumbing company to diagnose and fix your drain and plumbing problems. Roto-Rooter has a solid and reliable staff of plumbers in Orlando that can handle any residential plumbing repair. You can visit the website here or give us a call at 407-886-7311.