To inspect your toilet, follow these instructions (The diagram and descriptions above will help illustrate the important parts of your toilet). Carefully remove the tank lid and make sure all the mechanisms are working properly. Also, make sure the fill tube is placed so that it empties into the overflow tube.
Question: How do I measure the height of a fill valve?
Problem: Float Arm Not Working Properly
Visually check to see if the overflow tube and the flapper are working properly. Do this by flushing the toilet, watching the flow tank mechanism, and listening. You should be able to hear the water flow shut off.
If the water does not shut off, has the water level risen above the overflow tube? If it has, gently bend the float arm down and adjust the water level. You want the fill valve to shut off the water when the water level is about 1/2 inch below the top of the overflow tube. This water line is marked in some toilet tanks. If adjusting the float arm doesn't fix the problem, then you will need to replace the fill valve.
Problem: Defective Flapper
Check for a worn or improperly seated flapper by dropping two dye tablets, or 5-7 drops of red food coloring, into the toilet tank. Do not flush. If there is a leak, the dye-colored water will seep into the bowl in about 5-10 minutes. If the water in the bowl changes color, the flapper needs to be replaced or realigned, and you should make the necessary repairs. When replacing the flapper it is important to replace it with the identical flapper that came originally with the toilet. The installation of the wrong flapper on a water-efficient 1.6-gpf toilet could result in water consumptions as high as 4.4- gallons for non-adjustable flappers and 3.3 gallons for adjustable flappers.
Problem: Pinhole Leak in Pipe or Float
A pinhole leak in the overflow tube below the waterline could produce an invisible leak. Check for this by shining a flashlight down into the overflow pipe. If you see running water, you have a leak and need to replace the flush valve.
Problem: Flush Valve Seat Not Smooth
The flush valve seat should be clean and smooth. If the flush valve seat has a build up of minerals or algae, has a rough surface or has become warped, it will not make a tight seal with the flapper. Take a nylon scrub pad and remove any mineral or algae build-up. If you find the seat to be rough or pitted, then you need to replace the flush valve.
Problem: Handle Needs To Be Jiggled To Keep The Toilet From "Running"
If the handle needs to be jiggled to keep the toilet from "running", the flush lever bar and chain, or the handle itself may be sticking. Adjust the nut that secures the handle in the toilet tank. If that does not work, you may have to replace the handle. If the handle is loose, tighten the nut that secures the handle in the toilet tank. If that does not work, you may have to replace the handle.