A flush valve toilet is a simple piece of equipment to understand and operate. Repairs, however, can range from very simple to fairly complicated. Knowing what is wrong is the first step in repairing your toilet.
Step 1 - Open the Toilet
The first step in fixing your flush valve toilet is opening it and testing each part. Remove the top of the toilet and place it on the floor. Turn off the water supply and flush the toilet. Watch to see if the flapper seals completely. Once the water is drained use a wet/dry vacuum to remove the rest of the water.
Step 2 - Check the Chain and Handle
If you have noticed, you need to increase the duration of the flush you need to add more water to the bowl. You can do this by raising the height of the float. Remove the old handle and clean it with a toothbrush dipped in vinegar. If the handle is corroded, you will need to replace it.
Step 3 - Check the Flapper
Your flapper must properly seal in order for your toilet to work to its full capacity. There are slight differences for each flapper so use your best judgment and a manual, if you have one available. You must remove the chain before you can remove the flapper. If you decide to replace the flapper the replacement must be as close to the current model as possible.
Step 4 - Check the Flush Valve
Replacing the flapper may not solve all of your problems. If you know you have a problem with the flush valve itself you may have to replace it. To do this, loosen the coupling nut that connects to the water supply and fill valve shank and remove the tube from the bowl. You may then remove the old flush valve and replace it. If you cannot remove the tank you will need to find a retrofit kit that will suit your needs.
Step 5 - Fill Valve
If you have a problem with the fill valve you will need to replace the entire unit. Use pliers to remove the mounting nut outside of the tank and remove the old fill valve. When you install the new valve install it so the critical level (CL) is at least one inch above the overflow pipe. When you replace the shank washer on the threaded shank, be sure it lays flat. Compare the CL level and adjust it as necessary. The valve pipe should go through to the outside of the tank. Use your hand to tighten the lock nut. Hook up the water supply. Back inside the tank, remove the overflow cap and attach the refill tube to the plastic angle adapter and refill nipple. Cut any excess tubing.
Once you have completed all of the repairs. Turn on the water and tighten any fittings. Flush the toilet to be sure it is working properly.