How to Repair a Running Toilet

A running toilet can be a simple thing to fix, and the water savings add up quickly. Start with the simplest solutions first. If those don't work, move on to the more serious repairs.

Step 1 - Fix the Rod or Chain

First, check the guide rod or chain on the tank flapper. If the rod is bent or the chain links are twisted, simply straighten them.

Step 2 - Adjust or Replace the Float

Next, check the float mechanism. If lifting the ball stops the water from running, try to bend the float arm down to get the right buoyancy. If the ball has water in it, it needs to be replaced. Replace it by unscrewing it from the arm and putting a new one in its place.

Step 3 - Clear, Clean or Replace the Flapper

If the toilet is still running, the valve seat and flapper may have corrosion or build-up, preventing the flapper from closing. Lift the flapper up and check for any objects in the way. Gently scour the seat and the rim. If there is a great deal of damage, replace the flapper.

Step 4 - Replace the Flush Valve

The flush valve assembly may have to be replaced if the toilet is still running. Take the old parts with you when purchasing the new inside gaskets and assembly to ensure a perfect match. If the shaft of the assembly is cracked, the whole shaft and assembly need to be replaced.

Replacing the flush valve involves removing the tank from the bowl. After removing the tank, turn it over and remove that large plastic nut in the middle of the tank. Remove the flush valve from the tank, take it to the hardware store and buy a new one. Install it and put the tank back on the bowl.

TIP:Doityourself's plumbing consultant Mark Vander Sande suggests, "You may want to get a new tank to bowl gasket and replace that, as well as new tank to bowl bolts. As long as you have the tank off, I recommend doing it all at once to avoid future problems. When installing the tank on the bowl, tighten the bolts one side at a time... slowly with the same tension on each side. If you tighten one side too tight, when you tighten the other side it may crack the tank.

Mark Vander Sande, professional plumber, contributed to this article.