Even if you have no previous experience in repairing toilets, there are certain basic problems and fixes that you can handle. Basic knowledge can save you frustration with ongoing problems and possibly save you money.
Constant Running or Partial Flushes
A toilet that won't stop running, shuts on and off, or performs phantom flushes can be fixed by first removing the tank lid. Find the thin chain that runs from the trip lever, which is connected to the back of the handle, to the rubber flapper.
Locate the flapper by flushing the toilet and noticing the red or black part that rises and falls. Make sure the flapper closes properly in the hole underneath it after flushing. Get a longer chain from a home improvement or hardware store if it is too short to let the flapper stay fully closed.
To unclog a toilet, position the plunger over the toilet drain and make a down-and-up motion with the plunger--slowly, to avoid breaking the seal created over the drain and splashing water out of the bowl. Plunge approximately 12 repetitions and look to see if the water starts draining from the bowl. Don't be discouraged if you have to repeatedly plunge to clear the toilet.
Don't use a plunger on a toilet after pouring in chemicals to clear a clog. When you do use chemicals, either to clean the bowl or clear a clog, wear protective rubber gloves and eye protection. Do not mix chemicals, and do not use them inside the toilet tank; they will damage the rubber parts of the tank components.