A toilet has an unlimited lifespan. However they are not indestructible. Most toilets have a tank and bowl. The flush uses water and gravity to clear and rinse the bowl. The fixtures are made of clay and porcelain that can chip, crack, scrape and break if tools or other objects are dropped or come in contact with the surface. Treating the tank and lid along with the bowl like a class plate is recommended.

1. Tighten a loose seat, tank or wobbly toilet.There are seat bolts at the back of the seat near the tank. There are usually tank base bolts under the tank. The fixture bolts are usually covered with small caps at the base of the fixture near the floor.
2. Maintain the caulking between the floor and base of the fixture to avoid water seepage from water leaking on the floor and possibly causing water damage to a neighbor below.
3. Exercise the angle stop (supply) valve once a year and replace it if it leaks or becomes frozen. Inspect the supply line and valve frequently for any leaks
4. Replace plastic supply lines every 3 to 5 years. Steel braided lines should last twice as long. While replacing an angle stop it is a good opportunity to replace the supply line as well.

In addition to a leaking angle stop (supply) valve or water supply line, water may leak from the over flow tube if the water level in the tank is to high, the flapper or seal is bad, the wax seal between the fixture and floor is bad or if the tank bolts are loose. The water level and tank bolts can be adjusted or tightened while the flapper, seal and wax seal should be replaced if leaking.

To test if water is leaking out of the tank into the toilet bowl, add about 5-6 drops of food coloring into the tank and do not use the toilet for several hours. Check the water in the bowl after several hours and if color water is in the bowl, water is leaking from the tank into the bowl.