The average life of a water heater is 13 years. Some may only last two or three years others last 20. What's the trick to make them last?

You can extend your water heater's life by knowing what makes it fail and performing a few simple checks and maintenance duties. The number one water heater killer is rust. There are several factors that speed up the rusting and corrosion process.

Anode rods wear out: Every water heater has an anode rod inside that electrochemically corrodes so the tank won't. Once it is spent, the exposed metal parts of the tank are under attack.

Solution: Check the rod every year and replace it if necessary.

Sediment build up: When cold water is heated, it forces minerals out of solution and forms solids, usually calcium carbonate. Those solids settle to the bottom of the tank between the heating unit and the water. In addition to slowing heat transfer, the build-up causes overheating that can destroy the glass lining and weaken the steel bottom.

Solution: Drain your water heater annually. If the sediment is excessive, contact a plumber to have it thoroughly cleaned.

Rust and corrosion on the tank: Leaks can cause water heaters to rust from the outside preventing drains and pressure valves from operating properly.

Solution: Check all plumbing connections for leaks and repair or replace as necessary.

Corrosive gasses: If the air surrounding your water heater contains salt, chlorine, or other corrosive chemicals, they can attack the combustion chamber and/or flue.

Solution: Do not store corrosive chemicals near the water heater.

Too hot temperature setting: The higher the temperature, the faster sediment accumulates. Every 20 degree rise in water temperature doubles the chemical action that causes rust and corrosion.

Solution: Keep the water temperature as low as possible. Normal tap water temperature is 120 degrees Fahrenheit.