The average water heater will last about 12 years according to industry statistics. Sadly, far too many water heaters fail long before that. With a bit of periodic maintenance, a water heater should last well into its teens or longer, thus, saving you money and reducing our nation's landfill sites.

Although there are various styles of water heaters in this country, the most popular is the tank type, which is fueled by natural gas. An electric variation contains one or more electrical elements that heat the water. In either case, a water heater will operate more efficiently and last longer if you perform a few routine tasks.
The most common reason for water heater replacement is a leaking tank. Although leaks can occur for a host of reasons, the two most common ones are sediment buildup at the base of the tank and electrolysis. Sediment can cause excessive temperatures that stress the tank linking, and electrolysis will result in pinhole leaks in the tank's lining.

Remove sediment buildup at the base of the tank by flushing the tank at least once annually and more often if you have hard water. To flush the water heater, attach a garden hose to the drain valve at the base of the tank and run the hose out to a location where hot water can be safely drained. Turn the valve on and allow it to run for several minutes -- until the water becomes clear. Since you will be dealing with hot water, be careful not to get burned.

For water heaters that have not been flushed in ages (those that might have much sediment at the base of the tank), we suggest using a chemical additive that will help dissolve the sediment and facilitate the flushing process. Such a chemical can be found in the plumbing or water heater section or your local hardware store or home-improvement center. Another excellent resource is a plumbing supply house that sells to the trade.

Use the chemical in strict accordance with the directions on the label. Usually the cold-water supply valve to the water heater will need to be turned off and the supply line removed from the top of the water heater so that the solutions can be poured into the water heater. After a time -- usually several hours -- the water heater can be flushed as described earlier.

Another sediment-busting technique that is being used by many water heater manufacturers is a curved dip tube. The dip tube is a small-diameter plastic pipe that carries water from the cold-water inlet at the top of the water heater to within 12 inches or so of the base of the tank where the burners are located. A curve at the end of the dip tube (placed at the proper angle) will create a swirling action that will help reduce sediment buildup and assist in the flushing process.

Pinhole leaks in the tank lining are prevented by a cathodic or ``sacrificial'' anode that is located inside the tank. It is a vertical rod with a hex head that runs from the top of the tank to within about a foot of the base. As its name implies, the anode is designed to give itself up to protect the integrity of the tank. Depending on its composition (zinc, magnesium or aluminum), the water quality and whether you have a water softener, an anode can require replacement as often as once a year. An anode should, however, last about three years. A replacement anode can be found in the water heater-plumbing section of your local hardware store or home center or at a plumbing supply store that sells to the trade. Removal and replacement can be a daunting task that might best

Water at the base of a tank is not always the result of a leaking tank and, thus, will not necessarily require replacement. A leaking water connection that might not be visible at the top of the tank can trickle down the outside (inside the outer shell of the tank) and show itself as a puddle of water on the floor below the tank. Careful inspection of the various connections using a dry towel and a flashlight might reveal a leak that can easily be repaired with a wrench in a matter of seconds.

The hot- and cold-water connections at the top of the water heater usually are made with flexible copper supply lines that are attached to the water heater with short lengths of pipe called nipples. Brass nipples and or dielectric unions should be used to prevent electrolysis. In addition, all pipe threads should be wrapped with Teflon tape or a similar material that prevents leaks.

Another likely location for a leaking water heater is the temperature and pressure relief valve (TP&R valve). The TP&R valve is a safety valve that is designed to open when the water in the tank becomes too hot or the pressure in the tank becomes excessive. The valve is attached to the tank by a threaded connection. Like the water supply connections at the top of the water heater, the TP&R connection can leak. The valve must be removed, the threads wrapped with Teflon tape, and then reinstalled to stop the leak. A faulty TP&R valve can be another, more serious, cause for a leak. A leaking TP&R valve should immediately be replaced to prevent a potential explosion.

The drain valve is another primary location on a leaking water heater. Unfortunately, most manufacturer-installed valves are of poor quality. Consequently, the valve can be difficult to operate and can leak at the spigot or at the location where it is connected to the tank. Therefore, we suggest replacing the cheaply manufactured gate valve with a high-quality brass-ball valve that can be easily operated. The ball valve will also facilitate the flushing process by improving the volume of water allowed to exist in the tank during the flushing process. Since a ball valve is opened and closed with a right angle turn, we suggest that you install a brass cap on the discharge port of the valve to prevent accidental operation that can result in burning or a flood.

Be alert to your water heater's needs and it will give you many years of energy-efficient, dependable service.