Hi Bill, Sediment buildup has really been reduced as a source of water heater failure with the advent of sacrifial anodes that are now installed in virtually all heaters, and have been for at least the last decade. The zinc anode tube gives off ions(rusts) and thus is sacrificed rather than the parts of the heater. Sediment buildup is essentially caused by dirt and small metal particles that come in the water and fall to the bottom of the heater. Draining out the impurities is an easy task that you can do once or twice a year, depending on your water source. Just attach a garden hose to the draincock at the bottom of the heater and run the hose to a floor drain or outside. Carefully open the draincock fully and allow water to flow out until it runs clear. There is no need to empty the entire heater and it should run clear in less than a minute. Close the draincock and disconnect the hose. Done. Word of advice: The plastic draincocks typically on the bottom of waterheaters are cheap and can get brittle over time. Be careful not to overtighten this as the seat will begin to drip water if forced. Many plumbers I know even advise against draining the units for this reason. I'd just be careful with it, especially once it reaches 10 years of age.