We know that you would like to extend the life of your water heater. One way to accomplish this is to flush your water heater every six months. To properly flush a water heater first connect a garden hose to the drain down valve. Run this hose to a nearby drain or outside for discharge, if you have an electric water heater make sure to shut off the power. If you have a gas water heater turn the setting to pilot next open the drain down valve after one or two minutes. Close the supply valve at a nearby sink turn on the hot water and leave it on. Then return to the water heater once the water heater is drained you can turn this apply valve back on and let the heater flush for one to two minutes.
Finally close the drain down valve and let the water refill to capacity. Return to the open faucet and wait for all air to be purged from the tank. And from the lines once the air has been bled shut off the faucet, if you have a gas water heater be sure to change it back from pilot to the previous setting. If you have an electric water heater turn the power back on be sure to consult with your owners manual. In some instances if the water heater is old or maintenance has not been kept up with flushing could cause more harm than good.