Flush your water heater once a year
Added
EPA WaterSense lists annual water heater maintenance for homeowners: look for leaks and corrosion, check the temperature and pressure valve, and flush the tank. Turn off the power supply first and drain into a spot that can handle hot water.
The result
Result: EPA WaterSense: flushing once a year reduces sediment buildup that can decrease efficiency.
Source
EPA WaterSense (opens the original source in a new tab). Check it for the latest numbers before you act.