Occasionally draining a water heater adds years to its life. A water heater should heat water and supply your house with hot water. While heating water, minerals and other sediments settle at the bottom of the heater. If you live in an area with hard water, the sediment builds up rather quickly and will clog the water heater's drain valve and damage the heater. That's why draining and flushing your water heater at least once a year is so necessary. You can call a plumber to drain your water heater, or you can follow these simple instructions and do it yourself.
- Shut off the heater's heating element. If it's an electric heater, turn off the circuit breaker. If it's a gas heater, turn the thermostat to the "pilot" setting.
- Turn off the water supply to the tank. The shut off valve is probably on a copper pipe that runs into the top of the tank.
- Locate the drain valve at the bottom of the water tank. Attach one end of a garden hose to the valve. Put the other end of the hose into a drain (e.g. a nearby sink) or toilet, or outside the house. This is where the water will drain out.
- Open the drain valve, where you just attached the hose. Notice the color of the water. At first it will have a dark, rusty color, as it's mixed with the sediment. After a few gallons have drained the water will turn clear.
- Close the drain valve when you see clear water coming out.
- Turn the water supply back on and wait for the tank to fill up.
- Turn the power or gas supply back on after the tank has filled with water.[sources: Hot Water, Chili Pepper]