Turn off the water heater power supply or gas control
Shut off the cold water supply to the heater
Let the water cool if needed
Attach a garden hose to the drain valve at the bottom of the tank
Place the other end of the hose in a safe drain area
Open a hot water faucet in the house to allow air into the system
Open the drain valve on the water heater
Let the tank drain completely
Open the pressure relief valve if needed to speed draining
Close the drain valve when finished
Remove the hose
Turn on the cold water supply to flush the tank if desired
Close the hot water faucet
Refill the tank fully before restoring power or relighting the gas
Check for leaks around the drain valve and connections