Tips on Maintaining a Water Heater
Give the water shut-off valve a twist to keep it from seizing.
If it is a gas water heater, set the gas valve to "Pilot" to prevent the burners from coming on throughout the flushing process. If electric, turn off the circuit breakers.
For gas water heater, make sure the flue is draining air properly by lighting a match next to the bell housing and watching the smoke. The smoke should be going up the flue.
Test the temperature relief. To test it, put a bucket below the extension pipe and open the valve. Water should flow when it's open and stop when it's closed. Set the thermostat to the recommended setting of 120 degrees F.
Check the pilot light on gas units; it should be burning blue and steady. Instructions for re-lighting the pilot are usually written on the side of the unit.
Check the burner operation by removing the flame shield, moving back and turning up the thermostat. Look at the flames to make sure they are burning blue and steady.
Drain the sediment from the tank by attaching one end of a garden hose to the drain valve at the bottom of the unit and put the other end outside or near a basement floor drain.
Safety Tip: Be careful because the water can be scalding hot.
Turn the thermostat down and shut off the cold water supply to the unit and then open the drain valve.
Open the temperature/pressure relief valve at the top of the tank by lifting the lever. Leave the valve open.
Open the drain valve at the bottom of the heater allowing the water to flow out of the garden hose. When the water out of the hose is running clear the flushing is finished. Close the drain valve, turn on the cold water supply and set the thermostat to the recommended setting.
Open a hot faucet in the house and let it run until no air bubbles come out. Turn the heater back on.