With a little effort, you can keep your gas and electric water heaters working efficiently. Some repairs are simple, like how to drain a gas or electric water heater and pressure relief valve and tank or pilot light maintenance. However, if you aren’t comfortable working with gas or electricity, always CALL A PROFESSIONAL.
1) How to Check the Pressure Valve
Both gas and electric water heaters have a safety device called a temperature and pressure relief valve, or T&P valve for short. In the event the tank overpressurizes, the relief valve opens and releases the pressure. If the valve doesn’t operate correctly, the tank can overpressurize and explode.
Don’t Forget: Always wear gloves, goggles and other protective clothing while performing maintenance on your water heater.
Turn off the electricity to the water heater or turn off the gas to extinguish the pilot light. Shut off the cold-water inlet to the water heater.
Position a bucket to catch water from the pressure relief valve. Pull the trip lever on the valve. You should hear a slight rush of air or see some water and vapor exit through the pressure relief valve. If you don’t, drain the tank and replace the valve.
To replace the valve, remove the discharge pipe and unscrew the valve from the water heater. Note the stem length and buy an exact replacement. Screw the new valve into place, tightening with a wrench. Reattach the discharge pipe, turn on the water and either reconnect the electricity or restart the pilot light according to the manufacturer’s instructions.
2. How to Flush the Tank
Sediment buildup in the tank can reduce your water heater’s energy efficiency and also clog your water lines. Avoid these problems and increase the life of your unit by flushing the tank each time you check the pressure relief valve.
Turn off the electricity to the water heater or turn off the gas to extinguish the pilot. Shut off the cold-water inlet to the water heater.
Connect a garden hose to the tank’s drain valve. Locate the draining end of the hose in an area that won’t be adversely affected by the scalding hot water.
With the pressure relief valve open, open the drain valve and allow the tank to drain completely. Completely draining the tank ensures that you’ve removed all of the sediment possible.
Close the tank drain valve, disconnect the hose from the valve and close the pressure relief valve. Open all the hot-water spigots in the house, and turn on the cold-water inlet to the tank.
Close each hot-water spigot as water begins to flow from it. After all the spigots are closed, turn on the electricity to the water heater, or turn the gas switch to run.
3. Gas Water Heaters: Lighting the Pilot
With the gas valve in an “on” position and the control knob set to “pilot,” press the knob and push the igniter button. The light will blink when it’s lit and you should see a small flame through the view pane. Set the temperature to 120 degrees Fahrenheit.
Caution: Read and follow your manufacturer’s lighting instructions for more detailed instructions on lighting the pilot.
Good to Know: Newer water heater models have a smaller pilot light, which may be hard to see. If so, darken the room and look carefully through the sight glass in order to see the pilot light.
Also Good to Know: The first time a gas water heater is lit it may produce condensation. You may hear dripping sounds or see a small puddle of water in the drain pan. Condensation is normal and will go away once the water heater has reached its normal operating temperature.
Excerpted from Lowes.com