While demand for tankless water heaters continues to increase, more than 95% of homes have conventional storage tank heaters installed. About half use electric resistance or heat pump technology to produce hot water, while the other half uses natural gas or propane.

If you’re like most, the only time you think about your water heater is when water fails to come out of the faucet or the tank starts to leak. Most homeowners overlook the importance of regular maintenance, which can lead to decreased efficiency, higher energy bills and premature replacement. The U.S. Department of Energy (DOE) estimates the average product lifetime for storage tank water heaters to be around 15 years. By annually doing the routine maintenance described below, you can help assure your water heater provides the efficiency and longevity you expect.

Before starting, use a thermometer to identify your hot water temperature at the faucet located furthest from the hot water heater. Most water heater manufacturers preset thermostats at 140º Fahrenheit (F). The DOE recommends a setpoint of 120°F to optimize efficiency, slow mineral buildup and reduce corrosion. Temperatures lower than this can pose a slight risk of allowing bacterial growth, while temperatures above 140ºF significantly increase inefficiency from standby heat losses and create scalding risks. For every 10 degrees the temperature is lowered, you can expect to save up to 5% in water heating energy use.

Next, take safety precautions. This should always be your top priority. Before beginning:

• Turn off the power: For electric water heaters, switch off the circuit breaker. For gas-fired units, turn the gas valve to the “pilot” position.
• Identify the cold-water line supplying the water heater and close it.
• Wait a few hours after turning off the power to allow the water in the tank to cool.
• Wear gloves and goggles to protect from hot water and debris.
• If you have a gas water heater, ensure the area is well-ventilated to prevent the buildup of harmful gases.

Now, perform the following maintenance steps:

1. Test the Temperature and Pressure Relief (TPR) Valve. The TPR valve is a critical safety device that releases internal pressure if it becomes too high. To test it:

• Place a bucket under the discharge pipe connected to the TPR valve.
• Lift the valve’s tab to release some water.
• If water flows freely and stops when you release the tab, the valve is working correctly. If not, the valve needs to be replaced.

2. For electric resistance and heat pump water heaters, inspect and replace the anode rod if it is less than half-inch in diameter. The anode rod attracts corrosive elements in the water, thus protecting the tank.

3. Flush the tank to remove sediment. Sediment buildup can reduce your heater’s hot water volume, require longer runtimes to provide hot water and corrode elements in electrical units. To flush the tank:

• Connect a garden hose to the drain valve at the bottom of the tank.
• Open the valve and let the water drain into a bucket and not a floor drain. Sediment could plug the floor drain, creating another problem.
• Once the tank is empty, briefly open the cold-water supply to stir up any remaining sediment.
• Continue flushing until the water runs clear. Close the drain valve, disconnect the hose, and refill the tank. Double-check to assure the TPR valve is closed to prevent flooding the floor.

4. If necessary, adjust the temperature setting.

• Locate the thermostat. While they are often installed on the bottom exterior of gas-powered units, they are usually located behind access panels on electric units. Also, electric units usually have two (top and bottom) thermostats.
• Adjust the dial in the direction you want your hot water temperature to be. You may need to use a screwdriver to adjust the dial. Most thermostats do not have markings that exactly correspond to the desired temperature. Therefore, small adjustments followed by waiting a couple of hours and checking the temperature at the faucet may be necessary to establish the desired temperature.
• Since electric hot water heaters usually have two thermostats, assure both are adjusted to the same setpoint.
• Remember to turn the water heater off or set the thermostat to its lowest setting if you’ll be away from home for more than three days.

1. Your local utility wants to help keep you effectively and efficiently in hot water! For other ways you can save energy while running your household or business, contact your local utility.