Understand How Your Storage Water Heater Works

Understand How Your Storage Water Heater Works

A storage water heater does just what its name implies—it stores and heats water. Storage water heaters typically hold 20-80 gallons and heat the water constantly so that it is always available. Most water heaters are natural gas-fueled, although propane and kerosene are also used. Homeowners without natural gas lines often choose electric water heaters.

Whether gas or electric, water heaters are fairly simply and straightforward in operation. Read on to learn more about how these work.

Gas Storage Water Heater

A gas-powered water heater is operated by a burner under the tank with gas piped to a valve. A thermostat senses the temperature of the water and thereby regulates how much fuel is delivered to the burner. The burner is ignited by spark ignition or a pilot light. Toxic emissions are vented from the burner through a pipe that runs through the tank and, generally, out the roof through a flue. Newer water heaters may have fan-assisted vents that are piped through a wall.

Heated water runs through an outlet at the top, and cold water then enters to refill the tank through a diffuser dip tube. A shutoff valve regulates the flow of water.

Water heaters have a magnesium or aluminum anode rod that cuts down on corrosion from minerals in the water through the ionization process. Sediment buildup can otherwise shorten a tank’s life.

Tanks are equipped with drain valves at their base, either for draining the tank or flushing out sediment. If you have hard water, flushing the tank annually will extend its life. Water heaters also have a temperature-pressure relief valve near the top of the tank, which automatically opens when pressure or temperature is too high. The valve should be tested occasionally.

Electric Water Heater

Electric water heaters work basically the same as gas models, although no flue is needed since there are no combustion gases.

Visit the Valley Heating, Cooling, Electrical website for more on how a storage water heater works or for more in-depth information on most HVAC topics. You can also call us at (408) 868-5500.

Our goal is to help educate our customers inthe South Bay Peninsula and Santa Cruz areas of Californiaabout energy and home comfort issues (specific to HVAC systems).