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Understand How Your Storage Water Heater Works


A storage water heater does just what its name impliesandmdash;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.

How Does Your Storage Water Heater Work?

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 tankandrsquo;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.

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

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