Which Water Heater Is Right for You?

Storage

A storage water heater holds a reservoir of hot water and operates by releasing hot water from the top of the tank when you turn on the hot water tap. Cold water fills the bottom of the tank after use.

Lasts 10-15 years.

Lower purchase cost.

Allows for simultaneous, multiples uses of hot water.

Standby heat loss can occur, wasting energy even when a hot water tap isn't running.

Tankless (a.k.a. Demand)

Tankless water heaters, also known as demand-type or instantaneous water heaters, provide hot water only as it is needed, eliminating standby heat loss.

Lasts about 20 years.

8%-34% more efficient than storage water heaters.

Could save $100 or more annually with an ENERGY STAR qualified tankless water heater.

Have lower operating costs.

Higher initial cost.

Hot water output limited to about 2-5 gallons per minute; multiple heaters may be needed if hot water demand is high.

Solar

Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. (There's more on the types of solar water heaters here.)

Lasts about 20 years.

50% more efficient than gas/electric water heaters.

Can be used in any climate, and the fuel—sunshine—is free and a renewable resource.

Higher initial cost.

May require a backup system for cloudy days or high-demand times.

Tankless Coil

A tankless coil water heater provides hot water on demand without a tank. When a hot water faucet is turned on, water is heated as it flows through a heating coil or heat exchanger installed in a main furnace or boiler.

Lasts about 10 years.

No standby heat loss.

Efficient during colder months while heating system is used regularly.

Lower installation and maintenance costs.

Inefficient for many homes, especially in warmer climates.

Indirect

An indirect water heater uses the main furnace or boiler to heat a fluid that's circulated through a heat exchanger in the storage tank.

Lasts about 10 years.

Energy stored by the water tank allows the furnace to turn off and on less often, which saves energy.

Used with a high-efficiency boiler and well-insulated tank, indirect systems can be less expensive, particularly if the heat source boiler is set to "cold start."

Requires a storage tank.

Can be inefficient for many homes, especially in warmer climates.

Heat Pump

Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. To move the heat, heat pumps work like a refrigerator in reverse.

Lasts about 10-15 years.

Can be 2 to 3 times more energy efficient than conventional electric resistance water heaters.

ENERGY STAR qualified models can save almost $300 annually on electric bills.

Can only be installed in locations that remain in the 40º–90ºF range year-round.

Require at least 1,000 cubic feet of air space around the water heater.

Increase the load on space conditioning appliances during heating months.