Promises of endless hot water, lower energy bills and maximized storage have many homeowners converting from traditional tank water heaters to tankless. But for some, the benefits may not outweigh the cost. Before you make the switch, weigh the pros and cons to determine whether a tankless water heater is the best fit for your home.

How do tankless water heaters work?

Compared with a conventional tank-type water heater, a tankless water heater provides hot water on demand. As water is drawn, it is quickly heated by high-powered burners within a heat exchanger system of coils — heating only what you use. Theoretically, a tankless water system can provide an endless supply of hot water, so long as it falls within the tank’s gallons-per-minute capacity.

What are the benefits?

Tankless water heaters offer significant energy savings. The U.S. Department of Energy estimates that tankless water heaters can be as much as 34 percent more energy-efficient than conventional water heaters. And Energy Star estimates that a typical family can save as much as $100 or more per year with a qualified on-demand water heater. Of course, there are other benefits to consider as well.

First, experts say tankless water heaters will last 20 to 25 years on average — much longer than a traditional heater, which will typically last from seven to 14 years. Second, tankless water heaters are much smaller than tank heaters. And, because they can be mounted on the wall, they can free up space for storage and other uses. Finally, tankless water heaters are a better choice for the environment — not only because they consume less energy, but also because they generate less waste than traditional heaters.

What are the drawbacks?

Perhaps the greatest downside to tankless water heaters is the cost. Homeowners pay as much as triple the cost of tank heaters for tankless varieties, which can typically range from just under $1,000 for an electric model to $3,000 for a gas-powered model, including the cost of professional installation.

Another downside is a tankless water heater can only move water through its pipes so fast. While it can theoretically supply an endless amount of instant hot water, it may not keep up if with demands beyond its capacity. And, just as you would with a standard heater, you’ll need to run the water long enough to clear the pipes before the hot water gets to the faucet.

Finally, installing a tankless water heater may not be as simple as swapping your old tank-style heater for a new one. Your home’s gas piping, gas meter and gas line may not be sized appropriately for a gas-fired tankless heater, for example. Or your electrical system may require an expensive capacity upgrade. An improperly installed unit may not only underperform, but it will also present a safety hazard.

Is a tankless water heater right for you?

Here are some things to consider:

Utility upgrades: An electric model will need the proper voltage, amperage and circuit breaker. Gas-fired models will need proper equipment and venting.

Size and location: Tankless heaters are smaller than tank heaters and may be mounted on an interior or exterior wall. Tankless heaters should be located within 50 feet of a power source.

Installation: Every water heater should be installed by a highly rated plumber or heating, venting and air conditioning (HVAC) contractor. Dealers typically include installation in the purchase price.