Tankless water heaters mount unobtrusively on the wall, in a shallow closet, or even in an adjoining garage or attic.

Share story

If you’re remodeling, adding a new bath, or simply planning to replace a hot water heater that’s on its last legs, it’s worth looking at energy-efficient tankless water heaters. Is an investment in the new tankless technology the right answer for your home and family’s hot water needs? An expert offers some pros and cons for tankless and traditional hot water systems.

“Most of us have lived in homes with a traditional water heater, one of those large cylindrical storage tanks,” says Gale Bellows, a service manager at South West Plumbing in Seattle. “It’s powered by gas or electricity, and holds anywhere from 20 to 80 gallons of hot water. And that’s enough for most households, most of the time.”

The problem, Bellows says, is when a large family wants to take showers in the same time frame every morning. “You’re going to run out, and that last person is going to have a chilly experience.”

In the 1990s tankless hot water heaters, first popular in Europe, appeared on the market in the U.S. They, too, are powered by gas or electricity, but there the resemblance stops. No more large cylinders taking up space in your basement or utility closet — tankless water heaters mount unobtrusively on the wall, in a shallow closet, or even in an adjoining garage or attic.

Convenience counts

The big “wow” for people discovering tankless systems is how speedy they are.

“What people like about them is that they’re so responsive,” Bellows says. “When you turn on the shower, you can have hot water in seconds. And everyone appreciates that.”

If your home is one where hot water from the basement water heater has to travel a long distance to reach the second floor, you are probably the ideal candidate for a tankless unit.

“No one wants to waste all that water, waiting for some hot water to arrive,” Bellows says. He adds that it’s very common for people to install a tankless unit to serve an upstairs master bath or a bathroom that’s been added on at some distance from the water heater. A tankless unit can easily be added to work with an existing traditional hot water system.

Lower energy bills

In the long term, a tankless water heater can dramatically decrease power consumption, saving on monthly energy bills. That’s because they only heat up water when it’s needed, and aren’t keeping 50 gallons of hot water heated around the clock and when you are on vacation.

Bellows says you can expect the new tankless units to last almost twice as long as a traditional tank, another way that you’ll achieve savings.

Concerns about cost

However, if installation costs are a concern, you may want to stick with your existing tank-style water heater or replace it with a more efficient model. A tankless unit will give you substantial savings over time (as much as $1800 over the life of the unit) but the up-front cost is greater.

“You can expect to pay about $3,000 for the installation of a whole-house tankless unit,” Bellows says. “They are often more difficult to hook up to the existing plumbing system.”

Replacing a traditional water heater can run between $3000 and $5000 on average.

Planning for capacity

The good news about a tankless system: You’ll never run out of hot water. The unit will continue to heat water for as long as your tap is turned on. Most tankless water heaters supply from two to five gallons of hot water per minute. That’s ideal for a shower or for doing the wash. Tankless heaters powered by gas often provide a higher flow rate than those hooked up to electric power, Bellows notes.

Unfortunately, if you need to use hot water for the dishwasher, showers, and the washing machine at the same time, the two-to-five gallons per minute “flow rate” won’t be able to keep pace. For some people, the solution is to install multiple tankless units to meet demand. For others, the desire for a higher maximum flow rate is a reason to stick with a traditional tank.

Bellows points to federal government data that shows that homes where the daily use of hot water is 41 gallons or less, on-demand tankless water heaters can be as much as 34 percent more energy efficient. “Take a look at your current hot water usage, and you’ll get a really good idea of which way to go with your new system,” he says. “The traditional storage-tank models are still the most commonly used, but the high-efficiency tankless systems are rapidly gaining in popularity.”

South West Plumbing has been serving King, Pierce and Snohomish counties for more than 35 years. All South West Plumbing plumbers are highly trained and arrive prepared with fully stocked trucks. We work evenings and weekends at no extra charge.