Energy efficiency, space savings and easy installation are just some of the perks of these water heaters.

Have your customers ever complained about being the last one in the household to take a shower, and running out of hot water while shampoo is streaming in their eyes? Have they danced a little jig trying to avoid the freezing water? Or tried to take a shower or bath when the washing machine is on and ended up with lukewarm water at best? Tankless, or instantaneous, water heaters dominate the European and Asian water heater market, while the United States primarily uses tank-type water heaters. Until just a few years ago, there were only a few tankless water heater manufacturers with a presence in this country. But that's changed. “Now, all the major players from Japan, as well as many European manufacturers, are all in the United States, and they all are experiencing growth,” notes John Confrey, manager of technical operations at Noritz. The Japanese company established California-based Noritz America in 2002 to design and produce water-related products for use in the United States. Its latest product, the N-132, generates 380,000 Btus and flows 13.2 gpm. It is the largest tankless gas water heater in the world, the company claims. With about 10 million water heaters sold in this country each year, only about 100,000 of them are gas instantaneous water heaters, says Kyle Murray, vice president of marketing for Controlled Energy Corp. CEC's new product, the Bosch ProTankless 635 ES, was specifically designed for the U.S. market and made its debut at the ISH North America trade show in Las Vegas this past fall. “The acceptance of the trade in the last few years has really turned around. And that's because consumers are demanding the product.” Today's consumers are more sophisticated, educating themselves about a certain technology or product before making a purchase, especially on a big-ticket item such as a water heater. And tankless water heaters do cost more than tank-types, but the payback is the energy savings down the road. “The whole concept is really taking off here in the U.S., and this market is expected to increase 15 percent this year,” explains Tiffani Thompson, specialty product sales manager at Rheem Water Heaters. Its tankless gas water heater, the RTG-42PV Tankless Water Heater, also was shown at ISH North America. “Consumers are becoming more aware of the tankless option, and there is increasing awareness about tankless water heaters by contractors, builders, plumbers and HVAC companies.” Custom home builders are definitely taking notice of tankless as a whole-house alternative, says Ray Rasalan, Takagi's central regional manager. (Takagi's Flash T-KJr. earned recognition for industry innovation in the area of hydronic space heating as part of ISH North America's New Product Showcase.) Custom homes have a lot of fixtures using hot water, such as multihead shower systems and 80-gal. tubs. Buyers of these homes want to be assured they won't run out of hot water.

What's The Difference?

The major difference between the two types of water heaters is how they heat water. Tank water heaters heat water up slowly and store it for later use, while tankless heaters “flash heat” the water on demand. A higher Btu input heats the water faster, which is instantaneously delivered, and no storage is needed. “Tankless heaters are more energy-efficient because they eliminate the standby heat losses that are inherent in a tank-type design,” explains Frank Stiebel, president of Stiebel Eltron, which makes electric tankless water heaters. A typical 40- or 50-gal. residential tank-type water heater is about 50-60 percent efficient, while tankless units have about 80-84 percent efficiency. No storage means less energy is used; there is no cycling on and off to keep the water at the desired temperature. “You can go away for the weekend and use absolutely no energy for the water heater,” Murray notes. “And you can run 20 showers, one after the other, and never run out of hot water.” Installation and service are easier because the units are so small. A typical tankless water heater is compact and lightweight, usually no larger than a big suitcase, and one person can carry it in and install it. Compare that to the 40-gal. tank that takes at least two people to install and can fill up a small room. Because of their smaller size, tankless units can be installed almost anywhere. Wall mounts are typical, with venting directly through the wall, but heaters can also be mounted on the floor. “This size difference frees up space, makes installation easier and, in fact, allows many installations that would not have been possible with a storage tank,” Confrey explains. That includes outdoors, Murray says, as long as you live in a warm, nonfreezing environment. In a retrofit application, homeowners can gain a whole room for storage or work space just by switching from tank to tankless. One cautionary note: When looking at tankless water heaters, it's important to properly size the unit, as well as the gas line and flue, to achieve maximum performance. Longevity and dependability are other attributes of tankless heaters. Takagi's tankless heaters are designed to last 12-14 years, and Controlled Energy has units in the field that are more than 20 years old. Because of the compactness of the units, it's easier to keep them from corroding by using high-quality materials such as copper, stainless-steel and high-tech plastic, Stiebel says. “These are designed to be fixed,” Murray says. “If a part goes bad on it, you replace the part, not the whole heater as you would with a tank-type heater because it's usually leaking.”

Electric Vs. Gas

Most tankless units sold in this country are whole-house gas units, but electric units are available for areas that have affordable electric rates. “You need a good size electrical service to be able to operate these,” Stiebel notes. “They use a lot of electricity when operating, so you need a newer electric system to run electric tankless units effectively.” In a retrofit application, the size of the amperage draw would probably be too big for the load of the house, Murray adds. Electric tankless water heaters require a very high amp draw in order to provide the same flow rates that gas units have. There are also electric point-of-use tankless heaters, which are connected directly to the appliance or fixture that uses hot water. These are used mostly in commercial applications, but also can be used in residential applications.

It's All In The Design

What about differences between Japanese and American products? “The difference is really driven by the difference in consumer expectations in the two countries,” Confrey says. “In Japan, space savings and efficiency have been a big concern for many years, while in America these have only recently become major issues.” Because of these concerns, Japanese companies such as Noritz and Takagi have had to come up with more sophisticated and advanced technology for tankless heaters. The principles are the same with all tankless water heaters, but each manufacturer has a different design. Takagi has computerized controls to measure flow and water temperature, as well as to stabilize the water temperature within the unit. Noritz has electronic burner controls and uses the latest combustion technology to keep emissions low. American models may not be as advanced, but they do have some unique design characteristics. The Bosch ProTankless uses a ceramic burner, as well as some boiler controls and technologies to work with tankless technology. Rheem's tankless heater has an oxygen depletion safety device, which monitors oxygen, carbon dioxide and carbon monoxide levels, as well as an overheat limiter that protects the combustion chamber. On the European side, Stiebel's tankless heaters use a copper-clad heating element and two safety thermostats: 1) a scald-guard thermostat, which keeps the water temperature below 130 degrees F; and 2) a safety thermal cutout, which has a manual reset. With all the different tankless models on the market, it is possible to find the exact one to fit your customers' needs. The industry may be slow to change, but savvy consumers are eager to embrace new technology that makes their lives easier and more comfortable. “Although this was once referred to as a 'niche' market in this country,” Thompson says.