When asked about how best to optimize hot-water delivery, contractors and homeowners increasingly think of tankless water heaters. That’s no surprise. While these units tend to cost more to purchase than traditional tank-type units, they allow endless showers with no worry about running short and can last five to ten years longer then conventional storage water heaters. And because tankless units don’t heat water when it’s not needed, homeowners pay lower energy bills. In new construction, tankless water heaters can even lower overall construction costs by freeing up valuable square footage in the home.
There’s also evidence that propane and gas tankless units perform better than electric in cold climates. In a test for a January 2019 Consumer Reports article, gas models consistently heated water to the setpoint temperature, but some electric units couldn’t keep up when supply water was colder than 58 degrees Fahrenheit — which it is in most of the northern United States. (Note that while Consumer Reports tested natural gas units, propane burns at a nearly equal flame temperature.)
To help your customers achieve the most satisfying hot water experience, it’s important to educate homeowners about the benefits of tankless water heaters and clear up any common misconceptions. Two objections homeowners might have are about maintenance and lag time.
If you install tankless in a home with hard water, homeowners should plan to use a softening system or do an annual flush to prevent calcium deposits. That regular maintenance helps keep the unit functioning over its maximum life span — estimated at more than 20 years. Some people have a plumber do the flushing, but it’s not complicated and plenty of videos online show homeowners how to do it.
Austin, Texas, builder and remodeler Matt Risinger has installed a lot of tankless units for customers. He says preparing your homeowners with a softening system or a plan to flush their own unit can provide them with significant savings. “If you have a softening system, you may never have to worry about maintenance,” he says. Plus, a softening system can also improve the performance of dishwashers and washing machines in homes with hard water. (See Risinger debunk the myth that tankless units don’t run on well water here.)
With less need for professional service, homeowners can spend more time enjoying the benefits of their tankless units. “People love the luxury of limitless hot water,” says Risinger, who also installed a tankless water heater in his home.
Eliminating the lag
The keyword is “limitless,” not “instant.” Tankless manufacturers have heard complaints from customers whose contractors didn’t explain this. “Some people assume that tankless delivers instant hot water to the fixture, but that’s not the case,” says Bronwyn Planasch, Southern California builder sales manager at Noritz America. A tankless unit has to fire up and get up to temperature before it can push out the cold water in the plumbing system between the water heater and the fixture. “With especially cold supply water, that might take a few seconds longer than with a tank water heater,” Planasch says.
Tankless water heaters offer flexibility in their installation location due to their small size and versatile venting, so one option is to locate tankless water heaters in close proximity to frequent hot water uses such as the master lavatory and kitchen sink. Tankless units can be installed inside or outside the home to help achieve that goal.
You can also eliminate the lag with a recirculation pump, but Planasch advises against setting it to run constantly like you would with a tank water heater. A better option is to control the pump with a timer and an aquastat so that it runs only during peak hours — usually in the morning and early evening — and within a selected temperature range. There will be a lag time for hot-water use during nonpeak hours, but for most homeowners, that’s an acceptable tradeoff for lower energy bills.
Another tankless advantage is that you can get units with the recirculating pump built in. Noritz and Rinnai both offer this feature. You can install them in a new home with a dedicated return line or in a retrofit that uses a crossover valve to direct return water through the cold-water line back to the water heater.
And a timer isn’t the only control option. David Federico, brand director at Rinnai America, says that his company offers a motion sensor, a wireless push button, and a smartphone app that homeowners can use to start the pump. Rinnai’s units will even integrate with popular IoT systems such as Amazon Alexa, Google Home, or Samsung SmartThings. “You can just say, ‘Alexa, I’m going to take a shower,’” he says. That’s hot-water delivery, optimized for the smart-home era.
To help educate your customers on the benefits of tankless water heaters, three climate-specific fact sheets provide an easy reference on how the energy savings and long life span of tankless units provide a lower annual cost of ownership than alternative options. In a moderate-demand home in a cold climate, for instance, a propane-powered tankless water heater has annual energy costs $208 lower than a 50-gallon electric water heater and a 10 percent lower annual cost of ownership. Check out the fact sheets for cold, mixed, and hot climates.