Tankless hot water heaters

It's Time to Consider Tankless

Tankless FAQ's

It's often been said that what you don't know won't kill you.  In the case of tankless water heaters, it may hurt a little.  You see, tankless technology has been gaining momentum, and the time to consider a change may be sooner than you think.  I know, questions keep arising with concerns about the technology, but the evolution of the tankless water heater is undeniable.

What about hot water supply?  With rising energy costs, is tankless a viable option?  PHC News conducted an exclusive Q&A interview with some of the best and brightest minds in the tankless water heater industry to help answer some common questions heard around the country.  The participants:  Matt Beaulieu, marketing coordinator, Noritz America;  Jim Conners, residential product manager, Rheem water heating;  Maryke Gillis, Brand manager, Bosch Water Heaters;  Ted Kwak, president,  AQ Energy;  Matt Murtaugh, marketing manager, Rinnai North America; and Hiro Yamada, director of marketing, Takagi.

1.  Describe the benefits of tankless.

Beaulieu:  The benefits include endless hot water, energy savings -- 50% savings in your hot water energy costs -- space savings, environmentally friendly -- lower NOx emissions, long life span -- 20 years (2-3 times longer than a tank), and for commercial applications -- ASME accreditation, NSF, true commercial components and features.

Conners:  Tankless water heaters can provide a continuous supply of hot water for as long as is needed.  Unlike storage water heaters, there is no wait for hot water during times when the amount of stored hot water has been depleted and the water in the storage tank in being reheated.  Tankless water heaters are very energy efficient because they maintain no storage and use fuel only when there is a demand for hot water.  Tankless water heaters have a much smaller footprint than storage water heaters, so they take up less space in the home and can sometimes be placed closer to the point where hot water is needed, eliminating long waits for hot water or the need for circulating loops.  Models specifically designed for installation indoors/outdoors provide added flexibility when choosing the location.

Gillis:  They are very small and can hang on the wall, thereby saving valuable floor space.  Tankless water heaters are designed with replaceable parts and are built with such materials as copper, stainless steel and aluminum.  Energy savings from 20-50% is only one segment of savings.  Also they are almost entirely recyclable, so if you ever decide to replace one, it doesn't have to go to the landfill.  They will not develop a corrosive leak like a storage tank water heater, saving you from expensive water damage in your home.  (Note: a tankless water heater can leak if exposed to freezing temperatures or has a manufacturing defect.)  Lastly, it maintains its efficiency throughout the lifetime of the unit.  Storage tank water heaters decrease in efficiency over time due to mineral build up: this is due to the fact that storage tank water heaters store hot water, giving those minerals a chance to settle out and bake from the heat onto the walls of the tank and onto the heating element in electric models, thereby reducing heat transfer.

Kwak:  Typical high-end tankless water heaters can deliver between 180 gallons to 200 gallons of hot water every hour on demand.  A tankless system guarantees an endless supply of hot water with output of more stable and safer temperatures compared to a traditional tank type water heater.  A traditional tank water heater that stores and heats water at all times will have a higher operating cost compared to a tankless water heater that only heats water as needed.  Also, with its higher energy factor, it doesn't waste energy like traditional tank water heaters.  Since a tankless water heater is roughly the size of a small suitcase, it can be installed relatively anywhere.  Using a tankless system can free up to 80% extra storage space versus a traditional tank type water heater.  Also, a tankless water heater uses much less fuel, producing far less exhaust (low emission) than a traditional tank type water heater.  A tankless water heater supplies hot water endlessly with easy installation and it can be used for various types of applications.  For example, it can be used for different types of heating applications (radiant floor heating, fan assisted hydronic heating, snow melt system, and more) and large volume purposes such as hotels, apartments, and industry applications.

Murtaugh:  Unlike antiquated hot water tanks that heat and reheat the same water 24 hours a day, our tankless water heaters only heat water when it senses a demand from an open water source, yielding a never-ending supply of hot water.  The system shuts off automatically when the water source is tapped closed; therefore, the consumer is saving money and energy by not paying to heat water that's not being used.  Rinnai tankless water heaters have a digital, easy to use control pad, allowing exact user specifiable temperatures, which helps prevent scalding accidents.  Rinnai tankless water heaters provide flexibility in wall-mounting locations.  In indoor locations, the unit uses no make-up air and vents directly to the atmosphere.  With exterior mountings, the consumer is removing a combustible device from the home and freeing up the valuable floor space.  Additionally, the unit can be mounted in a flush-mounted, recessed box.  Hot water tanks are known to leak and rupture, disseminating extremely hot water in its surrounding area. The Rinnai is tankless and does not hold any water within the confines of the wall so there is no risk of spillage.

Yamada:  In a nationwide consumer study conducted by the public Strategies of Washington, homeowners were asked, "What is the one luxury you couldn't live without?"  Overwhelmingly, the response was hot water.  In fact, 90% of the people surveyed said hot water.  For installers, offering tankless water heaters as a solution to a frustrated homeowner increases their profits and puts them in the forefront of technology.  Over the past year, plumbers who install tankless units have seen a dramatic increase in referrals, some up to 30%.

2.  With the rising costs of oil/natural gas, is tankless the better water heater alternative?

Beaulieu:  Tankless gas water heaters can save the home or business owners, on average, 50% per year in operating costs.  This estimate was on figures from the last couple of years (based on gas prices and current operating cost).  The savings may be higher now that gas/oil prices are increasing.

Connors:  Because there is no storage, a tankless water heater has no standby loss.  Standby loss ( heat loss when the storage water heater is not in use) can account for 20-30% of the operating costs for a storage water heater.  Additionally, all Rheem models have fully modulating burners, which means they will use only as much gas as needed to meet the demand, compared to storage water heaters, which use the same BTU rate regardless of how much water is being used. 

Gillis:  A tankless water heater is on only when you call for hot water.  A tank-style water heater is constantly heating and reheating the water 24 hours a day, even when you're not home!  Additionally, tankless water heaters usually have a higher efficiency rating than a tank, as a tank loses its efficiency over the life of the heater.

Kwak:  The average gas-fired, tank-type water heater has an energy factor (EF) of between .55 and .58.  All higher end tankless water heaters have an EF of greater than .80.  That alone will lead to a savings of approximately 35% on the gas you use for hot water.  With energy prices expected to increase, consumer demand for more energy efficient products will force tankless to become the standard rather than the niche in the future.  There are already numerous governmental support programs out there to support high-energy efficient products and also many programs specifically for tankless water heaters.  Consult with Danny Heineman and Sons, Inc. for more detailed information.

Murtaugh:  Compared to water heater tanks that heat and reheat water 24 hours a day, tankless water heaters are more efficient since they only heat water as it's being used.  This, in turn, saves the consumer money and energy by not having to pay for water that's not being used.

Yamada:  Absolutely!  The inherent benefits of a tankless water heater make it the ideal long-term solution for alleviating the burden of higher energy costs.  Because tankless water heaters heat the water on-demand, they do not need to run 24/7 to keep the water warm.  Because of this, homeowners are able to save up to 50% on their water heating bills. 
 3.  Is there a noticeable return on investment?

Beaulieu:  Tankless water heaters can be two to three times more expensive up front (just the units themselves), but the difference in costs and what you save from operating costs can be recovered in two to five years.  Also, being that the units last two to three times longer than a tank, you will see the savings for the entire lifetime (where you may have to install two more tank type heaters as well).

Connors:  By comparing the average operating costs provided on the appliance EnergyGuide labels included with every water heater and listed in our product specifications, most homeowners will notice a 25-30% reduction in energy usage, compared with a comparable gas storage water heater.  
Gillis:  The potential for a 30-50% decrease in your energy bills can be a signigicant incentive. 
 Kwak:  You will see a faster and greater return with a higher energy factor unit.

Murtaugh:  There is a noticeable return on investment with a Rinnai tankless water heater.  Depending on the amount of water being used and energy costs, a Rinnai often pays for itself between 1.5 and three years.  Plus, with the 20-year life expectancy of a Rinnai tankless water heater, most people will need to replace their roof before replacing their Rinnai water heater.

Yamada:  Tankless water heaters are expensive up front, but the initial cost is recouped within the first few years and the consumer sees a return on investment.

4.  Is the tankless industry still evolving?  If so what are some innovative things your company is doing?

Beaulieu:  Yes, the tankless heater industry is constantly evolving.  Some of the innovations Noritz is doing are:

  • Acquiring certifications and approvals, such as ASME, the National Board, NSF, for applications where these are required.
  • Take research and customer feed back and turn them into features and benefits from tankless.
  • Increasing the capacity without changing the efficiency. 
  • Improve the features to be able to expand the product line to be used on more and diverse applications.
  • Constantly improving customer service and technical support, as well as changing the efficiency of the distribution and training network.

Connors:  Tankless technology is not new.  Is is the most commonly used type of water heating equipment in Europe and Asia, but it is still relatively new to the United States.  The key to success with the technology is to understand its benefits and limitations, and to understand the water heater demands in the U.S. marketplace.  Rheem has the experience to make the most of this technology and is committed to providing training for those involved throughout the distribution channels.  We also provide important tools, such as easy-to-use sizing programs and a continuous process of new-product introduction to meet the wide range of water heating demands.

Gillis:  More and more people are seeking alternative water heating solutions and they like what they see with the tankless products.  Bosch is looking at cascading and heating applications utilizing innovative internal product components only available on Bosch water heating products.

Kwak:  As with all technology, products continue to improve.  Higher efficiency and easy integration will be key themes moving forward in the tankless industry.  AQ Energy is contributing to the integration of tankless and heating applications with the introduction of the "heating box."  This revolutionary product will make the combo system design (potable water and space heating) and installation of tankless water heaters simple and easy.

Murtaugh:  The industry is still evolving and Rinnai is continuing to design products that give consumers the benefits of leading new technologies without changing their lifestyles.

Yamada:  Yes!  Like all industries, we are constantly working to improve our technology and the products we offer.  Consumers are demanding more reliable, more powerful and more energy efficient water heaters, not just tankless, and Takagi is committed to meeting these needs.  In fact, our newest tankless water heater, the T-H1 was recently rated as an Energy Star product.

6.  Describe some common misconceptions about tankless?

Beaulieu:  That one is needed for each point of application -- single point use.  All of our units are for the entire home or business (depending on the application).  They are not efficient.  Tankless water heaters run between 80-85% efficiency, much higher than traditional tank types.  The technology has changed alot in the last 20 years.  They are expensive - $4,000-5,000 per unit.  Even the highest priced unit (essentially a commercial boiler) is at the lower end of this price range; overkill for a lot of apps, but still lower than traditional commercial boilers and at a lower operating costs.

Connors:  Frequently called "instantaneous," to some end users;  this implies that hot water will be at the fixture immediately.  The reality is that any cold water in the pipe between the fixture and the water heater still needs to be bled off.  Also, properly sizing the tankless water heater for the application is crucial.  Tankless water heaters are available in different sizes and with different performance capabilities.  There is no single solution that will work in every application.

Gillis:  A)  You can't use a tankless water heater if you have hard ground water.  Since tankless water heaters do not store hot water, minerals have less of an opportunity to settle out of the water column and build up inside the heat exchanger.  Additionally, the flow of hot water through the coiled heat exchanger flushes the product each time hot water is used.  The use of a water softener is fine with a tankless water heater, and is recommended if you commonly experience hard water problems in your home.  B)  A tankless water heater will not provide enough hot water for the whole house.  It's important to choose the proper model to meet your home's hot water needs, which is based upon the maximum flow of hot water you need at one time.

Kwak:  The most common misconception is that tankless units cannot handle a North American home's water demand.  This is just not the case.  Any tankless water heater in the 180 MBH~200 MBH will be able to supply a minimum of two showers worth of water in the coldest of climates.  This easily meets the demand of most single-family homes in North America.

Murtaugh:  Consumers do not understand how a Rinnai tankless water heater, which is the size of carry on luggage, can fulfill the water heating needs of an entire average-sized home.  Answer:  The Rinnai tankless water heater technology has been designed to utilize up to three water outlets simultaneously.  For example, a consumer can operate a dishwasher, washing machine and take a shower at the same time and at a desired temperature for each outlet, without running out of hot water.

Yamada:  Most consumers hear tankless and think "point of use."  They see their size and assume that a tankless heater cannot possibly supply enough hot water for a shower or a load of laundry.  However, with the right model and right installation, tankless water heaters actually have the ability to be more powerful than their counterparts.

7.  Is the tankless catching on with most contractors or do they need more education on the subject?

Beaulieu:  Tankless is catching on with many contractor/installers, as well as specifying engineers and homebuilders.  There is always more education required on the subject, especially for people new to the concept.  Noritz has training sessions every week throughout the United States to train, or re-train people on tankless installation and their benefits.

Connors:  The contractors who have taken the time to understand the technology and attend training classes held by Rheem have been very successful, but further education is still required.  Tankless water heaters are still very much a contractors and installers who understand the technology will be the ones who can best answer consumer questions and help the homeowner choose the right water heating solution for his application, whether it be tankless or storage.

Kwak:  Although the market for tankless products is increasing significantly, contractors that still have not installed a tankless unit are in the majority.  Contractors that want to be ahead of the curve in terms of the energy saving products should consider tankless today.

Murtaugh:  Since 2002, there has been a substantial increase in the number of builders and installers who are incorporating and using tankless water heaters in their projects.

Yamada:  Every day more and more contractors and installers are embracing tankless water heaters, but we still have a long way to go.  Tankless water heaters still make up only a fraction of the water heater market, but with energy costs on the rise, more consumers are beginning to ask for on-demand heaters from their contractors.  We need to continue to educate contractors about the benefits of tankless water heaters.


 Tankless FAQ's

The experts are bombarded by numerous and various questions regarding tankless water heater technology.  Phc news has compiled some of the most popular questions.

1.  How exactly does a tankless water heater work?

When the hot water tap is turned on, the water enters the heater.  A flow sensor detects the water flow and the computer automatically ignited the burner.  The water circulates through the heat exchanger and the heat exchanger instantly heats the water at the designated temperature (this takes approximately six seconds).  When the hot water tap is turned off, the unit shuts down automatically.  This process may vary by different brands of tankless water heaters.

2.  How do you size a tankless water heater?

To size a tankless water heater always look for its maximum flow rate at gallon per minute, not gallon per hour.  You always have to think of a situation where the demand is at the peak flow capacity, either simultaneous use of showers for residential or simultaneous use of faucets and different appliances for commercial applications.  With any doubts, you can contact Danny Heineman and Sons, Inc. directly to choose a right model for your application.  The main determining factor is the flow rate of the household fixtures and the number of fixtures.

3.  Can I change the temperature on the water heater?  How can I change it?

Most tankless water heaters have options to adjust temperatures either by dipswitches or a remote temperature controller.  Typical set temperatures of the water heaters is around 120 degrees.  However, depending on the application you are working on, some of the tankless water heaters would allow you to adjust above 180 degrees.

4.  Can the unit be used in a recirculation system?  And in doing so, does it de-rate the warranty?

Yes it can be used in a recirculation system effectively with the proper pump and the application does not de-rate the warranty.

5.  Is the installation harder than a tank?

No, plumbing and gas connections are similiar to storage tank water heaters but proper sizing of the gas line and proper venting are critical for all installations.  A professional should be considered.

6.  What is the life expectancy of the unit?

Life expectancy of the unit is calculated to be 15-20 years, although that number can be increased if the unit is used in conjunction with a pre-filter or a water softener.

7.  Do these units use more gas thank traditional tank-type water heaters?

As opposed to a traditional tank-type unit that has a standing pilot light burning gas constantly, units only consume gas when hot water is needed.  The units require a larger amount of BTU's only when the units are first fired up.  After the initial firing the units modulate down to a moderate BTU level.