Stiebel Eltron pioneered the development of tankless water heaters in Germany during the 1950s and is now the largest supplier of tankless electric water heaters in the world. Stiebel Eltron has a long track record of reliable performance and superior technical design and innovation. In the US tankless water heaters have only become popular during the last decade. Tankless is here to stay. Homeowners are becoming increasingly aware of the benefits of tankless water heating as cited below.

2. What are the three biggest benefits to tankless water heaters?

Energy Saving - In comparison to electric tank style heaters the homeowner will save 15-20% on the water heating portion of their electric bills. As you know, tank-style heaters are continually having to heat and reheat water throughout the day to higher than necessary temperatures, due to heat dissipation through the wall of the tank. This results in stand-by losses of 15-20% of the kWH used.

Space saving - our largest Tempra 36 model is only about 22 inches wide, the Tempra™ 24 about 15 inches wide, both about 15 inches high and 5 inches deep. Compared with the bulky traditional tanks, this can provide a great deal of space saving and present various mounting alternatives. Point-of-use units are even smaller, with our Mini™ measuring 6.5” high x 7.5” wide and 3.5” deep.

Unlimited supply of hot water - the Stiebel Eltron tankless, electric hot water heaters provide a continuous supply of hot water - on demand – only the amount you require, when you require it, for as long as you need. There will be no more waiting for the tank water to reheat once depleted. You simply set the temperature of the water you want on the front dial. Several sensors and microprocessor ensure that the temperature of the water does not deviate from the set-point dial selection.

Seismic proof construction - the SE tankless electric water heaters are not subject to seismic code. There is no need for preventative construction, as is required with tank-type heaters.

3. Do you have any statistics on the amount of energy savings a homeowner can expect?

See “Energy Saving” above. The average home uses about 5,000kwh for water heating if an electric water heater is being used. 20% of that would be 1,000kwh that is saved every year by using a Stiebel Eltron tankless electric water heater. These savings can be achieved with small additional initial investment. The additional incremental installed cost of a tankless system versus tank type is small.

4. How specialized is installation? Are there programs to teach remodelers about installation?

The installation of a tankless water heater is not difficult but should be carried out by licensed plumbers and electricians. If locating the unit where the tank-type unit once stood, all that is necessary is to bring the cold and hot connections to the inlet and outlet points on the tankless unit and utilize the existing household pipe runs. We recommend the use of braided steel flexible connectors, but other familiar means of connecting the unit are acceptable. The existing wiring and breakers for the tank-type will have to be replaced which is an easy job for the electrician. If relocating, the compact size of the tankless unit gives the homeowner many options for hanging on a wall or placing the unit out of sight in a cabinet.

If the plumber or remodeler opts for hard piping of the unit, caution needs to be used when sweating pipes close to the heater that the casing is not damaged in the process. After the installation, the filter should be checked for any debris caught in the line from solder or teflon tape, etc. which can often obstruct the water flow and affect minimum water flow activation rates.

Unfortunately, there is no installation program currently available. We are working on a troubleshooting program which we hope to have up on our website soon.

5. Is there anything a remodeler should keep in mind before installing or recommending tankless?

Correct sizing of the tankless heater is key. Please use the TEMPRA sizing chart that is on our web site and in the TEMPRA literature. Once you know which model you need then check with your electrician to make sure the size of the electric service is sufficient. In some cases, the size of the electrical service has to be increased to accommodate the additional load that is created by the electric tankless unit. We have a lot of helpful sizing and technical information on our website at www.stiebel-eltron-usa.com.

Further, the homeowner / remodeler can actually tailor the usage points to maximize the output of hot water. This can be done by using newer, low flow shower heads (1.5 – 2.0 gpm) and aerators on all the faucets. These can still provide the homeowner with acceptable flow rates. There really is no need to have a 2.2 gpm aerator on the kitchen sink. This can easily be less, and the difference can be made up elsewhere with additional hot water flow.

6. What are some common FAQs you hear from contractors?

What is the best way to correctly size a Stiebel Eltron tankless, electric water heater? (Correct sizing of the tankless heater is key. Contractors should use the TEMPRA sizing chart that is on our web site and in the TEMPRA literature. Once you know which model you need then check with your electrician to make sure the size of the electric service is sufficient. In some cases, the size of the electrical service has to be increased to accommodate the additional load that is created by the electric tankless unit. We have a lot of helpful sizing and technical information on our website at www.stiebel-eltron-usa.com.)

What type of water heater is best as a backup to the solar thermal system? (The Tempra™ whole house tankless, electric water heater provides and ideal backup for a solar thermal system when the sun needs a little help.)

What is the best location for a tankless, electric water heater? (If you are building a new house or apartment make sure that you place the tankless unit in a location that minimizes the pipe runs to the hot water draw off points. This way you can make sure that as little water as possible is wasted. When someone turns on the hot water, less water has to be flushed before the hot water gets to the faucet.)

What is the best means for making the plumbing connections to the SE tankless water heater? (We recommend the use of braided steel flexible connectors, but other familiar means of connecting the unit are acceptable.)

What is the most common plumbing problem after an installation? (The inlet water filter screen should be checked for any debris caught in the line from solder or teflon tape, etc. which can often obstruct the water flow and affect minimum water flow activation rates.)

What is the most common electrical problem after an installation? (The electrical technical data regarding wiring and breaker sizes must be adhered to, in order to guarantee a successful installation.)

How can you get the most out of a tankless hot water system? (Contractors can actually tailor the usage points to maximize the output of hot water. This can be done by using newer, low flow shower heads (1.5 – 2.0 gpm) and aerators on all the faucets. These can still provide the homeowner with acceptable flow rates.)

Part 2

Submitted by Stiebel Eltron USA. Stiebel Eltron produces some of the highest quality electric tankless water heaters, thermal solar products, automatic hand dryers, and space heaters. For more information you can visit their website at www.stiebel-eltron-USA.com or call (800)582-8423.

A) The solar market is booming. Though a solar system is not inexpensive to purchase and install, many people are deciding to go ahead with it as a hedge against the current and future price volatility in the fossil fuel markets. There are federal, and in most cases state incentives, which can cut the cost of an installed system up to about 40%.

B) Stiebel Eltron tankless electric water heaters are nearly 100% efficient, converting 100% of consumed electrical energy into heat. Gas models will have a reduction in efficiency of 10-20%, due to the combustion process and venting requirement.

Energy Saving - The average home uses about 5,000kwh for water heating if an electric water heater is being used. 20% of that would be 1,000kwh that is saved every year by using a Stiebel Eltron tankless electric water heater. These savings can be achieved with small additional initial investment. The additional incremental installed cost of a tankless system versus tank type is small.

C) Because the Stiebel Eltron tankless water heaters are all electric and do not require venting of combustion gases into the outside atmosphere, they provide the user with a much smaller environmental footprint. Inside the house they are also more efficient with regard to a space usage footprint. Our largest Tempra 36 model is only about 22 inches wide, the Tempra™ 24 about 15 inches wide, both about 15 inches high and 5 inches deep. Compared with the bulky traditional tanks, this can provide a great deal of space saving and present various mounting alternatives. Point-of-use units are even smaller, with our Mini™ measuring 6.5” high x 7.5” wide and 3.5” deep.

8. What would you consider is your top seller in regard to technology and why?

Stiebel Eltron is continually making improvements to its line of Tempra™ whole house tankless, electric water heaters. A Tempra™ upgrade and new Tempra™ Plus model are coming in 2008. These will include an upgraded basic model which will be capable of heating water to 140 degrees, among other enhancements. Additionally, Stiebel Eltron will present the Tempra™ Plus models which will automatically adjust the water flow rate in case the unit is not able to maintain the set point temperature.

9. Is your company involved with “green” building?

Yes, as “green” building is becoming increasingly important throughout the nation, Stiebel Eltron is making sure that people are being informed of the energy and space saving benefits that tankless water heaters can provide. Also, our solar thermal systems provide the largest amount of saving, and we encourage people to plan for a solar thermal system if they are designing a new house by setting the piping structure in place now for easy retrofit down the road.

10. Anything else you’d like to add?

When it comes to water heating, tankless is the way of the future. For very little additional investment you can get substantial energy savings. In this age of rapidly rising energy costs there is a big need to find technologies that give you a lot of “bang for the buck”, which provides good savings and little added initial investment.

If you are building a new house or apartment make sure that you place the tankless unit in a location that minimizes the pipe runs to the hot water draw off points. This way you can make sure that as little water as possible is wasted. When someone turns on the hot water, less water has to be flushed before the hot water gets to the faucet. In many homes it also make sense to place a point-of-use unit under the kitchen sink.

If homeowners / remodelers research the proper sizing for the application at hand, they should be perfectly content with a tankless water heater. As tankless water heaters are heating cold water as it passes through the unit from a city or well source, there is logically a finite gpm flow rate in order to heat the water to your target temperature – usually 110 degrees for a good warm shower or bath. Tankless units are dependent on the amount of water flow (gpm), and the amount of temperature rise required (difference between incoming water temp and outgoing temp from unit). The larger the temperature rise required, the fewer number of gallons per min can be heated to the set-point temperature. Graphs of this temperature rise and gpm flow rate relationship are available directly from Stiebel Eltron or at our website (www.stiebel-eltron-usa.com). The incoming water temp will vary some throughout the year and thus the curves will shift slightly. This might mean that some tasks will need to be scheduled in sequence, which should not be a problem because there is an unlimited supply of hot water available through the tankless heater.

Back to Part 1

Submitted by Stiebel Eltron USA. Stiebel Eltron produces some of the highest quality electric tankless water heaters, thermal solar products, automatic hand dryers, and space heaters. For more information you can visit their website at www.stiebel-eltron-USA.com or call (800)582-8423.

Conventional tank type water heaters currently make up the majority of water heaters in North America. Unfortunately, they’re a very inefficient way to heat and store water. They heat and store hot water when you’re at work, sleeping, and even when you’re on vacation. Not a great way to save on those rising energy bills. Tankless (on demand or instantaneous) water heaters, on the other hand, only heat water when it’s needed. Since there is no 24/7 storage of hot water, no constant reheating of the stored hot water, tankless water heaters come with a significant energy savings advantage.

Tankless hot water heaters provide hot water instantly when the hot water faucet is turned on. The water is then heated rapidly as it passes through the tankless water heater unit. When the faucet is turned off, the unit is then shut down. This provides for a improved efficiency, as you’re only paying for the energy that is utilized, avoiding the standby losses so commonly associated with conventional tank type models.

Tankless water heaters come in two common forms: gas and electric tankless water heaters . The gas tankless water heaters are most appropriately used for whole house applications and are commonly more powerful, but come with more requirements than electric. Gas lines must be routed, along with specific venting and combustion requirements. Much of this can be avoided with electric models. Due to higher electricity costs, however, these are most appropriate for single point or point-of-use (POU) applications. Examples would include a bathroom or kitchen usage.

Going with a tankless application can result in a broad range of energy savings. Results of up to 50 percent lower energy costs are possible, according to the U.S. Department of Energy. This, of course, is dependent on the efficiency of your previous unit, your water usage, and the type of your new application.

One advantage that tankless hot water offers over tank type models is an endless supply of hot water. We’ve all been in a shower, only to be shocked by a sudden surge of cold water. This is a big disadvantage that comes with traditional tank type units. They have a limited capacity. The tankless water heaters will never run out of hot water, as water is continuously heated as it passes through the heater.

You get clean water with a tankless system. Traditional water heaters store water in their tanks. Over time these tanks are susceptible to rust and scale build-up. The older your tank, the more rusty it can become. Rather than showering with water from an old rusty tank, tankless units allow you to shower with clean water, as water just simply passes through the unit as it’s heated. Additionally, the life of tankless units may be longer than that of traditional tank types due to fewer corrosion issues.

A more obvious advantage is that tankless water heaters come in very compact sizes. The fact that they’re much smaller than traditional tank units, affords them a number of advantages. Their space saving design not only frees up extra room, but they can be located in a number of locations. Tankless water heaters are commonly installed on walls, in attics, in closets, inside or outside. Special precautions must be followed for proper installation, however.

The most notable advantage of all is the energy savings inherit with tankless hot water heaters. Whether you’re running an electric tankless water heater or gas-fired tankless water heater , the savings are often substantial. Traditional tank water heaters have to constantly maintain hot water temperatures. This is not a very efficient method, as much energy is lost. Tankless applications allow you to eliminate these unnecessary standby losses. Depending on a number of variables, such as hot water usage, your climate, and overall efficiency of your tankless set-up, you can save anywhere from 10 to 50 percent on your hot water bill.

There are two typical tankless water heater types, electric and gas water heaters. Electric tankless water heaters heat cold water via an electric element as it passes through the unit. Similarly, gas tankless water heaters heat incoming water via a gas burner as it enters the gas-fired unit. They both have certain advantages. Gas tankless water heaters are often utilized for entire house applications, where as electric tankless water heaters are often utilized for point of use applications, such as lavatories or kitchens.

The following represents a very simple step by step explanation on how a gas tankless water heaters work. An electric tankless water heater works very similarly, but utilizes electric heating units (step 4) rather than a burner:

The specific output of a tankless water heater unit is an important factor when purchasing a tankless water heater. The output of a given tankless water heater is determined by its maximum flow rate. The maximum flow rate is measured when a desired temperature rise is met. Most tankless water heaters provide flow rates of approximately 2 – 6 gallons per minute. Most commonly, gas type tankless water heaters have superior flow rates when compared to their electric counterparts. As a result, gas-fired tankless water heaters are the most frequent choice when it comes to a whole house application.

When selecting a tankless water heater it’s important to determine your needs. Are you looking for a point of use set up? If so, an electric type tankless water heater might be the best fit. Do you need a hot water for the whole house? If that’s the case, you’ll probably need something that can provide a large enough flow rate to insure two simultaneous hot water draws. Let’s say a shower and washing machine running at the same time, for example. Most electric units just don’t have the flow rates to meet those needs. For those in need of even larger flow rates, multiple tankless units can be set up in parallel.

Pros:

Energy Savings
The most obvious benefit associated with tankless water heaters is their superior energy efficiency when compared to traditional tank type water heaters. These traditional tank type water heaters heat, reheat, and store hot water 24 hours a day, 7 days a week. Heating water when you’re not using it or not even home, results in substantial energy, or standby losses. Tankless hot water heaters, on the other hand, only heat water when it’s needed. These savings can be dramatic, as tankless water heaters use 30 to 50 percent less energy than units with tanks.

Endless Hot Water
One of the major flaws inherit with tank type water heaters is that they can only hold a certain amount of hot water. If this hot water runs out, so does your luck, as cold showers are less than desirable. Tankless (on demand or instantaneous) water heaters heat water instantly, with no reliance on storage. Tankless hot water heaters can insure that there is never a shortage of hot water, as long as it’s operating within its capacity.

Clean Water
Traditional tank water heaters store water in their tanks. Depending on the tanks age, they can have considerable scale and rust buildup. Using hot water from an old rusty tank is something many people do daily, without even thinking about it. Tankless water heaters, as the name implies, has no tank to collect buildup, water is simply heated as it’s passed through the unit. Also, the benefits of avoiding corrosion mean that tankless units will last much longer than tank types.

Compact Size
Due to the rather compact size of tankless hot water heaters, they can provide considerable space savings. Tankless water heater units can be utilized just about anywhere. Installation on walls, inside or outside, in attics or closets, are common. Small tankless electric water heaters can be stored under sinks. Gas tankless water heaters should be installed centrally, and proper precautions should be followed.

Cons:

Initial Cost
Current costs to purchase a tankless water heater are higher than that of traditional tank water heaters. They range in price from $150 for small point-of-use unit, to upwards of $1,200 for higher end gas-fired tankless water heaters. As a general rule, the more hot water a tankless unit can produce, the higher the cost. It’s important to weigh the higher initial cost of a tankless unit with the future operational cost savings, resulting in improved energy savings and longer life expectancy. Looking at the overall picture, initial cost may not be such a con, after all.

Installation
The installation costs associated with installing a tankless water heater unit are substantially higher than that of traditional tank units. These install costs are often predicated on the fuel type of your chosen tankless unit. Gas tankless water heaters are the most complicated installs. They require certain vent, combustion, and gas line requirements, this complicates the installation, which adds to the costs. Electrical tankless gas heaters are cheaper to install, but may require multiple circuits. New construction is the ideal time to install a tankless unit, as the costs are minimized. This would not be a do-it-yourself project unless you’re a contractor or have comparable skills.

Limited Flow Rate
All tankless water heaters are limited by flow rate. Many of the higher end units have a maximum flow rate of about 6 gallons per minute (GPM). So, even if you’ve got a tankless unit with suffucient BTU output, you’ll still be limited by flow rate. This could present problems for homes where multiple hot water taps are running simultaneously. If you’re running a bath, washing your clothes, and running the dishwasher, this could present some hot water shortages. A solution to flow rate issues might be to supplement with point-of-use units at heavy use locations, or even run gas units in parallel. Analyzing your simultaneous needs to determine your peak hot water flow demands is always recommended before selecting a tankless water heater.