The Best Electric Tankless Water Heater by Price Range

Electric tankless water heaters are trending due to their compact sizes and efficiency. The market is flooded with a big array of models with different features and price ranges – they’re also known as demand-type water heaters.

Using the best electric tankless water heater possible is often recommended by governments as an energy efficient alternative of gas storage water heaters.

Having all these options makes it difficult to compare and choose between the best. If you are facing the same problem, don’t worry, we’ve compared more than two dozen popular models and selected the best one for you:

Out top pick comes from a well-recognized century-old European brand, Stiebel Eltron that is known for its high-quality heating products. Even though they are based in Germany, its electric tankless heaters are popular all around the globe, including North America.

Their latest Tempra Plus series model, the Stiebel Eltron Tempra Plus is an example of why they are considered among the best brands in the market. This powerful electric heater comes with a digital temperature display, and a knob to easily adjust the required temperature. You can adjust the temperature from 86F to 140F that makes it suitable for most parts of the United States.

As it is among the most powerful units in the world, it can raise the temperature by 50F, which is the best electric water heaters can offer.

With a flow rate that ranges from 4.0 GPM to 8.0 GPM and advanced flow control, it makes sure to offer you a consistent flow of warm water. The flow rate varies based on the natural temperature of the groundwater in your area.

To make this detailed guide and product review even more valuable, we’ve listed a couple of more options: The Sio Green IR260 POU Electric Tankless Water Heater if you’re on a budget, and a runner-up to our first option, the EcoSmart ECO 7 Electric Tankless Water Heater if you want  a bid range price but a good alternative to the Stiebel Eltron Tempra. Below, you’ll find a break down of each of the best electric tankless water heaters .

Our Best Electric Takless Water Heater Selection based on Price (Top, most affordable and mid-range): 

We’ve already mentioned out top of the line is Stiebel Eltron Tempra Plus 36 so let’s dive into the other options:

For those who are on a budget and looking for a cost-effective option, we find Sio Green IR260 POU as the best option.

It is compact and offers limited 1.5 GPM flow rate that makes it a good fit for people living alone or couples.

With its flow rate, you can’t use it for multiple people at a time. However, it works great for limited use and a warmer climate without adding much to your energy bill.

Manufactured by Sio Green, another US-based brand, the tankless heater uses advanced infrared technology that removes the metallic taste of the water you may experience with other tankless water heaters as the water doesn’t pass through metal. In addition, the infrared heating ability makes it easy to clean and become long-lasting with no metal corrosion.

The use of liquid flow regulator keeps a constant check on your need and heats only according to your needs, saving on energy.

Overall, this small, affordable, and easy to install tankless heater is a good option for limited use and warm areas.

EcoSmart ECO 27 is also one of the most powerful tankless heaters available in the market. This one comes from a US-based brand that is known for its energy-efficient tankless water heaters.

The ECO 27 is part of their most popular ECO series water heaters. As you get a lifetime warranty with this product, it makes for a safe investment. You can use it for both cold and warm areas, but the flow rate varies from 3.0 GPM to 6.0 GPM based on the temperature of groundwater.

With 99.8% energy efficiency rating and advanced self-modulating technology, the ECO 27 can cut your heating energy bill by half.

You can also set the temperature on the digital display from 80F to 140F.

This compact but powerful water heater can provide you with consistent hot water to two showers at a time in cold areas, and even more in hot climates.

Our Criteria

Here is our detailed guide what about what we looked into. You can also read about the features you want to compare when buying a tankless electric heater.

Who Can Find it Useful?

If you are someone who is looking for an energy efficient, compact tankless water heater to replace your old traditional water heater, this article along with the listed products are exactly for you.

These heaters not only save space in your home, but they are also easy to install, eco-friendly, runs on electricity, and allows you to avoid gas. They also provide consistent hot water irrespective of their compact design.

For those who prefer electricity over gas, again this guide makes perfect sense. And why not? Even though gas may be cheaper  compared to electricity, the tankless electric heaters are very low in overall cost and can save up to 44% on energy costs.

In addition, they don’t produce any greenhouse gases, consume less energy, are more durable, and keep a consistent flow of warm water. If you want something like this, continue reading.

Buying Guide: What to Look for in the Best Electric Tankless Water Heater?

Listed below are the features we used to test and compare each product. The following features will not only help you understand how electric tankless water heater work, but also allows you to make an informed decision when buying one.

What is the Incoming Water Temperature in Your Area?

To start with, you must have an idea of the natural temperature of water in your area. In addition, what is the temperature you are looking for as an output? This is because, in terms of heating capability, electric heaters lag behinds gas heaters, with an average capacity of 30F-50F temperature rise to the actual groundwater temperature.

However, is this enough for very cold areas?

Unfortunately, not in most cases. This is why electric heaters are the best fit for warm climates, like the Southern United States. However, powerful units like the Stiebel Eltron Tempra Plus 36 can work in cold climate as well.

You need to look into the rise to temperature it offers to your groundwater. The electric tankless water heater only makes sense for you if the answer is yes.

Flow Rate (Maximum GPM)

The next important thing is to look at the flow rate you want. What needs do you have? If you have a large family, with a chance multiple people using hot water at the same time, you need a more powerful water heater with a higher flow rate. If you are only a couple or someone who lives alone, the low flow rate can also work.

Keep in mind – the flow rate is measured in GPM, which is gallons per minute. The higher the GPM, the more powerful the water heater is (and more expensive as well).

For example, our top pick offers a maximum GPM of 4.0, that makes it powerful enough to work for large families as well as for commercial use.

But as mentioned, the more GPMs it offers, the more expensive it gets. This is why our budget option Sio Green IR260 comes with a maximum GPM of 1.5. The efficiency of storage gas water heaters depend on their capacity, in tankless water heaters it depends on the flow rate.

Due to the use, you can run out of hot water available in the water heater tank, but in the case of tankless water heaters, you can only run out of hot water if the flow rate exceeds the limit offered.

For example, if you are using water in the kitchen sink, bathroom shower, and for washing clothes at the same time, your water flow rate may exceed 1.5 GPM, which means, the Sio Green IR260 is not enough for your needs in such case.

How to Calculate GPMs

If you're wondering how to calculate GPMs (Gallons Per Minute), the "crafty" way of doing it is to time how much time it takes to fill a gallon water tank and then divide 60 seconds (1 minute) by the time it took to fill it up and you will have the GPMs of that faucet.

We recommend to fill it up 3 times and then average the time to have a more accurate measurement.

If it took an average of 8 seconds to fill it up: 60/8 = 7.5 GMPs


One of the most important things to look into is warranties. The more and longer you get, the better it is. It also shows that the manufacturer is confident about their product. As tankless water heaters don’t have any tanks that need to be taken care of, they are durable and long-lasting, without leakage issues.

You can find warranties offers from 5 to 10 years. Even lifetime in the case of EcoSmart ECO 27. However, a good-quality tankless heater can work for as long as two decades if maintained properly, which is almost twice the lifetime compared to the traditional storage water heaters.


Even though available in compact sizes, you can still find different designs, shapes, and sizes. You may have to measure the area where you want to place it before buying one. Also, they don’t need ventilation as gas heaters, so installation and placement are much easier.

Input and Efficiency Ratings

When buying a tankless water heater, you can find a BTU rating associated with it. So what is it? The BTU, the British Thermal Unit, describes the energy input required by the water heater to heat water.

For example, 1 BTU equals the energy required to raise the temperature of 1 lb water by 1F. This means, higher the BTU rating, more GPMs can deliver. It also depends on the climate. For colder regions, the water heater requires more energy to raise the temperature.

As electric heaters can affect your monthly energy bill, you may also want to buy an energy efficient water heater. You can find energy ratings in percentage for each tankless water heaters, that may range from 80 % to 99.9%. This reflects the percentage of fuel converted into heat. The higher the percentage, the lower your energy bill.


Unlike traditional storage water heaters, tankless water heaters use a wide variety of materials other than steel, like copper. The new technology like infrared used in Sio Green IR260 POU even allows the water to avoid metal that keeps the taste of the water clean. This way, water heaters are easy to maintain, long-lasting, and don’t build-up lime-scale. Infrared heaters are also a good fit if there is a high density of minerals in the water.

Let’s check our selected three best electric tankless water heaters against these checks in detail.

The Stiebel Eltron Tempra Plus 36 is part of the Tempra Plus series from Stiebel Eltron. The latest series is also an upgrade from their standard Tempra series. This means you are getting the most advanced and powerful tankless water heater ever produced by the German brand.

Even though the most expensive one on our list, Stiebel Eltron can still be a cost-effective option in long-term as its advanced self-modulating power technology helps you reduce the energy cost by 20%. The energy efficiency rating is 99% which means it converts almost all energy into heat.

They are designed for whole house use, so makes an excellent fit for large families. You can also use them for commercial use with the maximum GPM of 8.0 for warmer areas and around 4.0 GPM or colder areas. This means, two to four people can easily use consistent heat water at a time.

The compact eco-friendly water heater does not emit any gases which means no venting is required. So installation and placement is easy, as it only weighs 19 lbs. The Tempura Plus series uses advanced technology to ensure flow control (not available in Tempura series), that makes sure you get consistent temperature without any unpleasant fluctuations. This means, when multiple people start using hot water, it reduces water flow to maintain temperature, a feature not available in most other tankless water heaters.

The digital display allows you to easily adjust the required temperature. Made of high-quality copper heating chambers, this one comes with 7 years of leakage warranty.  

As it is the most powerful unit among the Tempura Plus series, it consumes 36 kW of electricity and runs on 240 A voltage, so it must be hard wired.  It requires a minimum of 300 A electric service, but draws 150 A. For installation, you need a minimum of 3 x 50 A DP and may have to upgrade your electric panel.

It uses Stiebel Eltron’s patented microprocessor technology to achieve and keep an accurate temperature. The water heater allows you to set the temperature anywhere between 86F to 140F. On average, it can easily rise water temperature to 35F while keeping the GPM to 7.0 to 8.0. In terms of performance, it is the best you can get from the electric tankless water heater.

The high flow rate also makes it a good fit for commercial use, a sector where the use of an electric tankless water heater is also trending. And why not? According to a recent study by Eemax, the use of electric tankless heaters boost profits for the restaurant industry.

For those who are looking for a powerful option that can handle multiple hot water use at the same time, EcoSmart ECO 27 is another good fit. Again, with the help of digital display and control panel, you can easily adjust the temperature you want. With its maximum flow rate of 6.0 GPM, it can support three showers and a sink at the same time without a drop in temperature of hot water.

This one comes with a 99.8% energy efficiency rating which means you save money on your energy bill. The EcoSmart ECO 27 also uses self-modulating technology which means you get consistent temperature without fluctuation. With an average temperature rise of 40F, it is a good fit for warm as well as cold climate.

For installation, you need a 240V electrical system, as it draws 112.5 A. It consumes 27kW and requires at least three breakers of 40 A each. Made of high-tech and advanced options like thermal auto protection as well as high-quality copper and stainless steel, this is a long-lasting and durable product. In fact, one feature that makes it a more luring option than our top pick is its lifetime warranty.

It is smaller and lighter than the Tempura Plus as it weighs only 13.75 lbs, that allows you to fit it even in tight corners. As it runs completely silent, emits no gas with no ventilation required, it also offers you peace of mind being eco-friendly.

The above two options are for whole house use, and thus consumers more energy and also costs more. But what if you use something affordable, smaller, more enegry-efficient, for limited use and a warmer climate?

Well, in that case, you don’t have to spend more on the above two options, as Sio Green IR260 POU can easily meet your needs for half the price. First, it is an infrared heater which means it uses better technology (patented Quartz element) to heat the water without the use of metal. You don’t get a metallic taste in water with this one.

In addition, it is smaller and saves a lot more in terms of energy bill costs (up to 65%). It runs only on 6kW and 30 amps, so your electricity consumption is pretty low. But this also means it offers you maximum GPM of 1.5, that makes it fit for one person use at a time. It works best for the areas where the groundwater temperature is at least 67F or more.

As there is no metal corrosion due to infrared use, it is only easy to maintain and long-lasting. However, it comes with two years of warranty. You don’t need venting for this one as well, while its compact design also allows you to install it in your kitchen or bathroom.

It comes with manual four power levels to switch between along with temperature adjustment knob. You also need only one 30A power breaker, so installation does not require much of electrical work.


Even though the Stiebel Eltron Tempra Plus series and EcoSmart ECO series come with the most advanced and best electric tankless water heaters, there are some other options available from popular brands as well.

Like Stiebel Eltron, another popular German brand is Bosch, that comes with its own series of tankless water heater. However, its efficiency for 26.9 kW model is 97%, which is less than both Stiebel Eltron Tempra Plus and EcoSmart ECO 27. It also lacks power ( with 3.5 GPM maximum output) compared to Stiebel Eltron Tempra Plus 36 but can match EcoSmart ECO 27 on average.

Similarly, Titan SCRN N-120 and Rheem RTEX-13 are also whole house use electric tankless water heaters, but again, with a maximum flow rate of 4.0 GPM, they are no match of Stiebel Eltron Tempra Plus 36. In addition, Titan and Rheem as brands trails behind both Stiebel Eltron and EcoSmart in terms of recognition.

Final Words

The two top options on our list are an excellent fit for the whole house or large families use. They cost a little more, but you get the best value for money in terms of temperature rise, durability, and high flow rate. Both models are energy efficient and eco-friendly that keeps your energy bill under check.

The Sio Green IR260 POU, on the other hand, is for a warmer climate, and individual use. The low-cost option saves you money as the initial cost as well as on energy bills. All in all, your final decision depends on your needs as well as the area you lives in.