5+ Most Efficient Electric Tankless Water Heater Reviews 2020!

Purchasing and installing the most efficient electric tankless water heater provides the users with the constant hot water supply, low energy charges. It can also improve the resale value of your house. Well, such tankless water heaters are really shaping the way of life of the users with a fantastic working performance by making the method of acquiring a constant supply of hot water simpler. The search for the best ones is very hard. That is why we have embarked on a trip to search for the best ones available in the market.

Analyzing the history of the brands, products energy charges, levels of quality, and the after-sale service, the most efficient electric tankless water heater reviews mentioned below are the most worth purchasing ones. Aside from the reviews of the products, there’s also basic knowledge on the energy charges of the electric and other kinds of tankless water heaters you can never overlook. Here we go!

Top 6 Most Efficient Electric Tankless Water Heater:


Most Efficient Electric
EcoSmart 11
EcoSmart ECO 11 Heater3.8 x 8 x 11.5 inches6.5 poundsCHECK ON AMAZON
The Runner Up Electric
Stiebel Eltron 224199 Electric
Stiebel Eltron 22419921.7 x 20.1 x 9.6 inches16.1 poundsCHECK ON AMAZON
Hot Selling Electric
Rheem RTEX-13 240V For Tiny House
Rheem 240V RTEX-134 x 9 x 13 inches4 poundsCHECK ON AMAZON
Point of Use Electric
Marey ECO Self-Modulating Heater 2020
Marey ECO Self-Modulating Heater3.1 x 7.5 x 10.8 inches7.5 poundsCHECK ON AMAZON
On Demand Electric
Stiebel Eltron 24 Plus Tempra4.6 x 16.6 x 14.5 inches1 poundsCHECK ON AMAZON
Cheap Energy , Electric
Ecotouch Electric Water Heater15 x 11.1 x 4.9 inches6.95 poundsCHECK ON AMAZON

The Most Efficient Electric Tankless Water Heater Reviews:

The following some of the best picks of ours; make sure to check them out to get your hands on the best water heater for your house.

1. The Most Efficient Electric Tankless Water Heater; EcoSmart ECO 11 Heater:

EcoSmart 11

Perfect For The Small Apartments:

The compact size of this unit can really fit the small corner of the house, spares floor, and wall space for the small apartment usage. By heating up to two GPM of water, you can make use of this tankless unit for one shower use or as the point of use. Constant and stable hot water can rally bring along a pleasing user experience. In the warmer areas, you can also utilize one sink and one shower simultaneously.

Energy Saving:

This tankless water heater comes with self-modulating technology. It can really adjust the flow rate and power based on the amount required, so as the energy and heating charges are decreased at least fifty percent. It can heat the water just when you turn the device on, which leads to less heating loss.

Simple To Operate:

EcoSmart follows the principles of the brand and sticks to manufacture heaters that are environmentally friendly. Plus, the design of this model is also simple yet modern, can also add up to the house decor when installing it in your bathroom or around your water sink. It also has an LCD display, which shows the exact temp of the water, and the buttons below allow the users to adjust the water temp by one increment at a time.

Digital Temp Control:

The LCD screen on this tankless machine shows the exact temp of the water with a one-degree increment. Being the leader in the tankless market for around ninety years, this German design is still gaining admiration because of the brilliant performance they provide.

Advanced Water Flow Control:

This tankless water heater has huge boots to fill. The shining feature of this device is the advanced water flow control, which can really maintain the temp of the water for keeping it stay hot no matter how many units run simultaneously. Once the demand for the heated water exceeds the unit’s capacity, the system decreases the flow for maintaining the stable water temp.

Compact & Small Shape:

As big as the briefcase, it needs a modicum of storage space in the bathroom of yours. The sleek design of it can really coordinate flawlessly with any house décor, particularly those of the modern kind. Unlike the tank water heating systems, it can never run out of the heated water. The total silent work gin brings along perfect and smooth user experience.

3. Hot Selling Energy Efficient Tankless Water Heater; Rheem 240V RTEX-13 Heater:

Rheem RTEX-13 240V For Tiny House

Digital Panel Control:

The external digital panel really makes it simple to operate it for adjusting the temp of the water. By turning the buttons available on it from left to right, you can increase or drop the temperature of the water with a one-degree increment. You can see it on the LCD display panel.

Heavy-Duty Material:

The durable copper material can really adopt on the device for prolonging the service life of the tankless unit. The non-corrosion design of this unit allows it to be long-lasting and durable. With the average lifespan of around ten years, this device is well worth the cost.

98 Percent Energy Efficiency:

Passing through the electric tankless water heating unit standard, this machine can really promote the energy efficiency of it as high as ninety-eight percent, allowing no standby loss of any heat, and decreasing the energy charges accordingly. Plus, the fitting of the device is super simple; follow the directions, and you can do it all on your own.

4. Best Point of Use Energy Efficient Heater; Marey ECO Self-Modulating Heater:

Marey ECO Self-Modulating Heater 2020

Energy Efficient:

When comparing this tankless device with the conventional water heating units, it can really save around sixty percent on the energy charges. The unique ECO line of this machine maintains a ninety-eight percent efficiency level throughout its whole using life. If under the cautious maintenance, the lifespan of this unit can prolong long enough for getting great bang for your money.

Multiple Point Of Use:

This tankless water heating system is perfect for two points of use at the same time when you live somewhere warmer in the southern parts of America, while in cold regions, this tankless machine is perfect for one sink around 1.3 GPM. Activated by the low pressure of the water, it offers a constant supply of hot water the moment you open your faucet.

Cheap Cost:

Prices no more than two hundred dollars, you can acquire this advanced point of use water heating device home. The German-designed unit with the stainless steel interior can really keep it long-lasting and durable. Adjusting the temp of the water is super simple; with the help of an LCD display, you can really adjust the water temp with one-degree increment.

5. Heavy-Duty Energy Efficient Tankless Water Heater; Stiebel Eltron 24 Plus Tempra:


Advanced Water Flow Control:

Applied with the advanced water flow control, it really provides with the stable heated water temp. By adjusting the power based on your flow rate and the amount of water you need every day, it provides with a comfortable bathing experience. The buttons that are preset let the user get the desired water temp according to the habit.

Digital Display:

The German-designed device can keep it in the leading position in quality and performance levels. The large water flow rate can supply constantly heated water for the whole house usage. Winning the top standard level, it can really promise a long life of the device.

0.99 Percent Energy Efficient:

The energy efficiency of this device can really reach up to ninety-nine percent, much higher than the conventional models, and even higher than the other energy-efficient units. Thanks to the self-modulating technology it comes with, the heated water flows out only when the users require it, which helps in saving even more energy.

6. Cheap Energy Efficient Tankless Water Heater; Ecotouch Electric Water Heater:


Advanced Self-Adjustment:

The smart self-adjustment technology shines in balancing the temp of the water through monitoring the temperature setting and the water flow rate. The optimal design really proves to save around ninety-eight percent on energy efficiency, leading to the low charges on the energy and water bills.

Instant Heated Water:

Being the low-priced electric energy efficient instant water heating device, the performance of which can stay equally balanced as the high-end models. Utilizing under 5.5KW power, it offers the users hot water that will never run out. The second you switch your tap on, the heated water flows out, and there’s no more waiting so long for the heated water any longer.

Multiple Protection Devices:

Equipped with several protection units, this tankless water heater can really ensure the using safety. The separated electricity and inner water lines design can keep the interior materials away from being corroded or leaked, which can actually prolong the lifespan of this unit.

Do not desire to purchase the electric tankless water heating system? Then, you can also keep on reading because we have also picked out numerous energy-efficient propane and gas tankless water heating systems for you.

The Most Energy Efficient Gas Water Heater Reviews:

1. Large Flow Rate Energy Efficient Gas Water Heater; Rinnai V94IN Heaters:

Rinnai V94IN 2020

Application Remote Control:

It comes with mobile application control. This feature offers the users to control the temp of the water and on/off remotely when turning the device into the vacation mode. The schedules and timers turn off the device automatically for saving the energy.

9.4 Gallons Per Minute Of The Water Flow Rate:

The max water flow rate of 9.4 gallons per minute provides the users with a constant supply of heated water. In the warm areas, it’s able to support two showers use simultaneously, while for the cold areas, you can make use of one sink and one shower properly. For the middle-sized house and even for the family of four, you can make use of it perfectly.

Warranty Guaranteed:

It comes with twelve months of warranty for the heat exchanger and sixty months for its parts; the limited warranty can bring reassuring feeling in utilizing this system. Plus, the considerate after-sale service of the company allows resolving the issue in time on the device you get.

2. Outdoor Gas Tankless Water Heater; Rinnai RU98EN Ultra-NOx Condensing Heater:

Rinnai RU98EN Ultra-NOx Condensing Heater


This Rinnai tankless water heating machine benefits in the high energy efficiency with the condensing design of the model. The unused heat and gas are recovered, directing to the decrease in the standby loss.

Low NOx Design:

Unlike other gas water heating machines spending much cash on the energy charges, the low NOx design of the machine can really meet the nitrogen oxide emissions standard of Texas and California, which is highly eco-friendly and spares more cash in the energy charges as well as the electricity charges.

Outdoor Installation:

The venting facilities are essential for the natural gas water heating systems, serving for releasing the wasted gas throughout the use. The outdoor fitting, however, can save the cost by allowing the wasted heat and gas gone naturally.

3. Most Efficient Propane Water Heater; Rinnai V94EP Heater:

Rinnai V94EP

9.4 Gallons Per Minute Of The Water Flow Rate:

9.4 GPM of the water flow rate can really support the large and middle-sized family on two showers in the warmer areas, and one sink and one shower in the cold areas. There’re also multiple devices in diverse water flow rates that are accessible based on the requirements you have.

Outdoor Installation:

The outdoor fitting of the propane tankless water heating system can really free the users from getting the venting facilities. The wasted gas is released directly out of the home, which not just can save the expense in appending the venting devices but also can improve the safety of using of the unit.

Smart Technology Equipped:

This tankless water heater also comes with the smart mobile application control, permitting the users to control the device on/off with vacation mode. For saving the electricity and energy, it also comes with the timers for automatically switching off the tankless unit when it’s left unused for about twenty minutes for the safety of the users.

How Efficient Are The Electric Tankless Water Heaters?

Among propane, electric, and the natural gas instant hot water tankless water heating systems, the electric ones tend to be the most energy-efficient ones. The propane and gas’s energy efficiency can really reach around eighty to eighty-five percent, while the electric type can reach more than ninety-eight percent, which means the low standby loss of the heat. You might also think in a simple manner, the propane tankless water heaters, and the natural gas tankless water heaters, as the name proposes, adopt gas as the main power source for starting the water heating unit. For the indoor fitting, there have to be the venting facilities available. Why? Because of the wasted gas, it produces to emit.

A few of the water heating devices with the condensing design can really recover the hidden heat that might have lost in the conventional tankless water heating machines, directing to the less energy loss. However, compared with the gas tankless water heating units, the electric ones make use of just electricity as the main power source, no venting facilities are required, and you don’t have to maintain it frequently as the natural gas models do. It can really prove that the electric tankless water heating systems can save twenty-four percent to thirty-four percent cash on the using charges than the traditional tank ones. The lifespan of the electric models can be around twenty years.

The Overall Glance At The Energy Charges And Savings Of The Tankless Water Heater:

In terms of the efficiency of the water heating model, the majority of individuals will ask, Will the instant water heating charges much cash? Are they pricey to fit? Well, before buying the best ones, the savings and costs are really the significant aspects to think about. If you’re one of the individuals paying immense attention to the prices, here we provide an honest breakdown for you.

The Installation Cost:

First of all, you ought to acquaint that the fitting charges on the tankless water heating machines are usually higher than the conventional tank types. The fitting fee differs according to the models of water heaters you choose to have. For the electric water heating device, the fitting cost is quite low; you can basically do all this on your own simply by following the directions given by the companies or to watch some installation video on YouTube.

Contrarily, the natural gas heaters, particularly the ones that support the whole house usage, are likely more pricey. They need the professional electricians to append the additional wiring at your house, and there’re venting systems you have to get. The overall expenses on the fitting take around five hundred dollars; certainly, the exact cost relies on the place you live in.

Energy Savings:

From the statistic on the energy savings of the tankless water heating machine vs. tank water heating machine, the anterior one can really win in saving fifteen to forty percent of energy. If you try to go with the electric ones, then first go through the energy efficiency, the ones with ninety-five percent or above are the perfect ones to get your hand on. The using charges of the electric and natural gas on-demand water heating systems are basically the same, but the natural gas really exceeds a little.

Do The Tankless Water Heating Units Make Use Of More Water?

Not really. The main disparity between the tank and tankless water heater lies in the principle of their working. For the tank water heating device, there’s a storage tank aiming for storing the cold water, and it can really heat up that stored water once the user switches the unit on. Thus the waiting time for the heated water is long-drawn-out, and you might have a problem in using the heated water when you’re full of activity going out. The tankless water heating systems also recognized as the on-demand heater or the instant hot water heater outshines for the constant supply of hot water of these, which denotes that you can never run out of the heated water if you choose the right size for you.

Now return to the issue, do tankless water heating units make use of more cold water? No! The amount of cold water they require in the heating process is the same; the main disparity is by utilizing the instant hot water, you don’t have to knock your bathroom door and get the children to take a short shower because of the lack of enough heated water. Well, to such situations, the tankless water heating machines do make use of more water during you are relaxed in taking the hot water bath.

Does The Electric Tankless Water Heating Systems Save More Energy Than The Gas Ones?

When you compare the costs of electric and tankless gas heaters, you’ll find the gas ones much more costly than the electric models, prices more than five hundred dollars, a few high-end ones take around one thousand dollars even, while its counterpart can take around five hundred to seven hundred dollars. In terms of the operating charges, the electric ones for its ninety-eight percent energy efficiency exceed that of eighty-five percent.

However, at the thumb rule, the using charges of the electric ones tend to be more costly than the gas ones, because of the high charges on the electricity. To cut a long story short, the electric tankless water heating devices can really save more energy than the gas ones, but the using charges tend to be a little higher than that.