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Top 8 Best Tankless Electric Water Heater (Reviewed 2020)

Last update on 2020-10-20 at 18:56 / Affiliate links / Ratings / Images from Amazon Product Advertising API

Endless Supply Of Hot Water With The Right Electric Tankless Water Heaters

All homeowners will tell you that maintaining a family home  can be quite expensive or less expensive. Something is always breaking down and needs to be fixed or replaced. However, the most expensive thing about owning a home is the electrical/energy bills/energy efficient/energy use. Having an outdated home appliances can really make a dent in the home budget.



More and more people have started turning to modern ecological and cost-effective solutions. One of the best solutions to a big water bill(utility bill) is having the best electric tankless water heaters. 



Upkeep and maintenance are incredibly simple, and the electric tankless water heaters will save a lot of money in the future. Because I want to save you money, I’m going to give my top choices for tankless and gas tankless water heater on the market. 



If you want to know how to choose the tankless water heaters reviews for you — keep on reading.

Best Electric Tankless Water Heater That Stands Out This (2019) - A 8 Comparison Highlights

Here are the 8 tankless electric water heaters that we have given a summary of what we have learned and researched about. We encourage you to read this before jumping in the full tankless electric water heaters below.

Product Name
Our Rating
EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology

EcoSmart has created an innovative self-modulating technology which can save a lot of water and power. The heater also comes with a limited lifetime warranty.

Stiebel Eltron 224199 240V, 1 Phase, 50/60 Hz, 24 kW Tempra 24 Plus Whole House Tankless Electric Water Heater, Advanced Flow Control

This tankless water heater has a sleek design, and the major components are recyclable. Also, it features an innovative technology which helps with water flow rate.

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

Rheem’s heater is a great choice for smaller households. Also, it has a self-modulating feature, and the 5-year warranty is an excellent bonus.

Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas

Takagi’s water heater is a great fit for smaller households. Moreover, it has numerous safety features that will prevent the unit from overheating or freezing.

Bosch Electric Tankless Water Heater - Eliminate Time for Hot Water - Easy...

The hot water supply is enough to power three bathrooms in a warmer climate. Also, it is 97% energy efficient(energy consumption).

EcoSmart ECO 11 Electric Tankless Water Heater, 13KW at 240 Volts with...

This is one of the best heaters for hand-washing. I recommend using it in bathrooms, wet bars, or recreational vehicles. There is a 1-year limited warranty for this unit.

Rinnai RUC98iN Ultra Series Indoor Natural Gas Tankless Water Heater, Twin...

The Rinnai is compact and easy to install. It has the capacity to supply hot water to three taps simultaneously and has an excellent warranty.

Stiebel Eltron Tankless Water Heater – Tempra 29 Plus – Electric, On...

Amazing Flow Rate Control features, combined with the digital temperature control memory setting, make it a great heater for smaller households.


A Full Product Review On The Electric Tankless Water Heater

Now, let’s talk about my top choices for the tankless electric water heaters. I’m also going to discuss all of their features and benefits and include a short explanation of different sizing guides. I’m even going to tell you who my winner for the best electric tankless water heater is and how you can make it work for your home.

Best Choice

EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology

1. EcoSmart ECO 27

The Ecosmart eco 27 focuses on making and distributing green energy efficient products. Furthermore, all of their energy products can be used in commercial, residential, and industrial settings. 



The ECO 27 is one of my top contenders for the house tankless electric water. The Ecosmart eco 27 model is one of the most powerful electric tankless water heater in the ECO water line. The electric tank is big enough to supply water to a whole house, even in colder conditions. 



Furthermore, the best electric tankless water heater comes with a lifetime limited warranty. 



The warranty means that EcoSmart will replace any parts that have broken over the heater’s life. Also, they claim this model can save up to 50% on your heating the water at cost (water heating costs).



All of the components are made out of copper immersion and steel. The heater has self-modulating technology. With this technology, the heater will adjust the energy usage on its own based on how much hot water you need.

This particular model from eco line will be most efficient in a warmer climate. For people living in California, Florida or Arizona, the heater can supply enough hot water to four shower faucets and one hand sink. 



Someone from the midwest, for example, could turn on two shower heads and a hand sink at the same time and still have hot water. However, all of my readers who live in the northern parts most likely won’t have that kind of hot water system.



Eco says that the heater will produce enough hot water for two showers. That being said, while the hot water is good, it might take more time to get the hot water running. I recommend checking the sizing guide to find which heater will best fit the climate in your state.

A video on eco smart tankless water heaters

2. Stiebel Eltron Tempra 224199

Stiebel has been an industry leader for years when it comes to manufacturing water heaters. They have one of the biggest selections of tankless electric water heaters on the market.



Moreover, they also make various hand-washing products, as well as water pumps and electric fans. The heater features the company’s trademark Advanced Flow Rate Control technology(activation flow). It will limit the cold water supply and decrease the pressure slightly if the demand for hot water is too high.



However, even though the pressure is lower, the water output will still be at the desired incoming water temperature. Also, just as the Eco 27, this electric tankless water heater has the self-modulating technology.


Thanks to that feature, it will reduce the overall energy savings consumption.



Now, I would recommend this heater to anyone working with a small space savings.



The water heater models has a sleek design which can be incorporated almost anywhere. Also, it is much easier to dispose of once it stops working.



Finally, all of the major components of the heater are completely recyclable.

Now, compared to the ECO 27, the Eltron isn’t as powerful. stiebel eltron tempra plus claims that, in hotter climates, their heater could power hot water to three shower heads at the same time. 


However, that’s only for a couple of the warmer states in the US.


For the most part, it will only supply one shower, and one hand sink at the same time.



Where it falls short for us is its demand for hot water in colder environment.


A electric tankless water heater of this tank size can only power one fixture with hot water. Moreover, countries in the north-eastern part of the US will have a much weaker water flow rate. 



I recommend taking a look at stiebel eltron tempra plus size chart. It might give you a better idea of where the heater will be most efficient.

3. Rheem 240 Volts

Rheem makes numerous heating water and cooling systems for both residential and commercial use. While their boilers, furnaces, and thermostats are amazing, let’s take a look at why this model could be the tankless unit electric tankless water heater currently on the market. 


Their Professional Classic electric tankless water heater has an energy efficiency rate of 99.8%. This model has a modulating control unit, and it can supply hot water to multiple sinks at the same time.


The installation is quite simple, and it has a great design which can fit in almost any small space. The heater is made from copper and brass. 


These two heating elements combined make the model much more durable, and the parts can be easily replaced. Also, the model comes with a 5-year primary warranty, which is two years longer than the Stiebel model.

This model has numerous applications. You can use it for a shower, sink, or dishwasher. Depending on where we put it, it will have different water pressure.



However, Rheem claims that no matter which home appliances it’s hooked up to, the heater can provide an uninterrupted flow rate of hot water. 



Furthermore, they say the number of back-to-back showers is limitless. On the other hand, I wouldn’t recommend using more than one fixture at the same time. As soon as more than one faucet is open, the heater needs much more time to produce hot water. 


Also, from my experience, this can cause the hot water to run out quickly.

4. Takagi T-KJr2-IN-NG

Takagi is also one of my choices for the water heater reviews for residential use. All of their heaters have top-of-the-line safety features. 


With freeze protection, Hi-limit switch, and the overheat cutoff fuse, you will never have to worry about a breach in combustion. The heater has a self-modulating feature which will help reduce the energy bill. It also has a remote control and a power cord. 


Most of the components are made out of steel. Stainless steel components decrease the chance of limescale buildup forming. The model comes with a 15-year heat exchanger warranty and 5-year limited warranty. 


The warranty only applies to heaters in residential use. Keep in mind that the warranty is only applicable if a licensed electrician installed the heater. Also, the heater requires category 3 steel venting.

Since this model is a non-condensing unit, it’s better suited for smaller water applications. In colder environment, the heater can supply only one shower and one kitchen sink with hot water.



Moreover, the tap needs to be running for a few gpm gallons per minute before the hot water reaches it. 


On the other hand, in warmer climates, Takagi says their heater is big enough to supply hot water to two shower heads and one kitchen sink at the same time.


Nevertheless, I would recommend it for smaller households.

5. Bosch Tronic 6000 C

Bosch is one of the most renowned and trusted companies in the world. From furnaces, boilers, to storage tank water heaters(storage tanks), they have invested a lot in thermo-technology in recent years.



It comes as no surprise that Bosch is one of my top contenders for the best electric tankless water heater. The model is advertised as a “whole house electric heater,” which is supposed to provide enough demand for hot water for both residential and commercial use. 



Depending on the application, Bosch says this heater can supply one to three taps with hot water at the same time. With a minimal standby loss, it is 97% energy efficient(energy consumption). Also, the heater has a built-in flow rate sensor(flow sensor). 



The sensor will ensure a constant output temperature rise(temperature output) of the incoming water. Moreover, it has a filter screen on the inlet and scale resistance.

In warmer climates, the heater is able to produce enough hot water to supply two to three bathrooms. 



On the other hand, in colder regions, the heater will only be able to supply one bathroom with hot water. Before buying anything, you can check out this sizing guide to see which model will work best for your whole house. 



I would recommend this model for smaller apartments or office spaces, as well as in-law suites.

6. EcoSmart ECO 11

Next, we have another heater from EcoSmart. This is a smaller heater compared to the ECO 27 model. I believe it could be the natural gas tankless electric water heaters for smaller applications, such as hand washing. 



It would make a great addition to any bathroom, recreational vehicle, or boat. This model is a true point-of-use system with on-demand for hot water at any moment. 



Also, it has a advanced flow control technology of half a gallon per minute and includes a sink aerator. It is a smaller model, and I would recommend using it only for a single sink. Using it for a shower or multiple fixtures would just cut the hot water flow rate. 



All of the components are made out of copper and steel. The unit is durable, and all of the parts can easily be replaced. Moreover, it is compact and can be stored almost anywhere. This also comes with a limited lifetime warranty.

The ECO 11 is comparatively much smaller than the ECO 27. In warmer climates, the heater could supply one shower and two kitchen sinks at the same time. 


However, the hot supply is limited, and it takes a few minutes for the hot water to start running. On the other hand, in colder weather, it can only supply two kitchen sinks with hot water. I recommend checking ECO’s size chart to determine how well this unit would work for you.

7. Rinnai

My next contender for the title of a electric tankless water heaters comes from the company Rinnai. The company focuses on manufacturing various heating water equipment, such as heaters, boilers, and furnaces. 



This model, which is the tank size of a suitcase, is easy to install and great for indoor locations. It is a condensing type of electric tankless water heater, which means it is extremely energy savings-efficient. 


All of the heaters from their RUC line are Wi-Fi capable. There are two types of warranties for this product — commercial and residential. 



The residential warranty covers 12 years for heat exchange, 5 years for part replacement, and a 1-year labor warranty. 



On the other hand, the commercial warranty is a bit shorter, as is expected. 



Both the heat exchanger and replacement warranties are for 5 years, while the warranty is still one year.

This unit from Rinnai can supply multiple fixtures with demand water heater at the same time. However, if more than two faucets are running at the same time, the heater needs a few minutes to deliver hot water to both.


On Rinnai’s website, there is an excellent sizing calculator. All you have to do is choose your preferred usage and zip code. The calculator will ask to choose between condensing and non-condensing units. Moreover, you can choose if you want a heater with or without a tank.

8. Stiebel Eltron 29 Plus (stiebel eltron 224199 240volts)

Finally, we have another product from Stiebel. This model features some of their trademark heater technology, along with some new improvements. 



Let’s see why the Eltron 29 has the potential to be the best electric tankless water heater. The heater comes with the flow rate control technology for maximum energy savings efficiency. 



The Digital temperature control led display accurately shows the current incoming hot water temperature range(water temperature rise). 



Also, the monitor will show the current water savings on the lcd panel screen. There are two heat water temperature control memory settings. With them, you can save your desired temperature of the incoming heat water, which is an amazing time-saver.



This heater has a sleek and compact design, perfect for small spaces. 



Moreover, the installation process is quick and simple. All of the major components are made in Germany and are recyclable. Finally, the warranty only applies when a licensed electrician installed the unit.

Eltron 29 Plus is one of Stiebel’s most powerful tankless heaters. In warmer climates, it can supply demand for hot water to four shower heads at the same time. 



The company claims the hot water supply is infinite. However, depending on the climate you’re in, the water pressure may vary. You can find their sizing guide here.

Electric Tankless Water Heater Reviews - A Buying Guide On What To Consider

There are a few things that will determine when you should change the electric tankless water heaters. Even though it might seem that the unit is working fine, here are four telltale signs you need a new one.


1. Considering the Climate


Depending on the climate you live in, the water heater will behave differently. For example, I have friends who live in Florida, and they tend to have a tankless electric water heatersthat have a lower GPM (gallons per minute) output temperature. When it’s in warm surroundings, the heater spends less energy(energy use) losses than usual to heat up the water.



However, what type of water heater do we get if we live in a cold climate? Well, we’ll need a heater that has an output of at least 30% or even 50% above average. As a simple example, let’s say that I need a heater with an output of 4 gpm to 5 GPM.

If I were to live in Alaska or somewhere up in the Rockies, I’d need one whose output(temperature output) is at least somewhere between 6 and 8 GPM. 



Of course, manufacturers provide climate zone charts for their products. Depending on where I live in the USA, I can pick a heater that would withstand the climate and heat the water more quickly.

water heater

2. What Will the Heater Cover?


Personally, I prefer to have one large heater for the whole house. However, it’s not uncommon to have hot water on demand in individual areas of the house. 



To those who prefer this type of heating, I’ve provided a simple chart that covers typical flow rates for each individual fixture in a house:


  • Lavatory heater: 0.5 GPM (gallons per minute)
  • Bathtub heater: 2.0– 4 gpm (gallons per minute)
  • Shower heater: 1.5–3.0 GPM
  • Kitchen sink heater: 1.0–1.5 GPM
  • Pastry sink heater: 1.5–2.5 GPM
  • Laundry sink heater: 2.5–3.0 GPM
  • Dishwasher heater: 1.0–3.0 GPM

I don’t live in a huge house, but if I were to get one, I’ll need a heater that can cover a lot of ground. For that reason, it’s a good idea to add up all of the GPM usage requirements that my household might need.


In other words, if I need a heater in my kitchen, my bathroom, the outdoors, etc., I just crunch the total number of GPM that their heaters ought to cover and use that information to find a single, powerful tankless electric water heaters.


3. Basic Electric Requirements


Before deciding on an electric water heater, you should consider three important elements: the voltage, amperage, and the breaker.



In terms of voltage, most major retailers sell products with the following ranges: 110V, 120V, 208V, 220V, 240V, and 277V.


Next, there’s the amperage. Each individual heater requires something different when it comes to the amp draw. Therefore, you should be careful and make sure that your home supports the electrical demand for hot water you’re interested in.



Finally, there’s the question of the breaker. The safest option is to put your heater on its separate circuit. In fact, you might even purchase one that requires connecting to several circuits to work.

building codes

4. Price

When shopping for a water heater, it’s important to factor in other potential expenses. For example, unless I can do it myself, I still need to pay for the installation of the heater, which will require professional help.



One major part of electric water heater shopping is the warranty, more specifically reading the fine print. For instance, my current heater requires a professional technician to look it over for regular maintenance. 


If I were to try and fix the problem myself, or if I were to try and install the unit without consulting a technician, any lifetime warranty I have would become worthless. Moreover, I would have to spend additional money on a new electric tankless water heaters.

A Video in choosing an eletric water heater on youtube

To Conclude – Finding The Best Electric Water Heater That Works For You

So, now that you’ve seen what types of the best electric tankless water heater there are, how to do proper maintenance, and my top picks for the electric water heater reviews, only one question remains. 



Which of these will be crowned the electric tankless water heaters of all time?

I’ve given this decision a lot of thought, and my winner is the Rinnai RUC98iN. The reason I chose this one as the tankless electric water heater reviews were mainly its hot supply of water. 



It is the most reliable heater compared to all of the other heaters, and the warranty is pretty extensive. 


Moreover, it isn’t prone to corrosion or limescale and requires little maintenance.



Have you ever thought that you need also to keep your home safe? 


Here are some great surveillance cameras that will make sure your safety is a priority: 5 of the Best 8 Channel Security System

Other Recommended Tankless Water Heater Reviews
Frequently Asked Questions
hot water
Are Electric Tankless Water Heaters Worth It?

They absolutely are. When you install the best electric tankless water heaters, you’ll never run out of hot water. In addition, because of its size and compact design, a tankless heater can fit anywhere around the house, large and small tight spaces alike. 

Moreover, it’s easy to install and tends to be more durable than tank heaters with a longer life expectancy.


Finally, getting a tankless heater is a more cost-effective option when you consider the big picture. A tank water heater might actually cost less than other options, but that’s not factoring in the installation and maintenance. On the other hand, if you invest in a tankless heater, you’re set for the next few decades. More importantly, they are easier to maintain and don’t break as often as tank heaters. 

How Much Electricity Does A Tankless Electric Water Heater Use?

Because the best electric tankless water heaters works ‘on-demand’ (i.e. it doesn’t store hot water), it consumes less energy. But the exact amount of electricity used by an individual heater will depend on many factors, such as the size of our house and the number of fixtures using it.


Generally speaking, you can run the best electric tankless water heaters for two to three hours a day and still get hot water at any point; that to me is energy efficiency at work right there.


An average tankless electric heater does save a lot more energy than its tank counterpart. In fact, a tank heater that uses 41 gallons or less of hot water daily is almost 34% less effective than a typical tankless product.


Some models, like EcoSmart ECO, contain state-of-the-art self-modulating technology, allowing them to control their energy output for optimal heating. 

What Is The Downside Of A Tankless Water Heater?

There are several downsides to owning a tankless electric water heater. For example, I won’t have any hot water during a power outage. Moreover, due to its heating system, the best electric tankless water heaters will have some difficulty providing lukewarm water, which might be a detriment to some users.



However, by far the biggest setback to owning a tankless heater is the price. An average cost of buying a tank gas heater and having it installed is around $$$. On the other hand, the average for a tankless heater, installation included, is $$$$, at least.

Which Is Better: Gas Or Electric Tankless Water Heater?

Rating gas(gas lines) and mini-tank water heater is tough since there’s no real winner between the two; if you want to know which type of heater is better, you’ll need to figure out how it best suits your needs. 



To me, an electric tankless heater is better since it heats up the water quickly and saves energy. But I know for a fact that lots of users prefer gas-powered heaters since they cost less per month than electric ones. After all, natural gas expenses are generally lower than the cost of electricity.

Is A Tankless Water Heater More Energy Efficient?

When compared to their tank counterparts, tankless water heaters tend to save more energy and provide a higher-quality output. In fact, I can save as much as 40% on my bills once I switch to a heater with no tank. As I stated earlier, a tankless electric heater only works when it’s necessary, unlike tank heaters which are on 24/7.


But an electric heater isn’t just energy-efficient. It also happens to be quite beneficial for our overall health. Rust and scale tend to build up inside of the tank of a regular heater, which can infest our drinking water and cause us to get sick. However, with a tankless heater, I can always expect clean, fresh water to come out.

What Breaker Do I Need For A Tankless Water Heater?

There are several steps to finding out the size breaker we need for a tankless water heater:


  • Finding out the heater’s power (in watts)
  • Division
  • Multiplication

The first step is easy enough — all we have to do is find out what the pull of the watts is. A residential spinning heater has an optimal quantity of 1500W.

Next, we have to achieve the optimal pull using the heater’s current-voltage. A standard socket requires 120V. Therefore, we divide 1500 by 120 and get 12.5


Finally, we find out what the safe circuit load is by multiplying 12.5 with 125%, which gives us 15.6 amps. However, a 15.6-amp breaker might not be enough, so I suggest going with the next highest possible rating of 20-amp one instead.

How Long Do Tankless Water Heaters Last?

A typical storage water heater can last up to 15 years. In comparison, electric tankless water heaters have a life expectancy of 20 years, at the very least. In addition, I can extend the life of my tankless heater by replacing some electrical components.



Of course, any water heater has the tendency to break early. While electric tankless water heaters do last longer than tank ones, we should still perform regular maintenance and replace any part that can potentially damage it. 


Constant water flow and the outside elements can also affect the shelf-life of a heater. Overusing a heater beyond its capacity is also not a good idea, as it is guaranteed to wear it down well before the warranty coverage date

Do Tankless Water Heaters Run Out Of Hot Water?

Electric tankless water heaters do not have any tanks, which is why they don’t store any hot water. Instead, when a hot water tap is on, cold water goes through a pipe into the unit. An electric element then heats the water, making it instantly hot and ready for use, eliminating the need for a hot water tank, to begin with.


Naturally, there are some limits to what even an efficient tankless water heater can do. For example, its output will limit the rate of water flow. Simultaneous use of several taps in the house can also strain the heater and as a result, you’ll run out of hot water. However, if we’re referring to individual heater output, I’d agree that a tankless water heater will technically never run out of hot water. Moreover, if I install several heaters in my house at strategic locations, I don’t even have to worry about straining a single unit with simultaneous tap use. 

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