Holds a Master’s degree in Engineering and is keen on her own home’s climate. Sometimes we think that Carolina owns every single product she writes about – that’s how profound and insightful her reviews always are.
For 8 years, Richard had been working as an HVAC specialist and AC unit installer since his student years. Now, he’s our main consultant on every technical aspect that may arise during our tests and research.
Last updated: July 14, 2021
Traditional tank water heaters are starting to die out, being replaced by safer, smarter technology in the form of electric water heaters. The best electric tankless water heater can offer big savings on your utility bills, as well as being easy to install and providing non-stop hot water whenever you need it to. So there are a lot of advantages of having this kind of heater in your home, and we’ve found some of the very best models you might be interested in purchasing.
In order to identify the best tankless electric water heater models, like our Editor’s Choice, the Stiebel Eltron 29 Plus Tempra, we’ve analyzed a lot of different options, reading through both expert and user reviews in order to see which heaters people enjoy using the most. We considered a lot of different factors in our list, including the flow rate, dimensions, warranty, and temperature ranges of each heater. We’ve chosen heaters of different prices too, in order to find an option that can appeal to every budget and every household.
Below, you’ll find a comparison table to show the results of our findings. The table lists all of the best tankless water heaters, ordered with the very best-rated model at the top. Further down the page, you’ll find in-depth critical reviews of each model, complete with some pros and cons, as well as the specifications and dimensions of them all. Finally, you can read through our electric tankless water heater buying guide to learn more about these kinds of heaters and choose the best one for you.
Top 6 Electric Tankless Water Heaters Review 2021
Stiebel Eltron 29 Plus Tempra – Editor’s Choice
Flow rate: 0.77 – 4.5 GPM
Temperature range: 86 – 140°F
Dimensions: 16.6 x 4.6 x 14.5 inches
Warranty: 7-year limited
Extra features: Advanced Flow Control feature maintains hot water temperature
At the top of our list, the best tankless electric water heater we could find was the Stiebel Eltron 29 Plus Tempra. This is one of the most expensive heaters out there, but it more than justifies its high price tag through its powerful performance and impressive set of features. Providing non-stop, on-demand hot water, this heater gives you exactly what you need.
The Stiebel Eltron 29 Plus Tempra is a stylish and attractive heater, with an easy to read digital display and a relatively compact housing that can be easily mounted on the wall. It has a maximum flow rate of 4.5 GPM, so it can easily satisfy the vast majority of households, but may not be quite sufficient for the biggest of homes and the largest of families. It comes with a 7-year warranty, providing total peace of mind to the user, and a lot of excellent features.
One of the best features of the Stiebel Eltron 29 Plus Tempra is the Advanced Flow Control, which keeps the temperature of your hot water stable and steady, with minimal fluctuations for maximum satisfaction. This tankless electric water heater also comes with a savings monitor feature that shows how much energy you’ve saved over time, and the whole thing is designed to give the user a lot of useful information at a glance and provide only the best levels of performance too.
Why is it special?
Advanced Flow Control feature
Savings monitor tells you how much you’ve saved
What are the flaws?
Not the best option for very large homes or families
EcoSmart ECO 27 – Best Energy-Saving Water Heater
Flow rate:3 – 6 GPM
Temperature range: 80 – 140°F
Dimensions: 17 x 17 x 3.7 inches
Extra features: digital temperature controls
Next up, we have the EcoSmart ECO 27, and if you want to invest in a tankless water heater to cut down on your energy bills, this might be the perfect model for you. The EcoSmart ECO 27 is one of the best electric tankless hot water heater models in terms of energy efficiency. It’s very effective at lowering your energy usage and saving money on your utility bills, and you can make up for the initial installation and purchase costs very quickly through the money you’ll start saving on hot water.
The EcoSmart ECO 27 can provide up to 50% of savings. It offers incremental, precise digital temperature controls too, letting you adjust the temperature by a single degree, and it has a very low activation flow rate, so you can start heating up water whenever you need it. Plus, it’s very small and compact, saving a lot of space compared to a big tank.
It comes with a lifetime warranty as well, so you’ll always be protected in case you encounter any issues, although some users have found that the warranty doesn’t always apply in certain issues, so you need to read the fine print and be sure of everything before purchasing this heater. The only other issue we could find with the EcoSmart ECO 27 is that the installation process can be difficult, so you might need to hire a professional.
What stands out?
Great for energy saving
Impressive maximum flow rate
Low activation flow
What cons did we manage to find?
Tricky installation process
Some warranty issues
Rheem 240V RTEX-18 – Best Whole House Water Heater
Flow rate: 0.7 – 7 GPM
Temperature range: 80 – 140°F
Dimensions: 4 x 15 x 19 inches
Warranty: 5-year limited on heating chamber, 1-year parts
Extra features: digital temperature display with adjustments in 1-degree increments
Next, we come to the Rheem 240V RTEX-18. Arguably the best tankless electric water heater for the whole house, this model features a high maximum flow rate, so it can fit in nicely with larger homes and households and always provides the non-stop flow of hot water you need, even if multiple people around the home are using faucets or taking a shower at the same time. In short, the Rheem 240V RTEX-18 can handle anything you throw at it.
A durable and well-constructed tankless water heater, the Rheem 240V RTEX-18 also features a digital display and very precise temperature controls, letting you set the temperature exactly where you want it. It’s easy to use and actually quite simple to install too. Many buyers of this water heater have reported that they were able to install it without any professional assistance, so if you have a little bit of DIY experience then you might be able to save some cash fitting this unit yourself.
On the downside, the warranty for the Rheem 240V RTEX-18 isn’t the strongest as it only covers a single year for parts failures. This model is also a bit chunkier and larger than some of the others on the list, so if you’re switching to a tankless water heater because you want to save some space, you might want to choose another model.
Why are we impressed?
Very efficient for families and larger homes
High max flow rate
Very accurate temperature controls
Quite easy to install
What negatives must you be aware of?
Not the best warranty
A bit bigger and chunkier than other models
Titan N-120 Tankless Water Heater – Most Compact
Flow rate: 1 – 4 GPM
Temperature range: not specified
Dimensions: 13.8 x 9.8 x 4.8 inches
Warranty: 10-year limited
Extra features: energy-saving – 60% savings compared to conventional heaters; 99.5% efficient; suitable for all types of water, including well water
And now we have the Titan N-120 Tankless Water Heater. An efficient and reliable heater, this one comes with a 10-year limited warranty, which is one of the best and longest warranties of any tankless water heater. It also offers major savings of up to 60% on your utility bills when compared to conventional water heaters, so if you want to start paying less for hot water, this is a good option to choose.
The maximum flow rate of the Titan N-120 Tankless Water Heater makes it a good option for small to medium homes, and it’s important not to push it too far, as it won’t be able to handle too much hot water demand all at once. One bonus of this model, however, is that it can work flawlessly with all types of water, including well water, so if you do have a residential well installed and want a good heater, the Titan N-120 Tankless Water Heater could be a great choice.
The Titan N-120 Tankless Water Heater is also a very compact and convenient heater, about the size of a phone book. It isn’t too difficult to install, but we do still recommend that you get a professional to help you when fitting this one. Some users have reported that the company’s warranty policy doesn’t always apply unless a licensed professional has been involved in the installation.
What makes it stand out?
Strong efficiency rating
Works with all kinds of water
Very compact and convenient
Which disadvantages must you keep in mind?
Needs professional installation
Rheem 240V RTEX-13 – Easiest to Install
Flow rate: 0.4 – 4 GPM
Temperature range: 59 – 140°F
Dimensions: 4 x 9 x 13 inches
Warranty: 5-year limited on heat chamber, 1-year on parts
Extra features: digital LED temperature display; 99.8% energy efficient
Another entry on our list of the best rated electric tankless water heater models is the Rheem 240V RTEX-13. Compact and stylish, this heater really looks the part and is very easy to install and use on a day to day basis. It comes with an attractive, digital display to show you exactly what temperature the device is set to and make your adjustments accordingly, and it’s small enough to save a lot of space in your home as well.
The Rheem 240V RTEX-13 also stands out as one of the most energy efficient water heaters around. It can offer an energy efficiency rating of 99.8% in total, helping you save huge amounts of cash in the long term. You’ll also get precise temperature controls with the Rheem 240V RTEX-13, able to adjust the temperature up and down by a single degree each time, and this heater comes with one of the widest temperature ranges too.
The flow rate and design of this tankless water heater means that it’s only really good for small homes. Most of the positive user reviews for the Rheem 240V RTEX-13 are from people living in cabins, apartments, and small homes in general, so if you have a larger space, you’ll need to choose something with a higher maximum flow rate. The Rheem 240V RTEX-13 also has quite a high asking price when compared to some other models.
What are its best features?
Highly energy efficient
Very easy to install
Attractive digital display
Large temperature range
What could be improved?
Only for small homes
Not the cheapest
Marey Power Pak Plus – Budget Pick
Flow rate: 0.66 – 1.9 GPM
Temperature range: not specified
Dimensions: 4.8 x 11.1 x 10.2 inches
Warranty: 1-year replacement parts and labor
Extra features: filter on water inlet to prevent damage from sediments; saves up to 60% on electricity bills
Last but not least, we come to the Marey Power Pak Plus, which is our Budget Pick for this list of the best electric tankless water heaters. Many people tend to assume that electric on-demand water heaters are quite expensive, but this model is very affordable, so can appeal to those with smaller budgets or people who don’t need high flow rates. If you’re looking for the best electric tankless water heater for RV usage, for example, this could be a great choice.
The Marey Power Pak Plus is a very small heater and it’s quite a basic model too. It has quite a low maximum flow rate, so it can’t handle medium or large homes, but could work perfectly well in a smaller living space like an RV or an apartment. It doesn’t have a great warranty either, but aside from these simple flaws, it’s a great model.
The Marey Power Pak Plus can offer big savings on your utility bills, providing up to 60% more energy efficiency than a regular tank heater. It also comes with a built-in filter to clear out sediment and help preserve and protect the heater for longer. This means it’s one of the most durable and long-lasting models on our list, so you can rely on it for years to come without any problems.
Why did it make our list?
Can offer big savings
Available at a great price
Comes with a built-in filter
Durable and long lasting
Very compact and convenient
What is not ideal about it?
Basic budget model
Not strong enough for larger homes
Things to Consider
You’ve seen some of the best electric tankless water heaters money can buy, so now let’s take a closer look at how to choose the right one. There are lots of reasons why you might want to buy a tankless heater and many different models and features to think about. Read through our full electric tankless water heater buying guide to find out more.
Advantages of getting an electric tankless water heater
There are a lot of different advantages to investing in an electric tankless water heater. Here are just a few of them:
Save Money – The number one advantage to having an electric tankless water heater is the amount of money it can save you in the long term. The initial costs can be high, but over time, the lower utility bills caused by this kind of heater will start to show their value, and the best heaters, like the Stiebel Eltron 29 Plus Tempra, can save you a sizeable amount of cash.
Constant Hot Water – Another of the biggest advantages of these kinds of heaters is the fact that they’re able to provide non-stop hot water. With a tank, you only have the hot water in the tank to use, and then you have to wait for more water to be heated up. With a tankless heater, the flow is constant.
Easy Installation – Tankless water heaters tend to be much easier to install than tank heaters. Not only are they smaller and simpler, but they can simply be mounted onto the wall and then connected to the plumbing and electric. You can usually simply follow a step by step guide to install them, or ask a professional for help.
Save Space – Naturally, a tankless heater is way smaller than having a big water tank around, so they take up far less room. They tend to be about a third of the size of a typical tank heater, so that gives you more options in terms of installation, and they don’t even need to have any ventilation either.
More Durable – Electric tankless water heaters tend to be more durable and longer-lasting than traditional tank heaters too. This is because tank heaters can start to degrade over time, especially in areas with hard water, whereas modern electric tankless heaters are built to last and have less exposure to eroding elements.
Features to consider when choosing an electric water heater
There are a lot of different features to think about when shopping for your next electric water heater. Let’s take a closer look at each feature and see why it matters and how important it might be for you.
A very important feature of any electric heater is its flow rate. The ‘activation flow rate’ tells you the minimum flow rate needed to actually turn the unit on, while the ‘maximum flow rate’ lets you know how much hot water it can disperse at any one time. Households that need lots of hot water will want to seek out tankless heaters with high flow rates, like the Rheem 240V RTEX-18.
The temperature range of a tankless water heater tells you the maximum and minimum temperatures of water it can offer. The wider the range, the more flexible the heater is, and some of the best tankless electric hot water heater models have very wide ranges, like the Rheem 240V RTEX-13.
The temperature controls of your electric tankless water heater are what allow you to adjust the temperature and get it just right for you and the other members of your household. Some heaters will feature manual controls, while others will offer digital displays. Digital controls tend to be better and are more modern overall. Another thing to think about is what kind of increments the controls offer. Some will allow you to be very precise, adjusting temperatures by a single degree in order to get the exact temperature you crave, while others are a little less accurate with their increments. For the most part, digital temperature controls tend to provide this 1-degree precision.
Energy consumption and efficiency
One of the main reasons so many people choose to switch to electric tankless water heaters is to save money and reduce their energy consumption. So, if this factor matters most to you, choosing a model with a strong energy efficiency rating is very important. Some heaters are much more efficient than others, consuming less energy, being kinder to both the environment and your bank account, but you still need to make sure you’re choosing a heater with enough power to supply the right levels of heat to your property. To save electric energy you can always choose a gas tankless water heater.
Where will you be installing it?
When buying a water heater, the first thing to do is think about where you’re going to install it. In most cases, the unit will need to be mounted on a wall, and then connected to the water source, before being hooked up electrically. You need to make sure that you choose an area with enough space for the model you want to install. Be sure to measure out the space in your home accordingly and check the dimensions of the heater you want to buy, checking that the measurements are just right before actually buying your heater. These heaters can be really small, like the Marey Power Pak Plus, for example.
The installation of a tankless water heater can be quite simple, but this will depend on the model you buy. If you don’t want to worry about having to pay an electrician or plumber to help you out, choosing a heater with simple installation can be a great idea. You also need to think about where you’re going to install it, checking that you have enough space, making sure you have the right tools for the job, and ensuring that you have the right connections to suit the heater you choose.
When investing in something as important as a water heater, it’s important to have some kind of protection on your purchase in case anything goes wrong. This is why it’s important to take a look at what kind of warranty the manufacturer offers for their heaters. Many modern electric tankless water heaters are designed with durability in mind, able to last for more than two decades with minimal problems, but it’s still good to have a long warranty, as seen on the Titan N-120 Tankless Water Heater, providing peace of mind for you and potentially saving you a lot of money if anything goes wrong.
This really depends on the model you buy and your own DIY abilities and experience. Many electric tankless water heaters are designed to be quite easy to install, but you’ll still need the necessary skills to do so. Installation of these units includes both plumbing and electrical work. If you have experience in these fields, you can install the heaters yourself, and the whole process can be done in just a few hours or less. However, if you don’t have the necessary experience or just want to have total peace of mind, getting a professional plumber and/or professional electrician to help is a good idea.
The average life expectancy of a tankless water heater really depends on how much you use it, as well as the quality of the model itself and the kind of water you have. In general, a good quality heater can last for up to 25 years, and many make it to around 20 years with regular maintenance, cleaning, and checks. One of the advantages of an electric tankless water heater is that the technology is much more durable and has proven highly effective all around the world, made from strong materials that can resist wear and tear over time.
In the vast majority of cases, people will notice significant improvements in terms of the amount of money they’re spending on monthly or annual utility bills with a good quality heater like the EcoSmart ECO 27. Various factors will influence the amount of money you save, however. For example, if you take long showers and use lots of hot water, your savings will be minimal. So if you really want to get the best value out of your water heater, you should try to follow smart water and energy-saving practices like short showers and not leaving the water running unnecessarily. Generally, manufacturers of these devices claim savings of up to 60% on average, but this varies depending on where you live, how much your energy generally costs, and your habits.
Overall, our top-rated electric tankless water heater is the Stiebel Eltron 29 Plus Tempra. With its Advanced Water Control and savings monitor, this water heater stands out from the crowd as one of the most fully-featured models on the market today. It’s strong, reliable, and nice to look at too.
Our second best electric tankless water heater is the EcoSmart ECO 27. Perfect for energy saving, this heater can really work some miracles on your utility bills, saving you a lot of money on hot water in the long run and providing to be a sound investment.
Finally, our third favorite electric water heater is the Rheem 240V RTEX-18. Big and powerful, this tankless water heater is the perfect option for busy households and large families that tend to use high amounts of hot water throughout an average day.