When planning a home renovation, upgrading your cabin or cottage or simply replacing a hot water heater, many Americans are making the switch from a traditional hot water tank to a point of use / on-demand electric tankless water heater. There are several benefits to using electric tankless water heaters; among them include monthly electricity savings, cheaper up-front costs as well as ease of installation.
In general, electric tankless water heaters are used under a sink or for single appliance use. If you need a tankless water heater for your whole home, we recommend looking at a gas powered unit.
Electric Tankless Water Heaters: Buying Considerations
There are several factors that need to be considered before you purchase an electric tankless water heater, which we’ve outlined below.
Incoming Water Temperature
Electric water heaters work best when they don’t need to raise the temperature more than 30F. Even the most powerful units aren’t capable of producing a temperature rise of 50F with any reasonable flow rate. If you live in the Northern United States or Canada, you may want to consider buying a hot water tank, or opting for a gas powered unit that is capable of a higher temperature rise. If you live in the Southern United States or plan to use the heater during spring and summer months, an electric unit can be the perfect choice.
Flow Rate Needs
Different appliances and faucets require different amounts of water. For example, a bathroom sink will use far less hot water than a washing machine or a dishwasher. Electric tankless water heaters will be rated in terms of their flow rates, and it’s an important factor when deciding which unit to buy. In general, the higher the flow rate, the more expensive the unit and the more electricity it will use.
|Bathroom Sink||0.5 GPM|
|Standard Shower||2.5 GPM|
|Low-Flow Shower||1.5 GPM|
|Washing Machine||1.5 GPM|
|Kitchen Sink||0.5 GPM|
|Laundry Sink||1.0 GPM|
These water heaters come in a variety of sizes, and it’s important that you measure the space you plan to install the unit before you purchase. In especially tight spaces such as under a kitchen or bathroom sink, you may need to opt for a smaller unit to preserve space.
Most traditional tankless water heaters use metal materials that will build up limescale and require annual maintenance. However, there are newer technologies being used, such as infrared, that build up much less scale and require less maintenance, but for a higher price and generally smaller flow rates. Depending on how hard the incoming water is, you may want to opt for an infrared unit that will require far less maintenance and won’t be likely to break down.
Electric Tankless Water Heater Comparison Chart
|Name||Our Rating||GPM||View Price|
|Stiebel Eltron Tempra Plus||4.8||4.0||View Price|
|EcoSmart ECO||4.7||3.5||View Price|
|Rheem RTEX-18||4.5||3.0||View Price|
|SioGreen IR8000||4.5||3.0||View Price|
|Bosch Electric Tankless||4.2||2.0||View Price|
Electric Tankless Water Heater Reviews
The following units are our top reviews of the best electric tankless water heaters in each category.
Our Top Pick: Stiebel Eltron Tempra Plus
Stiebel Eltron’s flagship product, the Tempra Plus, is widely recognized as the very best electric tankless water heater in the market today. With one of the highest GPM flow rates available at 4.0 GPM with the ability to raise the temperature 50F. This is by a wide margin, the best performance you can expect from an electric tankless water heater.
We also love that even though this unit is the most powerful you can find, it is not much more expensive than a unit half it’s price. And that makes it all the worth while when paired with the advanced flow control, which we’ll explain.
The Tempra Plus is one of the only units to also have advanced flow control, so you can limit the amount of flow when it’s not required, resulting in even more energy savings. Think of it as Eco Mode for your water heater. For more information on advanced flow control, have a look at this short video:
While this unit is the most powerful you will find in electric tankless, it is not powerful enough to provide hot water to an entire home. We would recommend installing a unit in each room that requires hot water. It is powerful enough to run a shower and a bathroom sink; a washing machine and laundry sink or a dishwasher and a kitchen sink.
The bottom line: If you want the best electric tankless water heater available, and don’t mind spending a few extra bucks, this is the unit for you.
Close Second: EcoSmart ECO
A close second for the best electric tankless water heater is the EcoSmart ECO. The top model (Eco 36) has one of the best GPM flow rates available at an impressive 3.5 GPM with a temperature rise of 40F. While not as powerful as the Tempra Plus, this unit is generally sufficient to provide hot water to an entire room, such as a kitchen, bathroom or laundry room.
If you are looking to power your entire house with the EcoSmart ECO line, you will need to purchase several units, ideally one for each room.
As you’ll see with the rest of the tankless water heaters, both the EcoSmart ECO and the Tempra Plus are in their own class. Their performance is roughly similar and sufficient for any’s room needs. What we prefer about the EcoSmart is the design, it is the clear winner in terms of visual appearance. If you need to place this in a laundry room, it will have an elegant and modern feel even if the water heater is exposed.
If you want an in-depth review of the product, check out this great video that shows how to install it, power consumption, water temperatures and more of the Eco 27 Unit.
The bottom line: If you want a powerful and beautiful electric tankless water heater, this is the unit for you.
Best Value: Rheem RTEX-18
Rheem continues to be an industry leader in hot water heaters, from commerical grade tanks to residential electric tankless. Their top electric model, the Rheem RTEX-18 offers some of the best value in water heating. Notwithstanding the peace of mind you get when buying from a company that has been around for decades, but you get most of the features available from premium models at a lower price. Usually the premium brand costs more, but in electric tankless water heating you can get the big brand for less.
Rheem claims this unit can provide 4.4 GPM of hot water flow, but in real world tests with cold incoming water, we have found 3.0 – 3.5 GPM is more reasonable to expect. Of course, 3.5 GPM is a sufficient flow rate to power the hot water needs of mostly any room in the house.
The challenge we have with this unit are the large dimensions, meaning it may take up too much space under a sink. In addition, it isn’t the most visually appealing unit either. For many people, these might not be factors they are concerned with if you have lots of hidden space to place the unit.
The bottom line: If you want good value and a good brand for an affordable price, this unit is for you.
Best Infrared: SioGreen IR8000
If you live in an area with particularly hard water, or are looking for a water heater for an RV or tiny home, you should consider the SioGreen IR8000. This electric tankless water heater was made with non-metallic materials, meaning limescale doesn’t build up on the unit. This is one of the only heaters in the market that doesn’t require any maintenance thanks to this innovative technology.
Of course, this tremendous advantage is not without it’s downside. The SioGreen IR8000 isn’t capable of very high flow rates at a 50F temperature rise. It is definitely best suited in late spring to early autumn or in warm climates that don’t require a high temperature rise.
Infrared technology in tankless water heating is a relatively new technology and we expect to see improvements over the coming years as the maintenance aspect of going tankless can be an issue for many people.
It is also worth noting that this water heater is visually appealing and looks as high tech as it is. This water heater is advertised as a whole house water heater, but we think you’d be disappointing with a single unit for an entire house.
The bottom line: If you don’t want to bother with annual maintenance and don’t require a lot of power, this unit is for you.
Most Affordable: Bosch Electric Tankless
Rounding out our list of the best electric tankless water heaters is the Bosch Electric Tankless. A compact, highly efficient unit that uses very little energy and backed by a premium brand may be exactly what you need if you have very modest water heating needs.
If you looking for a simple water heater to install in your summertime cabin or cottage for a small bathroom, this is the perfect water heater. For less than $200, you can enjoy hot water just like at home!
It would also be suitable for providing hot water to a sink. Anything more than that this will prove to be insufficient; that said, there is no need to spend a lot of money on a water heater if your needs are modest.
The bottom line: If you want a small, simple and affordable water heater for the summertime, this is the perfect unit for you.
Buying an electric tankless water heater is a much simpler task than going with a gas powered, whole house water heater. Depending on the appliances to be used with the water heater, you will purchase the adequate size for your needs. The main factors are the incoming water temperature (the colder it is, the more power you need) and the flow rates you require.
Despite what all the manufacturers say, there is no electric tankless water heater that can adequately provide hot water to an entire house, especially if you don’t live in the south. We highly recommend that you install a seperate water heater in each room that requires hot water.
You can also extend the life of your water heater by purchasing a whole house water water filter at the source.