Looking to replace a tank style hot water heater and lower your electricity bill at the same time?
An electric tankless water heater could be the solution to your water heating needs, but you need to make sure you have the right one. Different models serve different needs.
Instead of thinking about which one is the best, you have to consider if it is the best choice for what you need it to do.
In this article, I will go over the top 5 electric tankless water heaters for different categories so you can decide which one is going to solve your particular problem.
After the list of reviews, keep reading for the buyer’s guide that explains in detail what you need to look for.
You can see how they stack up head to head in this comparison table below if you don’t have time to read the whole article. Otherwise, keep reading for more details.
Amperage draw: 3 x 50 A 3 x 44 A
Amp 12A/Volts 120
Thermal efficiency is 98%
113 A amperage draw
Self-modulating heat sensor
Resists hard water
In this article:
- How I rated them
- What to look for
- Best Whole House Model – Stiebel Eltron 36 Plus Tempra Review
- Best Point of Use Electric Tankless Water Heater: Bosch Tronic 3000 T ES8
- Most Accurate Electric Tankless – Ecosmart ECO 27 Review
- Best For Small Apartment – Rheem RTEX-13 240V Review
- Best Cheap Electric Tankless – Marey ECO150 Review
- FAQ About Electric Tankless Water Heaters
- Benefits of an electric tankless water heater
- Wrapping it up
How I rated them
The following list comprises the top brands in the electric tankless water heater arena.
There are dozens of different ones to choose from but the ones in this best of list are dependable, easy to install and offer great warranties.
What to look for
To understand which inline on demand water heater is going to work best, you need to consider a few criteria. Then read the list to see which one ticks most of the boxes that you need.
GPM are the Gallons Per minute that you will get from your electric tankless water heater. Remember, you can’t think in terms of capacity as there is no storage tank. You have to think in terms of water flow at any one time. In other words, how many fixtures will you be using at once.
There are a few factors that go into how many GPM you need to cover so read the detailed guide on how to size a tankless water heater first and then circle back here once you understand what you need. It even has a handy calculator for you to determine your GPM.
In a nutshell, your incoming water temperature and the type of fixtures you use at once will determine your ideal GPM. If you need to have a shower running at the same time as your dishwasher, then that will impact your ideal GPM.
Amperage, voltage and watts
The second most important aspect is how much electricity it will draw. You need to make sure that your system can handle the tankless heater kicking on while other appliances are working. If you don’t have this right then you will be tripping circuit breakers every time you use your hot water.
Many newer houses will be fine, but you may need to retrofit an old house with an old circuit breaker.
Pay close attention to the minimum circuit breaker required.
All of the on demand electric water heaters on this list are as energy efficient as they come. They can save you up to 30% on your electric bill as there is very little heat loss. The range to look for is no less than 85% efficiency ratings to see that kind of saving on your bill.
The physical size of the unit is something to consider if you are limited in space. The benefit of an electric tankless over gas is that they are much smaller and you have more options on where to install, but the size still is a consideration.
If you only need endless hot water at one fixture, then check out the reviews of the point of use tankless water heaters instead as those are more geared to your needs.
Best Whole House Model – Stiebel Eltron 36 Plus Tempra Review
- 8 GPM for 30°F Temperature Rise
- No Venting Needed
- Takes Up Very Little Space
- Advanced Flow Control for High Water Demand
- Auto Modulation Saves up to 30% Energy Costs
- Expensive installation should only be done by a professional
There aren’t many electric tankless water heaters for the whole house that can actually supply enough GPM for multiple fixtures.
The exception being the Stiebel Eltron 36 Tempra.
With a very generous 8 GPM you can run a shower, faucet and even a washing machine at the same time.
It offers constant temperature output so it will always deliver hot water at the set temperature even if you are going beyond your GPM. It will slow down the water flow so you don’t end up taking a lukewarm shower if you have too many fixtures going at once.
And to save on electricity, it uses Advanced Water Flow Control to use only as much energy as needed to get the water to the correct temperature.
Made in Germany with the kind of engineering you would expect from Germans, this Stiebel Eltron Tempra 36 Plus is the top rated tankless electric water heater for the whole house.
If you live in a warm area, your energy costs will be lower, you will enjoy a steady stream of endless hot water and will take up very little space.
For the price, it just makes sense to go with Stiebel when your water demands are high.
- 19 pounds
- 21.7 x 20.1 x 9.6 inches
- 86°F to 140°F Temperature Range
- Min. required breaker(s): 3 x 50 A DP
- 0.77 GPM Minimum Water Flow Trigger
- Wire Size: 3 x 6/2 AWG
Best Point of Use Electric Tankless Water Heater: Bosch Tronic 3000 T ES8
- 1.8 Gallons Per Minute Flow Rate
- Can be installed under a sink or in a closet for Point of Use applications
- 98% thermal efficiency rated
- Advanced Flow Control for High Water Demand
- 145°F maximum temperature
- Hard wired so must be professionally installed
When you are limited on space, the Bosch Tronic 3000 is ideal as it is smaller than a shoe box and still gets you 1.8GPM. This is usually enough for one normal fixture or two low flow fixtures.
I highly recommend this for use in an RV or a cabin. In fact, it is affordable enough that you could have several in your house and eliminate the need for a whole house model.
It has a thermal efficiency of 98% so almost all of the energy used is to heat the water without only a tiny bit going towards heat loss. You’ll see considerable savings on your water bill.
For the price, size and efficiency, this is a home run. It is backed by a trusted brand in Bosch and offers a good 6 year warranty. It can be installed easily under a sink in no time at all as long as you are comfortable hard wiring it to the breaker.
The only downside is that the GPM may not be enough for more than one fixture if you don’t use low flow.
- 29.5 pounds
- 17.5 x 17.5 x 14.5 inches
- 1440 Watts heating capacity
- 65 – 145°F temperature range
- Min. Required Circuit Breaker Amperage: 50
- Wire Size: 6 AWG
- ¾” Male NPT water fittings
Most Accurate Electric Tankless – Ecosmart ECO 27 Review
- 6.6 GPM water flow rate with 30°F temperature rise
- Digital temperature control in 1° increments
- 90% smaller than similar units
- Copper and stainless steel components for efficiency and longevity
- Saves up to 50% on energy costs
- Installation can be expensive due to the cost of the wires and breakers needed
With savings of up to 50% off of your electric bill, it is no surprise that the Ecosmart ECO 27 is one of the most popular electric tankless on the market today.
The temperature can be adjusted in 1°F increments up to 140°F. That combined with the self modulating mode means that you never have to use more energy than necessary to get the temperature that is perfect for you.
The size makes it seem like it won’t be able to keep up with the demand, but the truth is that it is ideal for a medium sized household with two bathrooms. It fits under a sink making it perfect for an apartment.
For those with a medium sized, single family house, then this is the best electric tankless water heater. It gets the job done and saves money.
There is a lot to love with this endless hot water heater. So much so that if you have a bigger house with high demand for water, then I would recommend putting two of these in so you can run multiple points at the same time. It also helps to have each one close to the point of use, too.
- 14.7 pounds
- 17″ x 17″ x 3.625″
- 0.3 GPM flow rate activation trigger
- 113 A amperage draw
- Min Required Breaker: (3) 40 DP
Best For Small Apartment – Rheem RTEX-13 240V Review
- Super easy to install without a professional
- Gets 4 GPM flow rate
- Takes up a small amount of space
- Great for studio apartments or guest bathrooms
- Max temperature of 140°F
- Flow rate slows down when water demand is high
At 99.8% efficient, it is as energy saving as possible. Many people report seeing over 30% reduction on their electric bill after installing this.
If you have low hot water demand, then this small electric tankless water heater is ideal. Small apartments that need to have two fixtures working at once will still get good GPM.
Like the other units reviewed here, it has a self modulating mode to adjust the energy needed to get the temperature right. And the water flow rate will slow slightly if your water demand is too high at one time so you don’t lose temperature.
This is an excellent on demand hot water heater that is efficient, small and economical. It will last quite a few years with a 5 year warranty to back it up. It should pay for itself within the first year of use.
That said, it is not for every household.
High water demand houses or ones that are in colder Northern climate, then you should consider a bigger whole house on demand water heater. If you need a bigger one, then take a look at the RTEX-24 by clicking the link.
- 8.5 pounds
- 4 x 9 x 13 inches
- 13 KW
- Required Breaker: 60 Amp
- Wire Size: 6 AWG
- Copper immersion heating elements
Best Cheap Electric Tankless – Marey ECO150 Review
- Very cheap price
- Up to 3.5 GPM with 30°F temperature rise
- Resists hard water and corrosion
- 0.5 GPM low flow trigger
- Easy to read LCD screen
- Very easy installation
- Very low GPM in colder climates
Sometimes you get more than you pay for.
When your hot water needs are not that high, you shouldn’t have to spend a lot for a great tankless water heater. The ECO150 is just the ticket since it is a great budget tankless heater for small homes.
Though if you do need more GPM and don’t want to spend as much as the Stiebel, you can go with the ECO 36.
Though the ECO150 doesn’t have the bells and whistles of the other units reviewed on this list, it does a great job at delivering the hot water you need with great efficiency.
This is a pretty straightforward affair. If you want to save money and still get a decent gallon per minute water flow rate, then don’t look any further.
A 5 year warranty will give you peace of mind that you made a good purchase.
- 8.7 x 3.5 x 14.2 inches
- 10.1 pounds
- Requires double pole 70amp breaker
- Requires 6 AWG wire
FAQ About Electric Tankless Water Heaters
No. The beauty of these electric on demand water heaters is that the installation is very easy as they have no exhaust and don’t need to be vented to the outside.
Yes. You should be flushing your tankless water heater at least once a year to keep it running properly. Minerals in the incoming water build up on the heat exchanger and will lower the efficiency. Too much build up and it will stop working eventually.
Yes and no. They are very efficient and will save you money on your electric bill, but you don’t get nearly as much GPM from an electric like you do with gas. Read my review of the best gas tankless here if you need a bigger tankless.
This is highly dependent on where you live and how much needs to be done for the installation. If you need a new circuit breaker box then expect to pay over $1,000 but if it only requires a simple hard wiring under a sink then it should cost less than $800.
Benefits of an electric tankless water heater
There are several great reasons to install an electric tankless water heater. Take a look below
The size of the electric tankless heater is small enough to be installed just about anywhere. Under the sink, in a closet or laundry room are all possibilities. Because of this, you can get your tankless heater close to the point of use which saves on labor and the cost of the pipes.
Not only that, but they don’t need to be vented so that also saves a ton of money.
Of all the types of tankless water heaters, the electric ones are the least expensive. In fact, you can buy two or three for your whole house for less than the cost of a single gas version in some cases.
Faster hot water
Though it actually takes a little bit longer for an electric heat exchanger to get the water to the correct temperature than gas ones, you end up getting the hot water to the fixture faster.
this is because the small size allows you to place the unit closer to the fixtures where you need it. A whole house tankless heater can be quite far from the furthest fixture and take up to a minute to get the hot water there.
An electric usually only needs to get the hot water a few feet to the fixture so you get hot water in seconds.
Wrapping it up
The best electric tankless water heater is the one that fits your needs best. That’s why I didn’t single any one of these over another since they all serve different purposes.
They are great for ease of use, cost effectiveness and easy installation. If you live in the South or have a small household with low water demands then I definitely think this is the way to go.
If you have any questions about any of the best electric tankless water heaters on this list then drop a line in the box below and I will get right back to you!