Best Electric Tankless Water Heater Reviews 2020

Electric Tankless water heaters that run on electricity are the most affordable option for homeowners looking to retrofit their system.

Just as with gas-powered models, electric systems will save lots of money on your energy bills, and give you constant hot water on demand without the limitations of a tank!

Whether you live alone in a studio apartment or in a bustling household with many bathrooms, there are tankless electric water heaters to suit any application!

As your tankless plumbing experts, we’ve done the research to help you find your perfect unit! We’ve come up with a list of great models, sorting them into top sellers, highest overall quality, and the best value models. Keep reading to find the right one for you.

Best Electric Tankless Water Heater Reviews

This is the complete list of all the best electric tankless water heater

Stiebel Eltron 36 Plus Tempra, Tankless Water Heater

Imported from Germany, the Stiebel Eltron Tempra Plus 36 has an innovative design and outstanding build quality. It is an extremely efficient, precise machine, well worth a larger price tag in the long run. This one is a great choice for a larger household (two or three bathrooms) with high demand for hot water.


It’s a very smart design. The Tempra will automatically adjust its internal settings to use the exact amount of power required with minimal wasted energy. In times of high use, it will also adjust the water flow, which helps to ensure hot water even in frigid temperatures. Reviewers were thrilled with its performance. Most say it stays absolutely constant, regardless of how many fixtures or appliances you have running.

Some of the other hot water heaters will have a lag or a drop in output when another source requiring hot water (i.e., faucet, dishwasher) is turned on, which can affect your shower temperature. The Tempra 29 Plus will automatically adjust in real time by slightly lowering the water pressure, preventing uncomfortable temperature fluctuations when you’re trying to get clean.

The Tempra’s unique system is so effective that the manufacturer doesn’t even list a maximum flow rate! That makes this one ideal for high-usage applications where you don’t want to have to think about rationing hot water usage. Of course, depending on inlet water temp and total flow rate, the effective temperature rise decreases with higher flow rates (for information, see this chart). The Tempra does a very good job of compensating, but it’s not a miracle worker.

It has a three-year warranty on parts, which is better than most others on the market. Plus, it has the added bonus of being made in Germany, so you can be assured of superior build quality and reliability over other models. The Tempra has an outstanding reputation for long-term, problem-free performance.


At close to $850, the only big downside to this unit is the price, which is on the higher side for tankless electric heaters. This one is priced close to many gas units, though it is more powerful than gas units that cost roughly the same amount.

Some buyers weren’t as impressed by the automatic management system as others. A couple of reviewers thought it didn’t work as well in the cold as the company claimed, and one reviewer noticed a temperature drop with the dishwasher and the shower on at the same time. However, the vast majority of reviewers said the smart controls more than lived up to their expectations.

Overall: This is the best high end electric tankless water heater out there designed for high-demand residential use. This one is the ideal choice for a five-six person house, with the potential to seamlessly run two showers at once, even two high-flow showers. It’s probably overkill for smaller applications, but if you want the absolute best of the best for your smaller house and can afford the Tempra, we have a hard time finding any reasons why you shouldn’t buy this model.

Rheem RTEX 13 Electric Tankless Water Heater

The Rheem RTE 13 has been one of the most popular units on the market. We’ve recommended it ever since we put our first guide together. Now, there’s an updated version, the RTEX 13! It’s just as efficient, rugged, and space-efficient as its predecessor. Plus, the new model adds a digital thermostat with user-friendly controls, as well as even more durable innards!

If you live alone, this is a terrific choice. It would work similarly well for couples or roommates in one bathroom apartments where shower times are staggered. Many folks will also find that it’s a convenient single-room option for a guest suite or washroom.


It has a maximum flow rate of 4 GPM, which is a lot for the price. This one is an ideal choice for a one-shower-at-a-time household, or for homes with dual showers that are equipped with 1.5 GPM (low flow) fixtures.

It’s one of the most compact options out there, and it fits in tight cramped spaces very easily-even in a small cupboard, or above the sink. This unit is “ultra compact,” so it can be installed practically anywhere, which, again, is a nice benefit for smaller residences.

The RTEX 13 is also cheap enough that energy savings will pay for the whole thing fairly quickly into the process–one reviewer claimed that it paid for itself (unit and install cost) in 17 months! That’s one of the best turnover periods out there.

While the previous model didn’t quite live up to Rheem’s legendary reputation for build quality and reliability, this model does! The RTEX13 hasn’t been on the market very long, but it seems much more rugged, and so far has a perfect reliability record!


Reviewers say that the stated flow rate might not live up to expectations in especially cold climates, especially in larger households. That’s true of most tankless water heaters, especially models that don’t have smart management systems in the controls. If you live in a very cold area and are planning to use this for more than one low-flow shower at once, this might not be the best choice for you.

In terms of overall functionality, this unit has a relatively low output rate. You will probably have to limit yourself to one shower at a time if you don’t have low-flow fixtures installed in your bathrooms.


This Rheem is a great choice for smaller households (1-2 people) without a tremendous demand for hot water, or for bigger households willing to do one hot water task at a time. This one is not the best choice for the colder northern climates, though, and it’s not for medium/larger households who don’t like to think about managing hot water usage. If you need a compact solution for small-scale use, though, we don’t think you can do any better!

Ecosmart ECO 27 Electric Tankless Water Heater

The Ecosmart ECO 27 is Ecosmart’s most powerful heater, designed to handle on demand water heating in even the coldest climates. In warm climates, it can supply most fixtures in your home at the same time.

In fact, many buyers used it as their sole water heater for lake houses, cabins, or other vacation properties. And the price is, comparatively, quite reasonable. It’s a good option for medium-size households with more demand or a colder climate to deal with than the Rheem can handle.


Ecosmart claims the ECO 27 can heat 3 GPM in the coldest of inlet water temperatures (37 degrees), and 6 GPM in warmer climates. That’s a great output rating for the price. This one is a great choice for medium-sized households (3-5 people) looking to save money on their electric bill. It’s also a more consistent performer than the Rheem during the colder months.

It has a similar modulating control system to that of the Stiebel. The Ecosmart also adjusts its power usage and pressure settings to keep a consistent output for you. And, as with the Stiebel, that means increased efficiency and increased energy savings on your bill!

Best of all, it has a lifetime warranty on the unit itself, which is by far the best warranty on the market.


One reviewer cautioned against taking Ecosmart’s performance claims at face value, noting that it did not heat sufficiently at 3 GPM in cold inlet temperatures. Most folks found that the unit performed well in colder areas, but some were less impressed that others. It’s always a good idea to check your inlet temperature before you buy, especially if you live at high altitudes or in far northern regions.

Some reviewers reported hassles in qualifying for the lifetime warranty. There’s some fine print, so you’ll have to be careful to register your unit properly and install it according to the manufacturer’s instructions. Buyers also warned of long customer service wait times when they had issues. This one’s not quite as good over the long term as the Tempra.

This unit probably won’t supply enough GPM for larger households (5+ people) with simultaneous shower needs, unless you’re in a warm climate all year round. For most of us, the Tempra is the better choice for high demand. If you’re in a consistently warm spot, you may be able to save some money by opting for the cheaper Ecosmart.


The ECO 27 is largely well-reviewed; even the people with warranty issues note that their units worked well when they were repaired. The ECO 27 is a great choice for most households, especially for those who need a bit more output or climate compensation than the Rheem can manage. As we’ve said, though, it’s not ideal for larger households which regularly run multiple hot water draws at once.