Best Electric Tankless Water Heater 2020 – Reviews & Top Rated

Best Electric Tankless Water Heater

The electric tankless water heater is an advanced product from the traditional tank ones you used to know.

This device has more advanced features that fit  your modern lifestyle, especially saving you a lot of space. 

There are various kinds of this product on the market that may get you confused. Therefore, we provide you with the list of the best electric tankless water heaters in 2020, and hope you can find the suitable one for your family.

Top ​3 electric tankless water heater 2020



​EcoSmart ECO 27

​EcoSmart ECO 36

​Stiebel Eltron Tempra Plus 36 kW

​Editor's Rating:

​4.0 / 5

The ECO 27 Electric Tankless Water Heater is a wonderful device from EcoSmart - a brand from the United State. This brand aims at providing green energy products that are economical and efficient for consumers.

This 13.75 lbs device owns an activation flow of 3.0 GPM, ensuring that you have enough water required for bathing. 

ECO 27 has a unique self-modulating technology that can save  up to 50 percent on water heating cost.

The digital temperature control allows you to adjust the water temperatures up to 1-degree increments. So don’t need to worry if you were burned as the excess temperature needed from water.

Most hot water heating systems operate best in the 67 F degree of water area, so in the cold weather condition, when the water inlet temperature is less than 67, it could lead to poor performance of the tankless water heater.

And such the case happens with ECO 27; the power is rated only 27 KW, so it takes time to heat the cold water.

The fantastic feature we love is the stainless steel covering the burning system. Therefore, the structure can resist hard water (water contains high minerals), thus increasing its durability.

There are many features on this product that can satisfy most of the users, but sadly, the lifetime warranty is limited. So even it’s durable, you should take care of it properly unless you want to spend more money on maintenance and replacement. 

Overall, this product suits people living in warm area best as they don’t need high electric power to heat the warm water.  


  • ​Elegant design
  • ​Stainless steel covered
  • ​Silent heater operation
  • ​50% bill cost saving
  • ​High flow rate


  • ​Limited lifetime warranty
  • ​Not very powerful heating system

​Editor's Rating:

​4.0 / 5

it’s another device coming from Ecosmart company. There are not many differences in the size or technologies between ECO 36 and ECO 27. They both have the electrical saving system, stainless steel covered, etc.

But there still some innovative advances that make ECO 36 have a higher price than ECO 27. First and foremost,it has a lifetime warranty so you can have it repaired if any problem occurs till the rest of your life. 

The flow rate of ECO 36 can reach 6.5 GPM (gallons per minute) in suitable condition, which is higher than that of ECO 27. Big GPM means the device can provide more hot water in a period of time.   

Besides, as the ECO 36 is rated at 36 KW, so it can heat the water faster than ECO 27, which has only 27 KW. For instance, in a cold area, although water can decrease below the 50 F degree, the ECO 36  still is able to deliver up to 3.5 GPM.

The only setback of this product is that the heating process won’t start until the flow rate reaches 0.25 GPM.


  • ​Powerful and fast heating process
  • ​Lifetime warranty
  • ​Silent operation
  • ​50% bill cost saving


  • ​A little expensive
  • ​inelegant designed

If you live in a cold area and you are finding a powerful electric tankless heater with power-saving mode, then the ECO 36 is a suitable product for you.

​Editor's Rating:

​4.4 / 5

Now we come to the last product on this list, which was made from Stiebel - a famous brand from Germany.

The products from Stiebel is famous around the world due to their high quality of materials and durability.

The Tempra Plus 36 kW have a robust flow rate compared with the ECO models. It can reach at 4.0 GPM in water 50 F degree thanks to the wide margin.

This device has a unique feature called advanced flow control, allowing you to limit the amount of water flow when nobody uses. This flow control system can save you a lot of energy as well as water consumption.​

However, this electric tankless water heater has less fantastic functions or efficiency compared to the ECO 27 and ECO 36.

Of course, it has basic features like the digital temperature control that helps you avoid getting excess water temperature. It also can saves you up to 20% of electric cost. .

The burning bar inside made from copper without the stainless steel covered. So you should clean the hot bar annually or the substances in water can make it rust faster.

Although the size of Tempra Plus 36 KW is more compact than the ECO 27, its weight is more substantial than other products in this list.


  • ​High water flow rate
  • ​Powerful heating system
  • ​Compact size
  • ​Advanced flow control system
  • ​0% electric power saving


  • ​No stainless steel covered
  • ​Heavy
  • ​Only 7 years for warranty

​The Stiebel Eltron matches users who need to have a high rate of activation flow for water supply.

Things you should look for in an electric tankless water heater

This buying guide will help you know some critical parts that you should look for in a quality electric tankless water heater.

The maximum flow rate

Take an example; you want to run a hot water faucet simultaneously with a shower, and the total flow rate equals to 4.0 GPM (gallons per minutes). So you have to purchase a device that can provide more than 4.0 GPM.

So before buying a water heater, check the water provided equipment in your house to know what is the flow rate you need.

The temperature rise

For most users, the suitable temperature of the outlet should be around 100 - 120 F degree, so if your product cannot heat the water to the demanded temperature, then it’s a waste of your money.

This situation is not a big deal at a warm place, but in a cold area, the water temperature inlet is about 50 F degree. Therefore, To reach the 100 F degree, the heater must produce enough power to raise the water temperature from inlet quickly.

The warranty

Please read carefully the warranty policy of the water heater you concern about. Many clients have ignored it as they think the tankless water is super durable.

People think right; the tankless water can last longer than a tank water heater as it doesn’t have the water storage. Thus, the tankless heater system would not be deteriorated by hard water.

But we still have to take care of other essential parts inside such as the heat exchanger or the heat bar. So it’s better to have a lifetime warranty.

To Sum Up

In our opinion, the product from EcoSmart is the most effective ones. It’s powerful in heating water but still economical. 

But A Stiebel Eltron Tempra Plus is excellent for a house that needs high water flow rate.

So what about you? What is your best electric tankless water heater? Comment your ideal below. And please share this post if you find it helpful.