The Best Under Sink Tankless Water Heater 120v - E-Trine

The Best Under Sink Tankless Water Heater 120v
Product Reviews Tankless Water Heaters
814 Views 0 June 12, 2019

Water heaters have certainly become a must in every home. That’s why engineers and scientists are working hard on making newer and even handier models of water heaters to fit our needs. They are getting smaller, more compact and way more energy-efficient.

Under sink tankless water heater, or mini-tank, is probably the smallest of them all. It can fit under a sink, obviously, or under a counter, as well. Many users are opting for this kind of electric water heater because of its convenient size. It can fit anywhere – from an RV to the garage or kitchen.

In this article, we listed our top 3 picks for the best under sink tankless water heater 120V. Also, you’ll be able to read a bit about tankless water heaters in general, in order to understand why they are the best choice.

EcoSmart ECO 11
EcoSmart ECO 11
1.5 gallons per minute6.5 x 13.5 x 10 inches
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Stiebel Eltron DHC 3-1
Stiebel Eltron DHC 3-1
0.5 gallons per minute18.9 x 7.9 x 14.2 inches
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Bosch ES2.5
Bosch ES2.5
2.7 gallons per minute14 x 10.8 x 14 inches
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Best 120v Under Sink Tankless Water Heaters

EcoSmart ECO 11 Electric Tankless Water Heater, 13KW – The Best Under Sink Tankless Water Heater

EcoSmart ECO 11

After reading the specifications of this amazing water heater model, you will agree that it deserves the number one spot as the best under sink tankless water heater 120V.

Just like the Stiebel Eltron DHC 3-1, ECO 11 has the self-modulating feature. You can choose how much energy will be spent at any given time.

ECO 11 is also very modern looking and utilizes the latest technology. There’s a thermostat knob that you use to set the temperature you want. It will be displayed on a small digital monitor above. That is a simple addition that actually makes the job easier.

This model is also very small and light in weight. It’s by far the smallest on our list. It weighs only 6.5 pounds and is 6.5 x 13.5 x 10 inches in size. Its size enables you to fit it almost anywhere you want without having to change anything.EcoSmart Sizing

Another fantastic thing about this water heater is that it works well in any climate conditions. It doesn’t matter if it receives hot or cold water. However, the flow will be a bit lower in colder climates. But still, you will get hot water anyway. This is a rather insignificant flaw considering most water heaters usually can’t even operate with cold water.

User reviews of this tankless water heater are almost consistently positive. Out of the three water heaters presented in this article, ECO 11 takes the cake in all the categories. That’s why it’s our number one pick as the best point of use water heater.



  • Works well in any climate conditions
  • Small and lightweight
  • Utilizes modern technology



  • Low flow in colder climates


Stiebel Eltron DHC 3-1 Electric Tankless Water Heater, 120V – The Most Energy-Efficient

Stiebel Eltron DHC 3-1

Stiebel Eltron is an American company that uses German engineering. They are known for their quality water heaters. And DNC 3-1 is no different.  

The whole point of Stiebel Eltron’s DHC series is to create the most energy-efficient boilers. They are designed to recycle water, so it’s not thrown away. Also, these are said to use 50% less energy than other water heaters.

The DHC 3-1 is a 120V point-of-use water heater that can be used for both residential and commercial areas. In other words, they are suitable for both kitchens and bathrooms, as well as mall restrooms, office kitchens, etc.

This model uses copper heating, which leads to a smoother and more seamless performance. Water heaters with copper structures have a longer lifespan, and they are less likely to break or stop working.

Another interesting thing about DHC is that it has both manual controls and automatic flow controls. So, basically, you can choose the temperature yourself, but the automatic part will control the water flow. That is a great feature that will stop you from wasting precious water. This way you also save money and energy.

This under sink hot water dispenser is currently one of the best on the market. Its advanced technology is what makes it stand out from the rest.



  • Flow reduction control
  • Energy-efficient
  • Lightweight
  • Resistant to corrosion



  • Limited 3-year warranty
  • Works better in warmer areas
  • Too slow sometimes


Bosch ES2.5-Point-Of-Use Electric Mini-Tank Water Heater, 2.7-Gallon – The Best-Seller

Bosch ES2.5

All the Bosch point-of-use water heaters from the 3000T series are highly appreciated by users. There are many reviews on the Internet, which I recommend you check out.

This Bosch under sink water heater is the best of the best. It comes in three sizes – small, medium and large. Also, you can place it anywhere you want – hang it on the wall, put it under a sink… Really, anything at all. This model is ideal for smaller living spaces such as RVs and boats.

One heater will be able to support only one sink area. But that’s completely reasonable considering its size. Hot water lasts for a few minutes at most, but there’s no need for more water since it’s a sink water heater.

Just connect it to the main water line near the sink, and it’s ready to use whenever you please. Another great thing about this Bosch point-of-use water heater is that it can be an addition to a big tank water heater. Install the ES2.5 and connect it to the bigger water heater to have even better flow and faster heating.

It’s really no wonder that this model is one of the top-sellers in the industry. That’s why it gets a respective third place on our ‘best under sink tankless water heater’ list.



  • Modern design
  • Suitable for many small places
  • Warms water fast
  • Easy to install



  • Hot water doesn’t last long
  • Occasional leakage problems


Buying Guide

Why Tankless Water Heaters Are the Way to Go

‘Tankless’ is a word that has been mentioned more than a couple of times in this article. So, it would be nice to know what it actually means, wouldn’t it?

Jokes aside, it is important to know what you are buying and why you’re buying it.

Tankless water heaters, as opposed to conventional storage water heaters, heat the water ‘on demand’ rather than storing it in a tank. Tankless boilers are much more popular than conventional ones because of their sheer practicality. They are smaller, faster, and they cost much less overall.

Because they heat water ‘on demand’ and not all the time, they are much more energy-efficient. Tankless water heaters can certainly help you save some money.

Sometimes the issue with tankless water heaters can be their low flow. However, it’s a common practice to have a couple of tankless water heaters around the house. That way, nobody will run out of hot water.

Point of Use Water Heaters

Point of use heaters (or POU) are the most energy and water-efficient types of water heaters.

under sink tankless water heater 120v

When you’re using other types of water heaters, some of the heat can dissipate in the system while it’s traveling from the central heater to the sink. But you can prevent this by installing a point of use water heater system.

Installing this kind of water heater is a bit challenging, so it’s recommended that you do so when you’re building from scratch or changing the piping system. It does pay off, however. You will surely notice the difference over time and realize that water heaters are really economical.

Final Verdict

Although Bosch’s ES2.5 and Stiebel Eltron’s DHC 3-1 are both astounding water heaters, the first place has to go to EcoSmart’s ECO 11. Let’s compare them a bit.

When it comes to the utilization of newer technologies and modern design, all three are pretty tied. But ECO 11’s modulation knob is what sets it apart from the others. This feature is truly unique. It looks great, too.

Now, DHC 3-1 has the copper heating which makes it more resistant to corrosion, which is great. But it’s still not enough for it to be the winner!

ECO 11 works with any climate, whereas the other two don’t. Or they do, but the flow is just too low, and then they are useless. This advantage that ECO 11 has over other heaters is crucial for some users.

To sum up, ECO11 basically has everything that you might want in an under sink tankless water heater 120v.

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