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Best Under Sink Tankless Water Heater 120V [Top 7 For 2021]

best under sink tankless water heater 120v

A big leap from the traditional water heaters, the 21st-century water heaters have the great advantage of delivering instant hot water. These heaters save time, energy and money. You do not have to connect long pipes to your kitchen or bathroom from the central water heater; you can plug these in close to your tap and enjoy instant delivery.

Whether it is a bathroom, a sink faucet, a kitchen sink, an office area, an RV or a garage, an under-sink water heater is an ideal option. Due to this, we have compiled reviews of some of the best under sink tankless water heater 120 V on the market alongside a buying guide to aid you in choosing right.

best value

Ecosmart ECO Mini 1
  • Lightweight & Compact
  • Ideal For A Point-Of-Use Application
  • Budget friendly price
  • Design Is Aesthetic


Camplux ME60
  • High Water Storage Capacity
  • 1-year water heater warranty
  • Ergonomic design
  • Hot water readily available

Top 7 Table Of Comparison

ProductFeaturesOur Rating

Bosch Tronic 3000 T
Size: 4 Gallon

Dimensions: 13.75 W x 13.75 H x 13.5 D Inches

Price: $$

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Camplux ME60
Size: 6 Gallon

Dimensions: 15.75 W x 21 H x 15.5 D Inches

Price: $$

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Ariston GL2.5
Size: 2.5 Gallon

Dimensions: 14 W x 14 H x 10.25 D Inches

Price: $$$

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Thermoflow UT10
Size: 2.6 Gallon

Dimensions: 18 H x 12.2 W x 11 D Inches

Price: $

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Stiebel Eltron 074050
Size: 10 Gauge

Dimensions: 14.2 W x 18.9 H x 7.9 D Inches

Price: $$

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Ariston GL4S
Size: 4 Gallon

Dimensions: 14 W x 14 H x 12.25 D Inches

Price: $$$

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Ecosmart ECO MINI 1
Size: 1.5 Gallon

Dimensions: 14.5 W x 10 H x 10 D Inches

Price: $

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7 Top Rated Under Sink Tankless Water Heater 120V Reviews

1. Bosch Tronic 3000 T - Best under sink water heater

Bosch Tronic 3000 T

Isn’t that amazing that you no longer have to go through the hassle of boiling cold water? With the Bosch Tronic 3000 T ES2.5 Under Sink Water Heater, you can have hot water the very minute you need it.

This Bosch compact unit is useful for apartments, boats, basements, RVs, pool houses, garages, and kitchens. Despite the small construction of this electric mini tank water heater, it is incredibly reliable and packed with features that rival several other heaters. The video below demonstrates just how useful this under sink water heater is.

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2. Camplux ME60 Mini Tank Water Heater

Camplux ME60 Mini Tank Water Heater

All Camplux products are especially known for their quality, innovation, portability, and ability to save energy to give the best outdoor experience. This 6 gallon tank under sink water heater does not fall short of this Camplux standard.

This water heater makes hot water available at the point when it is needed. Moreover, it greatly reduces the losses generated by heating – wait time is minimized, saves both bills and energy.

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3. Ariston GL2.5 Electric Water Heater Mini Tank

Ariston GL2.5 Electric Water Heater Mini Tank

If you need an under cabinet hot water heater that is aesthetically designed to suit your décor, then the Ariston GL2.5 electric mini tank water heater is an excellent choice. It can fit directly under your sink, and it’s an excellent choice for sinks that are independent of a major source of water.

So instead of the long waits for hot water from the primary source, you can enjoy the thermostatically controlled hot water.

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4. Thermoflow UT10 Under Sink Hot Water Heater

Thermoflow UT10 Under Sink Hot Water Heater

While this unit might not be suitable to serve as the major water heating system of a home, it is an ideal choice if you need to get faster warm water on a particular sink. Consumers appreciate the featured thermostat on this unit which makes it possible for a user to get lukewarm water of 45˚F or even hot water of 167˚F.

This electric under sink hot water heater is basically perfect for every season as there is a frost protection mode and an energy-saving mode. It can be used for patio sinks, small apartments, kitchens, wet bars of basements, boats, garage, doctor’s office and RVs.

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5. Stiebel Eltron DHC Water Heater - Best Tankless Water Heater for Shower

Stiebel Eltron DHC Water Heater

Eliminating all stand-by losses is the goal of this Stiebel water heater. Compared to other typical storage heaters, this unit consumes 50% less power. It is designed to be installed at the point of usage. This product design enables it to last for a longer period.

This instant hot water under sink heater operates by producing 0.5 gallons of water per minute (GPM). It is suitable for use in most places – residential areas, office restrooms and/or kitchens, restaurants, showers, hotels, warehouses and gas stations. 

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6. Ariston GL4S Electric Under Sink Water Heater

Ariston GL4S Electric Under Sink Water Heater

The Ariston GL4S is a greatly improved version of the Ariston GL4. This new version features a knob for temperature control which can be easily accessed, unlike the former version. Its compact design sports a glass-lined exterior design and it can fit into small to medium sized kitchens.

Another great attribute of the GL4S is its easy installation. It requires zero hardwiring, and with a 15A outlet, it is ready to be used.

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7. Ecosmart ECO Mini 1 Water Heater

Ecosmart ECO Mini 1 Water Heater

Of the best under sink water heaters available on the market, ECO Mini 1 is a great choice that delivers the desired results. Its super design is further equipped with a 1.5-gallon tank capacity which makes it an ideal option for the sink, bathroom, and laundry areas.

It is lightweight, compact and one of the very affordable mini tank heaters on the market.

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Buying Guide

Before delving into the world of 21st-century water heaters, there are some factors you have to consider. To have an optimum experience with under sink tankless water heaters, each of these factors is crucial. So, before purchasing any of these water heaters, you have to make a calculated decision.

The Two Types of Under Sink Heaters

Firstly, you have to be aware that there are two kinds of under the sink water heaters. It could come with a tank like the Bosch Tronic mini tank water heater, or it could be tankless such as the Stiebel Eltron. Tankless water heaters are created in such a way as to heat water fast, so a storage tank is not needed. These tankless water heaters take lesser physical space and can easily be mounted.

However, the mini-tank in the other kind serves as a reservoir. The tank ensures that the user has hot water in the few seconds instead of waiting for incoming hot water. The tankless model does not have a storage tank, but it provides an unlimited supply of heated water. On the other hand, the tank-type is limited by the capacity of the tank.

Water Usage

Before you purchase an under-sink water heater, you should be equipped with an awareness of the water you intend consuming. When you choose your water heater, you should consider how you want to use it and where.

Do you intend using it on boats, kitchen sinks, bathrooms or in commercial areas? For instance;

  • Kitchen sinks consume 1 – 1 ½ gallon of water each minute
  • Bathtub consumes 2-4 gallons of water each minute
  • Dishwater uses between 1 to 3 gallons of water each minute
  • Showers consume 1 ½ - 3 gallons of water each minute

If you have considered purchasing a tankless water heater, you should be aware of its limitations. As they do not rely on reserved water, there is a targeted amount of water they can heat up which is the GPM rating

The higher the GPM rating is, the more the amount of hot water delivered by the unit. For under sink water heaters, the size you purchase should depend on the number of people in the area where it will be used (e.g., the home).


Very important, you need to consider the size of the under sink water heater carefully. Lightweight units are generally preferable as they can easily fit into small spaces. But this depends on how you intend to use an appliance; if you plan on using the heater for the kitchen sink, shower and washer simultaneously, a bigger unit might be a better choice.

Energy Efficiency

Good water heaters should use less water and less fuel (electricity or gas). To help your wallet and the planet, it is wise to be energy-smart. So, purchasing a water heater that uses up everything is not a good option.

Easy Installation

You should check out reviews to ensure that the unit can be easily installed. There are some such as the Ariston GL2.5 reviewed in this best under sink tankless water review that can be installed singlehandedly.


Bosch Tronic 3000 T

All the models reviewed in this list of the best under sink tankless water heater 120V are effective and ideal for you. However, we strongly recommend the Bosch Tronic 3000 T model. 

This multi-purpose under sink water heater is highly efficient. It has received several positive responses from most customers and is in high demand because of its effectiveness. It works instantly and delivers the desired results. We rate it max 5 stars.

Our Rating

What we Liked:

  • Extremely Durable
  • Easy to Install
  • Instant Hot Water Available

What we Disliked:

  • None

    Verner Ellen

    Hi, my name is Verner Ellen. I am a homebody whose interest is in getting the best home tools and equipments to help with the the everyday house chores. I also love fitness, cooking and grilling. Maintaining a clean and comfortable home is my lifelong passion.

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