Best Under Sink Water Heater (Reviews And Buying Guides)

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Under sink water heaters are an innovative way of producing warm water at home and in offices. With the, best under sink water heater. the water temperature raising procedure happens almost immediately. They are usually compact in design, and you can install it under bathroom sinks, kitchen sinks, and a few other places where the need for hot water may arise. Take a quick look at the best under sink tankless water heater available in the market.

It is not easy to clean dishes or wash your hands with cold water when the ambient temperature is low. This scenario is particularly challenging, especially in winter. In times like this, there has to be a provision for the flow of hot water through taps. It is only an under sink instant water heater that can make this possible. They do not require the conventional installation of long pipes, and they do not need too much space.

They are easily installable close to the point of use, and they are quite economical also. This trick is because the cost of heating will greatly reduceable following this procedure. All in all, you can consider an under sink tankless water heater as a lower version of a central water heating system. Have you made up your mind to purchase an under sink water heater but a bit uncertain about the type and brand? This under sink water heater reviews will help you make a decision real quick. 


1. EcoSmart ECO 11 Electric Tankless Water Heater​

EcoSmart ECO 11

This EcoSmart ECO 11 Electric Tankless Water Heater​ is an under sink hot water heater with a lifetime warranty. Its design and technology are patented, and it is an energy saver. It can heat 2 gallons of water in 1 minute. It can also serve 2-sinks at the same time, and it is ideal for multiple and single applications. This heater helps you reduce your electricity and energy bills. The basic specifications and electrical requirements for this heater are 240V, 13Kw. With this heater, you can never run out of hot water. It has an item weight of 6.5 pounds and a product dimension of 3.8 x 8 x 11.5 inches. It has a digital temperature control settings that allow you to pick the desired heating range. The users are also able to control this under sink water heater with remote control.


  • Compact design.
  • Attractive and beautiful.
  • Space-saving.
  • Energy-efficient.
  • Easy to install.
  • Durable heater.
  • Energy saving
  • Easy to maintain.
  • Extremely lightweight.


A few leakage concerns.

2. Bosch Electric Tankless Water Heater​

Bosch Electric Tankless Water Heater

This Bosch Electric Tankless Water Heater reduces your hot water waiting time. It has a minimum electrical requirement of 120V, 1440W, 12A, and a thermal efficiency of 98%. It can heat 2.5 gallons of water per minute, and it is excellent for small spaces. The weight of this water heater is 15.5 pounds, and it has a product dimension of 13.8 x 10.8 x 13.8 inches. There is a 6-year warranty on this heater and a 2-year warranty on its parts. It has an external dial for easy adjustment of temperature. It comes with a relief valve, and we can use this device as a secondary heater. Users can mount on this heater the wall, a shelf, or on the floor. This heater is insulated to minimize energy loss. It also features a glass-lined tank.


  • Sleek and attractive design.
  • Easy installation and configuration.
  • Compact design.
  • Lightweight.
  • Lesser wait time.
  • Safe & Easy To use
  • Good thermal efficiency.
  • Portable heater.
  • Energy-efficient thermostat.
  • Temperature control functionality.


  • It has a tank. Hence, it does not supply water endlessly.
  • Few leakage concerns.

3. Bosch Under Sink Water Heater

Bosch Electric Tankless Water Heater - Eliminate Time for Hot Water

This water heater has a heat output of 9.5Kw. Bosch Under Sink Water Heater operates on 220V, 40A source and has a thermal efficiency of 98%. It is fit for an RV or boat,  garage, pool house, wet bar, kitchen, and a few other places. It has an impeccable design that makes it blend perfectly with existing furniture. Also, it can be wall-mounted. It helps you save energy and cost of electricity.

This heater is not designed to retain water, and it does not take up too much space. There is minimal heat loss and is backed by a 5-year warranty while there is a 1-year warranty on its components. It has a product dimension of 12.2 x 3 x 6.5 inches, which makes it perfect for even the smallest of spaces. It has an item weight of 5 pounds. With this heater, you wouldn’t spend too much on energy and electricity.


  • Lightweight
  • Fast heating
  • Price is reasonable
  • Fast heating.
  • Easy to install.
  • High thermal efficiency.
  • Compact unit.
  • Beautiful and attractive.


  • Few issues with the flow sensor.
  • Sizeable pressure drop.
  • Not thermostatic.

4. Atmor tankless water heater! AT-900-03 ​

Atmor tankless water heater

This Atmor tankless water heater has a maximum flow rate of 0.5 GPM. It works well when connected to a 30A single-phase circuit breaker, and it ensures you have hot water at all times. comes with a pressure release device, and it can only work for a single sink. It can be wall-mounted, and it does not require a battery. There is a 7-year warranty on the product and a 2-year warranty on its components. It features a canister for the detection of a drop in water pressure. This heater is well insulated, and there is no risk of electric shock. The minimum electrical requirements are 3kW, 110V, and it has an item weight of 4.25 pounds. The product dimension of 11.9 x 8.7 x 4.2 inches makes it useful for small spaces. It does not require a battery. For safety reasons, ensure a competent and qualified electrician installs this unit.


  • Compact design.
  • Lightweight unit.
  • Space-saving.
  • Sleek and colourful design.
  • Ensure thermal efficiency and heat output.
  • Appreciable price range.


It draws too much electric current.

5. Ecosmart pou 3.5 Electric Tankless Water Heater ​

Ecosmart pou 3.5

The maximum flow rate of this ecosmart electric tankless water heater is 0.5GPM. It is ideal for use in strip malls, boats, wet bars, kitchen and bathroom sinks, as well as recreational vehicles. It provides continuous heat, and it draws 29A of electric current. Item weight of 4 pounds means it is not a heavy unit. Also, it has a product dimension of 3 x 11 x 6 inches. The minimum electrical requirements are 120V, 3500W. There is a 1-year warranty on the heater and its elements, and it does not make use of a battery. This heater helps you reduce the cost of electricity and energy.


  • Portable and space-saving.
  • It draws minimal electrical current.
  • Easy to install.
  • Attractive design and appearance.
  • Not expensive.
  • Lightweight.


  • Flow rate cannot be adjusted.
  • Not fast-warming.
  • Chocking hazard.

6. Ecosmart eco electric tankless water heater

Ecosmart eco electric tankless water heater

Ecosmart eco electric tankless water heater produces hot water almost instantly. It can be installed close to the sink to eliminate the need for lines and pipes. Also has a 99.8% energy efficiency, and users can plug into a standard 110V, 12A outlet. It can either function as a sole heat source or as part of an enormous hot water source. The unit weighs 15.8 pounds, and it delivers a heat output of 1440W. The product dimension of this water heater is 16.2 x 11 x 11 inches, and there is no need for a battery. A 5-year limited warranty backs the heater while its parts have a warranty of one year. It is compatible with reverse osmosis water. This heater currently enjoys rave reviews on several marketplaces. Whooping 62 % of users have given it a perfect 5-star rating.


  • Affordable price.
  • They are sturdily built.
  • Instant heating.
  • Energy-saving.
  • Good thermal efficiency.
  • Saves-water.
  • Good flow rate.
  • Digital output temperature display.


Chocking hazard.

7. Eemax electric tankless water heater

Eemax electric tankless water heater

This eemax electric tankless water heater will conveniently fit under your kitchen and bathroom sinks. It is manufactured in the United States of America and designed for domestic use. It can be mounted on the floor and the wall. The heater greatly reduces the time taken for hot water to reach the tap. It features a 120V outlet plug, an adjustable temperature range (50°F to 140°F), an elegant design, and a 1400W heat output. The manufacturer has made from quality copper material, and a warranty of 5 years backs the heater. It does not use a battery, and it has an item weight of 20 pounds. Product dimension is 10.4 x 11.8 x 14.5 inches. Ensure you make use of the unit valve when installing the unit. All in all, this is not a bad, point-of-use water heater.


  • Fast heating.
  • Energy-efficient.
  • Easy to install.
  • Sleek design.
  • Easy temperature regulation.


  • There is no read-out.
  • Pressure relief valve leaks.
  • Dimensions are a bit bigger.
  • Not portable or space-saving.

8. Chronomite Tankless water heater

Chronomite Tankless water heater

This Chronomite Tankless water heater makes use of microprocessor technology. Hence, unlimited hot water is guaranteed. Users can install it at the point of use, and this eliminates the need to lay long pipes. Also, this component reduces hot water delivery time significantly. It has a flow rate of 0.5GPM. It has a heat output of 3600Wand an electrical specification of 30A, 120V. No battery included, and no battery is required. This water heater weighs 4.47 pounds, and it has a product dimension of 9.6 x 2.8 x 6.2 inches. It is certified safe for use in the kitchen and bathroom.


  • Easy to install.
  • Easy to maintain.
  • High thermal efficiency.
  • It is not expensive.


  • Not durable and does not last long.
  • Noise in operation.

9. Thermoflow tankless water heater

Thermoflow tankless water heater-min

This Thermoflow water heater uses German technology to achieve an energy-saving operation. It is perfect for patio sinks, RV’s and boats, garage, kitchenettes, and bathrooms. You can select an operating temperature between 45°F and 167°F. It can either function in the energy-saving mode or frost protection mode. This water heater is suitable for use during summer and winter. Energy loss is exceptionally minimal, and hot water delivery time is significantly low. It can be used in combination with another heat source or as a sole heat source. This best electric water heater can also serve as a buffer. explore the best electric water heater review.

Some of its features include an auto cutoff protection for additional safety and a wire gauge. It can store up to 2.6 gallons of water. It has a product dimension of 18 x 11 x 12.2 inches and an item weight of 14.63 pounds. The manufacturer has made from quality stainless steel material, and the voltage requirement is 120V. It can be floor-mounted, and it does not make use of a battery. It is important to note that this heater will not work well if the users install it where there is a high chance of freezing.


  • Overheat protection.
  • Sleek design.
  • Impressive heat output.
  • Temperature can be selected.
  • Energy-efficient.
  • No waste of water.
  • Quality material.
  • Portable and space-saving.


The temperature dial is not easy to understand.

10. Camplux ME40 Best For Under Sink Use​

Camplux tankless water heater

This heater can store up to 4 gallons of water. It is very comfortable to install under a sink or basin. It will work well in a garage, attic, boat, wet bar, and bathroom. The user can control the temperature range with an external dial, and a pressure relief valve is part of installation requirements. The unit is well insulated and energy loss is minimal. To prolong the lifespan of the heater, ensure it is unplugged when it is not in use.

It features an adjustable thermostat and an indicator lamp. It has a sleek and beautiful design that easily fits into existing furniture. The heater plugs into a 120V outlet comfortably, and it can be the floor, shelf, or wall-mounted. A pressure relief valve and has an item weight of 21.2 pounds. It has a heat output of 1440W and package dimension of 23.1 x 13.2 x 12.3 inches. It is for indoor use and can serve 2 to 3 sinks.


  • Nice safety features.
  • Efficient heat output.
  • Easy installation.
  • Effective temperature control.
  • Easy to maintain.
  • Fast heating.


Leakage concerns.


Under sink water heaters are further divided into 2 – tankless under sink water heaters and the mini-tank electric water heater. The difference between the two is in their design and how they work. A tankless under sink hot water heater does not have storage space. Hence, hot water leaves the radiator through an outlet almost immediately it filters in through the inlet. This type of under sink water heater supplies hot water directly to your faucet within a twinkle of an eye.

The mini-tank water heater has a storage capacity, the size of which is determined by the product manufacturer. It is designed to retain water and make it hot. Both types of under sink water heaters are unique in their way.


The principle of operation of an under sink hot water heater is a pretty straightforward one. However, it is very similar to how a gas water heater delivers hot contents. Coldwater finds its way into the radiator through the dip tube that serves as an inlet. Then the temperature of this water gets raised by the electric heating elements embedded in the heater tank. After having its temperature increased, the hot water slopes upwards and circulates to all parts of the house that needs it through the heat-out pipe. for installing under sink water heater.

ADVANTAGES OF AN under sink hot water heater

Here are a few benefits of having an under sink water heater.


Having an instant hot water heater under the sink installed at the point of use automatically eliminates the stress of jumping from place to place in an attempt to fetch warm water. Whether you need it for dish-washing or you want to have your hands cleaned, an under sink water heater makes it more accessible. There will always be hot water. Without breaking a sweat, hot water flows out of your faucet in a little under ten to fifteen minutes. This component is unlike a conventional tank water heater that cannot deliver hot water instantaneously.

More extended Service Life:

An under sink water heater lasts longer than a conventional tank heater. A typical under sink electric water heater will still be in use even after 20 years of installation. A standard tank water heater cannot last as long as this. In fact, in most cases, an under sink water heater will outlive a conventional tank heater. This fact is because the components of tank water heaters are always at work since they have to heat and reheat water always. However, the elements of an under sink water heater are only spurred into action when hot water is needed. Hence, there is a lesser chance of wear or tear.

Better Energy Efficiency:

An under sink water heater uses a lesser amount of energy than a standard tank heater. However, studies have shown that under sink electric water heater is over 34% more energy-efficient since they do not necessarily have to work all the time.

Easy to set-up:

Many of the instant hot water heaters under the sink in the market only require some basic knowledge of plumbing and electricity before they can be installed or maintained. They can easily be put together in no time. Users can mount them on a wall, shelf, or floor.

Great time saver:

With an under-sink water heater, the waiting time for hot water is significantly low. It supplies hot water instantly and at your desired temperature. However, you wouldn’t have too long before hot water flows out of your faucet. Asides that, most recent designs of under sink water heater incorporates digital and remote control. Hence, you do not necessarily have to be close to the heater before you determine what you want it to do.


Can an under sink electric water heater be used in a restaurant?

Yes, it can. However, you may have to install several heaters since numerous persons may want to wash their hands or clean dishes at a time.

Where should an under sink water heater be installed?

Remember that, users should install the under-sink water heater close to the point of use. It is very easily installable in the bathroom, kitchen, boats, and recreational vehicles, and the garage.

How safe is an under sink water heater?

Under sink water heaters are usually tested for safety before the manufacturer companies dispatch the products to the market. There are no hazards associated with the use of this device. However, safety also depends on your compliance with installation and usage instructions. If you do not install it properly, you run the risk of a fire hazard or an electric shock, and this explains why we recommend contacting a qualified electrician for installation and set-up.

How long does an under sink water heater last?

An under sink water heater has a longer lifespan than a standard tank heater. If used correctly and well maintained, and under sink water heater can serve you for up to 20 years.

Where can I buy an under sink water heater?

Under sink water heaters are available in so many online and retail stores. You can also find them in electronic stores. They are not hard to find.


Compact and small house:

Under sink water heaters are usually compact in design. This feature ensures that they can fit into small spaces. If they are made big or bulky, they wouldn’t be easy to install in those small spaces. Hence, they are portable and quite handy.

Beautiful and impeccable design:

Most under sink water heaters come with a sleek and attractive design. They are usually designed to add beauty and color no matter wherever you install them. If an under sink water heater will not give your home a facelift in terms of color and style, do not buy it. Elegance and style are equally important. It makes no sense spending on a device that is ugly or unpleasant to the eyes.

Heat output:

This is the whole essence of its purchase. If an under sink water heater will not raise the temperature of water sufficiently, it is useless. What we want is something that can supply hot water immediately and instantaneously and not another cold water source. A right water heater should have an excellent thermal output, minimal heat loss, and impressive heat efficiency.

Low current consumption:

A good under sink water heater does not gulp massive electrical flow. It should have a low power consumption rating and help you bring down your electricity and energy bills. You don’t want to run into debt just by purchasing a single device.


A good under sink water heater should also be pocket-friendly, albeit the functionalities of the unit have a massive bearing on how much it will cost. That said, the cost of the purchase of an under sink water heater should be reasonable. However, have it in mind that there is no fixed price for a heater. Different manufacturers have different rates for different models, depending on what each heater can do.  It is also important to note that an under sink heater costs more than a standard tank heater.

Durable and versatile:

A good under sink water heater should be durable and long-lasting. Nobody wants to spend on a gadget that will pack up in no time. It should also be versatile. Although designed for use in one sink, there are a few heaters that can comfortably serve 2 to 3 pans at a time even if they cost more.


We have discussed everything about an under sink water heater. We have given you an insight into some of its primary operating principles and how it functions. We have also taken time to let you know what to expect from the right heater as well as its basic electrical and energy requirements. It is not easy to make the correct choice especially when you do not have adequate knowledge of the device or gadget involved, and that is why we have created this guide. We believe that you should take an installation decision based on some of the principles and tips outlined here. Do not buy an under sink water heater blindly.

If you do, you will regret it because there are some financial and economic implications. There are also a few safety concerns from making the wrong choice. Your judgment should consider the essential features an under sink water heater should posses. In line with this, you can choose from any of the 10- Undersink water heater reviews. These are some of the best in the market, and you can equally rely on our selection process. However, if you have other ideas or feel otherwise, make sure your choice of under sink water heater meets with the minimum requirements explained in this text.