Best Under Sink Water Heaters of 2022

Best Water Filter for Kitchen Sink

An under the sink water heater is used to get hot water from your sink. It’s a great solution if you don’t want to get into advance plumbing or have a connecting come from somewhere else.

But deciding which under the sink water heater to buy can be a touch decision. I’ve spent some time researching and using various heaters and here is what I’ve found.

If you want to learn more about water heaters, read this article I wrote about water heateres. I encourage you to read it!

The best under sink water heater is the Ecosmart Eco Mini

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My thoughts: Based on my testing, the Ecosmart Eco mini is the best under the sink water heater. It is small and fits nicely and is powerful to deliver hot water within minutes.

I was able to install it easily and getting it working out without much issue. I really like the design of the water heater. It fits nicely under my sink and doesn’t take up too much space.

The heater can deliver water a a rate of 1.3 gallons per minute to 3.1 gallons per a minute, so it’s pretty powerful.

Reasons why I like it:

  • Very cost effective
  • Compact size
  • Sleek design

Another water heater that I like: Ariston ANDRIS 4 Gallon

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My thoughts: This is a class A water heater that is ideal for households with no central hot water system. It is one of the best water heaters we will talk about based on its performance and unique features.

One of the unique things about the Ariston water heater is that it remembers how you use water. By doing so, it can save up to 15% of the expense on energy.

Based on its design, it increases its temperature to 650C to eliminate risk bacteria such as Legionella. This makes it ideal for hospitals, schools, and care homes.

It has an elegant design. For example, it has an eco-display that is immersive and allows you to easily control the temperature. A led indicator also shows the level of the water temperature. Therefore, you can have hot water when you need it.

It is easy to install, and depending on your choice. You can mount it on the floor, shelf, or wall. However, it must be installed the right way up.

Reasons why I like it

  • It has a long lifespan
  • The device is easy to operate.
  • The device is easy to operate.
  • It has an enameled tank that promotes anti-corrosion

Good value option: Bosch ES8

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My thoughts: This water heater has a tank with a capacity of 7 gallons. This makes it a good choice for those who have a hot water demand while looking for a short waiting time.

Installing the product is easy, and it can be either floor, shelf, or wall-mounted. The mounting strategy determines the tank storage capacity.

When installed vertically or horizontally, it will have a tank storage capacity of 7 gallons 5.1 gallons, respectively. It has a seating capacity of 1440 Watts and can regulate a temperature of 65-1450F.

ES8 is cost-effective and suitable for a low budget.

However, it has a heavyweight. But this might not be an issue if you’re only concerned about its storage capacity.

Because all the stress you might face may be from carrying after delivery and its installation, but you can have it handled by professionals.

Reasons I like it

  • It is cost-effective.
  • It is easy to install.
  • Has a large storage capacity.
  • It is suitable for high hot water demand.

Solid option: Bosch Tronic 3000 ES4

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My thoughts: This is a tank-type water heater with a tank having a capacity of 2.5 gallons. It has a dimension of 13.75 W x 13.75H x 10.75 D, and it is popular for its many features.

However, the most exciting is its durability. The water heater is easy to maintain and made from glass-lined material responsible for long service life.

It has an independent installation that involves the use of the cord plugged into a 120V power outlet. It can also be used with a large hot water source.

This water heater can supply two sinks and remove the waiting time most water heater has. The heater can be easily installed shelf, wall, or floor.

It is designed with an attractive look that blends with your decor.

The manufacturer claims it has 98% energy efficiency. Also, for maximum energy efficiency, it is made with a thick CFC-free insulating material.

Reasons I like it

  • It is energy efficient.
  • Quite easy to install.
  • It has lightweight.
  • Has 6 years warranty.

READ: How Does A Hot Water Tank Work

Self modulating option: Ecosmart Eco11

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My thoughts: Ecosmart Eco11 is a 57A tankless heater made of highly durable copper and stainless steel. This design is ideal on two grounds. One is that it makes it aesthetically pleasing. While the other is that it helps reduce costs on energy consumption.

According to the manufacturer, it saves up to 60% of energy when used. It has a temperature regulator in 10 increments. Therefore, you are in absolute control of the water temperature.

This water heater is easy to operate and can be installed anywhere you want it to be. Its compact size helps you have more space available for other things.

It is also easy to maintain, and its faulty part can easily be replaced.

The unit has a digital temperature control that automatically adjusts the temperature after it has been set to a particular temperature.

Tinsay 2.1 Gallon 8L Electric Mini-Tank Water Heater

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My thoughts: One exciting feature of this water heater is that it is applicable for different water pressure and different areas. For example, if you’re located on a high floor with low water pressure, you don’t need to worry about whether this water heater will fulfill your demand.

It has a 1500W power rating and an option to automatically regulate the temperature. The importance of this is that it promotes effective power and energy consumption.

This water heater can be easily installed without the need for much expertise. It has lightweight, which eases installation and its small size makes it suitable for installation in the kitchen, restroom, bathroom, etc.

Good for outdoor use: Camplux ME25

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My thoughts: The Camplux ME25 is an integral member of any under-sink water heater due to the many exciting features that it boasts of. It is not only known for its feature but also its high quality and elegant design. Therefore, as a user, you are guaranteed a product with a long life.

It is a 1.5KW power-rated water heater with a 2.5-gallon mini tank and a power cord of 120V. It has a dimension of 14.5″ H x 11.75″ L x 10.38″ D and an external dial that allows you to adjust the water temperature while protecting the body against overheating.

This is further corroborated by its energy-saving and money-saving features.

It is insulated, which means heat loss is reduced, and it has a 2.5-gallon mini-tank where hot water can be stored until you need it.

The product is also UL-approved, which ensures a high safety standard and can be mounted on multiple fronts such as the shelf, wall, or floor.

Good warranty: ECOTOUCH Point-of-Use

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My thoughts: One exciting feature of this water heater is its ability to produce hot and instantly and sufficiently.

It is a compatible companion for a sink, and it has a self-adjustment feature in terms of temperature and pressure. The unit is energy efficient.

This water heater can be easily installed. It also has an appealing design making it convenient to use.

It has a power rating of 5.5KW and 240V, which allows the water heater to provide hot water instantly. Its temperature adjustment feature uses the flow rate and temperature setting to alter power input.

For example, when the flow rate reduces, the power input is reduced because the amount of heat needed to increase the temperature is reduced.

If this is not done, it can lead to the production of scalding water. The temperature adjustment also saves energy.  The product can also be mounted on multiple fronts, such as the shelf, wall, or floor.

READ: Why Is My Tankless Water Heater Not Working

Good energy saver: Stiebel Eltron 233219

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My thoughts: The Stiebel Eltron water heater is one of the best under-sink water heaters when looking at aesthetics and performance. It has a 2.5-gallon mini-tank which is one of its exciting features.

It is also applicable for different water pressure in different areas.

For example, if you’re located on a high floor with low water pressure, you don’t need to worry because this type of water heater will still fulfill your demand.

It includes an option for automatic regulation of temperature that allows you to set your desired temperature, and the heater will automatically adjust it afterward.

The importance of this is effective power and energy consumption.

This water heater can be easily installed without the need for much expertise. It has lightweight with an appealing design.

The characteristics of small size are to make it suitable for installation anywhere you want.

Another option I like: Rheem RTEX-18

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My thoughts: This is a water tank with a compact design, which makes it fit anywhere in the kitchen. It has an adjustable temperature with an accuracy of +10 and a led display.

With this feature, users can easily decide the temperature of hot water they want. It also has a flow rate of 4.4 GPM and a durable copper immersion with two heating elements.

Its elegant design will make your kitchen deliver on a high level in aesthetics. Depending on your choice, its design allows you to either have it wall or floor mounted.

The tank has a capacity of 2.5 gallons which is suitable for average water usage.

Buying Guide For Under Sink Water Heaters

Before you buy any under sink water heater, you need to use this guide to be able to know which sink water heater you will end up buying.

What size water heater do you need?

You see, size has become important in whatever you want to buy.

If you are buying this under sink water heater, ensure that you make your choice and pick which one best suits your home because the under sink water heater comes in a variety of sizes.

Although this is usually based on how much hot water you need.

What is the maximum flow rate?

Normally since you haven’t bought the heater yet, you can always check this out in the manual provided by the manufacturer. Some water heaters begin calculating the maximum flow rate.

Flow rates are usually calculated simply, by measuring the amount of water that flows through the faucet or through the supply line over a minute.

This amount of water should be measured in gallons. Then add up all the appliances using the hot water, and their flow rates to find the maximum flow rate.

At least any water heater that you buy must provide you with at least many gallons per minute of water.

Gallons of water used?

This is also quite similar to the flow rate. To calculate gallons used, simply add up the gallons each required by each of these appliances or the faucet for over an hour.

You should also ensure that your water heater has the capacity to deliver such a flow of water. To calculate your flow rate, it is approximately the value of your maximum flow rate multiplied by 60.

The storage kind of tank water heaters may offer just enough gallons to match the up to the use on paper but they do not drain fully and they must be returned constantly in order to meet demand.

A larger model will also be necessary to provide constant water flow over time.


The higher the temperature rises, the lower the flow rate. Hence making larger water heaters a better option for situations that are in high demand.

Since hot water is usually around 120 degrees Fahrenheit, your water heater needs to be capable of bringing water temperature that is up to about 70 degrees or more although this all depends on the appliance using the water.

So if the temperature rises higher, then the flow rate will be lower and this will make the water heater a better option for the high-temperature situation.

Consider your water heaters.

Check if you want the gas or electric model water heater. However, the main difference lies in your budget. It all exists in energy hookups, the sustainability goals, and also the local utility costs.

This should be carried out when choosing a water heater. Either you decide if it is tankless or tanked.

You also need to consider the existing power sources.

That is if your facility does not have a gas source currently available. Then a gas water heater is likely to be quite expensive to install.

The prices for both gas and electricity have the tendency to fluctuate depending on your area and it must be factored into costs.

Power Outages

The gas water heaters have the capacity to work during a power outage even as the flame is powered by gas which continues to flow even without power.

The electric models will definitely shut down unless they are connected to backup power.


The gas water heaters normally use fossil fuels. However, the electric water heaters are also connected to the power grid which may also use coal or even has fuel.

You should always check for a more sustainable option when it comes to efficiency.

That is, how much fuel a water heater burns. Models that are highly efficient reduce waste and they do this by converting more fuel into heating the water than compared to standard models.

Consider the price as well

Normally, the electric water heaters tend to be less expensive however, they can be quite expensive to operate. In your buying journey, you must also understand that the installation costs for both electric and gas are similar. Tankless heaters often have higher costs.

What You Need To Look Out For In Under Sink Water Heater

One of the best ways to get the best product in a market that is difficult to choose from is to make a shortlist.

However, to make such a shortlist, you have to consider the features you should look out for. Below are the features that any under-sink water heater must have.

Flow rate

The flow rate is an important characteristic that you must look at before getting any under-sink water heater. If you need a constant flow, you need a heater with a high gallon per minute. Therefore, it will be easy for the heater to supply the necessary amount of hot water.

Energy Rating

Using hot water is like heaven on earth and what reminds us that we are still on earth is the electricity bill. If you use hot water constantly, you wouldn’t want a water heater that uses too much energy.

If you go for such, you will have to cope with a large electricity bill. Therefore, it is ideal to go for a water heater with low energy consumption.

Heating Capacity

The demand for hot water plays a major role in what type of heater you need. This is expressed in the heating capacity of the heater.

Therefore, depending on what you want, you should choose an under-sink water heater with this capability.

Now you know about the features to look out for. The next thing is to help you with your short-list by introducing the best under-sink water heater. Below are the top ten favorite under-sink water heaters.

Frequently Asked Questions

Q: What happens to the cold water sitting in the pipes when the heater is connected to the hot water line?

A: When the tap is opened, the hot water in the unit begins to flow out. The cold water sitting in the unit now enters the unit to be heated. So if the tap remains open, then the newly heated water flows out, eventually replaced with the water from the main water heater.

If you want to keep a constant water temperature, you can set the unit temperature to equalize the main water heater temperature just so that if you want to keep a constant temperature.

Q: What amp breaker is required?

A: Normally, conductor and overcurrent protection are required, and are to be sized at 100% of the manufacturer’s branch recommendation for any tankless electric heaters. Now a 60 amp breaker is the same price as that of 40 or 50.

Although it is the wire that costs more. A #6 AWG wire is what is required for a 60 amp circuit breaker. However, of you undersized the wire, it could overheat and even catch fire. So it is better to follow the sizing of the manufacturer.

Q: Can you install it in a mobile home?

A: Yes but if the output of the heat, where you line an area with cold water. If you also live in an area where there is cold water from the ground then it means that the ground will be cool.

Meanwhile, you can also use a 30 – 40gallon hot water tank in a mobile home, unless it will be used for showers or except if you live in an area with about 60F water temp. Heaters like this may work well in a construction trailer that has only sunk to use the water.

Q: Can a tankless water heater be installed and used on an RV?

A: Heaters often require 60 amp double pole breakers and about 240 volts. Usually, the RVs do not always have sufficient storage.

Q: Can this be hooked in, with a garden hose?

A: Of course, you can. However, you need to buy some hose to adapters at the hardware store. But be sure it is full of water before plugging it in.

Q: Will the water heater work on double sinks in the bathroom?

A: Yes it will. If you have a bathroom and a sink and a shower, you are likely not to encounter any problem while using this product.

Q: Can this supply a single shower in cold climate areas?

A: Watch out for these heaters because not all can work in cold climate areas. There are specific water heaters that can work in cold climate areas so check out your area and begin to look out for a water heater, that fits your environment

Q: Do I need to call a technician or plumber to help me install my water heater regardless of the type?

A: No, if you can go through the stress especially since you have the installation manual with you. However, if you do not know how to go about it, simply hire a plumber or a technician to help you out so that you do not fix it the wrong way or spoil something in process of fixing it.

Q: Are there warranties?

A: Yes. There are warranties available for some of these products. Some last for as long as 6 to 12 months it all depends.


For people with a constant need for hot water, an under-sink water heater can make a difference.

However, choosing one might be a problem since there are many things you have to consider in terms of aesthetics and performance.

Therefore, this article introduced the best under-sink water heater and what you need to know before getting it.

While the decision depends on you and your budget, with our list and features you should look out for, choosing will be easier.

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