Best Under Sink Hot Water Heater

With every waking moment, there comes something that will make our lives just a little easier. In the house, the one-room experiencing massive changes in the kitchen. From the garbage disposals to the kitchen appliances like the under-counter refrigerator things change.

Under Sink Hot Water Heater

Under sink water heater is one such needed appliance. It makes it easy to reach the needed water temperature quickly. For those in the tropical climates, you might not understand the need for this, but if you live in areas affected by the winter seasons you need it.

Best Under Sink Water Heater Comparison Table

Product Name

Product Image


Fuel source



Bosch Electric Mini-Tank Water Heater



4 gallons

Check Price

Electric Tankless Hot Water Heater




Check Price

Portable Outdoor water heater



1.32 gallons

Check Price

Electric Tankless Water Heater



1.5 gallons

Check Price

Stiebel Eltron Tankless Electric Water Heater



4 gallons

Check Price

ECOTOUCH Tankless Water Heater Electric



1.5 gallons

Check Price

But what is it?

From the name, it’s simply a water heater that is mounted under the sink. They are some of the tiniest electric gadgets. Sometimes however you put them in the restroom closet. So, it goes under any sink.

Under Sink Hot Water Heater

The water heater is also referred to as the point of use water heater, instant water heater or under-counter heater. Since the heater isn’t the replacement to the large water heater, you can install them in line with the current water heater or directly on the faucet.

Here’s how it works: it heats the water as it passes through it or it heats a small amount of water and keeps it in the tank set for when you need it. Mostly they will help in situations where you have the water heater set far away; thus, it takes it time to heat the water.

In other instances, the need for the hot water may be more than the large water heater can handle. Thus, the under sink heater will cover some needs.

Well, it doesn’t matter whether you are a novice or knowledgeable about the underwater heater; the article will help you make the right decision.

Types of Under Sink Water Heaters

They come in two types of under sink water heaters

Under sink water heaters with tank

From the name, this is an under sink water heater that has the tank. So, it will heat some water, then keep it waiting for the time when you need it.

The tank water heaters take on the same features as the traditional water heaters. You have to let the water to heat first before you can use them. Basically, it keeps you from having to waste the water as you wait for it to heat up.

Sadly, once you have exhausted the water in the tank, you will have to give it time to heat up some more water.

Under sink tankless water heater

This is the design that doesn’t have a tank to keep the heated water.  It heats the water as it passes through it. So, unlike the tank one, it will give you hot water continuously. As long as you have water running, it keeps heating it. Thus, there’s no end to the hot water.

If you are looking for ways to save on energy, this should be the best choice as it only works when needed. It doesn’t work like the conventional water heater or the tank under sink one.

You see the regular conventional water heater, keeps hot water in the tank, which makes it not so energy efficient. For those with very small spaces and multiple use needs this is the best option.

Why You Need the Water Heater

I know you have the traditional hot water heater. So, the under sink hot water sink will help boost your needs. It doesn’t come to replace the big water heater.

It comes to serve you for the minimal hot water needs. So, you could fix it on the kitchen faucet or one bathroom in the house.

Under Sink Hot Water Heater

Are you a traveler?

For anyone who loves to travel but mostly in the recreational vehicle, you should think of this option. It instantly heats the water and cuts the cost and need for space in installation. If you go in the boat severally too, you will need the same.

You use small amount of water

It makes no sense for you to heat a whole tank of water when you are going to clean about four dishes. The instant tankless water heater will serve you best for such instances. In fact, you don’t have to wait for the water to heat up. You can instantly use it.

When remodeling the house

If you have recently decided to remodel the house. It makes sense to make such additions. They will serve to save on the energy and water sometime.

Best mini under sink water heater1. Bosch Electric Mini-Tank Water Heater Tronic 3000 T 4-Gallon (ES4)

Bosch electric heater is one of the mini water heaters that will serve you well and powerfully. This heater will deliver the hot water in an instant. This is a type that will heat just 4 gallons of water at a time. But worry not because it has a 98% energy efficiency.

It further uses 120V for the heating process, and it only uses 1440 watts. Also, it has temperature and pressure relief valve. It also has the energy efficiency where it uses the CFC insulation to retain the heat and temperature.

The tank it has is further glass-lined and this makes it durable. Being a compact size under sink heater, it’s lightweight such that you can mount it on the wall, floor or even the shelf. Not to mention its perfect design that suits most decorations and designs.

Although it’s small it can supply the water to two sinks at a time. Thankfully, it has a rapid rate of recovery. This means you won’t have to wait for long to heat the water. For most people, its installation is a breeze if you can get the waterline.


  • It’s lightweight and compact, making it fit on every space you think of.
  • It will provide instant hot water since it has a quick recovery rate. It will take it only 10 minutes to reheat the water again and then the flow goes on.
  • It has a longer warranty than most other heaters.
  • It has a direct and good manual which will make the installation easy.


  • The water doesn’t last as long since it’s a mini tank style.

2. Electric Tankless Hot Water Heater

Did you know you can even have a mini tankless water heater? It takes it just three seconds to heat the water. The way you adjust the water heater temperature is by adjusting the water flow.

Since it has a compact body, it’s quite easy to install it. You can use it in the kitchen, bathroom, or any other part of interest. Furthermore, it employs safety features like leakage control, hydroelectric isolation to keep you safe.


· It’s a high-quality gadget as praised by most clients.

· Ideal for those with small families.

· It’s the easiest to use and the safest gadget in the house.

· It heats the water quickly.


· It’s so small for anyone who has a growing family.

Best outdoor under sink water heater

3. Camplux 5L 1.32 GPM Portable Outdoor Tankless Propane Water Heater

Even if you enjoy the outdoors, you can have hot water in the comfort of the sinks. For it to work though, unlike most other water heaters, you don’t have to use high water pressures. It just needs you to start running the water, and instantly you will have the hot water.

It will further deliver the regular temperature balance between 46 degrees and 8 degrees. Also, it has a 1.32 GPM. This is one you need since it can heat rapidly. It, like most other under sink heaters, is compact.

It further has a foldable handle that you can keep off the way. Remember to allow it some venting space. It’s ideal when you are using it outside, but you can also use it indoors if you have a good ventilation system in the house.

It’s safe to use, especially since it has overheat protection, flame failure, and anti-freezing protection. With this tankless heater, you can enjoy the hot water during camps.


· You can use it for the outdoors making it practical to carry for your camping holiday.

· It has great safety measures to keep you safe as you operate it.

· It’s efficient and fast in operation.

· It doesn’t use electricity for the process, but it will deliver the end product needed.


· You can’t drink the water it heats. It uses gas for heating.

The best value under sink water tank

4. EcoSmart ECO 11 Electric Tankless Water Heater

This water heater is not only one of the fairly priced ones, but it will cut up to 60% of the water heating cost. Its features are the greatest when it comes to the topic. I like that it has the self-modulating feature to let you choose the amount of energy you are comfy to use.

The ecosmart only utilizes modern technology to deliver a powerful service. Just be sure to install it right as you give it enough space. Because without the right installation, it won’t work right for you.

As expected, you have the gadget being small and sizeable for almost every under sink size. For this reason, you won’t need changes under the sink before the installation. Mind you; it’s never affected by the different climatic conditions.

It works in all the different climates, whether hot or cold, the under sink water heater is effective. Notice that you will notice a slight difference when it gets colder though. It usually has a slower flow rate. But isn’t it better than most water heaters that won’t work in cold environments?


· It has a limited warranty

· Its compact size makes it fit in almost every space you have. Therefore, you don’t need to change the under sink construction.

· It’s not affected much by the climatic changes.

· It has a good price for its value.

· It supplies hot water constantly with its 2GPM. That means that it works first and effectively.

· During warm weather, it will heat the water in the two different sinks and showers all at once.


· It still has a low flow during cold temperatures.

· Although it has a lifetime warranty, it only applies if you use their personnel to install it.

Best commercial and residential water heater

5. Stiebel Eltron 074050 120V, Tankless Electric Water Heater

You can compare this gadget to the regular conventional water tank heater because it heats your water the same way. The essence of the under sink water heater is to save on energy, and it does save on the energy because you will use up to 50% less energy.

Initially, the brand always worked to make the best boilers which they still do. Thankfully, today they make some of the best under sink heaters as well. This heater you can use for both commercial purposes and at residential places.

There are no restrictions; consequently, you can use it under any sink. It uses the copper heating method for effectivity during the heating. They mostly have a longer lifespan than most other heaters. It offers quiet operation.

What’s even better is that it will deliver the hot water on an instant. You won’t run short of hot water with its 4GPM rate.


· It’s best when it comes to energy efficiency control.

· It’s lightweight and thus easy to install.

· It will resist any form of corrosion.

· Its compact size allows you to use it regardless of the kitchen size.


· You will need an expert for the installation.

Best digital water heater

6. ECOTOUCH Tankless Water Heater Electric

For the consistent hot water supply buy this gadget. The good thing is that it maintains the temperature and you don’t have to wait for the water to heat up again. It will further never overheat since it adjusts the power with a different level of flow.

With the touchpad control panel, you will easily set the temperature to the desired level. You don’t have to use malfunctioning buttons when you have it. It further employs the safety measures to keep you and the tool safe as you work on it.

It uses different lines for inner water and electricity. This is approved for UL by ETL, and it thus will serve you over a long duration.


· Its compact in size thus will fit in any under sink space.

· It’s flexible for use; thus, you can use it in the kitchen, school bar, and many other places.

· The water you heat is safe to use and drink.

· It utilizes modern technology and its energy saving.

Benefits of The Under sink Water Heater

Cuts on cost

Utility cost is slowly getting high with the demand for more money to source for electricity and water. The under sink water heater, makes you not use the large heater when you, for example need to wash a few utensils. This, therefore, cuts on cost tremendously.

It’s flexible

If you don’t need one in the kitchen, then you may need one in the bathroom. Some people use then in offices and schools. It’s all a question of where you want it. Notice that you can install it anywhere you wish.

Covers for when the big hot water jams

For those days when your regular water heater jams on you, the under sink heater is useful. This is particularly true when you need to use hot water urgently. Always use the under sink heater as the electrician is taking care of the big heater.

They are relatively fast and efficient

It doesn’t take the under sink water heater long before it delivers the hot water. It comes out in an instant, thus its instant heater name. A tank-type heater is going to take a few minutes to heat the water, though. So, if you are always in a hurry this may serve you way better.

It doesn’t affect the environment much

You don’t have to keep the water running for it to get hot. Therefore, there’s no wastage. Also, you don’t have to waste energy, getting a lot of unnecessary water hot.

It’s small and easy to install

You don’t have to think of where you will place it because it’s the compact size. So, it will fit under the sink in the cabinet or just about anywhere. You won’t be carrying weights when installing it too. For those of us who love the DIY business you will enjoy the heater.


For the most part, the heaters are durable, and they will take even longer. The mini water heaters will last longer than the larger ones, especially since they are easier to repair.

Things to Consider When Buying Under Sink Hot Water

Like any other appliance, there are things you will need to know before deciding to buy the item.

Check the size of the unit

In this case, unlike other appliances, you don’t have to check the room where you will place it. It’s one of the tiniest gadgets.

So, you need to confirm the dimension of the water heater to know whether it fits under the sink. This then shows that you should also have the dimension of the under sink space.

The capacity

As earlier mention, you can have the tankless or the tank under sink water heater. For the tank water heater, know the capacity of the tank. It will help you if you want more hot water at a time. But if you don’t use a lot of hot water then you may go with a small size like 2.5 gallons.

Performance and popularity

Well there are many brands that sell under sink hot water heaters. But you are safer when you buy the heater from a popular brand. However, consider the performance of the heaters as well based on the features they should have.

Fuel source

Under sink heaters run using different fuel sources. They can use natural gas, electricity, or propane. Therefore, it depends on where you want to use the heater. For home use, most people choose the electric ones.

The energy efficiency

You are buying the under a sink water heater, especially the tankless one because it helps you reduce the use of energy. They are the best when it comes to energy efficiency but still getting the hot water.

So, before you buy one check that it has a high rate of efficiency and if you can get one that’s over 90% energy efficient, then you are good to go.

The flow rates

The only way you will have hot water flowing to your taps constantly is by ensuring you only buy the heater with a high flow rate. Thus, check the GPM before buying it if you can find those with over 5 GPM, the better. This is also dependent on the number of people in your house.

Recovery rate

This is the amount of water it can heat. You will find it with the tank heaters. Subsequently, most of such heaters will heat the water to 90 degrees if you emptied all the water in the tank. And this will take an hour to do so.

Remember, the higher the recovery rate, the better the under sink heater.


the installation of Under Sink Hot Water Heater

Unless you are a handy type of person, you should let the plumber install the water heater for you. Depending on the water heater you buy, you will know whether you can install it or not.

The budget

What cost will you have set aside for this gadget? You don’t have to spend too much to get a high quality under sink water heater. Just make sure it meets all your needs. You can spend as little as $150 or as much as $1000.

How to Install Under sink Water Heater


Notice that there are so many under sink water heater in the market. It’s all a matter of what you are after in the heater. From the list we created EcoSmart ECO 11 Electric Tankless Water Heater is the best. It not only gives you value but it’s also durable.