The Best Under Sink Water Heater 2022

An under sink water heater is a compact provides instant hot water and are available as a tank or tankless type. If you consider yourself to be good at DIY project, these devices can be installed fairly easily as their is minimal pipes or lines required.

The best under sink water heater is the EcoSmart ECO11, which is an electric tankless water heater that will help you save up to 60% of your energy costs.

Point of use water heaters that are installed under the sink provide hot water on demand. This means there is no waiting around for water to heat up and travel to your faucet. The other benefit includes far less water usage too.

See also  Gas vs Electric Water Heater

Table of Contents

Best Under Counter Water Heater

Under Sink Water HeaterDimensionsType
EcoSmart ECO 1111.5 x 8 x 3.75 InchTankless
Bosch Electric Tronic 300017.5 x 17.5 x 14.5 InchTank
Stiebel Eltron 22342019.5 x 21.5 x 8.5 InchTankless
Atmor AT-900-1311.9 x 8.7 x 4.2 InchTankless
Chronomite SR-30L9.6 x 2.8 x 6.2 InchTankless

Preparation is key for the under sink water heater being easy to install and more importantly use. It is crucial that you take all the required measurements and take into consideration the pipes and electrical supply for the installation.

One thing that many people forget to consider is the cabinet strength that you are installing the under sink water heater. It needs to be able to hold the water heater securely along with all the piping that goes to and from it.

Everyone wants fast hot water and there is nothing worse than waiting for your old heater to heat the water. Below is a list of the best under sink water heaters that provide instant hot water on demand and are relatively easy to install.

EcoSmart ECO 11 Electric Water Heater

The EcoSmart ECO 11 is a compact tankless water heater that is the perfect size to install under the sink. This device is designed to be energy and space efficient, so you’ll save a significant amount of money on your water bill without having to install a large, cumbersome heater in a conspicuous place.

EcoSmart claims you could save up to 60 percent on your water bill¬†and their heaters use a self-modulating technology to maintain your desired temperature efficiently. The device has a digital control panel, so it’s easy to adjust the temperature of your water. Here are some of the notable features of the EcoSmart ECO 11:

  • 11.5 x 8 x 3.75 inch dimensions
  • Digital temperature control in 1-degree increments
  • Activation flow is 0.3 GPM
  • Requires a 125 amp panel and 60 amp double pole breaker
  • Comes with a lifetime warranty

The heater is also relatively easy to install and maintain when compared to other products. The design is intuitive too and most of the components are replaceable, if necessary, and although there is some electrical wiring required, it’s not so difficult you can’t do on your own. The EcoSmart ECO 11 is one of the best under sink water heaters that’s very efficient and will help save you money over the years.

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Bosch Electric Mini-Tank Water Heater

The Bosch Electric Mini-Tank Water Heater is a small water heater with an efficient design that fits conveniently under the sink. The versatile design means that you can place it virtually anywhere in your house where you have the appropriate fixtures to hook it up.

It’s very easy to wall or floor mount this water heater if you need to. It’s unique in that it can be installed vertically or horizontally for the most efficient use of space. Here are the notable features of the Bosch Electric Mini-Tank Water Heater:

  • Comes in 2.5, 4, and 7 gallon size options
  • Heating capacity of 1440 watts
  • Temperature range of 65 – 145 degrees F.
  • Pressure of 150 PSI
  • Requires 120 volt power source
  • 98 percent thermal efficiency

The efficient design of this water heater makes it a great choice for those who need to install a water heater in an atypical location or who want to preserve as much space efficiency as possible. Bosch is a very reliable brand, and despite its small size, the Bosch Electric Mini-Tank Water Heater packs plenty of efficiency and heating power.

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Steibel Eltron Tempra Plus Water Heater

The Steibel Eltron Tempra Plus is the latest, most modern version of the Steibel Eltron under the sink water heaters. This compact design provides a continuous flow of hot water without taking up much space.

There’s no venting required and the water heater is specifically designed to be almost completely silent, so you don’t have to worry about loud or annoying noises when your water heater is in use. The heating elements also use high quality copper as their conductor, which has been proven to be very effective.

Here are the notable features of the Steibel Eltron Tempra Plus.

  • Comes in 6 different sizes ranging from 12 to 36 kW
  • Uses an electronic switch to activate, preventing noise
  • Copper sheathed heating element housed in copper cylinder
  • Uses advanced flow control for efficient heating
  • 240 or 208 V requirement
  • 150 PSI water pressure
  • 7 year warranty for leaks and 3 year warranty for parts

The Steibel Eltron Tempra Plus Tankless Water Heater is a very reliable option for those looking for an under sink tankless water heater. Although it is small, it uses the same durable construction and efficient heating mechanisms that you would find on a much larger water heater.

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Atmor Tankless Water Heater

The Atmor Tankless Water Heater is an under sink hot water heater that is designed to fit perfectly in your bathroom. It’s powerful enough to heat both the sink and the shower, but it isn’t so large that it will make your bathroom seem overcrowded.

It’s designed for heating efficiency and will help you conserve water as well. It will only turn on if there’s at least 0.5 GPM flow of water running, so you won’t have to worry about it turning on unnecessarily. There are three heat settings, and you can easily switch between them by pushing the buttons on the outside of the water heater.

Here are the notable features of the Atmor Tankless Water Heater.

  • Comes in 5 different sizes. Most powerful is 13 kW and 240V
  • 3 settings – 13 kW, 8.5 kW, and 4.5 kW
  • Recommended flow rate of at least 2.25 GPM
  • Must be connected to a 60 amp single phase pole breaker
  • Comes with a pressure relief device
  • Made from heat resistant polymer with a fiber glass compound

The Atmor Tankless Water Heater is very durable and is designed for safe water heating. It’s also very energy efficient and will help you save money on your water bill, and it fits comfortably under your sink.

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Chronomite Instant Flow Water Heater

The Chronomite Instant Flow Water Heater may be small, but it’s powerful enough to keep your home’s hot water system running efficiently. It’s specifically designed to be installed under the sink, and has a horizontal installation that connects with two chrome fittings.

It heats up very quickly in approximately two seconds as opposed to larger traditional heaters, which take a bit longer. This is an option that’s much more efficient than installing a tank water heater and it’s more affordable as well.

Here are the notable features of the Chronomite Instant Flow Water Heater.

  • 5 GPM flow rate
  • 2 mounted chrome compression fittings installed horizontally
  • 120 V, 30 amp power source requirements
  • 3/8 water inlet and outlet connections
  • Rear electric knock-out

The Chronomite Instant Flow Water Heater is a reliable choice if you want a water heater that works fast and is space-efficient. It’s relatively easy to install under your sink, and will ensure that you always have hot water when you need it.

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Under The Sink Water Heater Buying Guide

When shopping for an under sink water heater, there are many specific things you should look for to ensure that the water heater will actually fit where it’s supposed to go, and that it will provide you with the heating power that you need.

Under sink tankless water heaters are very energy efficient and can cut your electric bill down dramatically, but they’re only worth using if they are powerful enough to deliver hot water quickly and consistently. If you do have the room, you may opt for a standard tank water heater instead but most of the time, space is limited. Here are the features you should look for to ensure that you are getting a quality under the sink water heater.


As the water heater will go under the sink, you need to ensure that you are purchasing something that will fit in this space. Look at the dimensions of the water heater you are buying before making an official purchase, and then measure the free space you have under your sink, taking into account where the water and electrical connections are. Many electric tankless water heaters come in multiple sizes, so you can purchase the option that fits most comfortably in your space.

Electrical Requirements

Under sink water heaters do vary slightly in their electrical requirements, so it is very important to make sure that you are choosing a heater that can safely connect to your existing electrical panel. The electrical requirements are usually represented in amps or voltage.

Before making a purchase, determine how much output your electrical connection has, and make sure you are purchasing a water heater that needs the same amount of electricity. Many people may opt for upgrading their whole house surge protector to cope with the additional electricity draw from these water heaters.

Ease of Installation

One of the benefits of installing a water heater under the sink is that it’s typically much easier to do than installing a larger water heater with a tank. However, all water heaters are going to require some installation.

If you have it in your budget, it may be worth it to pay someone to install your water heater to make sure it gets put in properly. However, this isn’t always an option. Before making a purchase, look online to see if you can find installation instructions for the water heater.

Instead of an electric water heater, you may opt for a tankless gas water heater instead. This means you will have to carry out further tests with regards to the gas safety.

Under Sink Water Heater Installation

Temperature Controls

Something else that’s very helpful to have on an under sink water heater is accessible temperature controls. You won’t always want the water to be the same temperature – for example, you might want to make it warmer in the winter and cooler in the summer.

Temperature controls that are easily accessible will make it much easier to switch the water if you need to. It’s also helpful to look for a water heater with a digital temperature display, because then you will be able to easily see the temperature you are adjusting.

GPM Requirements

In addition to having certain electrical requirements for installation, most under the sink water heaters also have GPM, or gallon per minute requirements for the water systems they are attached to. The GPM indicates the flow rate of the water, or how fast it moves. If your water heater isn’t powerful enough for your plumbing system or vice versa, it will be very difficult for the heater to work efficiently.


It’s important that your water heater is made from materials that are meant to last a long time, even with their exposure to moisture and a range of temperatures. Most water heaters use some form of metal water pipe connectors that can conduct heat safely. It’s also very important that the tank itself is made from a material that can safely conduct heat and handle the pressure of water pumping.

Noise Level

It’s incredibly frustrating to deal with a water heater that constantly makes noise whenever it’s in use. This is a particularly big problem if you share your space with roommates or if your family has different daily schedules, because you never want to wake anyone up with your water usage. Look for a water heater that is designed to operate quietly to ensure that this doesn’t happen.


A solid warranty is a must have for any water heater or other major household item that you purchase. Water heaters are expensive, and so you will want peace of mind in case you need to replace a part or experience a leak that isn’t your fault. The longer the warranty is, the longer you will be protected. A longer warranty is usually an indication of better customer service on the part of the manufacturer, as well as better product durability.

An under the sink water heater is incredibly convenient, because it saves you space and won’t be an eyesore. They also are very energy efficient and will save you money on your electric bill. When choosing your under the sink water heater, be sure to opt for something that will last you a long time and work safely and quietly.


Installing an under sink water heater provides you with a device that can be hidden away and runs efficiently for instant hot water. They are far cheaper than the standard larger water heaters but this is due to their lower performance figures due to their compact size. All of our recommendations consist of under sink water heaters that can be installed on a range of budgets.

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