Best Under Sink Tankless Water Heaters in 2022 – Reviews & Buyer Guide

1. EcoSmart ECO 11 Tankless Water Heater – Under Cabinet Water Heater

Best under sink tankless electric water heater

Energy efficiency is the most desirable aspect of any energy-based appliance, and this feature is offered by the EcoSmart ECO 11 Tankless Water Heater. Therefore, this is one of the best under sink tankless electric water heaters, which will help you take off the significant load of the current used for heating your water. EcoSmart ECO 11 is specialized in energy-saving, and if you are an eco-conscious homeowner, you need this product.

To be more specific, EcoSmart ECO 11 will be helping you in saving 50% of your money and the electricity utilization for water heating. This instant water heater comes with the 0.98 energy factor, which remains uniform throughout usage. Also, this unit is known for whooping energy efficiency of 99.8%. Thanks to the EcoSmart manufacturers for using the self-modulating technology which has been patented earlier.

The optimal performance and energy regulation are ensured because of this technology. In addition to these features, this water heater is a compact one and comes with a sleek design. Therefore, it will be capturing your attention as you see it. In addition to this, you can observe the exact temperature displayed by the digital screen in addition to the attached thermostat.

Key Features

• It saves your money by saving energy
• The smaller and convenient design will enable easier installation
• The digital display will allow you to see the temperature of the water
• 1-year warranty expresses this heater’s premium quality

You will save loads of energy and money by opting for an energy-efficient design like EcoSmart ECO 11. This instant water heater will only be turned on as you use it, thus saving energy versatile. Also, the compact design and smaller size will allow you to install it below your sink. This water heater will be facilitating you as long as you keep it.

2. Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater – Mini Water Heater Under Sink

Best 240v under sink tankless water heater

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater is the perfect example of the excellent design with the digital thermostat and LED display. You have the complete choice to adjust the externally located thermostat for the temperature range of your desire. You can do this with the LED display, which is remarkable in accuracy and renders this heater one of the best under sink tankless water heaters.

When we purchased the Rheem RTEX-13 best 240v under sink tankless water heater, we were amazed by the flawless heating aspects. Thanks to the Rheem manufacturers for making this instant water heater with dual heating elements. These heating elements are composed of copper immersion that ensures excellent temperature rise as you open the tap. Furthermore, this pick is field serviceable as well.

The best performance of the Rheem RTEX-13 is attributable to the power control system, which is a self-modulating one. In addition to these features, we also want to share our experience of the easier installation of this water heater. It comes with the 1/2 NPT adapters in addition to the compression connections for water. These connections are 1/2 inches in size.

Key Features

• The simple installation makes it the best instant water heater
• The water flow rate of this pick is 3.17 GPM, sufficiently fulfilling your needs
• The durability of the heating elements is ensured due to the copper immersion composition
• Rheem RTEX-13 has the capacity for saving 99.8% of energy and money

Rheem RTEX-13 is an incredible choice to go for in 2022 because it will be saving 99.8% of the energy for you. Thanks to the energy-efficient design and performance of this heater. You can adjust the temperature with increments of 1 °F by using the external controls. The good news is that you will obtain a 1.5 GPM shower head with this product for saving water.

3. PrecisionTemp RV-550 Tankless Water Heater – Water Heaters Under Sink

Best under sink tankless hot water heater

PrecisionTemp RV-550 Tankless Water Heater is one of the best under sink tankless hot water heaters having suitability for the smaller tinnier house-based use and if you are an outdoor camping enthusiast. We have frequently used it during our camping days by attaching it with the mobile sink and other recreational vehicles (RVs). It is an exciting product for the trailers.

It is a handy and preferable product because of its propane fuel requirement for heating the water instantaneously. The good news is that it has an excellent performance despite using less amount of propane. To be more specific, it will be consuming only 20 pounds of propane and providing you with 940 gallons of hot water.

You only have to give your 1.5 Amp of the current supply to your PrecisionTemp RV-550, and it will do its job. However, we must tell you that you need to provide the 3 Amps for activations in the colder regions. The portability of this instant heater is attributed to the lightweight design. It only weighs 32 pounds. Also, the design is compact and space-saving to help you if you have a tight space.

Key Features

• Specially designed for the RVs, cabins, trailers, and mobile washing facilities
• Space-saving design occupying only 1/2 inches of space with 32 pounds weight
• Efficient technology system based on the reliable VariFlame
• Designing, assemblage, and examination for quality done in the USA

If you are primarily concerned about the security and protection of the electrical appliances, then you must not overlook an excellent choice like PrecisionTemp RV-550. This instant water heater comes with a free protection system. This system is associated with directing the burner for fire initiation, and as a result, the activation of all-electric elements takes place. You must grab this product to enjoy these all benefits.

4. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater – Undercounter Tankless Water Heater

Best mini under sink tankless water heater

Rheem RTEX-18 18kW 240V Electric Tankless Water Heater is an exclusive choice to opt for the larger GPM spanning over a range of 4.0 to 4.4. Thus, it will be satisfying the requirements of the household. In addition to this, the delivery of the hot water with a speedy flow rate renders this instant water heater to be one of the best minis under sink tankless water heaters to purchase in 2022.

Another good feature of the Rheem RTEX-18 is the promising energy-saving aspect. It can save up to 99.8% of the energy. Therefore, calling it to be the most environmentally friendly product won’t be wrong. In addition, it will be adding a handsome amount to your savings through its energy-efficient design. You are just one click away from setting the ideal temperature by using its control panel.

Rheem RTEX-18 has remained in our utilization, and we can assure you of the highly advanced system that it uses for heating your water. This is a self-modulation system for the adjustment of the temperature for fulfilling the hot water demands. You won’t find an instant water heater with this unique feature and intelligent design on the market.

Key Features

• Designed for fulfilling larger hot water needs
• Energy-efficient design with the low price
• Easier installation and replacement ensures
• Durable materials used for construction

Enjoying the instant heater’s promising and desired features by paying a fair price is not a bad deal to get yourself involved in. Rheem RTEX-18 is here to amaze you with high-performance, easier installation, and durable construction. Therefore, you must grab this opportunity of procuring this energy-efficient and economical product to meet your hot water needs.

5. Stiebel Eltron 220816 Sink Tankless Electric Water Heater

Best budget under sink tankless water heater

The intelligent design and pigtail in the pre-installed form of the Stiebel Eltron 220816 Sink Tankless Electric Water Heater will want you to purchase it for your home. It will catch your heart at first sight due to the sleek design, but you will admire it for its higher capacity later on. We are saying this because we had a similar experience with the Stiebel 220816.

You will be able to enjoy the infinite hot water supply with this tremendous instant water heater. In addition to this, Stiebel 220816 will is a user-friendly pick that you can mount without any effort. Also, you don’t need any prior expertise for installing it. With this best budget under sink tankless water heater, the gas losses are minimal. Since it has built-in three water heats that appear instantly and are involved in eliminating the heat losses.

Another best feature that we loved about the Stiebel 220816 is the lightweight design easing its portability and installation. The thermal efficiency of this heater is matchless because the hot water with it is just a few seconds away from you. Thanks to the manufacturer of this instant heating machine for using excellent heating elements made with copper and other components.

Key Features

• Space-saving design for adjusting in tight places
• Excellent embedded technology for energy saving
• Facile mounting options and more straightforward installation
• Warranty of the seven years for leakage and three years for parts

If you are looking for perfection in an instant water heater, it’s high time to purchase an excellent pick like Stiebel 220816 and enjoy all these perks. The reason for calling it perfect is the 99.9% energy saving which is peculiar about this great water heater. If you invest in this heater, we can guarantee you that it will not disappoint you.

6. Atmor 27kW/240V Electric Tankless Water Heater

Best commercial under sink tankless water heater

The smaller footprint of the Atmor 27kW/240V Electric Tankless Water Heater makes it the best commercial under sink tankless water heater to help you adjust it in a tight place. In addition to the space-saving design, it is also preferable for the excellent temperature range. You can change its temperatures between 90 and 135 degrees F and make your life easier and relaxed with it.

Purchasing Atmor 27kW back in 2019 was the best decision we made, and we are even using this great pick today. You can use the temperature control for setting temperature with an incremental aspect of 1 degree. It is easier to employ this digitized control center. Another mention-worthy feature of this heater is the self-modulating system.

The self-modulating system of the Atmor 27kW is based on the Thermo-Pro feature, which is associated with the efficient regulation of energy that it needs for heating water. Also, Atmor 27kW has an intelligent system embedded inside it that detects water flows automatically. This system will be turning on and off by itself.

Key Features

• Specialized for saving 50% costs
• Excellent for marketable or housing use
• Superior warranty for parts and leakage
• Safer design to ensure protection

Opting for the highly technologically picks can make your life easier. So why not opt for the highly advanced Atmor 27kW coming with the best technologies like ThermoPro and water flow fault detection? Just use the pressure relief equipment and install it at the best place under your sink to enjoy the hot water. This premium quality product will be delivering more than you expect it to be.

7. ECOTOUCH 5.5kw 240V Point-of-Use Tankless Water Heater

Best under sink instant hot water heater

The smarter self-adjustment and supplying sufficient hot water features of the ECOTOUCH 5.5kw 240V Point-of-Use Tankless Water Heater indicates the fact that you must not miss it. It is one of the best under sink instant hot water heaters because it has a more robust heating system with 5.5 KW of wattage. It is capable of heating up to 116 degrees Fahrenheit.

It’s time to get rid of the dysfunctional water heaters and use a safer and durable pick like ECOTOUCH 5.5kw. We are grateful to the manufacturers for using multiple types of protection devices. The good thing is that the quality and safety assurance of all the components has been done. So, they are 100% safe to use. The manufacturing design has kept the inner water supply line and electric lines in separate ways.

ECOTOUCH 5.5kw has the approval of the ETL and UL qualification. Thus, the outstanding functionality is legitimate to go with this instant water heater. It promises 98% of the energy-saving, and thus indirectly, you will be saving your money through this heater. This heater is specialized in adjusting the power inputs based on the water flow rate and temperature.

Key Features

• A smart system capable of the self-adjustment
• Energy-saving design with 98% of savings
• Ensures safety and durability for an extended period
• Excellent heating elements used

If your conventional tank-based heaters are troubling you, then you must replace them with an innovative and functional choice like ECOTOUCH 5.5kw. The intelligent heating system, matchless security and protection, convenient use, and durable construction will be excellent for your long-term benefit. If you use it properly, then this heating appliance will be accompanying you for an extended duration.

8. Tankless 220/240V Electric Hot Water Heater

Best under sink 220V water heater

If conventional water heaters are not fulfilling your hot water needs, then grab a Tankless 220/240V Electric Hot Water Heater offering you an exceptional higher temperature of 131 degrees Fahrenheit. That too without any sort of the pre-heating and making you wait. Getting the hot water within 3 seconds with the Tankless 220/240V makes it one of the best under-sink 220V water heaters to go for.

The best thing about the Tankless 220/240V is that it acts as a point. That means it has an efficient connection with the water intake unit to provide you with instant hot water. The energy-saving mode of this appliance is also outstanding. The manufacturer has installed innovative inverter technology in it for saving energy. As a result of purchasing Tankless 220/240V, you will be able to save your energy, time, and of course, money.

In addition to these features, this water heater is a user-friendly pick. You will be able to use its digital display and LCD touch screen control. These visual settings are effective for setting the temperature according to your need. In terms of installation, you will face no trouble because everything comes ready with this product package. So, you don’t have to spend additional expenses.

Key Features

• Lightweight option for mounting on walls of your desire
• It will be saving the energy and your money incurred on it
• Manufactured with the unique heating elements for matchless heating
• It is famous for the endless supply of hot water

Tankless 220/240V is a premium quality product that comes with safer and durable construction. Also, it has a long life span, and thus it will be benefitting you for many years. It has a corrosion-resistant shell made from premium quality tempered glass. So, you can wipe this high-quality product for cleaning it occasionally. This will be an excellent addition to your kitchen, hair salon, bar, community center, and school.

9. EcoSmart POU 3.5 Point of Use Electric Tankless Water Heater

Best under sink tankless water heater 120v

EcoSmart POU 3.5 Point of Use Electric Tankless Water Heater qualifies to be one of the best under sink tankless water heaters because it specializes in faucets that provide hot water. Also, the quantity of hot water production with this water heater is exceptional because it produces 0.5 gallons per minute. Thanks to the remarkable flow rate.

Another best feature of this instant water heater is the smaller shape and design. So, if you are looking for a space-saving design, then EcoSmart POU 3.5 can be the best option to go for. Despite the smaller size, the manufacturers have not compromised on the quality of this product. The flow control system of this water heater is highly advanced and responsive.

The water temperature will be adjusted automatically once you open the faucet. If you purchase it for use in the long term, it will save up to 60% of the costs incurred on water heating with conventional heaters. However, you must be mindful that EcoSmart POU 3.5 can support only one sink in a given period due to its smaller size.

Key Features

• This heater can heat at 0.5 GPM in case of warmer climates
• Capable of working with the lesser amperes of current
• It delivers hot water with the incredible speed
• The easier installation will not bother you with complicated steps

If you are a camping individual and want to enjoy trailing and other outdoor activities comfortably, then why not select the best under sink tankless water heater 120v made for recreational vehicles (RVs)? EcoSmart POU 3.5 comes in a lightweight and small size, due to which it becomes a perfect choice for offices, trailers, and boats, etc. Therefore, you must grab the one to enjoy all the benefits it offers.

10. iHeat Tankless S-9 240V 39A 9KW Stainless Steel Enclosure Electric Water Heater

Best under sink tankless water heater reviews

We were often missing the hot water during our parties at the beach or the yacht. It was the best time of our life when we learned about iHeat Tankless S-9 240V 39A 9KW Stainless Steel Enclosure Electric Water Heater. Now we have it as an integral part of such events. We love it for its durable construction and matchless heating capacity. Not just this, but you can use this water heater for the home kitchen or bathroom, which makes it among the best under sink tankless water heaters.

iHeat S-9 has excelled the other electric water heaters in the market because of its compact size, lightweight, and excellent performance. You can enjoy hot water in few seconds by mounting it on the wall or any other desires place. Just use the copper piping and provided adapters for installation, and you will be getting the best results by getting rid of the appliances that give you lukewarm water.

Among all the best features, we loved the touchpad of the iHeat S-9 because it is waterproof. When you purchase this item, you will feel grateful to the engineers who made this meticulous design and ensured safety for the customers. You can vary the temperature between 32 to 150 degrees and enjoy the hotter water as per your desire.

Key Features

• The compact size will be saving your space
• Manufactured with the premium quality steel
• Interactive touchpad which is also waterproof
• Expresses excellent capacity towards the rust and tarnishing

iHeat S-9 is the perfect example of the versatility and meticulous engineering output because of its waterproof touchpad and many other useful features that it offers. You will enjoy the excellent features of the perfect heating with excellent heating elements if you purchase this product. Based on our personal experience with iHeat S-9, we strongly recommend you to go for this product.

Pre-Purchase Considerations

After reading the review of the best under sink tankless water heaters in 2022, we hope you will be purchasing the top tier one for your home and another sort of camping needs. When it comes to the appliances you are buying to fulfill your home-based needs, you need to be careful about the quality and other features. The same rule needs to be followed for purchasing tankless water heaters.

However, you must be very clear about the pre-purchase considerations you need to consider before purchasing the final item. That is why we have blended our personal experiences with the opinions of the other regular users and compiled this buyer’s guide for you. You must keep these tips and tricks in your mind before finalizing the water heater. So, here we go with these tips and tricks!

Fuel Source

You need to make a meticulous check for the type of fuel your tankless water heater will be using. Ideally, you must opt for the water heaters which work on low-cost fuels. They will only be economical and energy-saving if they are running on cheaper fuels. For example, you may purchase a PrecisionTemp RV-550 Tankless Water Heater that runs on a meager quantity of propane.

In this case, PrecisionTemp RV-550 will be helping you in saving a handsome amount of money per month. If you succeed in observing this reduction in the cost, then you should not overlook such choices. On the other hand, if you see a water heater with a cheap fuel source, but its performance is faulty or slow, you must ignore such destructive items that will not serve you for a long time.

Energy Efficiency

Another important pre-purchase consideration is checking if the particular water heater you are preferring is energy efficient or not. Generally, different manufacturers will be providing you with an energy rating. This energy rating will give you an insight into the energy-saving potential of any water heater. Luckily, the top-tier picks that we have reviewed for you are capable of energy saving.

The energy rating of the different products is indicative of the potential of the appliance to show performance by consuming a lesser amount of energy. In this regard, you may pick the following items with the best energy efficiency:

• EcoSmart ECO 11 Tankless Water Heater
• Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
• Stiebel Eltron 220816 Sink Tankless Electric Water Heater
• Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Facile Installation

As you make the final purchase, you must not forget to check the installation procedure. Ideally, you should opt for the choices that are easier to install. Also, go for the items that come with the more accessible manuals to guide you. Otherwise, you will need a person to install it for you, and you will end up paying more money for getting their services.

The good news is that several tankless water heaters are coming with more accessible installation methods. However, sometimes, you may face the hard luck of getting a water heater with complicated instructions. Also, if you are using the manual to set up your water heater, you need to be very careful of safety measures. Some of the valuable water heaters with the easier installation are:

• EcoSmart ECO 11 Tankless Water Heater
• iHeat Tankless S-9 240V 39A 9KW Stainless Steel Enclosure Electric Water Heater
• Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater
• Stiebel Eltron 220816 Sink Tankless Electric Water Heater
• Rheem RTEX-18 18kW 240V Electric Tankless Water Heater

Award	Design	Tankless Heater Brands	Retailer
Best under sink tankless electric water heater	Best Pick	1. EcoSmart ECO 11 Tankless Water Heater – Under Cabinet Water Heater	Check Price
Best 240v under sink tankless water heater	Staff Pick	2. Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater – Mini Water Heater Under Sink	Check Price
Best under sink tankless hot water heater		3. PrecisionTemp RV-550 Tankless Water Heater – Water Heaters Under Sink	Check Price
Best mini under sink tankless water heater		4. Rheem RTEX-18 18kW 240V Electric Tankless Water Heater – Undercounter Tankless Water Heater	Check Price
Best budget under sink tankless water heater	Budget Pick	5. Stiebel Eltron 220816 Sink Tankless Electric Water Heater	Check Price
Best commercial under sink tankless water heater		6. Atmor 27kW/240V Electric Tankless Water Heater	Check Price
Best under sink instant hot water heater		7. ECOTOUCH 5.5kw 240V Point-of-Use Tankless Water Heater	Check Price
Best under sink 220V water heater		8. Tankless 220/240V Electric Hot Water Heater	Check Price
Best under sink tankless water heater 120v		9. EcoSmart POU 3.5 Point of Use Electric Tankless Water Heater	Check Price
Best under sink tankless water heater reviews		10. iHeat Tankless S-9 240V 39A 9KW Stainless Steel Enclosure Electric Water Heater	Check Price