Best Electric Tankless Water Heater Reviews, FAQs & Buying Guide (Top-Rated For 2024)

by Curtis Grossi | Last Updated: March 13, 2024
Best Electric Tankless Water Heaters

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Are you looking for innovative and reliable water heaters that won’t double your monthly energy costs? The best electric tankless water heater units generate water on demand without producing the standby energy losses common with storage water heaters. Tankless electric water heaters have a compact design and can be hanged safely on the walls.


These water heating units stay idle until a user opens the hot-water tap. They draw water from municipal water lines, and never requires a storage tank. Once the hot water tap is opened, water travels to the unit via a pipe, which then triggers the flow sensor to activate the electric heating element.

Top 3 Electric Tankless Water Heaters

1. Premium Pick: EcoSmart ECO 27 Electric

It is one of the most versatile and user-friendly electric heater, ideal for medium-sized households. You can save up to 50% on water heating costs with this digital unit.

2. Best Choice: Stiebel Eltron Tempra 15 Trend

It is one of the products that makes you wonder: “Why didn’t I buy this sooner?”. Worth every penny. It is one of the most innovative, and energy-friendly tankless water heaters you can buy today.

3. Best Value: Bosch Electric Tronic 3000

This 7-gallon water heater it’s one of the best-rated products from Bosch Tronic and can be easily mounted. It’s very budget-friendly.

The Reviews – Top 10 Picks

Here is our review of the top ten electric tankless water heaters that boast groundbreaking designs and high-efficiency ratings.

1. EcoSmart ECO 27 Electric Tankless Water Heater – Our No. 1 Pick

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EcoSmart is one of the world’s top-rated water heater manufacturer, known for creating flexible, state-of-the-art, and environment-friendly products. One of their biggest achievements lately is the manufacturing of the EcoSmart ECO 27 electric tankless water heater. It’s not only the most powerful and sophisticated heater they have ever created but also the most versatile and user-friendly electric heater ideal for medium-sized households.

The unit packs self-modulating technology to ensure accurate temperature control and digital control panel to allow for easy temperature adjustments. It’s versatile enough to work best under all climates, ensuring maximum water flow rate of 6.5 gallons every minute. The auto thermal protection adds to the unit’s usability, as it prevents overheating and overloading.

With this smart electric tankless water heater, you’re getting a lightweight unit, weighing less than 14 pounds, which can be installed virtually anywhere around the walls of your house. It’s low on maintenance and energy consumption, making it the perfect choice for small households.


  • It has an ergonomic design
  • Easy to install and maintain
  • It’s quite reliable and efficient
  • It can save you up to 50% on energy bills


  • Requires minimal flow rate
  • A bit costly

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2. Stiebel Eltron Tankless Water Heater Tempra 15 Trend – Our Best Choice Pick

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Rated very well in reviews, Stiebel Eltron Tempra 15 is one of the smartest, most innovative, and energy-friendly tankless water heaters you can buy today. The heater has a sleekly designed body that’s compact enough to fit well on your walls. It has a digital display that works efficiently to give accurate temperature readings and increase energy efficiency.

The pre-set temperature buttons allow for easy adjustment of the temperature memory settings. This water heater ideal for small to medium homes features a full power-modulation system and thermostatic temperature control. It’s effective enough to detect water flow rate and temperature to make accurate calculations of the required power.

And considering it has an advanced flow control technology, the unit guarantees streamlined hot water temperature control to offer optimal comfort. It’s the heater of choice for everyone who wants to enjoy continuous comfort and keep their showers hot throughout.


  • Operates efficiently and silently
  • Compact and small enough for easy fitting
  • Quite energy and user-friendly
  • It’s strong and durable
  • The unit has a sleek and attractive design


  • Its GMP output is a bit low
  • Requires a professional to install

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3. Stiebel Eltron Tankless Water Heater Tempra 29 Plus

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The Stiebel Eltron Tempra 29 plus is one of the most outstanding and innovative water heaters in the Stiebel Eltron Tempra series. Tempra 29 plus water heater is rated the second in the Tempra series when it comes to capacity. It has an advantage over other electric water heaters because it can serve the entire house with hot water continuously.

Tempra 29 plus water heater can be installed anywhere in your house and ensures continuous flow of hot water any time the need arises. It comes with a workhorse unit with 240v and 150psi.

It easy to maintain and adjust if need be and delivers 4.37 gallons flow within a minute. It is designed in such a way that it will occupy less space since no venting is needed to allow the free flow of air. This digital electric water heater uses coils to warm the water, unlike other systems that use burners.


  • It’s easy to adjust and maintain
  • It saves energy
  • It serves all the units in your house
  • It’s compatible with 208/240-volt standard electrical wirings


  • It is a bit expensive
  • It needs to be installed by a technician

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4. Stiebel Eltron Tempra 24 Plus Tankless Electric Water Heater

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The Tempra 24 plus is known for its high performance, compact size, and sleek design. It’s ideal for heating water for the whole house and guarantees high energy savings. User safety is assured, thanks to the high-limit switch that shuts the machine down in case of overheating.

The advanced flow control reduces water flow and keeps the temperature high during high demand periods. It also has an electronic temperature control knob that allows you to set your desired temperature flow. The voltage input options add to the equipment versatility since you can run it either at 208v or 240v.

Adding to the machine’s unequaled performance and usability is the smart microprocessor technology that includes flow and temperature sensors. These work by sending readings to the microprocessor to enable it to monitor and adjust the outgoing and incoming water temperature.


  • Energy efficient
  • Operates quietly and efficiently
  • Allows for consistent hot water flow
  • User-friendly and safe


  • It’s a bit costly
  • Not ideal for homes with no power connection

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5. Rheem RTEX-24 Residential Tankless Water Heater

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Rheem RTEX-24 residential tankless water heater is a superior heating system ideal for modern homes. The unit has external digital controlling units and advanced modulation units that make it easy for you to adjust temperatures and meet your demand for hot water supply. It is also equipped with three copper heating elements to ensure long term service.

The Rheem RTEX-24 tankless heater is designed to serve the whole house with hot water. It includes 3/4 NPT water connections, which make installation easy and quick. This water heater has a water flow rating of 5.9 GPM, making it perfect for homes requiring continuous hot water flow.

The energy consumption ratings of this water heater are low, and so it can save you greatly on energy bills. The fact that it is a tankless water heater, it only occupies minimal spacing, and so it won’t make your house look cluttered.


  • It has a digital self-modulation unit
  • The heater has three copper heating elements to ensure durability
  • It installs easily
  • It saves energy


  • Hot water can’t flow in multiple taps at the same time
  • The unit’s cost is a bit high

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6. Atmor ThermoPro Series Digital Thermostatic Control Electric Heater

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As one of the best electric water heaters from Atmor, the digital thermostatic control ThermoPro series water heater includes IP54 certificates. These make it a safe and reliable water heater for use in modern homes. The digital units allow for easy temperature adjustment. The fact that it’s created of corrosion-resistant and heavy-duty stainless steel make it a long-term investment.

With this high-end and user-friendly water heater from Atmor, you are assured of continuous hot water flow with no delays since it packs a superior self-modulating system to make that possible. The unit can efficiently heat water at 37 Fahrenheit and deliver it at a flow rate of 1.9 GPM.

The heater has a sleek and compact design. You can just hang it just anywhere inside your house or wherever you choose. Moreover, this heater has digital temperature control, which allows for easy temperature increments at a pace of 1 degree.


  • It heats water fast and efficiently
  • It’s made of stainless steel hence a long-term investment
  • It doesn’t require venting
  • It can save you up to 50% of energy


  • It’s quite costly
  • Doesn’t include pressure relief units

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7. Rheem RTEX-13 Tankless Water Heater With 240v Heating Chamber

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Rheem RTEX-13 counts among the top-ranked water heater brands trading in the market today. It is unique in style and sells at an affordable price. Once you have RTEX-13 residential tankless water installed in your house, be sure that you will have hot water available anytime the need arises.

The heater comes equipped with an external digital thermostatic unit and led displays that make it very easy for you to adjust temperatures. It is also fitted with two durable copper immersions that take the shortest time possible to heat water.

Its design is not complex, and therefore you can install it on your own instead of hiring a technician. It is very cost-effective in terms of energy usage because no energy losses incurred. It allows a flow rate of 4 gallons per minute.


  • It is easy to operate
  • It conserves energy
  • It is small in size, thus occupying less space
  • It is affordable
  • It is easy to install


  • It can only serve one unit at a time
  • It is good for small families

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8. Bosch Electric Tronic 3000 T 7-Gallon Mini Water Heater – Our Best Value Pick

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Bosch Tronic tankless water is one of the best-rated products from Bosch Tronic. This tankless water heater features a modern style and design, making it the best choice for use in modern homes.

Its small size and design make it space-saving. Installing such a modernized and reliable tankless heater is a great improvement in any modern house. It delivers hot water continuously to cater for all hot water needs.

Bosch electric mini-tank allows a flow rate of 5.1 gallons when horizontally installed and 7 gallons when vertically installed. Its great design makes it easy to install, and it can be installed anywhere in the house. It is easy to adjust temperature settings to meet your temperature.


  • It is space economical
  • It has a heating capacity of 1440W
  • It can be installed vertically or horizontally
  • Ensure a continuous supply of hot water
  • It is reliable


  • Couldn’t find one flaw

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9. EcoSmart ECO 2.5-Gallon 120V Electric Mini-Tank Water

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EcoSmart ECO MINI 2.5 2.5-Gallon water heater stands out when it comes to versatility and usability. It installs fast and requires no venting. The best thing about these units is that they are compact and so you can install as many as you want. It’s friendly to your energy bills, and adding it to your household equipment won’t sprout out the bills.

Also, this electric mini-tank water has a pressure valve and recirculation pump, which, if installed properly, minimizes the need to install two water heaters. The pressure valve helps boost and smooth out the functioning of the unit besides minimizing issues with leaks.

EcoSmart ECO MINI can lower your expenses if you settle for it when buying tankless water heaters. Advanced features such as Teflon tapes,1/2 female Brass Pipe Coupling with and 1/2 Male Brass Pipe Hex make installation easier and quicker.


  • It has an impressive and sleek design
  • There is pressure valve included
  • Lightweight-19.5 pounds
  • Analog temperature control


  • It doesn’t have a manual to instruct on installation

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10. Ecotouch Point-Of-Use Tankless Hot Water Heater

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The ECOTOUCH point-of-use tankless water heater is one of the sleekest water heaters that can be mounted on walls of any modern bathroom. The unit delivers hot water on demand and has one of the most efficient water heating elements that get the water heated in 3 seconds.

Its smart self-adjustment system enables the machine to automatically adjust its power consumption depending on the flow rate and temperature setting of the water. The hot water heats water to around 116-degree F. The unit suits best for modern skins as it doesn’t require preheating, considering the dispensed water is always hot.

Operating this water heater doesn’t expose you to any threats considering it includes multiple protection units. The heating components are created from durable and high-quality materials hence making it a perfect long-term investment. Also, an outstanding feature of the water heater is a digital display and touch, which allows for easy adjustment of the settings.


  • It includes a smart self-adjustment
  • Doesn’t cause scale build-up or leakage
  • It’s compact and sleek in design
  • It includes digital touch control panel


  • It’s a bit complex to install
  • It can only be mounted on the wall

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Comparison Chart

ModelBrandPriceOur RatingkWWeightDimensions
EcoSmart ECO 27 Electric Tankless Water HeaterEcosmart$$$$8.027 KW11 pounds3.6 x 17 x 17 inches
Stiebel Eltron Tankless Water HeaterStiebel Eltron$$$$9.014.4 KW1 pound4.6 x 16.6 x 14.5 inches
Stiebel Eltron Tempra 29 Plus Tankless Water HeaterStiebel Eltron$$$$$9.0
29 KW
1 pound4.6 x 16.6 x 14.5 inches
Stiebel Eltron Tempra 24 Plus Whole House Tankless Electric Water HeaterStiebel Eltron$$$$8.624 KW16.1 pounds21.7 x 20.1 x 9.6 inches
Rheem RTEX-24 Residential Tankless Water HeaterRheem$$$$8.224 KW17.8 pounds4 x 18 x 19 inches
Atmor AT-D18TP-AZ Instant Tankless Water HeaterAtmor$$$7.018 KW17 pounds17.4 x 5.2 x 13.4 inches
Rheem RTEX-13 Residential Tankless Water HeaterRheem$$8.413 KW4 pounds4 x 9 x 13 inches
Bosch Tronic 3000 T 7-Gallon Electric Mini-Tank Water HeaterBosch Thermotechnology$$8.61.44 KW29.5 pounds10 x 10 x 16 inches
EcoSmart ECO MINI 2.5 120V Electric Mini-Tank Water HeaterEcosmart$8.41.44 KW15.8 pounds16.2 x 11 x 11 inches
EcoTouch Electric Point-of-Use Hot Water HeaterEcoTouch$7.65.5 KW7 pounds15.1 x 10.9 x 4.8 inches

Tips And Factors To Consider When Buying Electric Tankless Water Heaters

If you’ve stayed with me to this far, it’s obvious your next most awaited investment will be a tankless water heater. Water heaters, especially the tankless ones, aren’t cheap. Unless you play your cards smart, you are likely to buy a tankless water heater because it’s budget-friendly without considering the long-term returns.

In our top ten product reviews and descriptions section, we have highlighted some core features of each of the products. However, we haven’t talked about the features in detail and what buyers, both new and experienced, should know before they make a choice. Stay tuned to know more about tankless water heaters, their core features, and the benefits of getting one.

Are Tankless Water Heaters A Worthy Investment?

The idea behind the creation of tankless water heaters was to bring an end to the common household water wastage issues in modern homes. These heaters generate hot water on demand and can save you up to 50 percent on energy costs. Ever since these units came into existence sometime in the 1990s, they have not only grown in popularity but also became more sophisticated.

The modern versions of tankless water heaters boast of advanced features like wireless connectivity, built-in recirculating pumps, and less hectic control and maintenance features. There’s definitely a perfect tankless water heater for everyone, and here is why you should get one.

1. Eliminates Water Wastage

Instant water heaters heat and dispense water on demand. They achieve optimal water conservation by eliminating the need for storage tanks, which are prone to leaks.

Even when insulated with the most efficient and durable insulators, standard water heater tanks are likely to give up over time. And in some instances, the leaks are so small such that you won’t notice them on time, meaning lots of water will be wasted in the process.

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2. Instant Water Heaters Are Compact

The tank-type water heaters must meet the required federal regulations of thicker insulation to keep standby heat losses low. And as you know, the thicker the insulation, the bigger the tanks. That makes them not compact enough to fit well in modern homes. Instant water heaters are as big as a suitcase, so you can conveniently hang them anywhere in your house.

3. Can Be Winterized Easily

Draining the tank of a water heater has proven to be one of the most challenging things vacation homeowners have to deal with regularly. It takes time and requires you to be very careful. Draining a tankless water heater takes a few minutes, and it is way easier and fun.

4. Instant Water Heaters Are Safe

Tankless water heaters contain no storage tanks, and so issues with leaks and water spills aren’t common. The exhaust and air-supply vents of instant water tanks are durably sealed, and so, no issues with carbon monoxide leaking into the unit owing to back-drafting.

Features To Pay Attention To When Buying Instant Water Heaters

Alongside your personal preferences and budget, there are things you cannot neglect when shopping for instant water heaters.

1. The Flow Rates

The reason you’re investing in a tankless water heater is to minimize energy bills and enjoy quality access to hot water when you want. And to achieve the best results, you must determine the flow rates of all the appliances that will connect to the instant water heater.

These are the average flow rates and temperatures of different appliances to help you choose the right choice of a water heater.

You’ve to know the amount of water and at which temperatures the appliances you have in place use hot water so you can decide which instant water heater has the most compatible hot water flow rate. If your fixtures are a bit large and aged, consider getting tankless water heaters with larger flow rate figures.

Consider heaters with a lower flow rate if your fixtures are smaller and more advanced. In case you don’t know how old the version of the fixtures you have at home is, you should consider heaters with a higher flow rate.

Check out also: Best Water Softener Shower Head Reviews

2. Decide Which Power Source Is Ideal For You

Tankless water heaters are either gas, solar, or electrically-powered. Whichever you choose, here is what you should know.

Almost 40 percent of tankless water heaters are electrically powered. Electrically powered instant water heaters boast amazing energy efficiency rates, though they are only ideal for homes that are connected to electric power grids. They eat up minimal space as they can comfortably fit anywhere in your house. It costs cheaper, installing electrically-powered water heaters if your home is already wired for electric water heaters.

Unfortunately, electric heaters aren’t powerful enough to be installed in larger families. They aren’t perfect for whole-house applications because it costs more to upgrade them. Larger families that opt for electric instant water heaters will be forced to install several units to ensure enough and continuous water hot water supply. When buying an electric tankless water heater, you must check things like the voltage, amperage, and circuit breakers.

Gas-powered tankless water heaters are the most powerful units you can find in the market today. They are fit for larger families and commercial installations. If your house isn’t wired for electric heaters, the gas water heaters will be the perfect deal for you.

These types of instant water heaters are way costlier. They are more durable and reliable, though. Based on the U.S. Department of Energy, liquid propane and natural gas tankless water heaters can save you up to $100 annually, while the electric counterparts can only save you $40 on energy bills annually.

In buying gas tankless water heaters, you have to choose from the three ignition options, which are standing pilot light, direct, and hydro-power ignitions. You must as well choose between direct venting and power venting options.

The need to make the world environmentally conscious has motivated some water heater manufacturers to create units that can tap solar power to ignite their water heating functions. Most solar instant water heaters are installed on the rooftop so they can efficiently tap and convert the sun rays into useful energy that would later be used to heat cold water.

Solar water heaters are the most costly choices, which require more extensive maintenance. The best thing about solar heaters is that they offer long-lasting service with lower ownership costs.

3. Type of Tankless Water Heater

We’ve three main types of tankless water heaters. These depend on the heating technology used as well as the equipment sophistication. The three main options are non-condensing, condensing, and hybrid condensing.

The non-condensing units use the original technology and novelty of the first-generation tankless water heaters, which were discovered in Europe and Japan. They have been in use for several decades now. The non-condensing tankless water heaters have a heat exchanger that heats the hot and boasts an Efficiency Factor of .82 to .85.

These types of instant water heaters are tested and confirmed to have unequaled reliability and performance. The only problem with these tankless water heaters is that they have hot exhaust, and so you must install costly stainless-steel venting.

These fall under the second-generation tankless water heaters that use two heat exchangers and an exhaust. The use of more heat exchangers and cooler exhaust to heat the water result in better efficiency of up to 94 percent. As with these instant water heaters, they can be vented using cheaper PVC. They have lower efficiency rates and cost more, though.

The third-generation tankless water heaters, also known as condensing hybrid, were originally manufactured in the United States. These advanced and more sophisticated tankless water heaters have a small water holding tank, with a capacity of one to two liters.

The small water tanks work to maintain a hot water reservoir and eliminates issues with lower efficiency. They can realize the required real-life efficiency of .92 to .96. Based on a study by the Gas Technology Institute, the condensing hybrid instant water heaters operate at a high efficiency of 94 percent and experience lower degradation owing to short draws.

4. The Intended Application

Currently, every model or brand of tankless water heater comes with features and competences fit for handling different applications smoothly. Most of the heaters come with labels highlighting what they can efficiently do. These are the main tankless water heater models and their core applications.

5. Reviews And Ratings

Every competition must produce a winner and a loser. In the competition for the best tankless water heaters, you will discover some products that outperform others in terms of functionality, sophistication, reliability, and durability. You want to buy and install a water heater that won’t disappoint you later, and so the least you can do is to evaluate and compare tankless water heater reviews and ratings carefully.

Almost all high-quality and energy-efficient instant water heaters that are designed to give optimum value for money will have hundreds of positive testimonials and good ratings alongside few criticisms from the unsatisfied clients.

You very well know as I do that nothing in this world regardless of how good and reliable it proves, will lack criticisms. And that’s why you should also be wary when evaluating tankless heaters that have no negative client testimonials. There are only two instances a product will have no negative reviews.

One is when the manufacturer or supplier deletes all the negative reviews, and the second is when people who have never used such products are paid to write manipulated customer reviews. Manipulated client testimonials are very easy to detect since they only tell one side of the story—which is the benefits you will get from the product.

6. Manufacturer Warranties And After-Sales Services

One area top brands and manufacturers triumph in is creating high-quality and durable products that meet customer quality expectations. Because they trust in the superiority of their creations, they always offer them alongside long-standing warranties and guarantees. Most of the top tankless water heater brands give one year of the unit body warranty and five years of heating element warranty. Besides the warranties, the top brands will offer the best after-sales services.

The lifespan of most tankless water heaters is estimated to be slightly higher than 20 years, but a lot can happen along the way, rendering the units useless. For that reason, ensure to get value for money by investing in heaters that have long-lasting warranties. Have a look at the customer complaints, and if you notice that most of them point to the direction of the product suppliers or manufacturers not honoring their warranty promises, you keep off buying such products.

7. Sophistication And Features

It’s the era of advanced technology and smart home integrations. Who doesn’t love the convenience of being able to control their appliances while miles away from home? What about the simplicity of being able to automate the functions of different appliances?

Nobody doesn’t love simplicity and convenience when it comes to running household appliances. Besides making sure your tankless water heater performs to your expectations and has the necessary amenities, you have to look out for advanced features.

Look out for sophisticated features like thermistor control valves and temperature display that add to the convenience and simplicity of operating tankless water heaters. If you want to integrate the water heater into your smart home system, consider getting one with Wi-Fi connectivity.

Keep your energy consumption rates low by opting for a unit with a self-modulating function. The self-modulation function works by adjusting energy levels, depending on your preferred temperature settings and volume of water used.

8. Durability And User-Friendliness

If there is anything tankless water buyers cannot take for granted is the durability of their selected products. Who wants to dash money to a product supplier after they are promised the best only to receive a nicely packaged piece of crap?

I am sure everyone wants to get value from every purchase. Thus, the least you want when buying an instant water heater is to get a product that will lose its value in weeks or even months.

Durably designed water heaters are going to bring a smile to your face because they will last for years, ensuring you optimally make the most of your investment. Top water heater brands have a long-life and will guarantee you of impressive performance for years. It’s good you search for a heater with a decent mechanism. It should be a machine whose spare parts are readily available in the market.

The user-friendliness of the tankless water heater is an important consideration, too. All a tankless water heater buyer wants is a product that’s easy and fun to operate. If a product cannot fulfill that simple obligation, its production is not worth it.

With a user-friendly tankless water heater, you’ll have a convenient and accessible product that performs to your expectations. Don’t be in a hurry to choose a water heater before you have confirmed the features and qualities that make it handy, accessible, and user-friendly.

9. Energy Consumption Rates

Adding a water heater to your household will definitely increase the power bills. That’s because it an electric equipment and will need the power to operate. But that doesn’t mean that it should sprout out the power bill so high such that you will regret ever investing in a tankless water heater.

To choose a tankless water heater that won’t raise your energy bills, ensure you first check the volume of water used in your household. These water heaters heat water on demand, and the more hours they stay active, the more energy consumed. If your household water consumption rates are quite high, consider settling for the most efficient water heater in the market to keep your energy bills under control.

In determining what water heater to buy, consider the temperature of the input water, as well. The input water in cold places will be colder, and so more energy will be used to heat the water to the desired temperature. Consider the temperature preference of the output water by users, also.

Get water dispensed at the desired temperatures without raising your energy bills by investing in tankless water heaters with external controls and thermostat temperature functions.

10. Ease Of Installation

Tankless water heaters are simply easy and fun to install. You virtually can hang these water heaters anywhere in your house and get everything working in minutes. However, that’s not always the case with all types and brands of water heaters. Some are a bit technical and require a high level of plumbing and wiring skills.

With most instant water heaters, all you should do is to place your unit on your desired wall surface, hook the output and input pipes securely, run water via the system to remove any accumulated air, install the needed circuit breakers, hook up the electric wires as per the user manual and then activate it for use.

When dealing with more sophisticated water heaters, the installation process may be a bit complex and demanding, though. Read the user manual carefully to know how to go about the on-demand water installation process. You may have to check with other customers to know how their installation experiences were. Because you don’t want to damage your appliance during the installation process, it is good you inquired about the installation complexities and demands beforehand.

11. Construction And Materials

There is an extensive range of materials used in creating electric tankless water heaters. The largest number of water heater brands and manufacturers use metals to create their products. Metals are naturally prone to limescale accumulation and would always need regular annual maintenance to stay strong and up to the task.

That doesn’t mean all sophisticated and advanced on-demand water heaters are made of metals. Some use stronger and more versatile materials alongside advanced construction technologies such as infrared. The appliances that employ infrared construction technology require less maintenance and accumulate less amount of scale.

They are way more durable and flexible and will serve you longer. The durability of such units is unquestionable, and their performance will surely woo you. For that reason, when buying electric on-demand water heaters, you must check the build quality and the materials used. It would be better you read the product descriptions to understand how it’s constructed and the materials used.

12. The Maintenance Costs

The cost of maintaining the advanced versions of on-demand water heaters that employ the latest design technologies is a bit high. Experts have estimated the maintenance cost at around $600 a year, which is surely high. The maintenance caters to everything, including general cleaning, care, repairs, and upgrades.

With regular in-depth cleaning, which involves flushing out all the units to clean off all the accumulated sediments and minerals, you’re sure to keep your appliance at a peak performance state. Regular cleaning and maintenance should be done to boost the appliance’s performance as well as keep it safe from potential more costly damages. Don’t ever forget that costly damages that require more technical spare parts can end up voiding the warranty.

The high cost of tankless water heaters is a burden itself, and so you wouldn’t want to add another financial burden to your life in terms of costly regular maintenance. Consider getting a high-quality heater from trusted brands and manufacturers to avoid common issues with costly annual maintenance costs.

13. The Heating Costs

You should as well consider the heating costs of the electric tankless water heater you are about to buy. You already have enough energy bills to pay, and even if you were to add them, you wouldn’t wish to raise them by 20% or 30%.

Replacing the electric tank water heater in your household with a tankless unit can save your home significantly in terms of energy costs. These units are designed to heat water only when the demand arises. They won’t heat water that’s not needed, hence won’t consume unnecessary energy to make your energy bills sprout extremely high.

All tankless water heaters don’t use the same heating technology. The costs of operating these units will differ from one brand to the other. Research the energy efficiency ratings of the water heating appliance you want to buy, and make sure you settle for one with the best energy efficiency ratings.

14. Brand And Manufacturer

It’s a common habit among product buyers to look out to the most trending and trusted water heater manufacturers for high-end and quality products. That’s because once a brand or manufacturer attracts the attention of different customers, it becomes hard for the customers to shift their loyalty unless the manufacturer gets out of business or starts creating low-quality products.

In regard to this same reason, you must be specific when it comes to the brand and manufacturer you trust to be your primary source for electric tankless water heaters. You want a brand that can be trusted and has established its reputation in the industry.

In our top ten product review section, we have outlined and reviewed the top-selling products from the best brands and manufacturers in the world. If you want the best tankless water heaters for your needs, you may need to search for products from the manufacturers behind the innovative and reliable water heaters we just outlined.

15. The Climate In Your Residence

As said earlier, electric instant water heaters heat water when it’s needed. They do have different power ratings and can effectively heat water to certain levels. The ability of an instant water heater to heat water to the desired temperature is usually affected by the temperature in the area you live in.

If you live in extremely cold areas, an ordinary water heater with basic features may not be the perfect choice for you. That’s because if it can only heat water by up to 40 degrees, it won’t make the water hot enough for your desired applications.

In cold areas, water temperature is extremely low. Let’s say the temperature is 50 degrees, and the heater can only heat it by 40 degrees, you will end getting partially cold water. To enjoy using hot water on demand while living in cold places, you are advised to settle for more powerful units that can heat water by up to 70 degrees as they will make your input water hot enough for the desired applications.

Best Uses For An Electric Tankless Water Heater (VIDEO)

FAQ – Questions And Answers About Electric Tankless Water Heaters

You’ve discovered the best tankless water heater to buy, but just before you create a cart and initiate the payment to complete the buying process, you realize that there is a lot you don’t know about these water heaters.

Don’t worry, as we are going to give you the answers to the most frequently asked questions about electric tankless water heaters.

What Is A Tankless Water Heater?

This is the most commonly searched question on search engines. Every day several hundreds of people learn about tankless water heaters for the first time. And once they do, they right away head to the internet to learn the truth about what these water heating systems are.

Tankless water heaters are simply the ultimate alternatives of tank-type water heaters. They are small and compact water heating devices that install well anywhere in the house, including the walls and sinks.

They usually heat water on demand, meaning they won’t waste lots of energy heating water that would not be needed instantly. The units supply the hot water constantly and can be installed either in commercial or residential buildings.

How Does A Tankless Water Heater Work?

Tankless water heaters don’t use any new water heating technology. They employ the same technique of heating water using coils or heating elements. For a tankless water heater to work, cold input water should be allowed to pass through its heating elements. Once the water flow sensor detects and determines the water flow rate, it alerts the unit’s computer, which ignites the burner automatically.

The water is then allowed some seconds to circulate around the heat exchanger, which raises the temperature to the desired hotness. The heating and circulation process will continue until the user switches off the water heater.

What’s The Difference Between A Tank And Tankless Water Heater?

Electric water tank heaters have insulated tanks, some of which are big enough to hold up to 20 gallons of water, while tankless water heaters don’t have a storage tank. In the tank heaters, the input cold water is stored at the bottom, while the hot water is stored at the top to allow for constant flow out until the tank is depleted. The input water in tankless heaters flows around a heating element until it is hot enough to be dispensed for use.

In storage water heaters, lots of heat is lost through the tank walls, which leads to standby heat losses. These losses could make you lose a lot in terms of heating costs. In the case of tankless water heaters, such issues aren’t common since the heaters heat and dispense water on demand. In fact, tankless water heaters promise to save you up to 30% on energy bills since no issues with standby heat losses.

What Technology Do Tankless Water Heaters Use To Heat Water Instantly?

Tankless water heaters are designed to activate themselves instantly when the built-in flow switch detects cold input water. They work in such a way that once you put on the faucet’s hot side, water will travel through the pipes, which is then circulated around several electric coils or burners. The burners and coil heat the water to the required temperature, and later release it for use by the target appliances or people.

Once enough water is heated and supplied to the required appliances, faucets, or users, you can shut down the hot water, which triggers the automatic shutdown of the heating elements and burners. This simply means that tankless water heaters only heat the water needed, and so the technique here is to ensure continuous and instant supply of hot water when users need it.

How Much Can I Save on Energy Bills When I Invest in A Tankless Heater?

Of course, you will, but the amount depends on a variety of variables. Since these units heat and dispense hot water only when the demand arises, taking long and simultaneous showers or connecting it to multiple appliances can reduce your savings.

That’s true since the unit has to strain to generate the maximum possible hot water, which triggers higher energy consumption and so higher electricity bills. Experts say that you can save up to 60% on electricity bills when you invest in a tankless water heater, but you may be surprised to realize that you only manage to save 5% or even 2%. The core reason behind this is that you pressure up the equipment a lot, making it to use more electrical energy.

Other key variables that will determine how much you save are the cost of electricity and climate in your area. If the electric costs are a bit higher than those in your neighboring towns, you are sure to spend more and save less. Also, if you live in extremely cold areas, you will have to spend more on electricity since the heaters have to heat the water for more hours for the desired temperature to be realized.

Is It Possible To Replace My Existing Tank Water Heater With A Tankless Unit?

Just like it’s possible to replace a tankless water heater with a tank unit, it’s possible to easily get rid of the aged tank water heater and have a brand new and advanced tankless unit installed. However, you must first address the two main requirements for replacing tank water heaters with tankless units.

If installing gas-electric tankless water heaters, you have to invest in special pipe vents and bigger gas supply lines because your new heating unit will need them to efficiently supply water to the heater and other appliances connected to the gas pipe. If you invest in an electric unit, you will have to invest in a bigger gauge wire and breakers that aren’t common with standard tank-type water heaters.

Do I Need One Or More Units To Enjoy Sufficient Water Supply In My House?

The number of tankless water heaters you need to install depends chiefly on your household water consumption rates. It as well depends on the tankless water heater model you settle for. If you get a tankless water heater with a higher flow rate, it will be enough to handle all your household hot water applications.

It’s up to you to decide what system to add to your household, depending on your core personal preferences. You can settle for tankless water heaters intended to supply hot water to one or two showers simultaneously. If the consumption rates in your household are a bit high, you should consider getting several units, though.

How Long Will My Tankless Water Heating Unit Last?

When handled with absolute care, the best gas-powered tankless water heater will serve you for up to 20 years. As for the electric counterparts, they can serve you for up to 10 years if you give them utter care and proper maintenance.

One of the main aspects that affect the service life of a tankless heating unit is the quality of installation and the area of installation. If installed professionally and in the right environment, tankless water heaters can live up to their predicted lifespans.

Is It Possible To Control The Temperature Of The Water Generated By My Water Heater?

Most of the modern-day tankless water heaters have a temperature control unit that lets you control the temperatures of the water dispensed. Some more advanced units have a display unit that lets you monitor the water temperature changes as well as adjust the unit to heat water to a specific temperature as per personal preferences.

The predicted minimal temperature a standard water heater can be set to so that the water dispensed comes out hot enough to meet the desired hot water uses is 98° F, while the maximum temperature is 140° F. When you get a quality water heater with an advanced temperature control unit, the maintenance work and access to the best diagnostic codes will be a breeze.

Can I Connect My Tankless Water Heater To The Existing Venting?

You can use the existing venting, but don’t ever forget that your unit may not function as expected. Every tankless water heater comes with a specified venting that’s confirmed and approved by the product manufacturer. Using a venting that’s quite different from what the manufacturer has specified risks your unit failing terribly.

The concentrate venting is the most preferred choice by most product manufacturers since it only requires one wall penetration for the exhaust and inhalation. If you cannot install the tankless water heater as per the manufacturer’s venting requirements, you should get an expert to install it for you.

Are Tankless Water Heaters Region-Specific?

The installation of tankless water heaters is subject to the set municipal and country building codes and regulations. Some states and cities around the world don’t allow the installation of certain types or models of tankless water heating systems. To save yourself against the hefty fines that may be imposed by the local authorities once they discover you have installed unapproved water heating units, you have to consult with them first to know their policies and regulations.

Some water heater models like the 3-phase and de-ionized aren’t covered under the return policies. Because of that very reason, tankless water heater buyers who live in territories with restrictions on which models or brands are backed by the states or city building codes and guides should take the needed precautions to avoid losing money in the process.

Why Is My Tankless Water Heater Taking Too Long To Heat Water?

So many things can make a water heater fail to generate hot water on demand as per the required time schedules. One of such things is when the home plumbing and electrical wiring has problems.

In the event the input water entering the water heater is more than expected, you will end up discovering that the unit takes longer to generate hot water. Also, if the electrical wiring has issues, the water heater will be forced to rely on the available electrical energy, which may not be enough to run it efficiently, hence the delayed hot water production.

Whatever the case, when such issues happen, it will be good you seek the professional help of a qualified sewer line and electrical wiring specialist. They will troubleshoot the problem and offer lasting solutions, ensuring you won’t experience such issues again.

Why Are Tankless Water Heaters Costlier Than Tank-Type Heaters?

The cost of tankless water heaters is for the value you reap from having the units installed in your home.
These water heaters are manufactured using heavy-duty stainless steel and copper materials, which give them the rigidity to last for up to 20 years. One key reason these water heaters are very costly is because of the CATIII stainless steel, which is needed for venting. These water heating units will initiate a money payback soon after you get one installed.

That’s because with any of these units installed, your water heating costs will go down, ensuring you save more in the long run. And considering that maintenance costs are low, you are sure going to have a wonderful money-saving experience with these great water heaters.

Does Tankless Water Heaters Work With Hard Water?

If you’ve hard water connected to your household, it’s good to inquire from the tankless water heater manufacturer of choice to know if their products support hard water heating. But regardless of what the heater manufacturer says about their products, you must keep in mind that that limescale is prone to accumulating inside the water line if the water flowing through it is hard.

Over time, the accumulated limescale will affect the way the water heater performs, making it not as effective as it should be. It’s strongly recommended you get the hard water filtered or softened before you allow it to pass through your household’s water pipes. Some more advanced water heaters have a digital unit that displays and alerts you when you need to descale the tankless water heater.

How To Size A Water Heater For My Needs And Applications?

When creating a size plan on what tankless water heater to install in your house, you must figure out certain things. Such things include but not limited to the number of bathrooms you have in place, the energy source, the temperature of the input water, the diameter of the gas line, available voltage, and the design of your interior.

You want to buy a high-quality water heater that will fit well in your existing water line as well as work perfectly well with the available electricity voltage.

Tankless water heater models differ when it comes to what they can do and the amount of water they can heat at different flow rates. And that’s the reason you should also consider checking the number of bathrooms and other faucets that will use the hot water. Ask for professional assistance so that you don’t settle for a tankless water heater only for it not to match your application requirements.

What Safety Features Do Tankless Water Heaters Have?

There are many safety features you will find on the top-selling tankless water heater brands. With the best units, you will discover safety features such as overheat limit wrap. ICAD monitor combustion, anti-scald protection, and flame failure monitor. Whichever brand or type of tankless water heater you choose, ensure you are getting a high-end product that’s certified and verified to be safe for use in modern homes.

Ensure you are getting a high-quality product that will perform to your expectations and won’t expose you to any security threats. It would be wise you check the product reviews to know what other customers think about the safety and reliability of the tankless water heater in question.


With everything said and done, tankless water heaters are no doubt the ultimate alternatives to tank-type water heaters. With these water heating units, you get access to hot water whenever you need it. There are many types and brands of water heaters to choose from, the reason you should pay attention to things that matter when buying.

Check the reputation and rating of the product manufacturer. Make sure to settle for top brands of water heaters like the ones we have just outlined above. Check product reviews and user ratings to know what customers think and if they can recommend such tankless water heaters to potential customers.

Curtis is the founder and owner of He is the lead guy concerning all the water-softening accessories in this site's guides and reviews. If he is not writing a reviews, guides or any other useful tips, you will find him testing them to find out their suitability. He is passionate about softening water. You will find him extremely helpful and always willing to educate the general populace all there is concerning water and its effects on their health and appliances.