The Best Tankless Water Heater Reviews in 2019 – PrimeHeaters

As a homeowner, you’ll definitely want to provide your family with a sufficient amount of hot water each and every day. In fact, you’ve probably already run into arguments, due to a lack of hot water and your children bickering over who gets to shower first. Upgrading your water heater is one reasonable way to rectify this problem and put an end to arguments once and for all. The industry has changed substantially over the years, so it is essential to utilize this guide, so you can acquire the information needed to find the best tankless water heater for your individualistic needs, preferences, and budget.


There are numerous things to take into consideration while trying to find the perfect one. For your consideration, the most notable will be explored below.

Electric or Gas

The debate over the efficiency of electric and gas heating has raged on for far too long and it is hotly contested even to this very date. Since there are benefits associated with both, it is general best to familiarize yourself with each and make a personal decision. Gas is more expensive upfront and also more difficult to install, since you’ll need to install a vent. Gas water heaters tend to be a little bigger than electric models as well. However, gas is more beneficial in one key area. They’re much cheaper to operate. Of course, it is essential to remember that both gas and electric depend on the price of their respective commodities, so this may not remain true forever.

Indoor Or Outdoor?

Next, you’ll want to consider where you wish to install your water heater. Some people will want to install it inside, but this is not necessary. Installing the unit outside is a good way to maintain the spaciousness of your home, but it will undoubtedly alter your home’s appearance. An indoor heater is ideal for those that want to have immediate access to it in case of emergencies and malfunctions. Gas is best outside, since it’ll help you avoid installing any type of ventilation.


There are numerous manufacturers of tankless water heaters and each one will deliver a handful of benefits, as well as some potential cons. EcoSmartRinnaiTakagi, and Ariston are all notable brands within the industry and all of their products are incredibly reliable. They also are well known for protecting their products with long warranties. With this in mind, it is essential to delve deeper into the histories and performances of each, so you can maintain your peace of mind, when making your investment.


If you’re going to be opting for an outdoor water heater, it is essential to choose one that is attractive. You obviously want hot water, but you do not want to transform your home into an eyesore. So, be sure to choose one that will look great alongside your home. Those installing the item inside in a concealed location won’t have to worry about this too much.


When attempting to find the best electric or gas model, you’ll want to make sure that you examine the unit’s performance and capabilities. Tankless models are substantially different from the tanked alternatives. So, the purchase will not be as simple as looking at the tank capacity. When purchasing a tankless model, you’ll need to examine its flow rate and the amount of water the tank can deliver each minute to ensure it can accommodate your entire family.

This information is readily available and should be designated as a GPM rating.


When taking the time to look for a top quality tankless water heater, you’ll find that the mass majority of top end products are fairly expensive. Although it isn’t necessary to spend thousands and thousands of dollars, it is a good idea to spend a little extra. Doing so will give you the ability to acquire a longer lasting and better serving device, as well as a longer warranty in most cases.


Finally, it is vital to examine the warranty provided. Although these products are designed for longevity and reliability, they can malfunction unexpected. Life is unpredictable, but a warranty can provide you with added peace of mind for some of these uncertainties. Longer is better and always opt for a reliable brand, which will be more than willing to stand behind their product and will live up to their word.

Review of the Best 5 Tankless Water Heaters

1. Stiebel Eltron Tempra 24 Plus Electric

Are you tired of standing around and waiting for your shower water to get hot? If so, it may be time to trade that traditional water heater in for a more modern, tankless one. These appliances have definitely changed the way people look at these kinds of products. A tankless heater is capable of providing instant and continuous hot water, so you are never kept waiting. The Stiebel Eltron Tempra 24 is one of the most reliable and efficient models on the market.

Stiebel ELtron Tempra 24 Plus main image

Notable Features

One of the best things about the Tempra 24 is its easy installation. All you need to do is mount it on a wall, connect water pipes, and plug the electric cable into a receptacle. Since you do not need to worry about venting the appliance, the installation process will be cut in half.

  • Energy efficient model
  • Compact, sleek design
  • Venting is not required
  • Operates on 240 volts of electricity
  • Weight – 15.4 pounds
  • Includes a 7-year warranty on the heat exchanger and 3-years on the parts
  • GMP – maximum 4.5

The Good

The Tempra 24 is capable of providing you and your family with a continuous flow of hot water. You can adjust the water temperature to suit your needs, plus it is a low decibel appliance. This is an energy efficient tankless water heater, so you should see some alterations in your water. In fact, the manufacturer guarantees consumers a 15-20% savings, but this is only on the hot water portion of your monthly water bill.

The compact and lightweight design is a major improvement from the heavy, bulky previous versions.

The Bad

There is one major downside to the Stiebel Tempra and that is a licensed plumber must be complete the installation. Most manufacturers stipulate this requirement, because they want to make sure the installation meets the city codes.


Tempra’s price tag is slightly higher than the competitor brand. However, when you consider the fact that you will always have instant and continuous hot water at your fingertips, the price will seem friendlier.

Overall Assessment

If you are on the market for a high-quality and energy efficient tankless heater, you should consider the Stiebel Eltron Tempra 24. It will no doubt make a great addition to your home.

2. Ecosmart ECO 18

Thousands of homeowners have already replaced their traditional heater with the more modern tankless model. There are many reasons why consumers prefer the tankless model to the traditional model, but one thing is for certain they can cut your energy expenses in half. The Ecosmart Eco 18 may be exactly what you need, because it is capable of heating 2.5 gallons of water every minute.

Ecosmart Eco 18 front

Notable Features

The ECO 18 is an energy efficient and low decibel tankless water heater. It will operate accordingly, without disturbing you or your family. The unit comes with a preassembled mounting bracket, so all you need to do is mount it on the wall.

  • Includes a limited lifetime manufacturer’s warranty
  • Energy efficient model
  • Adjustable temperature digital controls
  • GPM flow – 1.5
  • Weight – 14 pounds

The Good

If you take the time to size the unit with your home, you will receive the maximum benefits of the Ecosmart ECO. Its compact and lightweight design makes the ECO 18 suitable for apartments, flats, and condos. To provide homeowners with more floor space, the ECO will easily mount onto any wall in your home. Since it is capable of heating 2.5 gallons of water every minute, you can efficiently run two showers simultaneously, without experiencing any water temperate alterations.

The Bad

The only downside that can be found with the Ecosmart ECO 18 is the installation process. Consumers must hire a licensed plumber and invest in 2 40-amp breakers and a 150-amp electrical panel. This is going to be your biggest expense.


The price tag is fairly general, when compared to other brands. However, when you consider the limited lifetime warranty, this model cannot be beat. << Check the current price on Amazon by clicking here! >>

Overall Assessment

The Ecosmart ECO 18 is one of the sleekest tankless water heaters on the market. The quality of construction is impressive, so it will sure stand up to the test of time. After the installation is complete, you will always have instant hot water at your fingertips.

3. Ariston GL2.5 Electric Mini-Tank Water Heater

There are many excellent products on the market, but few can compare to the Ariston. The unit will not be ideal for everyone, but it will be absolutely perfect for some key situations. The Ariston Mini-Tank is compact, lightweight, easy to install, and incredibly affordable. Despite its small size and stature, it is a workhorse and can provide you and your family with enough hot water to supply a single sink. Continue reading below to find out more.

Ariston GL2.5 front image


  • Capable of storing 2.5 gallons
  • 14 by 14 by 10 ¼ inches in size
  • Weighs just 16 pounds
  • Protected by a 6-year warranty and 1-year on parts
  • Effortless installation, thanks to the plug-in power cord
  • Works as a point-of-use unit

The Good

There is a lot to like about the Ariston. Its small size ensures that it can be installed almost anywhere and you’ll never have to worry about the unit getting in your way or clogging up too much space. The interior tank is lined with glass, so it will last for a much longer period of time. Since the unit only weighs 16 pounds, you shouldn’t have much difficulty getting it installed. And of course, the unit is capable of producing and storing 2.5 gallons of water. That should be enough for a single sink and potentially a quick shower.

The Bad

Despite all of the positives, it is definitely true that the Ariston won’t be suitable for all households. It is simply too small to accommodate more than a single faucet. However, if you’re aware of these limitations and your specific situation aligns perfectly with the unit’s capabilities, you’ll love it.


The biggest selling point for the Ariston GL2.5 Electric Heater is its low price. The unit will attract a lot of consumers for this and this alone. However, it is essential to familiarize yourself with the unit’s limitations, before making your purchase. It can only be used as a point-of-use solution and cannot accommodate a big family. Nonetheless, the price tag is definitely suitable.

Overall Assessment

All in all, the Ariston is an excellent model, which will satisfy many consumers. It is reliable, sleek, and incredibly compact. If you have limited space and only wish to supply a single sink, the Ariston is definitely your best bet. Thanks to its low cost and warranty, the unit could easily be labelled a steal. Just make sure you’re aware of its restricts, before making your purchase!

4. Rinnai RL94iP Propane Heater

The Rinnai RL94iP is one of the very best tankless water heaters, which is capable of satisfying families of all sizes. It is slightly more expensive than many alternatives, but with the Rinnai, there will never be a need to purchase an additional one or upgrade to something bigger! The unit can deliver 9.4 gallons of water per minute, so you should be able to run all of the facets in your home, without any slowdowns.

Rinnai RL94IP front-side image


  • BTU rating between 10,300 and 199,000
  • Capable of delivering 9.4 gallons of water per minute
  • Temperature settings between 98 and 140 degrees Fahrenheit
  • 83% Thermal Efficiency
  • 12-Year warranty on heat exchange, 5-year parts, and 1-year on labor
  • Utilizes Propane gas

The Good

The good ultimately outweigh the bad. First and foremost, the unit is incredibly sleek. It can easily be installed anywhere and still look amazing. Secondly, the unit offers a large number of different temperature settings ranging from 98 to 140 degrees Fahrenheit. This gives you the ability to control your water, while also decreasing the potential for scalds. The unit possesses 83% thermal efficiency, so it’ll cut down your electric bill substantially. At 9.4 gallons per minute, the water heater can accommodate many sinks and showers at once.

And finally, the extensive, comprehensive warranties are undoubtedly major benefits.

The Bad

When taking the time to scour through electric tankless water heater reviews, you’ll find that many consumers love electric, due to the simplistic installation. This is where the Rinnai falters. Since the unit is propane powered, it will require the installation of a vent. Although this is to be expected, it is still somewhat of an annoyance.

The Price

The Rinnai RL94iP is definitely costly and will require you to spend extra, when compared to some of its competitors. For many, the price will be a major deterrence. However, it is vital to remember that the Rinnai’s performance surpasses many of its less expensive alternatives. When you experience the unit’s capabilities, you’ll agree that it is worth the price.

Overall Assessment

At the end of the day, the Rinnai has a minor setback, but it really isn’t a deal breaker. If you’re going to purchase a gas powered heater, you have to expect to install a vent, unless the unit is placed outside. The Rinnai is costly, but it is truly the only water heater you’ll ever need. Toss in the versatility and extensive warranty and you’ll agree that Rinnai is one of the best brands on the market.

5. Takagi T-KJr2-IN-NG

Takagi is widely known for their ability to deliver outstanding products at a margin of the price. This is true when it comes to the Takagi T-KJr2-IN-NG Indoor Tankless Water Heater. Thanks to a combination of features, simplistic installation, and immense reliability, the Takagi is definitely one of the best natural gas heaters. It is also sleek and will look great anywhere inside of your home, so there is no need to store it away in a cubbyhole.

Takagi water heater front


  • 140,000 BTU
  • Maximum flow rate of 6.6 GPM
  • Equipped with outlet thermistors for consistent temperature monitoring
  • Has an energy factor of .81 to .83
  • Energy Star certified
  • Weighs just 19.4 pounds
  • 10-year warranty on heat exchange and 5-year warranty on parts

The Good

All in all, there are numerous advantages associated with the Takagi T-KJr2-IN-NG. Despite its lightweight, the unit is capable of delivering a substantial amount of water. With a maximum flow rate of 6.6 GPM, you can rest assured knowing the Takagi will be able to supply your entire home with a sufficient amount of hot water. And, the unit has an energy factor of .81 to .83, so you can keep your family happy, while also slimming down your electric bill!

The Bad

There are truly only one or two minor problems associated with this product and one is to be expected, since it is a gas model. Due to the requirement of gas, the user will need to install a vent, before finishing the installation. This can make the installation a little more time consuming than the installation procedures for electric models. Also, the capacity might not be suitable for all households, but should be able to accommodate most.


When it comes down to it, the price of the Takagi T-KJr2-IN-NG is right on the money. It is slightly more expensive than some of its competitors, but it delivers additional benefits, which may not be available anywhere else. Plus, the unit is covered by an extensive warranty, which greatly surpasses many of the alternatives. With this in mind, the unit’s price is easily justifiable.

Overall Assessment

The Takagi is definitely a solid investment. As long as you’re fine with a gas water heater, this unit will deliver a satisfactory performance each and every day and will keep your family happy. What more could you ask for?

Our Pick: Stiebel Eltron Tempra 24 Plus

After extensive consideration, we’ve come to the conclusion that the Stiebel Eltron Tempra is the best tankless hot water heater on the market. It delivers all of the features needed to make used simplistic, safe, and convenient. It also delivers a sufficient supply of hot water and will undoubtedly satisfy your entire family. Thanks to the unit’s capabilities, the Stiebel Eltron Tempra isn’t a point-of-use solution or an add-on. It is a whole house solution and can deliver hot water to all of the facets and showers in your home, without any hiccups.

Stiebel ELtron Tempra 24 Plus main image

And, the unit is capable of cutting your electric bill down significantly. The costs associated to heating water will be slashed by as much as 15 to 20%! The digital temperature control allows the user to acquire the precise temperature they desire, so the potential of burns is completely eliminated. Finally, no venting is needed, so installation is much simpler. The combination of benefits makes the Stiebel overall the best of all. << Check it on Amazon! >>

Best Value / Best Tankless Water Heater For The Money:Ariston GL2.5 Mini-Tank

We can sympathize with consumers, who refuse to spend excessively for a water heater. In our humble opinion, we believe the Ariston GL2.5 Mini-Tank is the best bet for those homeowners, who also sympathize with this sentiment. Although the low price is definitely its biggest selling point, this amazing appliance delivers additional benefits, due to its size and capacity. It is very lightweight and compact at just 14 by 14 by 10 ¼ inches. And, it weighs just 16 pounds. The combination makes installation simple and you can easily place the Ariston anywhere inside of your home. << Click here to see it on Amazon >> The unit is capable of storing up to 2.5 gallons and can supply and entire sink with hot water. With this in mind, the Ariston is considered a point-of-use water heater and shouldn’t be treated as a whole home solution. Nonetheless, its small size, easy install, and capabilities make it an excellent investment. And, do not forget the extensive 6-year warranty!