Best Tankless Water Heater 2019 – Top Picks and Buyer’s Guide

You’re here because you’re in search of the best tankless water heater 2019, aren’t you? You’ve landed smack dab in the right place!

One of the biggest necessities you should definitely invest in now is a water heater. I’m not talking about the traditional, bulky, cost consuming tank water heaters. Tankless water heaters are all the rage now and with good reason.

When compared to tank carrying water heaters, tankless water heaters have many benefits over their predecessors. For one, it is less of a hazard because it doesn’t have a container just sitting there with enough sizzling hot water to constitute a hazard should there be a leak or something. These tankless water heaters are boil-on-demand, heating up only the amount of hot water you need in a matter of seconds, thereby saving you a ton on gas and electricity. Plus reports show they’re easier to maintain and last longer.

If you’re reading this that means you’re probably already looking into getting one for your office or home. You should know that just like every other product out there, there are some tankless water heater brands that stand head and shoulders above the rest. We’ve taken the time to do the requisite research to bring to you one of the best tankless water heater reviews featuring ten of the best tankless water heaters that are sure to give you optimum satisfaction this season.

Top Best Tankless Water Heaters 2019

1. Rheem RTGH-95DVLN Tankless Water Heater

This tankless heater model differentiates itself from its predecessor in that it is more environmentally friendly as it only runs on natural gas. A perfect fit for homes that rely solely on natural gas, especially in low emission states such as California and Texas and Pennsylvania.


High efficiency – Thanks to its innovative design it spots a condensing heat exchanger designed with stainless steel. This results in a 94% energy efficiency. This means there is little energy wasted here as it consumes energy responsibly and yields commensurate results in its functions.

Intelligent controls – I would term this a “smart” water heater. What with its top notch electronic controls (as in other Rheem versions) complete a remote control for flexibility and easier operations, it is definitely a pace setter in its own right. It also comes with an adjustable temperature range that ensures that the water is always hot enough but not hotter than necessary.

Overheating and freeze protection – The guardian film wrap layered around the water heater lowers the possibility of overheating. It’s antifreeze protection feature is often the difference between water freezing in your pipes and continuous, seamless operation at temperatures of –30 degrees Fahrenheit.


  • Can use multiple tankless units simultaneously (up to 20 units via different connectors) in periods of high demand.
  • With its water savings setting activated it can save up to 1,100 gallons of water for homeowners every year.
  • Can be operated at high altitudes, up to an elevation of 9,840 ft above sea level.


  • It may be environmentally friendly, but all good things come at a price and it is pricey!
  • If you do not reside in low emission states it’s probably not a good buy option for you – no matter how much you like it.
2. Ecosmart ECO 36 36kw 240V Electric Tankless Water Heater

With a dimension of 17” by 19” and weighing in at about 17 pounds, it is a compact design that can be installed anywhere in the house with minimal space requirements. The ECO 36 tankless water heater line is a top notch product line up with the 36kW version arguably its best release, according to a good number of the best tankless water heater reviews. It claims advantages, from handling a high demand of up to 6GPM to half your annual water heating costs.


Self modulating feature – Saves energy by controlling just how much energy it needs to burn through to produce the amount of hot water demanded.

Digital temperature control – This model has one of the best digital temperature control features on the market, allowing you to select the exact water temperature for your needs down to the degree, which is not the case for most other brands.

Copper and stainless components – It is designed with materials that ensure good thermal efficiency, thereby keeping it durable while maintaining ease of operation.


  • It is constructed with materials that ensure that it is easy to maintain.
  • Small and compact design means it doesn’t take up much space.
  • It is relatively affordable, especially compared to the Rheem water heater models.
  • Greater temperature control means that you save a pretty penny on annual water heating costs.


  • Its smaller size means that it cannot most likely struggle to handle high water output from two points or more simultaneously.
  • It may be cheaper, but customers feel its size stumps its performance and makes the cost feel like an overspend.
  • Is not an ideal option for large homes with high hot water demand.
3. Bosch Tronic 3000 T 4-Gallon Electric Mini-Tank Water Heater

Yeah. I know what you’re thinking. What is a tank water heater doing in this review? Bear with me and read on. It is arguably the cheapest water heater on the market. This sleek, 13.75’ by 13.75”, 4-Gallon capacity water heater (it does come in two other sizes) is so compact it can be mounted just about anywhere, whether up on a wall or under the sink. You’ll appreciate this when you count the cost of alternatively plumbing a hot water line to every sink in the house.


Semi–tankless ability – The designers knew of course that a maximum of 4 gallons of water can only do so much. This is why the Bosch was designed such that it can be connected to a large hot water source such as a tankless water heater to ensure uninterrupted supply of hot water.

Good insulation and durability – The tank is lined with glass which helps to raise its insulation score and durability against damage.

Temperature control ad safety feature – The knob design temperature control feature means it has better temperature adjustment than most heaters. Also, the temperature and pressure release valve prevents aids in safety by preventing the water pressure from going above the stated 150psi or 145 degrees Fahrenheit for the temperature.


  • It’s ability to work with tankless heaters makes it perfect for periods of emergency.
  • It is cheaper than most other heaters in the market.
  • Its lightweight and small design doesn’t take up space.
  • Top quality thermal efficiency.
  • Top quality safety measures/features.


  • It’s 4-Gallon size means it usually performs best when used solely for one water point
  • It is not an ideal heater for large houses or events.
  • It can’t cover high demands of hot water independently.
4. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas

Takagi is the first company to introduce tankless water heaters to the US markets. That ought to say something good about them. The T-KJr2 is the smallest in their lineup of tankless water heaters. It’s lightweight 19.4 pound design makes it the best tankless water heater for small houses and apartment units as evidenced by a myriad of tankless water heater reviews available online.


Good flow rate – This tankless water heater unit is designed to produce up to 6 gallons per minute of use.

Top quality temperature check – This feature prevents damage by making sure that the heater shuts down if the temperature goes beyond the maximum limit.

Air Fuel Ratio Sensor – It is built to ensure that emissions and harmful pollutants are kept to a minimum

Operational protection – The T-KJr2 comes with anti-freeze features and surge and digital meter protection all geared towards ensuring the lowest possible failure rate.


  • It’s got enviable staying power with its ability to meet hot water demands in a general household for up to 10 years.
  • It’s straight forward and easy to install. Just follow the step by step instructions that provided with the catalogue and you can’t go wrong.
  • The Advanced DIP switches mean you adjust the settings to remain at optimal performance at different altitude ranges.


  • It’s perfect for small to medium scale houses. For larger residences you may need more than one unit to ensure constant, uninterrupted hot water supply.
  • Somewhat limited usage per time as you cannot get more than 40 gallons of water in one single usage.
5. Stiebel Eltron Tempra Plus 24 kW, tankless electric water heater

Stiebel Eltron has been advancing technology for almost a century and is the company behind this innovative, sleek, briefcase like tankless water heater design. This Tempra Plus design is their greatest release yet from their water heater lineup. Besides the conventional water heater advantages, it does boast many technologically advanced features that enhance safety, ease of use and efficiency. That’s probably why so many people love it.


Advanced Flow Control – This feature is only available for the Tempra Plus versions. What is means is that the heater has been engineered to provide constant hot water supply at the consistent at the proper temperature throughout usage, even if the flow rate keeps changing.

Microprocessor and digital display temperature regulator – This model comes with a microprocessor that constantly monitors the temperature of incoming water so that it can heat at the right temperature to avoid under or overheating that an lead to scalding. Also, for further ease of temperature control, the Tempra Plus comes with a digital display and dial type temperature control.


  • No “cold water” moments as it maintains proper and consistent temperature
  • Optimal 99% energy efficiency
  • Saves up to 20% on your hot water energy bill.
  • Digital display and dial temperature knob makes use easier
  • Noiseless operation
  • All major components are recyclable so disposing of heater is not a threat to the environment.


  • Requires a specified power input system
  • Not the costliest but not very affordable either
  • Using too many water points simultaneously may cause a visibly reduced water flow rate.
6. SioGreen IR260 POU. 240V/6kW/30A. Infrared Electric Hot Tankless Water Heater

This 6.8 pound extra lightweight model of the SioGreen water heater doesn’t really hit you with any unpleasant surprises, which is a good thing. This was designed specifically for low flow usages such as for hand washing in bathroom and kitchen sinks and low flow showers. Try to connect it to a regular shower head and you will have gone over its design limit. This low 1.5GPM water heater can only work for an entire house if the water, it has to heat has already gained significant temperature of at least 72 degrees Fahrenheit. This means that it would keep in tow with a higher water demand regardless of its low GPM rate.


Infrared tankless water heater – Perhaps the biggest standout feature of this tankless water heater is that it is a coil-less heater. The heating system works with quartz infrared energy that heats your water without it having any direct contact with any metal. This singular technological innovation can prevent lime scale buildup (from hard water) and prevents the metallic elements from corroding.

Minimal controls display – One look at the display control area and you immediately know what everything is for – no operation manual needed here.


  • Absolutely perfect fit for small spaces (small apartments, studio, condo workspace, cabin)
  • Longevity largely due to its quartz infrared technology. It can work for up to 20 years.
  • A good option for areas with hard water and well water
  • Minimal chance of bacteria and algae present in the water
  • Parts scarcely need to be changed, which translates into low to free maintenance costs.
  • Made from recyclable materials.
  • Saves more water and energy than most major tankless water heaters


  • Not ideal for large size dwellings
7. Titan SCR2 N-120 Electric Tankless Water Heater 220 Volts

Here comes another tiny one, by far the most popular tankless water heater from the trusted Titan lineup. Taking up just 21 cubic feet of space, this compact heater is perfect for warm regions where it can serve up to two baths simultaneously at a practical flow rate. For colder climes, it can serve the same amount of use points, but at a lower flow rate. You get the best of the SCR2 N-120 though when you use it as a heater for a single point of use. Judging from some tankless water heater reviews I found online, this unit has garnered some pretty decent praise.


Digital temperature control – It spots a digital temperature control and also a thermostat that can be reset manually. Like in many other models, this one keeps the pace by providing a flexible power mode control for regulating the temperature.

UL and ANSI certification – One of the reasons people are so confident in this model is because it comes with UL approval #499 and also the ANSI-Z 10.03 certification. If you know what those mean, then that is enough for you to go out and get it.


  • Similar to the SioGreen IR260, its heating components are manufactured using dual incoloy/nichrome.
  • Lightweight and compactness means that installation can be handled by one person
  • Uses less energy and saves cost
  • No lime buildup or corrosion
  • Perfect for hard water or well water


  • Like other models of the same size, it doesn’t do well for large size dwellings, especially in periods of high hot water demand.
  • Isn’t at its best in colder regions.
8. Ecotemp FVI-12-NG High Capacity Gas Tankless Water Heater

This one is a hybrid of sorts. It requires both natural gas and electricity for full operations. While the gas handles the responsibility of heating the water, the electricity is for the powering the digital display and the internal exhaust fan. It sort of reversed the range definition of heaters in its bracket by having a higher minimum flow rate than most at 0.9 GPM and a lower maximum flow rate than most at 4.8 GPM. This heater unit belongs in the small heater category as it can only process a maximum of 12 gallons in one usage (this approximately translates to a house with only one bathroom).


Uninterrupted water supply design – As long as you use it within its stated capacity limit, the FV1-12 is committed to never go off on you in the middle of usage. This is thanks in part to the efficient and innovative heating components used for its manufacture.

Compatibility and flexibility – It can be easily mounted on any vertical space – be it a wall or anything else – available in your home. It is also designed such that you do not need a plumber to come to move around pre-existing plumbing systems before you can install and use it.

High-quality craftsmanship – Manufactured from non-traditional materials help to enhance its durability and strength while maintaining its lightweight. It also sports an easy to use a digital thermometer and self-diagnostic hardware.


  • It is designed to save you space so that choosing an installation point isn’t too much of a task.
  • There is a minimal risk of damage as the system doesn’t store hot water. It only heats what you use.
  • Its power ventilation lends to its safety and efficiency rating
  • Gas and water heating controls are fully independent of each other


  • Most tankless water heater users prefer fully electric heaters.
  • Larger homes will put undue stress on this unit.
9. Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

This propane powered heater is the best tankless water heater off the Takagi shelf when it comes to low maintenance and noiseless performance. Sure, it weighs about 38 pounds, but still manages a compact design for its weight. It also pumps out a whopping 6 gallons per minute, which suggests that it can work for small to medium households, handling several shower heads at a time. It also comes fitted with inlet and outlet thermistors to constantly monitor the temperature of water flowing in and out. Since it’s a liquid propane powered heater, it will need some form of stainless steel venting that you can purchase online or from any home improvement store close to you.


Remote control operation – This unit, like its natural gas-powered model, comes with a remote controller to give you that extra convenience.

High-temperature range – This propane powered tank as expected heats water to a pretty degree – above 150 degrees Fahrenheit.

Detailed installation manual – Whether you hire an installation expert or you decide to give it a go yourself, the manual is so detailed that you can almost never go wrong


  • The T-Kjr2-IN-LP is relatively affordable
  • Its compact design means it can be installed just about anywhere
  • Can cope with a sudden spike in hot water demand
  • Simple and easily adjustable settings for temperature and flow
  • Easy installation process


  • It can only use propane which significantly thins down its market share
  • May experience an interruption in flow if more demand that it is built for is exerted on it.
  • It is not the best choice for large size homes
10. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater

The first thing that tankless water heater will probably notice about this model is that it is quite pricey – and heavy too. But there’s a good reason for it. Rinnai, in one smart move, saved its customers from having to buy extra parts by being the first company to offer two different installation choices in a single unit. This natural gas tankless water heater comes with two venting options – PVC pipe and concentric venting options are both available atop the unit to ensure ease of access during installation. This small suitcase-sized unit is backed by Energy Star certification and an efficiency rating of 0.96. Here’s a rundown of some of its best features.


Noiseless operation – The RUC98iN is designed to operate at the lowest decibel level possible for a tankless water heater. You do not have to literally hear the unit heating up water.

Nice temperature range and lock feature – You don’t want your kids or any other person for that matter to fiddle with the temperature controls on your heater. That’s why this Rinnai model comes with a temperature lock feature so no one can gain access to it but you. Also, this heater can boil as hot as 140 degrees Fahrenheit in the standard model and 185 degrees Fahrenheit in the commercial model.

Large flow rate – This heater is the definition of commercial use. It’s got a wide range of flow rate. It can run as slow as 0.26 gpm up to a really fast 9.8 gpm and can serve several sinks and shower heads in one go.

Dual gas usage – Whether you prefer natural gas or propane doesn’t really matter with this heater, as it can use any of them. I’m guessing that’s a good option to have for a lot of people.


  • Can use natural gas or propane
  • Perfect for large size households and high hot water demand
  • Comes with two venting options
  • Its large GPM flow rate means an uninterrupted water supply
  • It is noiseless during operations
  • Temperature lock feature prevents unauthorized access


  • It is quite heavy
  • It is difficult to install without the assistance of an installation expert
  • Requires a good amount of electric power to keep from freezing during the winter season
  • It is pricey.

Best Tankless Water Heater – Buyer’s Guide

You’re here. I guess that means we can safely rule out the fact that you may be looking for any other kind of water heater beside the tankless variation. Maybe you’ve seen a friend’s or a colleague’s in action and you like its performance. Then you asked them and other users, and you got different “expert opinions” on which model is the best tankless water heater – which turned out to be a different brand for every person you asked.

When it comes down to it, none of the heaters we just reviewed is a bad choice. It all depends on your preferences, budget, needs and your current living situation. And since no one can evaluate your life more than you, then there are a few questions you have to ask that will definitely make settling for the perfect heater a breeze.

Where do you leave?

By this, I mean the region of the country and the state you live in. Whether you live in Alaska or North Dakota versus Florida or Louisiana, makes a significant difference. In the colder regions/states, the groundwater will be cooler than in places like Florida. This means that your tankless heater unit will have to use up more energy to heat up the water too. I guess that’s a question to answer with your monthly energy budget in mind.

What is your living situation?

Do you live alone in a small condo or studio apartment with one bathroom and two faucets? Or do you stay with four other people in a five bedroom house with as many shower heads and twice that number of faucets? I believe you know which of these living scenarios would have a higher water demand. Tankless water units are rated on the basis of their flow rate; some can only go as high as providing 2 gallons per minute of hot water (which may be ideal for in a one-man condo situation), while some others can run as high as 9 gallons per minute. So taking stock of the number of people you live with, their hot water habits and the number of water outlets available, you will be able to choose a tankless heater with the best flow rate.

What is the size?

If you live in a house with a generous amount of square meters, you may not see the relevance of this question. If you live in a smaller house, however, finding the right installation spot might be more of a challenge, which means you may tend to gravitate towards options that are typically smaller and take up less space.

What is your budget?

Your budget should encompass three major aspects: cost of purchase, installation, and maintenance. There are many tankless heaters whose design and construction materials prioritize one of these costs, usually, so you can save more on the other two aspects. Some models tend to be quite pricey, but have really high efficiency and much lower maintenance costs, while others can be wallet-friendly, but demand a chunk from you occasionally to keep them running at optimum efficiency. Installation costs usually depend on how many extra parts you may (or may not) have to buy and if the manual is detailed enough to allow a DIY or ambiguous as to necessitate bringing in an installation expert.

What are your state’s policies on heaters?

One huge question to ask here is that of the emission standards that apply in your state of residence. Some of us prefer the closer-to-nature, low emission natural gas, while others love the propane driven models. Some other people would ditch these for the electric versions. Either way, whatever you choose, make sure you are not violating any state codes or policies. We recommend you seek out an expert to help you sift through these regulations.


It is possible that in your unique situation, you will need to ask more than the questions listed above. You may need to know if you need an indoor or outdoor heater model (the latter requires no additional venting), if the water predominantly available in your area is hard water or soft water. You may also need to know which fuel type (natural gas, propane or electricity) is available in your area and which is cheaper too and cross-reference this information with the efficiency level of the different heater options available to you.

I know, it feels like a lot of work just to purchase a single item, but you must remember that picking the wrong one can burn up your savings in maintenance and unforeseen energy costs, can underperform badly or even violate a few regulations and policies. As they say, nothing good comes easy, right? Just take the time to do the requisite legwork and involve a professional whenever necessary. Nothing good comes easy, but they do come in the end. Happy shopping!