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

We’ve dedicated this comprehensive write-up to helping you pinpoint the best tankless water heater available for you in 2019. And, we’ve covered everything you’d want to know from how the best water heater looks to all the functional features to consider when scouting for a tankless water heater, and why you should have one in your home. Think of this as your all-in-one, in-depth resource for everything and anything tankless water heaters. Are we together? Great! Let’s get started.

The popularity of tankless water heaters is at an all-time high. And just as you’d expect, the market is already brimming with an assortment of options. For a homeowner like you, this can only mean one thing – choosing a good tankless water heater is becoming more complicated every day. How nice then, would be to know that we’ve done all the hard work for you? Awesome! Right?

Overview of The Best Tankless Water Heaters 2019

Yes, we scoured the market in search of top-rated tankless water heaters and sorted through them carefully to find out what makes each one special. In short, what we’re trying to tell you is that the tankless heater you’ve been looking for is a click away – literally! Come along with us – and you won’t miss a model that’s in line with what you want in our collection.

  1. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater
  2. EcoSmart ECO 27 Electric Tankless Water Heater
  3. Takagi T-KJr2-IN-LP Indoor Tankless Water Heater

1. Rinnai RUC98iN Ultra Series Natural Gas
Tankless Water Heater


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2. EcoSmart ECO 27 Electric Tankless
Water Heater


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3. Takagi T-KJr2-IN-LP Indoor Tankless
Water Heater


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4. Stiebel Eltron Tempra Plus


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5. Rheem RTG-64DVLN Tankless Natural
Gas Water Heater


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Best Tankless Water Heater 2019 – Top 10 Reviews

1. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater

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The Rinnai RUC98iN is the best natural gas powered tankless heater on the market. Its ability to heat water is on another level too, making it a good option for busy commercial settings and large homes with lots of demand for hot water. While costly, this unit has a flow rate of 7.5 gallons per minute to justify its lofty price tag. With that capacity, it will easily provide a constant supply of water for two to three bathrooms.


Temperature Lock System

Once you’ve set the temperature, you can rest assured it will remain the same thanks to this innovative function. In fact, this verifies the point that the RUC98iN is a great heater for commercial use or any other place where it’s at a risk of being manipulated. For those who may want to know, this unit has a maximum temperature setting of 160 degrees Fahrenheit.

Automatic Scale Detection

One of the reasons your tankless water heater is likely to fail is if there’s lots of scale accumulation. To clarify that problem, scale is the white, papery substance that attaches to pipes. The RUC98iN detects areas with scale deposits automatically which, by extension, helps increase its durability.

Stellar Energy Efficiency

With an energy factor of .82 gallon when running on propane or natural gas, the RUC98iN is indeed energy efficient. In fact, it is an Energy Star Certified water heater. Beyond that, it comes with smart chips to prevent short-circuiting, so will keep you and your family safe. Plus, this heater offers two placement options. You can mount it horizontally or vertically as per your preference or space constraints.

  • Space saving design
  • Digital controllers
  • PVC or concentric venting options
  • Installs in a cinch
  • Expensive
Read our full review of the Rinnai RUC98iN

2. EcoSmart ECO 27 Electric Tankless Water Heater

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The EcoSmart ECO 27 is a compact, highly efficient model with enough capacity to heat water for two showers running simultaneously. Reasonably-priced, it is arguably the best electric water heater if you’re on a tight budget. Ideal for a small household, cottage or cabin, it will save you up to 50% on electricity bills thanks to the patented modulation system, which increases its energy efficiency by up to 99.8%. For those interested in technical data points, this water heater has a flow rate of up to 6 gallons per minute.


Digital Temperature Control

Sure, any tankless water heater worth your money should allow you to control temperatures painlessly, right? Well, that’s what you get with the EcoSmart ECO 27, but with a little twist. It enables you to increase the temps in 1-degree increments. That way, you can set the exact temperature more precisely depending on what your own uses of the hot water.

Generous Flow Rate

The ECO 27 will give you up to 3 gallons of hot water per minute in areas with temperatures as low as 37 degrees Fahrenheit. In areas where the temperature of the incoming water is high, such as the southern United States, it can heat nearly 6 gallons per minute. Theoretically, this means that you can power up to four showers and a sink at the same time without running out of hot water. Brilliant!

Other notable highlights include digital temperature control and easy-to-replace elements.

  • Compact, stylish design
  • Stainless elements for durability
  • Occasional bouts of cold water (if the problem persists, install a valve to control the flow rate)
For our full review of the EcoSmart ECO 27 follow this link

3. Takagi T-KJr2-IN-LP Indoor Tankless Water Heater, Propane

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The Takagi T-KJr2-IN-LP is a mid-priced propane tankless water heater with a maximum flow rate of 6.6 gallons per minute. While its capacity isn’t enough for super large needs of hot water, it is sufficient for a home with up to three bathrooms. Now that’s a competitive performance when pitted against other high-end models such as the Rinnai RUC98iN.


AFR (air-fuel-ratio) Sensor

The Takagi T-KJr2-IN-LP comes with revolutionary sensor and thermistors to monitor efficiency while minimizing emissions. These sensors generate an energy factor of up to 0.83, which is far better than the 0.7 you get with tank gas heaters. As a result, this unit means more money in your wallet and consistently hot water in your taps and shower.

Exhaust/Temperature Safety Control

This function ensures that the Takagi T-KJr2-IN-LP internal components don’t freeze during cold weather. And there’s the built-in surge protector that turns off your water heater when it overheats. Meanwhile, the dual thermostats put you in charge of the temperature to which the water heats. And the best part is that you can control all these settings using a convenient remote.

Brilliant Temperature Range

The Takagi T-KJr2-IN-LP will heat the water from 99 degrees Fahrenheit (for home use) to 167 degrees Fahrenheit for commercial use. Our verdict is that this model packs enough punch for a unit of its size. It has a practical design too, which allows you to mount it in tiny spaces. And, speaking of tiny, you may want to know that the T-KJr2-IN-LP is the smallest tankless water heater by Takagi.

  • Robust, long-lasting design
  • Lightweight (weighs about 38 lbs)
  • Reasonable flow rate
  • Supports direct venting
  • Quite affordable
  • Reliable performance
  • Installation somewhat complicated

4. Stiebel Eltron Tempra Plus

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Leading off our best water heater reviews is this model by Stiebel. A high-end unit and one of the most powerful tankless water heaters you can find, it is a great pick if you live in cold regions where the temperatures of incoming water can drop to as low as 40 degrees Fahrenheit. It is a brilliant choice if you’re looking for a heater with a high flow rate (this thing can heat up to 8 gallons per minute depending on the temperature of the incoming water).


Advanced Flow Technology

The Stiebel Eltron touts a brand-exclusive technology that adjusts the flow of water automatically when it senses that the demand is higher than the heater can handle. Do you know what this means? Well, it means that you’ll always enjoy the hot water at constant temperature, unlike most heaters that start to produce cold water when the flow exceeds the heating capacity.

True Thermostatic Temperature Control

The Eltron isn’t in our best water heater roundup by some fluke. It is one of the few models that adjust power based on the temperature of the incoming water and flow rate. It will modulate its power output to match the heating demands of the incoming water to maintain the desired temperature of the water coming out of your showerhead or tap. Nice!

Intuitive Temperature Display

You’ll never have to guess the temperature at which the Eltron is heating water. It has a large display that shows you the temps in an easy-to-read digital format. Besides, it has a highly responsive dial selector that allows you to set the temperatures anywhere between 86 to 140 degrees Fahrenheit. In short, this tankless heater is excellent in every way. We only wish it was cheaper.

  • Five-star performance
  • Energy efficient
  • Automatic flow rate
  • Relatively expensive

To read our full review of the Stiebel Eltron 29 Plus Tempra follow this link.

5. Rheem RTG-64DVLN Tankless Natural Gas Water Heater

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Here’s another top-rated tankless water heater, this time by Rheem. It is a perfect alternative to the Rinnai RUC98iN if you don’t want to splurge. The RTG-64DVLN is, however, less powerful than the Rinnai RUC98iN so it will work best for small homes with one or two showers.


Remote Temperature Control

One of the most important considerations when choosing a tankless water heater (more on that later) is the ease of controlling temperatures. With the Rheem RTG-64DVLN’s patented UMC-117 remote control, you can fiddle with the temperature setting at the press of a button from a distance of 10 feet. In simpler terms, you may be able to adjust the temperature of the water coming out of your faucet without leaving the kitchen.

Next Generation Burner Technology

The RTG-64DVLN uses a well-thought-out heating system to give you super hot water in seconds. On top of that, it has a maximum water flow of 6.8 gallons per minute when the temperature of the incoming water is 35 degrees Fahrenheit. Note: the flow rate drops to 5.3 gallons per minute when the temp rises to 45 degrees Fahrenheit.

Concentric Venting

While concentric venting may not be a major highlight per se, it is worth noting that unlike most gas tankless water heaters, you don’t need an adapter with the Rheem RTG-64DVLN for ventilation. It uses a 3-inch by 5-inch concentric vent. And the beauty of it is that the venting system has an integrated condensate collector, which makes it easy to maintain your water heater.

  • Package includes a thermostat wire
  • Comes with an EZ-link cable
  • Hassle free ventilation
  • Space saving design
  • Performance dips when the flow rate increases
For the full review of the Rheem RTG-64DVLN follow this link

6. Eccotemp i12-NG Indoor tankless heater, 1/2 inch NPT water fittings

The Eccotemp i12-NG is sleek, with a five-star performance to match. It is the best tankless water heater if you’re looking for a model that allows point of use operation. It is compact too, but don’t let the size fool you. This unit has an impressive water flow of 3 gallons per minute. And oh, it uses natural gas, as opposed to electricity, so that could be ‘make or break’ for you.


Automatic Temperature Control

The Eccotemp i12-NG is an intelligent tankless water heater – one of the few on the market. It doesn’t require manual setting of heating temperature. Instead, it determines the temperature of the incoming underground water automatically and adjusts the heat. Plus, it heats the water based on the flow. All you have to do is switch it on and let it do the job. In essence, this means that you can leave this heater on ‘auto-pilot’ all year long.

User-friendly Interface

The Eccotemp i12-NG has a sleek touch screen and LCD display that indicates both the flow rate and the temperature. Additionally, its energy factor comes in at 79% with a temperature range of 35 to 40 degrees Fahrenheit when running at a flow rate of 3 gallons per minute. Note: the flow rate reduces to about 1.5 gallons per minute when temperatures increase to 77 degrees Fahrenheit.

Child Locking Technology

Nobody will mess with the Eccotemp i12-NG – not with its child lock on. And, we’re talking about interfering with the temperature settings here. With this functionality, this water heater is perfect if you have kids running around your house. Also, we couldn’t help but notice the horizontal stainless steel vent kit included in the packages for straightforward installation.

  • Energy saving
  • Long power cord
  • Sturdy gorilla glass casing
  • Power ventilation for safety
  • Uses electronic ignition system
  • Doesn’t work well in cold areas

7. Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater

A hot contender for the best tankless water heater 2019, the RTGH-95DVLN is the latest model by Rheem with an energy efficiency of 94%. A brilliant pick for indoor and outdoor use, this is a high-altitude performance model that can operate perfectly at 8,400 feet above sea level, unlike most other tankless water heaters.


Super High Water Flow Rate

The Rheem RTGH-95DVLN is a beast! It has a trailblazing water flow rate of 9.5 gallons per minute – the best-in-class. From a practical standpoint, this means that it will provide enough hot water for two showerheads, a dishwasher and your laundry washing machine, all at the same time! And the best part is that it uses energy sparingly. In fact, this could very well be the most energy efficient gas tankless heater on the market.

Self-diagnostic System

You have to carry out regular maintenance procedures on your tankless water heater if you’re hoping that it will provide reliable performance. The RTGH-95DVLN uses smart technology to warn you early enough of possible malfunctions either with the venting or supply of gas. That way, not only will you repair faults before they cause damage to the entire system, but also lower risks and avert accidents.

EZ-Link Connectivity

While the Rheem RTGH-95DVLN is all about giving you a five-star performance, it also supports EZ-link connectivity. Essentially, this means that you can connect two separate units and operate them as one. This functionality will indeed come in handy for big households with high demands for hot water.

  • Outstanding flow rate
  • Low emissions
  • Remote control
  • Industrial-quality design
  • Easy to install
  • Quite expensive

8. Bosch Tronic 3000 T 7-Gallon Electric Mini-Tank Water Heater

Our ‘Best tankless water heater’ reviews wouldn’t be complete without mentioning the 300T by Bosch Tronic. A cost friendly option, this is a perfect pick if you don’t have the money to splurge on the more expensive models. Make no mistake about it though; this unit may be affordable, but it doesn’t fall short on functionality.


Compact Build

The Bosch Tronic 3000 T is the smallest water tank on this list. Yes, it’s even smaller than the Takagi T-KJr2-IN-LP. So compact is this thing that it can fit under a sink cabinet. And, because it has an attractive, trendy design, this heater will blend seamlessly with your interior décor.

Point of Use Installation

You can mount the 3000T virtually anywhere, indoors and outdoors. The beauty of it is that unlike other models that require venting, this is a point of use heater, which, by extension, means that it is a ‘plug and play’ unit. In fact, all you have to do to get it to work is to tap into your cold water line and mount it directly – simple and straightforward. With such flexibility, this heater is great for your garage, patio kitchen, basement wet bar or powder rooms.

Reasonable Heating Capacity

The Bosch Tronic 3000 T may be small, but its heating ability is impressive. It heats water at a temperature range of 65 to 145 degrees Fahrenheit, which is enough for most needs in a typical household. Meanwhile, the flow rate of 7 gallons per minute is more than enough. Note: the 3000 T is also available in 2.5 and 4-gallon capacities.

  • Compact and lightweight
  • CFC-free foam insulation for optimal energy efficiency
  • Glass lined tank for extended use
  • Affordable
  • Stylish design
  • Supports multiple placements
  • Not ideal for large homes
Read our full review of the Bosch Tronic 3000 T by following this link

9. Takagi T-H3-DV-P Condensing High Efficiency Propane Indoor Tankless Water Heater

The Takagi T-H3-DV-P is the best tankless water heater in this collection if you want a model that can rival the traditional tank heater. Propane-powered, this unit has a flow rate of a whopping 10 gallons per minute – the highest of any water heater in the roundup. If you’re scouting for a single tankless heater that can take care of all your hot water needs, this one is it.


199,000 BTU Per Hour

The Takagi T-H3-DV-P thrives on its iconic power. With its superior output, this heater will provide a continuous supply of hot water for up to four bathrooms at the same time and three in a colder climate. It also has an commendable 0.95 Energy Factor. It is an ENERGY STAR certified model as well.

Computerized Safety

One of the primary concerns you should have about choosing your tankless water heater is its ability to keep you and your family safe. The brains behind Takagi T-H3-DV-P know this very well and as such, have automated this unit’s safety functions. From the built-in diagnostics and temperature controls to internal freeze protection systems, everything about this heater regarding safety is on point.

Revolutionary Heat Exchanger

The Takagi T-H3-DV-P comes with a durable commercial grade copper heat exchanger. This specific function allows it to heat water on demand within seconds. And then there is the direct power vent that gives you plenty of options for where to mount it within your home. Other notable highlights inclu the electronic ignition for ease of operation and the ultra-low NOx condensing technology to control emissions.

  • Can link with up to four heaters with no additional tools required
  • Comes with factory-installed power cords
  • Allows PVC venting
  • Expensive – but deservedly so

10. Rinnai V65EP 6.6 GPM Outdoor Low NOx Tankless Propane Water Heater

Wrapping up our tankless water heater reviews is this model by Rinnai. Ideal for both commercial and residential use, this workhorse has a maximum flow rate of 6.6 gallons per minutes, which is enough for two bathrooms. You can fine-tune its residential temperature from 98 to 140 degrees Fahrenheit, while for commercial applications it can reach up to 160 degrees Fahrenheit.


Built-in Gas Valve Blower

The Rinnai V65EP adjusts the incoming gas according to heating demands. In simpler terms, this heater uses a smaller amount of gas when the heating demand is lower and increases it when you need hotter water. And the beauty of it is that you’ll control the temperature setting at the press of a button.

Leak Detection

The V65EP uses smart chips to detect leaks and shut down the entire system to prevent damage. In fact, this is a standard function with all Rinnai tankless heaters, which makes them stand out from the competition. On top of that, this unit has a ‘bath fill’ feature that allows you to set the number of gallons you want in your bathtub.

Scale Detection

You don’t have to worry about the V65EP getting clogged, even when using hard water. This heater will detect calcification to increase longevity and to prevent corrosion. The result is a reliable performance that you can count on every time you need hot water.

  • Energy saving factor of 0.82
  • Troubleshooting feature to help you narrow down the problem
  • Replaceable parts – low maintenance cost
  • Not the cheapest of tankless water heaters

Benefits of a Tankless Water Heater

The number one reason you’d want to install a tankless heater in your home is cut down energy bills. You see, the best tankless water heater will help you save up to 40% on your monthly utility bill. Now, that’s more than 30% efficiency in comparison to a tanked water heater.

Other than being healthy for your wallet, tankless water heaters bring forth a myriad of benefits including;

You’ll Never Run Out of Hot Water

Tankless water heaters, by design, are on-demand heaters. In essence, this means that they’ll provide you with hot water whenever you need it. Think of them as heaters that allow you to enjoy the hot water at the press of a button.

Besides, you’ll never experience standby heat loss with these models. It is also worth noting that these heaters only require enough power to heat the amount of water needed at any given moment.

Unmatched Durability

A standard tankless water heater will last you five to ten years longer in comparison to a tanked water heater. While most models are high-end with high-end prices, the durability, by extension offers value for your money in the long run.

Compact Design

One of the major differences between tankless and tanked water heaters is that you don’t need a lot of space to mount the former. In fact, the best water heater should save you space and offer multiple placements on your wall. Most models that we’ve reviewed above offer indoor and outdoor installation complete with an anti-freeze kit. You can even opt for a smaller unit that can fit under your cabinet or closet for closer point of use.

Eco-Friendly Operation

Gas tankless water heaters have near zero emissions and are, therefore, safe for the environment. Most gas-powered models use low NOx technology to keep emissions as low as possible. Even the electric tankless water heaters don’t generate harmful greenhouse gas. Moreover, these heaters come with innovative features to prevent scalding water from reaching your showerhead or faucet.

Easy to Operate

It doesn’t require a lot of knowledge to operate a tankless water heater. The hardest part of using these models is installation. Once you’ve mounted yours all you need to do is to set the temperature on the unit’s dial and you’re good to go. You may even choose a model that supports remote control for hands-free operation.

No Possibility of Flooding

Unlike tanked heaters, you’ll never have to worry about possible flooding caused by a ruptured tank. This goes back to the point that tankless heaters are safe for you and your household. Speaking of safety, some models come with an integrated system that detects internal faults as they occur and give you a warning in advance.

See? There’s indeed more than one reason you should purchase a tankless water heater. The only thing you should remember is to check the flow rate of the unit you plan to get before spending your money on it. At the end of the day, you want a model that can handle your hot water needs, whether it is for residential or commercial applications. Note – We will explain about water flow and why it is important in greater detail in our buyer’s guide below.

How Does a Tankless Water Heaters Work?

In order to make the most out of your tankless water heater, you must understand how it operates. But before then, let’s start by breaking down how a tanked water heater works. The traditional heater system has a large tank that holds and heats the water. To give you hot water, the tank heats continually to ensure that the water stays at a constant temperature. The energy needed to keep the water hot when you’re not using it is known as standby heat loss.

Tankless water heaters, on the other hand, only heat the water when you need it, which means that there’s no standby heat loss. In fact, it is the lack of standby heat loss that makes tankless heaters more efficient.

The Heat Exchanger

A tankless water heater uses a heat exchanger to increase the water’s temperature. A heat exchanger is a device that works by transferring heat from one source to another and is common in car radiators, air conditioners, and refrigerators. In this scenario, the incoming flow of water activates the heat exchanger. In other words, when you turn on your hot water tap, it triggers the incoming water to circulate through the exchanger which in turns heats the water at your preferred temperature.

The Lag Time

Tankless water heaters are available in two options; whole house and point of use heaters. Whole house heaters are typically large, costlier and can work with more than one outlet at any given time. Point-of-use heaters, however, are small with the capacity to heat one or two outlets. Due to their size, they can fit in your closet or under a cabinet.

One benefit of this type of heater is that you can install it close to your water outlet to avoid water loss caused by lag time (the amount of time it takes for your water to reach to the faucet). In big households, the lag time can run up to several minutes. Theoretically, this means that while your utility bill may be going down, your water consumption will be going up. So, consider pondering about the lag time and how it affects your budget before deciding to go tankless.

As you may have already figured out, tankless water heaters come in either electric, natural gas or propane models. Almost every other point of use unit on the market is electric. Whole house models are natural or propane powered. Of course, the model you go with and the heating source that best works for you depend on a host of factors. Again, we shall look at these factors in our buyer’s guide that’s coming right up.

How to Choose the Best Tankless Water Heater (Buyers Guide)

Best Tankless Water Heater

While you may read water heater reviews to determine which the best model to choose is, it goes deeper than that. The thing is, tankless water heaters are expensive, and you can’t afford to make an error when selecting one for your household. What follows is a compilation of the most important considerations to make.

The Energy Efficiency

As stated, one of the benefits of going tankless is the energy efficiency these heaters have to offer. It, therefore, makes perfect sense to weigh how much the model you intend to purchase will save you in terms of utility bills. So, be sure to look at the Energy Factor (EF) before buying as it determines the overall efficiency. The higher the EF, the more efficient the water heater is.

Even then, a high EF doesn’t necessarily translate to lower operating costs. Electric systems, for instance, have a higher EF in comparison to their gas counterparts. But, because gas is relatively cheaper, they tend to offer a lower annual operating cost. Here’s a practical example.

A gas-powered heater can give you a 70 degrees Fahrenheit temperature rise if it has a flow rate of 5 gallons per minute. However, an electric model will only deliver up to 2 gallons per minute for the same temperature rise.

The Size

Of course, you can only invest in a specific tankless water heater if it can meet your needs. You have, therefore, to examine the model’s temperature rise and the flow rate. At the very least, you should expect your tankless water heater to deliver anywhere between 2 to 5 gallons of hot water every minute. And as we’ve seen, gas-powered water heaters can provide a higher flow rate in comparison to electric systems. To be safe, confine yourself to finding a unit with a flow rate of 8 gallons per minute. Better yet, you can use the following guidelines.

  • Bathroom faucet: 3.0 – 5.0 gallons per minute
  • Shower: 1992 4.0 – 8.0 gallons per minute
  • Kitchen faucet: 3.0 – 7.0 gallons per minute

Also, keep in mind other appliances that you may need to use such as washing machines and dishwashers. Other than that, you need to calculate the temperature rise to make sure that you’re selecting the right model. To do so, deduct the temperature of the incoming underground water from your preferred hot water output temperature.

Let’s say the incoming water temperate is 50 degrees Fahrenheit, and you set your output temperature at 120 degrees Fahrenheit. In such a case, you need to choose a tankless unit that can heat the incoming water at a temperature of 70 degrees to reach your desired temperature of 120 degrees. You should remember that the temperature rise will keep fluctuating throughout the seasons, all-round the year. Plus, the temperature of the incoming water will have an impact on the flow rate and speed of your heater.

The Fuel Type

This is indeed a critical decision to make when shopping for a water heater. The best tankless water heaters should offer a continuous flow of hot water while helping bring down your energy costs. By now, you know that there three fuel types to choose from; electricity, propane, and gas. The fuel available in your area of residence determines the type of tankless water heater that you select. It is always important to compare the cost of each fuel type before making your decision.

…Other Equally Important Considerations

The Fuel Supply Line -Your line of fuel supply has to be sized to provide the power needed to deliver instant water whenever you need it. Most gas tankless heaters have an output of about 200,000 BTU.

Ignition –There are three types of ignition systems. Expensive models have a complex ignition system in comparison to cheaper units. It is worth noting that the simpler the ignition system, the less the savings the heater will claim.

Venting – Gas tankless heaters require venting for proper functioning. While you can let the vents run through the rough horizontally, you’re better off picking a unit that supports category III venting for better combustion. Even then, it is essential to note that you’ll ONLY require venting if you pick and indoor gas tankless water heater.

Lastly, if you decide to go with an outdoor gas tankless water heater, you should make sure that it’s robust enough to endure the beating of weather elements. Select a model that features an anti-freeze kit.

Popular Tankless Water Heater Brands

Numbers indicate that some tankless water heaters brands are more popular than others. These manufacturers have set the bar by consistently churning out top models backed by a reliable performance. If you’re scouting for the best tankless water heater, there’s every chance that you’ll end up with one of the following brands.


Rheem has been perfecting the art of making top-notch tankless water heaters for more than nine decades. This company thrives on innovation and smart technology. Their best selling model is the Rheem RTGH-95DVLN, a powerful gas-powered heater with brilliant EF. For a company whose motto is to give you intelligent appliances for comfort, this manufacturer based in Atlanta Georgia will indeed continue to find its way into homes for years to come.


EcoSmart claims to give you tankless water heaters that work twice as fast. Their models are small and a hit with homeowners who don’t have a lot of space. And, just as the name suggests, EcoSmart’s mission is to generate and distribute quality green products. By the look of things, they’re doing exactly that and the consumers seem to agree. All EcoSmart water heaters have ETL certification so they’re safe to use. Did you know that EcoSmart is the only electric tankless water heater brand whose models have a FIDE certification? Well, now you know.


TAKAGI has made a name for making tankless water heaters with ridiculously high flow rates. Their electric models are compact too. But, it is the commendable performance that has made this brand a crowd favorite. Their water heaters seek to give you the best possible flow rate even in high altitude areas. In short, TAKAGI lives up to its slogan of giving you endless hot water!


While Rinnai is a relatively new entrant into the market, it has cemented its name as a brand to reckon when it comes to making world-class tankless water heaters. Based in Nagoya, Japan, Rinnai manufactures both electric and gas-powered water heaters. Fans applaud their excellent customer service and the long warranties attached to their model. In essence, this shows that Rinnai believes in the quality of their products and are not afraid to stand by it.

Stiebel Eltron

Stiebel Eltron is a Germany manufacturer of home heating appliances that has been plying its trade since 1924. Their tankless water heaters use state of the art mechanisms and are also one of the most advanced. They’ve proven to be a popular choice for people living in high altitude areas to due to their brilliant temperature rise. Stiebel Eltron claims to give you access to clean and crisis-proof heating solutions and we couldn’t agree more.

Bosch Thermotechnology

Bosch is yet another Germany tankless water heater manufacturer with headquarters in Wetzlar. This brand is all about making small and highly energy efficient units with the frugal homeowner as the target. Those who’ve used their water heaters remark that they provide hot water instantaneously, further justifying the company’s “invented for life” motto.

Frequently Asked Questions

And now, we list down the most commonly asked question in regards to tankless water heaters.

Is it possible to replace my existing tanked water heater with a tankless option?

Yes, it is very much possible. However, we must mention that you have to address some specific requirements before you can go tankless. First of all, you have to know that gas heaters (if you decide to go that route) require a special vent pipe. You’ll also need to have access to a stable gas supply line that will not only feed your water heater but also other appliances connected to that gas pipe. If you invest in an electric water heater, you will need a bigger gauge wire and breakers than the ones you’re currently using with your tanked water heater.

Is it safe to install a tankless water heater in my attic?

Okay, to begin with, it is impossible to give a definite yes or no answer to this question without seeing your plumbing piping. Nonetheless, before you decide to install mount a tankless water heater in your attic, you must be sure that you will not create a possible water siphoning condition. This is because your heater should not have air in the lines. Water siphoning, irrespective of the type of heater you are using may damage your system when there is not enough water in the lines.

I would like to install a tankless water heater in my vacation cabin or home. Is it possible to drain all the water when I’m not using the system to prevent freeze damage?

Yes, it is possible with most models. However, we recommend that you check with the manufacturer just to be sure. If you are given a green light to drain it, all you need to do is to empty both lines to and from your heater. Keep in mind that as long as there are no check valves, that is enough to drain all the water. And, just to be sure that there is no water in the heater we suggest that you empty in two halves. One before and after the unit – you should also consider blowing air through your water heater.

Is it advisable to install my own tankless water heater?

Well, in most cases, we wouldn’t recommend that you install your tankless water heater. In fact, almost all the time, the local plumbing code doesn’t allow you to do so. It may also interfere with the warranty and that is something you don’t want to do. Other than that, there’s every possibility that you might damage your heater even when you have the experience.

You see, most houses don’t have the required electrical configuration for safety and best performance. Besides, you may have to install 240-volt wiring. And, unless you’re replacing a gas-powered tankless water heater, you will also need gas lines and a gas meter for the upgrade. We’ve not even mentioned the venting requirements with most gas tankless water heaters and the actual plumbing that goes into mounting the unit. In short, when it comes to installing a tankless water heater, you’re better off hiring a professional.

I read that you cannot install some tankless water heaters in certain areas. How true is that?

Yes, there are some states and cities that don’t permit the installation of specific models of tankless water heaters for various reasons. It is therefore essential that you check with your local authorities before ordering for your heater.

Note – particular heaters such as 3-phase or de-ionized heaters don’t come with a return policy. The last thing that you want is to get stuck with a heater that you can’t return or one you can’t install due to local code restrictions.

Why don’t any of my tankless water heaters show the first-hour rating?

Tanked water heaters show the first-hour rating. The amount of hot water the heater can generate in an hour when the tank is full typically determines the first-hour rating. The case is different when it comes to tankless water heaters. You see, a tankless option doesn’t start with a tank of hot water, so it is not practical to expect it to have a first-hour rating as is the case with the tank option. What you get with tankless water heaters is the gallons per hour rating. The number of gallons per hour that the heater can generate when you raise the temperature of the incoming water determines the flow rate.

Which is the best temperature to heat my incoming underground water?

Well, this is a personal question because the opinion of how hot the water should be may vary from one person to the other. You should also consider that the temperature of the incoming water may different at various times of the year. Even then, a lot of studies have tried to determine what most people find comfortable, on average.

Based on these studies, we can throw in the numbers to help you to narrow down the possibilities. According to research, most people are comfortable washing their hands at near body temperature. You’re likely to walk into a shower that spurts water at a temperature of anywhere between 90 to 110 degrees Fahrenheit, primarily depending on whether you prefer a hot or cold shower. Almost everyone agrees that 58 degrees Fahrenheit is too cold for comfortable hand washing leave alone showering.

Exactly how much will a tankless water heater save me?

First of all, there is no dispute that going tankless will indeed save you money. The specific amount, however, depends on a number of factors. The cost of natural gas or propane, for instance, will determine how much money you end up saving. You may have to pay a more if you use lots of hot water. One thing remains clear though; you will never run out of hot water. And the best part is that you are totally in control of the temperature at which your unit heats the water.

How long will my tankless water heater last?

Tankless water heaters will last you long enough to return the value for your money. The type of installation and usage may also have a hand in the life expectancy of your heater. In general, most models on the market will last anywhere between 15 to 25 years. As long as you’re using quality water and the installation is on point, your model shouldn’t have a problem lasting for more than two decades.

There’s a catch though, even the best tankless water heaters require regular maintenance to stand the test of time. You have to clean yours on a regular basis to remove scale deposits and so on. If you have an outdoor gas tankless water heater, you should ensure that you install it in a place where it’s relatively safe from weather elements such as snow and heavy rainfall. Latest models come with a self-regulating internal mechanism that alerts you about any malfunctioning which also helps increase the durability.


Tankless water heaters have their place, now and in the future. With the world shifting to green and sustainable energy, it is almost impossible to imagine that tankless water heater will become obsolete. The best part is the fact that these units not only heat the water relatively fast but also do so without using a lot of energy which means more money in your pocket. And hey, who wouldn’t like to make some savings, especially if it is on recurring bills such as utility? The point that we are trying to make here is that you’re better off getting a tankless water heater, now more than any other time.

As is the case with any home appliances though, you have to shop right. Add the fact that most tankless water heaters don’t come cheap means that you have every reason to exercise due diligence before splurging. After all, you want to be sure that you are investing in a model that will indeed meet your hot water needs for years to come.

That said, we hope that the info provided here has brought you closer to choosing the best tankless water heater 2019. Most importantly we trust that our reviews have helped shed light on why you would opt for one model over the other. Plus, our informative part of this article has gone to great lengths to demystify tankless heater and what they are all about.

Now, you can narrow down your options out of the many choices on the market. We understand that models keep changing as new ones get into the market. On that front, we will keep an eye on what is happening in tankless water heaters circles and notify you as soon as it happens. In the meantime, all the models our reviews have the functionality you need to keep your home flowing with hot water whenever you need it. All you got to do is to select the model that you feel is in line with what you’re looking for. Also, don’t forget to shoot us any question you may have regarding tankless water heaters and we will get back to you.