Best Tankless Water Heater Reviews – Top 10 of 2018 – Seek Home Comfort

Best Tankless Water Heater Reviews – Top 10 of 2018

If you’re tired of the same old bulky tank water heater, you should consider browsing for something as innovative and energy efficient as a great tankless water heater. The tankless water heater reviews are presented to you in this article in order to help you make the optimal choice.

The in-depth tankless water heater reviews within the following content are sure to provide you with verified and specific information that you will require if you wish to educate yourself on the matter of the best tankless water heaters on the market.


While shopping for any type of product, especially those that they will be installing within their household like steam showers or water heaters, consumers usually spend large amounts of time (i.e., to read best steam shower reviews). It is often very hard to decide which product you will opt for once you narrow your choices down, but it doesn’t necessarily mean that you’ve found all the best ones.

In order to remove this lengthy obstacle for you, we have devised this extensive list of the best tankless water heaters currently on the market, which will elaborate in detail everything one should consider before purchasing a product like this.

After some reading, and with a little luck, you will be able to firmly decide which exact tankless water heater to purchase and why. It is extremely important to go through this tedious process, but we’ve made it an easy task for you.

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The Best Tankless Water Heater Reviews

First of all, let us introduce our top recommendations before we step further into providing the specifics of each product mentioned in the reviews:

  • StiebelEltronTempra 24 Plus Electric Tankless Whole House Water Heater, 240 V, 24kW
  • Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
  • Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater
  • Takagi T-H3-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater, 10-Gallon Per Minute
  • EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology
  • Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater, Concentric/Twin Pipe Installation
  • Rheem RTGH-95DVLN 9.5 GPM Indoor Direct Vent Tankless Natural Gas Water Heater

1. Stiebel EltronTempra 24 Plus Electric Tankless Whole House Water Heater, 240 V, 24kW

2 person sauna

It weighs 15.4 pounds and its dimensions are 16x14x4. It has the working pressure of 150 PSI(Pounds per Square Inch), at a voltage of 240V, wattage of 24W and amperage of 2×50. It requires no batteries and it operates according to a digital control panel with a hinged cover for ease of access.

What also makes this product desirable is its heavy-duty German revamp of the old, bulkier version. It saves energy equivalent to 15%-20% kW/H when compared to the classic tank water heater and it allows users to adjust the temperature as simply as pressing the dials at their fingertips.

It also comes with the Advanced Flow Control feature, which automatically adjusts the water flow so as to eliminate bothersome temperature fluctuation. This allows for an interrupted showering experience, meaning that the user doesn’t need to worry about the remaining hot water for the entire duration of the bathing process.

It has a maximum temperature increase of up to 92 degrees Fahrenheit, and it’s quite easy to install. It comes with installment instructions that won’t be troublesome to follow, allowing for a quick and easy DIY experience. Keep in mind that you wouldn’t want to install it in your bathroom only, as it will heat water in your entire household. You would preferably wish to place it where its buttons are made more accessible.

The said stats make the Stiebel Eltron Tempra Tankless Water Heater an excellent choice when it comes to making purchases in this line of products, which is also why we have chosen to place it this high on our list of reviews.

Things I like

Things I don’t like

  • Uninterrupted household-level heating
  • Built-in control panel
  • Easy installment instructions
  • No venting required
  • Extensive electric supply requirements
  • Considerable price

2. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas

cool tankless water heater

This superb tankless water heater comes from Japan, with convenient dimensions of 6.7×13.8×20.3 inches, weighing 38 pounds.

The Takagi T-KJr2U-IN-NG works on natural gas, which leads to enormous energy bill savings over longer periods of use. It can produce enough hot water for up to two bathrooms in warmer weather, and it also includes Ultra-Low NOx regulations of less than 14 ng/J (<20ppm). In other words, it is as environment-friendly as a gas-fueled water heater can be.

It is recommended for residential use, mostly for that of medium and small apartments, while it can still be used in any large home to heat a single bathroom. Its lack of size and capacity is replaced with other important qualities.

It has an energy factor of 0.82 for Natural Gas, making it a powerful gas-fueled tankless water heater. Its maximum flow rate of 6.6 GPM (Gallons Per Minute) at a 35F temperature rise (or 3.3 GPM at 70F rise) makes it a small but viable household appliance.

It comes with both a remote control and a power cord as standard features, with Category III stainless steel venting that is easy to install and has a very long lifespan, leading to a 15-year warranty for single-family domestic use.

It also comes with a wide variety of safety features, such as freeze, overheat and surge protection, as well as troubleshooting diagnostic codes, designed for the optimal safety of the user.​

Things I like

Things I don’t like

  • Natural gas
  • Ultra-Low NOx regulations compliance
  • Remote control
  • Economical pricing
  • Requires venting
  • Low area of coverage
  • Warranty reduced for commercial and multi-family use

3. Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water Heater

great tankless water heater reviews

This terrific tankless water heater bears some resemblance to the above mentioned Takagi, but its arsenal is devised of different qualities. While its competitor is a great match for any apartment dwellers, the Rheem RTG-64XLN Tankless Natural Gas Water Heater was designed for high ground. The Rheem tankless water heater reviews will provide more useful information to you.

Its dimensions are 10x14x26 inches and it weighs 38 pounds, with a 120V AC voltage (plug or Hard-Wired). It originated in the US, and it was specifically made to fit the needs of high altitude inhibitors. It is an outdoor, wall-mounted tankless water heater that was manufactured to provide warmth all winter.

With the all copper heat exchanger and the OFW (overheat film wrap) to protect it, it brings an innovation to this line of products. It can stand the heights of up to 9,840 ft. elevation above sea level and it was designed strictly to be installed outdoors.

Its Ultra Low NOx burner brings the same qualities as the Takagi to the table, which guarantees a safe environment for all the mountain wildlife and vegetation. Its flow rate of 6.4 Gallons Per Minute, though, makes it a medium efficiency tankless water heater.

It comes in only one color (Gray), featuring additions for more convenient use, such as the digital remote control, manual gas isolation valve, 10 feet-long thermostat wire and the extra plug extension.

If you prefer gas more than electric ones, you can find several gas water heaters for sale

Things I like

Things I don’t like

  • High altitude sustenance
  • Digital remote control
  • Thermostat wire
  • Natural gas
  • Most recent technology
  • Considerable price
  • Plug extension not included with outdoor models (must be hard-wired)
  • Transport packaging weight

4. Takagi T-H3-DV-N Condensing High Efficiency Natural Gas indoor Tankless Water Heater, 10-Gallon Per Minute

efficient tankless water heater reviews

Weighing in at 85 pounds and measuring at 11.2×17.8×24.9 inches is another Takagi tankless water heater, although it claimed a place on our list for different reasons than its predecessor.​

This reliable tankless water heater is the big brother of the one mentioned above, with a 199,00 BTU gas input and a four room heating capacity (three in colder climates). This Takagi product comes with a computerized management system, leaving the customer little to worry about.

It also runs on natural gas, and as such, satisfies the 2012 SCAQMD Rule 1146.2, relating to Ultra-Low NOx Emissions. It can be considered an optimal choice for large households and other spacious constructions.

Its on-demand endless supply of hot water, as well as compactness and energy conservation, make it a worthy competitor on the market, along with all the other features that it possesses.

Its flow rate of a staggering 10 Gallons Per Minute is almost unmatched by any competitor on the entire market, which is what earned it the honorable place on this list.

Things I like

Things I don’t like

  • State-of-the-art safety measures
  • Superb spatial coverage
  • Natural gas
  • Astonishing flow rate
  • Noise pollution
  • Considerable size and weight
  • Very expensive
  • Warranty information isn’t publicly available and must be requested from the manufacturer

5. EcoSmart ECO 27 Electric Tankless Water Heater, 27 KW at 240 Volts, 112.5 Amps with Patented Self Modulating Technology

efficient tankless water heater reviews

The EcoSmart Electric Tankless Water Heater is one of the most contemporary products on this list, featuring a slick and modern design that provides an enjoyable visual experience, in addition to its many perks.

First of all, it’s made up of copper and stainless steel components that allow for efficiency, extensive durability and very easy replacement. Its size is also quite compact, averaging at a minuscule 17x17x3.75 inch. It’s super lightweight as well, weighing only 17.4 lbs.

On the other hand, it will save you just as much energy as any average tankless water heater, since its electrical capacity requirements are quite high when compared to other products, up to 27 kW, 240 volts, and 112.5 maximum power draw.

The temperature is so adjustable that you can shuffle in between mere one-degree increments as much as you like, while it also comes with a limited lifetime warranty and self-modulating technology. This innovative allows for an automatic modus operandi, enabling the user to just turn it on and use hot water as much as they need.

Although its power consumption may seem like an issue in itself, it still saves over 50% on water heating costs. This product is a viable solution for any technology pundit willing to shed some bucks on a very high-quality appliance.

Things I like

Things I don’t like

  • Size and weight
  • Computerization of heating control
  • Remote control
  • Stainless steel
  • Affordable price
  • Extensive electrical supply requirements
  • Only 3 GPM flow rate in cold climates

6. Rinnai RUC98iN Ultra Series Natural Gas Tankless Water Heater, Concentric/Twin Pipe Installation

This is another Japanese best tankless water heater that comes with a variety of commodities. Here are Rinnai tankless water heater reviews: Weighing in at 82 pounds, with the measurements of 10×18.5×26 inches, it bears a lot of resemblance to Takagi when it comes to its 9.8 GPM flow rate.

It also runs on natural gas, offering the famous Ultra Low NOx Emissions, which make it suitable for any healthy environment without the risk of air pollution. It also comes with the concentric and PVC venting options, meaning it is rather easy to maintain.

The heat output power of 199,000 max BTU makes it a close relative to the Takagi yet again. However, this particular product comes at a significant price, regardless of the free shipping. In spite of it being worth the purchase, the consumers should be absolutely certain about choosing this tankless water heater after reading through all of the tankless water heater reviews.

The giants of this niche such as this product offer the most when it comes to energy saving, and should, therefore, be carefully considered, especially if saving on water heating bills is the primary goal of the consumer.

In the next article, I will cover Rinnai tankless water heater problems, rinnai tankless water heater price, rinnai complaints, and more detailed reviews.

Things I like

Things I don’t like

  • Excellent flow rate
  • Coverage of a very wide area
  • Natural gas
  • Remote control
  • Requires venting
  • Considerable size and weight
  • High price

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

This giant of the Rheem industry places another champion on board: The mighty RTGH-95DVLN features everything we’re used to seeing from Rheem – and more. The stainless steel condensing heat exchange is an obligatory trait for every Rheem item, while this particular one also features a built-in electric blower.

The product also comes with an exclusive feature called Guardian overheat film wrap (OFW), as well as a digital display for temperature and maintenance codes. While it’s also easy to install, it allows for very easy access overall.

The two-pipe direct vent system provides a simple venting solution, while there is nearly unlimited use time to these tankless water heaters. Using the extra MIC-195 + the MICS, you can manifold up to 20 units.

At the weight of 79 pounds and the dimensions of 18.5×9.8×27.5, its viability comes as no surprise. It was made to be similar to its relative when it comes to operating at low temperatures, but this time it is an indoor water heater. Regardless, it can still withstand temperatures of up to -30F.

Extremely versatile and innovative, this Rheem tankless water heater earns its place on our list fairly easily.

Things I like

Things I don’t like

  • Utilizes the latest technology
  • Natural gas
  • Retains its potential in low temperatures
  • Guardian overheat film wrap (OFW)
  • Fusion ability
  • High price
  • Requires venting
  • Only 1 year of warranty for parts

Tankless Water Heaters–Are They Right For You?

Tankless water heaters have been around for quite some time now, offering a whole new water heating experience by reducing bills and making it more momentarily interactive instead of a daily premise. With a tankless water heater, you don’t need to think about turning anything on or off beforehand. Simply flick it on whenever hot water is needed and it will provide as much as necessary. But, how to select a tankless water heater?

​A tankless water heater may appear complicated to an average Joe, while it’s actually anything but. It’s composed of no more than 7-8 parts, all of which are quite simple to grasp. Mainly, once you connect your water heater to your water supply and turn the shower valve, the cold water that enters it will trigger the water sensor, which will then signal the computer to start the heating process. The water will circulate around and through the ignited heat exchanger a few times, after which it will have the desired temperature.

​One of the few things that you do have to think about when it comes to using a tankless water heater is the price. They most definitely aren’t a cheap appliance, but some of them are quite affordable and yet extremely well-made. Consequently, an economical but great tankless water heater is an almost irreplaceable upgrade to your household.

Another considerable fact is that a good majority of these products is gas-powered, meaning you do need to plan gas tank replacements and such, but nothing more than that. However, if you decide to opt for one of the best electrical tankless water heaters, you don’t need to worry about that either. Your bill may go down only up to 50% if it doesn’t run on gas, but that is still more than enough of a reason to obtain this appliance. We will cover all the types later in the tankless water heater reviews.​

Types of Water Heaters​

​Now, how to choose a hot water heater? which type of water heater is the best fit for you?

In total, there are up to five different types of water heaters, all of which come with a tank and require pre-heating, except the tankless water heater:

1. Storage tank water heater

This is the most common type of water heater available on the market. Nearly every household still relies on them nowadays and they are hugely widespread. Like the name suggests, they consist of an insulated tank where water is heated and then stored until needed, thus I need to determine how big water heater do i need. The water emerges from a pipe on top of the water heater.

It also contains a temperature and pressure-relief valve, which is opened when either exceed a preset level.

The natural gas water heaters usually use less energy and cost less to operate(by about half) than electric water heaters, though you should take note that gas models are more expensive at the time of purchase.

2. Heat Pump (Hybrid) Water Heater

These water heaters capture heat from the air and transfer it to the water. They use up to 60 percent less energy than standard electric water heaters. While they do cost more than electric-only models, the installation is quite similar and the payback time is short. However, they do not work well in very cold climates and they need to be placed in an area that stays 40 to 90 degrees.

Because the heat pump is on top, in this case, a hybrid water heater needs clearance up to even 7 feet from floor to ceiling. Also, you will need about 1,000 cubic feet of uncooled space in order to capture enough heat from the air, including a nearby drain to discharge the condensate.

​3. Condensing Water Heater

Condensing water heaters are a viable option in the case where you are heating with gas and need a unit with a capacity of over 55 gallons. It is completely gas-fueled and doesn’t have a supply of its own, meaning it’s only useful for gas-heated homes.

These models are comprised of a tank like a conventional water heater, but that which captures exhaust gasses that would usually go out of the flue, which is considered energy waste. The gasses are induced through a coil in the base of the unit, where the incoming cold water is able to absorb most of the heat.

4. Solar Water Heater

This recent water heating solution contains a roof-mounted cell that absorbs the sun’s heat, before transferring it to a specific fluid with antifreeze similarities in a closed-loop system that runs toward the water tank. During the summer, these heaters allow for an enormous increase in savings, which makes them the most appropriate for warm and sunny regions. The savings tend to suffer in colder and cloudy weather, though, which makes it a quite restricted saving option. The majority of the models employ a backup system that starts up when necessary.

Even with local and federal rebates included, it will take an estimated 10 to 30 years to make up for the spent cash. While it is certainly the most futuristic and technologically advanced solution on the market, the potential buyers are advised to thoroughly consider spending that much money.

5. Tankless (On-Demand) Water Heater

Finally, the champion of this line of products is all about momentary usefulness, which is its main selling point. Instead of storing water, the tankless water heater uses heating coils to increase the water temperature as much as needed. They’re way more energy-efficient than a storage tank, but they provide a limited flow of hot water per minute, which is estimated to be 3.5 gallons on average.

They are optimal for those who normally aren’t drawing water for more than one use at a given time, such as running a dishwasher and a shower simultaneously. For any smaller household or a specific room in a large one, this product is ideal. It cuts the water heating costs down to a bare minimum and provides instantaneous heat.

The tankless models are best used at homes that draw on natural gas to heat the water. Certain electric models may require a pricy upgrade on the electrical capacity of the household, but the overall monthly costs are still largely reduced once this installment is executed.

Tankless and Tank Water Heater Reviews and Comparison

Just in case the above-mentioned explanations don’t quite relay the importance and innovative capabilities of the tankless water heater, we have devised a comparison of the fierce competitors in order to clarify all the differences to the furthest extent. To make this simple, we’ve decided to address the most important details of both tank and tankless water heaters and compare them:

Life Expectancy

First of all, every customer would like to know how long their not-so-cheap product will last before needing repairs or replacement. Now, those two are completely different things, but generally speaking about the timeframe between time of purchase and the time of complete and utter uselessness, they may differ.

Allegedly, every tankless water heater with a 12-15-year warranty lasts barely half that long. It is said that this happens due to the product not being on the market long enough for the customers to actually overrule this myth. This issue can also be attributed to the way in which the manufacturers treat the warranty. The users of this product require monthly maintenance service and it comes at no low cost either. However, the manufacturers that stands behind this statement like to clarify the evident difference in monthly costs even with this addition in mind.

On the other hand, tank water heaters are known to last for up to 15 years with few malfunctions. Their functionality tends to get impaired by the same issues that weigh the tankless water heaters down, but they are made in a way that lets them function with a number of issues. Most definitely, tank water heaters are cheap to maintain, but to what extent should one be prepared to go in order to avoid frequent servicing? Is paying a full water heating cost every month still worth it? It’s really up to the consumer to decide.

We can tell you only one thing for sure. As long as you don’t void your warranty, you don’t have to worry about anything. Word has it that this occurrence is too frequent, with all the rules that the manufacturers demand on complying to. Then again, the sheer number of customers tells a different story. Ultimately, it is still up to you to decide to take up this risk or to stick to your old tank.


Both tankless and tank water heaters tend to encounter certain difficulties after a time of service. Of course, a tankless water heater won’t have any tank-related issues, but its set of intricate parts requires monthly monitoring and servicing. This claim is also backed by the fact that tankless water heater warranties usually cover the heater itself for 15 years, while the parts are only covered up to 5 at most.

​It’s difficult to weigh 5 years of lower bills versus eventual additional purchases in order to keep your tankless water heater going, but depending on how much you pay to keep your tank water heater running every month, it may well be worth it. Aside from part malfunctions, tankless water heaters tend to “lime up” where there is hard water, which may result in frequent pipe replacements. They need to be well-drained before a longer period of inactivity in colder climates, or the pipes may suffer significant frost-induced damage.

​Being the big brothers of tankless water heaters, tank water heaters require considerably less attention. They may run into issues like sediment buildup, but they’ve been proven to run smoothly even with a large portion inside, resulting in a minuscule 5% efficiency decrease in the worst conditions. Any sort of tank water heater maintenance is also sure to cost far less than any tankless water heater would subtract from your wallet. The repairs are cheaper, the parts are more available, it’s been on the market for decades upon decades, and it’s simply more reliable due to its development over the years.

​All in all, while the difference in servicing costs may be considerable, there is still a lot more that the tankless water heater puts on offer. Also, the great tankless water heaters mentioned on this list were manufactured with various improvements relating to this specific area. This is the factor you need to take into account before anything else when purchasing one, but if you decide it’s worth it, go right ahead.

​Energy Savings

​Of course, the main selling point of every tankless water heater out there is that it spends energy only when needed, which should significantly reduce energy consumption. This is the very reason behind their mass production and market popularity which has brought them to your web browser. Yet, how true is this claim in reality?

​Truth is, a lot of the computerized tankless water heater software constantly operates on electricity. Consequently, if you aren’t using it at a given time, that doesn’t mean it still isn’t spending valuable energy and racking up your bill. A way to go around this issue is to always completely turn off your tankless water heater or buy one with an automatic pilot light, that will shut down whenever it’s not in use. They do save power, but not as much as you’d expect, if not given proper treatment.

​Tank water heaters are well-known for spending considerable amounts of energy on a more than regular basis. The plethora of hot water that it offers needs constant heating to remain at the desired temperature, which unavoidably takes a large portion of electricity. One of the largest costs that a large household pays per month most often comes from sustaining their tank water heater. The amounts of money that consumers have to spend on this appliance eventually force them to opt for something as innovative as a tankless water heater.

​There is no contest in this category. Tank water heaters take so much energy to run that they can’t even be compared to a properly run tankless water heater, which is the absolute winner of this particular comparison.


​One of the weaker selling points of any reliable tankless water heater is the actual purchase cost, aside from any additional costs that may require coverage during its lifetime. The better it is, the more expensive it is, the more expensive it is, the more expensive the eventual part replacements are. This is the undeniable truth about tankless water heaters.

​One way to put this is that the purchase is more worth it the more you pay. Basically, if you have to pay a lot for it, it is more likely to be an outstanding tankless water heater. To put it simply, you require the same amount of energy to heat up the same amount of water, no matter how you do it. Now, condensing tankless water heaters can put their innovative technology to use and reduce this cost significantly, but their prices are situated in the high range.

​Tank water heaters come at a lower initial price, while they will take way more money on the long run. A cheap tank water heater may even come at a price four times lower than that of a viable best tankless water heater, but it’s sure to drain large amounts of bill money over the course of a few years. This is why tank water heaters are going out of fashion, at the pace of frequency of choosing to pay more first in order to pay less later.

​Therefore, it’s recommended to put together a calculation of yearly savings with a tankless water heater that you’re considering for purchase and a tank water heater that you already own and measure them up. If the amount of money that you will spend on maintaining your tank water heater is greater than that of the tankless water heater’s initial price, the calculation is clear. Whether to pay less now and way more over time or vice-versa is completely up to you, but the market speaks for itself.


​When it comes to the multitude of services that tankless water heaters offer at the same time, as opposed to those that tank water heaters boast, it’s eventually down to a few key factors. The size of the object in which you will be using your water heater and a number of household occupants is a key factor. Both of these product variants have a recommendation, depending on the customer.

​Tankless water heaters usually don’t offer the option of heating water for more than two places at the same time. If you are taking a shower while your washing machine is running, be ready for some unavoidable heat fluctuation. However, there are some remarkable tankless water heaters that can rid you of this issue. This is why the tankless version is recommended for smaller homes and apartments, while even smaller living quarters such as cabins are an ideal place for their service.

Tank water heaters usually take care of the entire household at any given time, depending on their size and the amount of hot water stored. They were essentially made for this purpose, so they are mostly unchallenged by the performance of tankless water heaters when it comes to this section. However, dwellers of any smaller construction basically have no need to use them, as they tend to waste both space and money in these conditions.

​You should also keep in mind that certain tankless water heaters were specifically designed for colder or warmer climates. This essentially means that if you live in an area with extreme weather conditions, you’re way better off with the tankless variant. Those made for hot climates use the heat that’s abundant in the air to serve their purpose, while the ones designed for cold weather are much less likely to lose function in such conditions, as opposed to basic tank water heaters.

​Additional Issues

​The tankless water heater is a rather new product, and it will take the necessary time to perfect. Hence, it still faces certain problems that no tank water heater has had before. Although this may sound like a serious thing to consider, they are mostly trivial matters that are unavoidably included in the service of tankless water heaters.

​“The Cold Water Sandwich” is something that the newest tankless water heaters have overcome with state-of-the-art heating technology. Mainly, once the flow of water is halted, the water in the pipe will run cold, and that in front of the heater will trigger the heating again. This process causes a wave of cold water in between the hot, but it’s nothing to actually worry about anymore.

​While tank water heaters will instantly provide you with hot water once you rotate the red tap, the tankless version will let some cold water slip before the heating process overcomes the water temperature. This is also a problem of the past, which the tankless water heaters mentioned above have been rid of.


​While it’s not a bad choice to stick to your old tank water heater, there are various advantages worth considering if you’d like to go tankless. From minimized monthly bill costs to on-demand heat and climate-related advantages, a great tankless water heater will take your water heating process to the next level, with numerous benefits, at a considerable price.

​Tankless Water Heater Reviews: Pros and Cons

​The above comparison told you quite a few things about this product, but this section will cover every reason why and why not to purchase a good tankless water heater.


  • Large decrease in monthly bills
  • On-demand hot water
  • Additional storage space
  • Environmentally friendly
  • Long-term warranty
  • State-of-the-art heating technology
  • Remote control
  • Operating software computerization
  • 20-year life expectancy
  • Climate adjustability


  • High price
  • Large installation cost for tankless water heater
  • Many installation requirements (e.g. rewiring your entire house)
  • Large maintenance costs
  • Low coverage
  • Possible temperature fluctuation
  • Power source-dependent location
  • Lower warranty for specific parts

​Electric or Natural Gas Tankless Water Heaters?

​Once you opt for a reliable tankless water heater, you may be faced with the dilemma of which type is better, and why. Rest at ease, for we’ve prepared a thorough comparison of both variants available on the market. Let’s dig right into it, starting off with the most important factor:

Initial cost​

​When it comes to the initial product price, electric tankless water heaters have a significantly lower cost than their gas counterparts. Generally, whole house electric tankless water heaters cost somewhere around US$500-800, whereas gas tankless water heaters usually cost US$1,000 or more, especially if they encompass better quality equipment with electronic ignition systems. The installation costs are not included in the prices mentioned here (more on that below).

​Efficiency / Operational Cost

While gas tankless water heaters may be considerably more efficient than gas tank water heaters, their efficiency most often peaks at 80-85%. Inversely, most electric tankless water heaters peak at 98+% efficiency. Even though natural gas is usually a way cheaper input fuel than electricity per BTU of output power, this benefit is often outweighed by the higher efficiency of the electric tankless water heater, its longer service life, and cheaper installation.

To top it off, electric tankless water heaters cost much less than the majority of tankless gas models, assuming that you own the best electric hot water heater. What’s more, gas prices usually fluctuate more dramatically than electricity prices, while most economists agree that gas prices are now expected to rise substantially in the years to follow, whereas in most areas, the price of electricity should be relatively stable or at least on a much slower rise.


​Gas tankless water heaters contain complex venting systems and have many combustion air supply requirements, especially if installed in a confined space. The existing gas lines and venting ducts are seldom usable. For the requirement of side wall venting, things can get even more complicated. Thanks to their high gas consumption, the existing ventilation systems rarely fit the norm. The bottom line is that these requirements may make installation quite expensive.

​Electric tankless water heaters often aren’t bulky, around one-third the size of a gas tankless water heater. According to their convenient size and the fact that they require no exhaust gas ventilation, they can be placed virtually anywhere not feasible to install a gas tankless water heater.

Consequently, electric tankless water heaters can usually be located closer to the actual usage point. They can be placed in a closet, in a crawl space, under a sink, or a wide variety of other areas where the traditional tank water heaters and gas tankless water heaters cannot. Unless an electric system upgrade is required, the installation of electric tankless water heaters is usually much cheaper than that of a gas tankless water heater.​

Warranty, Lifespan, and Maintenance

Electric tankless water heaters require little to no maintenance. In fact, aside from cleaning the inlet screen filter from time to time, electric tankless water heaters generally do not need any maintenance. On the other hand, gas tankless heaters need to be inspected annually by a skilled technician in order to ensure safe fuel combustion and performance.​

In the event of an issue, electric units are inherently easier to troubleshoot, diagnose and repair. The pure simplicity of their design means they have a much longer lifespan. Gas tankless water heaters possess very complex heat exchangers and fuel control, which are much more difficult to operate on in the field.

Energy Source Availability

The availability of adequate electric energy, propane or natural gas, can naturally affect the decisions as to which exact type of tankless water heater is best for your business or home. Electric tankless water heaters are sorted amongst very high power appliances. Since they heat water completely on demand, their top electricity needs are quite substantial, even though their total energy consumption is noticeably lower than traditional tank-type water heaters.

Accordingly, it is usually required that a home has a 200 AMP, 208 to 240V electrical service in order to run an electric tankless water heater (the smaller ones that are suitable for warmer climate areas can usually be installed on even 100, 125 or 150 AMP electrical services). Certain homes or business don’t possess such electrical power and upgrades can often be expensive.

On the other hand, the installation of a gas tankless water heater will almost certainly prove to be uneconomical if the building does not have an existing natural gas or propane service at its disposal, or if the diameter of the incoming gas line is insufficient (which is a common occurrence). You can also find the list of best gas water heaters 2015 and 2016 for more details.

​Water Usage Habits and Needs

​For a majority of homeowners and businesses, their water usage patterns and needs won’t affect their choice of what exact type of water heater they should opt for. Electric tankless water heaters have the ability to provide from 3 to 8 GPM of shower temperature water, depending on the model selected and climate.

​The said stats are often more than enough to please the needs of nearly any family, while gas tankless water heaters are there to live up to even the highest expectations. Generally speaking, a large amount of gas tankless water heaters on the market are capable of providing somewhere around 10GPM, which is sure to satisfy any consumer’s flow standards.

​Homeowner Preference

​Due to safety reasons, certain homeowners do not feel comfortable with using natural gas or propane to power any of their home appliances. In such situations, an electric tankless water heater is the optimal choice for peace of mind. Other homeowners tend to have preferences for one type for varying reasons, including the availability of energy (gas or electricity) in the event of a major regional catastrophe such as a natural disaster. Other users may still prefer one type over the other due to environmental reasons.

​The best electric tankless water heaters have extremely high energy efficiency, with more than up to 98% of the electric energy supplied to the units actually being used for water heating purposes. On the other hand, gas tankless water heaters usually have an energy factor lower than 85%, while they also contribute to greenhouse gas emissions.

​Ultimately, every homeowner should weigh their own needs against the pros and cons of both alternatives. In spite of that, the market reports an overall favorite when it comes to casual households. A majority of small and medium homeowners and apartment dwellers usually go for the electric type due to the high initial cost of gas systems (including installation), their maintenance requirements, inherent complexity and shorter lifespans and warranties.

​Installation costs

​It takes a considerable amount of money to get every great best tankless water heater installed and running, but once you’ve made the purchase, it’s something you must unavoidably complete. We will now address any of your existing installation cost concerns.

First of all, the consumers that hire a pundit to install their tankless water heater should expect to pay either a flat fee or an hourly fee. The total installation cost varies depending on the type of tankless water heater that is being installed and the professional who installs it.​

Factors such as installing proper ventilation in order to prevent carbon monoxide poisoning and a complete alteration of the size of gas lines and fittings tend to take an average of 10 hours. Consequently, the customers that decide to install a gas tankless water heater are bound to face significant costs.​

Electric tankless hot water heaters don’t take nearly as much time to install. The ones such as a point-of-use electric water heater can even be installed right under the sink by a plumber with some electrical skills. The electrical timer, electrical outlet, and water supply lines required for the installation of this type of water heater usually don’t have a high total cost. The average time that this specific product takes to install is a mere two hours, which allows for the consumers to pay significantly less.

Another factor that affects installation costs is a reduction offered on specific tankless gas hot water heaters. Consumers can make great use of a tax credit on products that qualify with Energy Star. Tankless water heaters with the Energy Star symbol are energy-efficient appliances that comply with the government standards. Such products are also highly rated in quality, features, and performance.

​Consumers will also need to pay for the material and labor costs for the other parts that are needed in the installation. The accessories required for a tankless water heater usually include a tankless gas connector kit, termination vent kit, the two-piece lead-free brass tankless water heater valve set, in conclusion with fittings and mounting hardware.

​Condensing vs Non-Condensing Tankless Water Heaters

​Since the heating process in any tankless water heater including the best tankless water heaters in the list above works through combustion, it is necessary to know the combustion differences between condensing and non-condensing tankless water heaters.

​During a typical combustion, the tankless water heater burns the hydrogen content of the fuel, resulting in the production of hot gasses. One of those gasses is steam or vapor. Once that steam is cooled, it turns into water that is generally referred to as condensation. The condensation water is acidic (3-5 pH value) and thus corrosive, meaning it will corrode steel metals and other materials.

​A non-condensing tankless water heater will push the hot gasses outside through a vent, where they will proceed to cool down. The released gasses have temperatures of around 300 degrees Fahrenheit and thus need to be vented through non-corrosive venting materials capable of withstanding the heat. If your tankless water heater isn’t made of stainless steel or doesn’t have stainless steel secured venting at least, you are welcome to purchase stainless steel category 3 venting or better, at a significant price.

​The gases ejected from the tankless water heater contain up to 20% of the actual energy that heats the water, meaning a whole fifth of the heat-generating capacity is wasted by being exhausted into the open. The hotter the exhaust gases are, the less energy goes into heating the water, which is why non-condensing units have an efficiency average of 80%.

​Condensing tankless water heaters extract the heat stolen by the gases and therefore exhaust cooler gases, typically around 100 degrees Fahrenheit. Since the exhaust gases are made much cooler by this technology, you can afford to use a cheaper venting variant, as it can then withstand the low heat emissions.

​By managing to capture the residual exhaust heat and transfer its energy to the heating process, units with this technology are known for their remarkable 98% top efficiency. A condensing tankless water heater may be more expensive than the rest, but it is well worth it, considering its increased performance and reduced costs of various parts.

​Final Verdict

​With all of the newfound knowledge in mind, you can now be certain of any decision you make when deciding which product from this list to opt for. We will now proceed with the final comparison and our own personal favorite.

​For a mountaineer or any high altitude and cool climate dweller, products 3 and 7 are most definitely the optimal choice, due to their high frost resistance and the ability to benefit from unfavorable temperatures. This is as far as we will recommend them, due to the finer qualifications of the other 5 products when other climate types are in question.

​Products 2 and 5 are ideal for any apartment or small household, perfect for heating one room at a time. Product 2 runs on gas, while product 5 requires electricity. Both types will induce certain costs to run and set up, but they average out at about the same amount, while they are both very cheap and the most economical choices on this list.

​Products 4 and 6 both run on gas, take a considerable amount of money to install and they are the most expensive choices on this list. Regardless, these two products are the best large household heaters on the market with irreplaceable qualities. We would recommend nothing but these two products for the heating purposes of any spatial home or building.

​Finally, product 1 can take up the roles of almost all of its competitors, due to its Advanced Flow Control technology that none of the other products can offer. This perk allows it to cost significantly less than any large-area tankless water heater, while still performing its duty with prime quality. As it belongs to the mid price range in comparison to the other products on the list, and yet just as effective as any of them, we consider it to be an outstanding tankless water heater.

​Every passing day, significant amounts of homeowners decide to opt for a tankless water heater as a result of the realization of its benefits. It can be quite bothersome to try and find the finest available choice on your own, but we’ve hopefully ridden you of that issue.

Each brand has its own advantages and disadvantages. We will cover more brand reviews in the next articles. Some issues we are interested in are: ​Noritz tankless water heater reviews, navien tankless water heater reviews, navien tankless water heater problems, navien npe 240a problems, navien 240a complaints, navien ncb 240 problems, tankless water heater prices (i.e., navien npe 240a price, rinnai r75lsi price), and how to size tankless water heater.

​The tankless water heater reviews are sure to be your faithful companion when it comes to choosing an appliance of such importance.

​Think wisely, pick well, and enjoy your new state-of-the-art best tankless water heater!

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