Best Tankless Water Heaters to Buy in 2017 – Buyer’s Guide and Reviews

Tankless water heaters offer a myriad of benefits, one of the biggest being financial savings — sometimes as high as 60% savings based on some models power usage. Water savings and consumption reduction, convenience, instant access to hot water, small sizes that take up less space in a home. The ability to provide water to multiple sources such as two showers at once without anyone noticing the lack of water pressure are some of the other things people love.

Designed to be run on either electricity, propane or natural gas, there are a variety of options for homeowners to choose. And for the more adventurous among us, there are even outdoor hot water heaters that offer tankless technology and some cool innovations that haven’t yet made their way into residential uses.

In this review, we’ll provide you with an overview of the ten best tankless water heaters and provide you with a buying guide. So you know what you need to look for when you are ready to buy this function and affordable piece of equipment for your home, office, or cottage.

Best Tankless Water Heaters on the Market Today

Rheem RTGH-95DVLNNatural Gas9.5 GPM120V
EcoSmart ECO 27Electric3 GMP240V
Takagi T-KJr2-IN-NGNatural Gas6.6 GPM120V
Rinnai RUC98iN Natural Gas10 GPM120V
Stiebel Eltron TempraElectric4.5 GPM240V
Eccotemp FVI-12-LPPropane3.6 GPM110V
Marey Gas 10LPropane3 GMP2 D Cell battery
Camplux 10LPropane2.6 GPM3V
BOSCH TronicElectric 1.8 GPM240V
SioGreen IR6000Electric 3.6 GPM240V
Diagram of a tankless water heater

Diagram of a tankless water heater:

When assessing what makes a tankless water heater a good investment is the type of power that is required to operate it: electricity, natural gas or propane.

What’s more, when you decide to buy a tankless water heater you’ll want to consider how many people in your home will be drawing on the water source. How fast you want the water to heat up, and how quickly you can have the tankless water heater installed.

If you have a large family, you might want to mitigate the amount of disruption caused by having to have a new water heater installed. You’ll want to consider the kind of water pressure and temperature control that is possible. And you’ll want to make sure you have the proper wattage to support your new tankless water heater.

Some heaters will require professional installation and some you can install by yourself in a matter of minutes or hours.

For convenience, we threw in one tankless outdoor water heater so you can see the differences between them and the applications to suit your needs. Here is a comprehensive review of the ten best tankless water heaters on the market today.


Rheem RTGH-95DVLN – Great Deal of Power Savings

This tankless water heater from Rheem offers a 94 percent energy efficiency rating. It offers a stainless steel condensing heat exchanger that offers electronic controls which help you control the flow of hot water on demand.

The unit is intelligently designed and compact enough to fit in even the smallest bathrooms at home or in the cottage. It can be housed up to 38 feet away from the area that it is servicing via PVP pipe like traditional water heaters.

The tankless designs allow for less water usage over time, and it provides a great deal of power savings because the water heater doesn’t draw on valuable energy to maintain the heat of the water 24 hours a day.

The Rheem tankless water heater meets rigorous industry standards for quality and reliability, and it is backed by a ten-year limited warranty on the heat exchanger, plus a one-year limited warranty on parts.

This tankless water heater is run by natural gas and uses approximately 199,000 BTU to make the water heat up on demand. Installation of natural gas lines into your home may be required to have this tankless water heater installed, but once ready for installation; the tank takes no time at all to install.

It comes with a digital remote control so you can control the input and output of the water heater. And it has a 10-foot thermostat wired included for close proximity changes to the heating elements. What’s more, the unit is powered by a 120V power cord that comes with the package.

Pros and Cons

  • Uses less energy to produce hot water on demand.
  • Comes with everything you need to install it right away.
  • Remote, thermostat wires and power cord.
  • Great for a variety of locations in your home or cottage.
  • Can take a little longer for the water to heat up because there isn’t a constant supply of hot water sitting in a tank.
  • Can take some time to determine the best temperature for use for each person.

Click here to see reviews on Amazon

EcoSmart ECO 27 – Best for Multiple Bathrooms

The Ecosmart ECO 27 is but one of the many tankless water heaters offered by EcoSmart Smart Technologies. The ECO 27 offers savings of up to 50% off the cost of heating water in a more traditional hot water tank.

The unit features a digital temperature control that has a detailed degree control system, so users have more control over the hot water. Temperature ranges from 80 degrees Fahrenheit to 140 degrees Fahrenheit.

The unit features copper and stainless steel components that provide efficiency, durability and offers easy replacement of parts under if necessary.

It has a compact size that fits in any space, and its modern design means that even if you have to place it on a wall or a shelf in your home, it is not an eyesore. It also offers the patented self-modulating technology that Ecosmart owns that provides even more energy conservation.

When installing any new electrical component to your home, check to make sure that your electrical system can support the needs of a tankless water system. This unit requires 27kW, 240 volts.

As for the heating capacity, the ECO 27 can produce 3 gallons of hot water per minute at even the lowest temperatures. What’s more, it can support multiple bathrooms where more than one shower is being used at a time.

Pros and Cons

  • Patented technology heats water fast and consistently.
  • Can heat multiple showers and sinks without losing pressure and heat overall.
  • Company offers a multiple line up of models to fit your water heating needs.
  • Low power consumption and high water heating rates.
  • Lightweight and easy to handle during installation.
  • Measures only 17” x 17” x 3.5” in size.
  • The unit offers a remote control, but it is sold separately, which is not a deal breaker but is very inconvenient.
  • The limited warranty only covers electronics and the element of the heater; a more comprehensive warranty would be nice.

Click here to see reviews on Amazon

Takagi T-KJr2 – Good for Small Homes and Cottages

This natural gas water heater by Takagi offers a maximum water flow rate of 6.6 gallons per minute and uses only 140,000 BTU to heat the water being used. This model is one of the smaller units of indoor tankless water heaters offered by this manufacturer, and it is a good size for smaller homes and cottages that house 1-2 people.

Despite its small size, it weighs a lot more than some of the other models in this tankless water heater roundup. It comes in at a whopping 38 pounds, which might require two people for installation purposes.

The warranty on this model offers a ten-year limited warranty on the heat exchanger, a five year limited warranty on parts, and the manufacturer also offers a one-year limited warranty on labor. Despite it being only a year, a labor warranty is not common in the industry, so it is a nice feature in case something happens to your natural gas tankless water heater.

The Takagi T-KJr2-IN-NG tankless water heater features an energy star rating and is available in a number of sizes for various uses, including an outdoor version of the tankless water heater.

Pros and Cons

  • The manufacturer offers a better warranty than most tankless water heaters which includes a one-year limited warranty on labor.
  • The tank is small, so it takes up less space.
  • Good for a small home, summer home or cottage.
  • The tankless water heater is heavy despite its small size.
  • It offers a lower flow of water than other models on the market.
  • Might take a while for the water to heat up because of its small size.

Click here to see reviews on Amazon


Rinnai RUC98iN Best Space Saving Design

The natural gas tankless water heater by Rinnai offers a space-saving design that means it can be installed almost anywhere you would need to get access to hot water on demand.

Think the cottage, the summer home, or your small apartment. Don’t let the small size of this tankless water heater fool you though; it offers a great deal of heating power with a small footprint.

Using 199,000 max BTU, this model of tankless water heater offers ultra low emissions and uses a condensing technology to produce efficient water heating capabilities. With temperatures ranging from 98 degrees Fahrenheit to 140 degrees Fahrenheit, the water heats up fast and consistently.

The warranty offered by Rinnai features a 12-year limited warranty on the heat exchanged housed inside of the tankless water heater. 5-year warranty on parts and a one year warranty on labor for residential applications. Similar to the Takagi tankless water heater, the bonus of a one year warranty on labor is a nice touch from the manufacturer.

This water heater is a little on the large side of some of the tankless heaters reviewed so far: it measures almosts 19” in width and 26” in height. But it is still very small for what it offers in on-demand water heating options.

It is a little heavier than the other models as well, coming in at over 60 pounds total. Despite this, the flow rate of almost 10 gallons per minute makes it super fast and provides a great water flow overall for homeowners or apartment dwellers.

Pros and Cons

  • Great water flow of almost 10 gallons per minute.
  • Energy Star rating.
  • Small footprint.
  • Low voltage.
  • Comprehensive warranty including one year on labor for residential applications. And an option to buy an additional 2-year warranty for commercial applications and installations.
  • Despite its small size, the tankless water heater is one of the heavier ones in the lineup.
  • Offering 10 gallons of water per minute could add up fast if you take long showers or let the water run while you are doing dishes.
  • For commercial use, the tank has to be set for up to 185 degrees Fahrenheit, which could be dangerous if exposed to skin.

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Stiebel Eltron Tempra Top Rated Tankless Electric Water Heater 

The Eltron Tempra Plus tankless water heater by Stiebel offers digital temperature control. This unit does not require venting, which means it requires less effort to set it up and maintain it over time. It offers a sleek design that measures 15” in width, almost 17” in height, and nearly 5” in depth.

Homeowners and apartment dwellers can expect to save up to 20% of their home electric bill based on their previous bills using a traditional hot water tank.

This unit is electric, and not powered by natural gas like some of the other tankless water heaters in this review. Which means that the installation is minimal and it can be installed in a number of locations that don’t have access to natural gas.

The unit requires 208/240 volts of power to run, and it is backed by the proven reliability of German design and functionality in the industry. This tank is often priced at a more reasonable rate than other tanks. And that makes it popular amongst first time tankless buyers because they aren’t sure if they will like the model and water flow.

This model of tankless water heater is just one of the many models offered by Stiebel, and the range is staggering. It just goes to show that the company knows a thing or two about the various needs of homeowners in different areas and of different sizes.

The unit is very light: less than 16 pounds overall and coupled with its small footprint makes it easy to install, easy to move if necessary, and easy to maintain.

The Stiebel Eltron Tempra Plus tankless electric water heater offers a limited three-year warranty, but the product must be installed by a licensed professional in order to activate the warranty.

That’s an important distinction from the other models in this review because although it is light and easy to install if you want the warranty. You’ll need to pay for the installation fees which can range up to $1000USD depending on your location.

Pros and Cons

  • Small and compact design makes it ideal for home, cottage or other small dwellings.
  • No need to ventilation this unit.
  • Requires little voltage to run.
  • Electric, so no need for natural gas installation and maintenance.
  • Offers warranty but with stipulations to activate the warranty.
  • The stipulation to activate the warranty only after it has been installed by a professional makes this a hard sell. The manufacturer boasts about how easy the unit is to install but then sets limitations on the warranty.
  • Complaints of issues with water chemical composition rotting the units from the inside out – if you have hard water, you might need to get a water softener to accompany this unit depending on where you live.

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Eccotemp FVI-12 High Capacity Propane Tankless Water Heater

This high capacity, low energy propane tankless water heater by Eccotemp offers a digital temperature display with independent gas and water controls to get the temperature just right for your needs. This unit promises no more cold showers and promises to run hot the first time, every time.

Powered by an intense propane flame inside the unit, the water becomes instantly hot, and the unit comes ready to install immediately. It is for indoor use for homes, small houses, apartments and you can even use it at the cabin.

Economical, using only 2 watts and 1.07 amps of power during operation, you can expect to save money over the long run with this efficiency tankless water heater. It offers a maximum water flow rate of 3.6 gallons per minute which means that you won’t waste a lot of water trying to take a shower or do the dishes.

However, this tankless water heater is not recommended for multiple users at a time, following the directions will make your water heater last that much longer.

What’s more, this sleek unit simply plugs into your standard electrical system at home so you can install it quickly and easily yourself. You will need a separate propane tank ranging from 20 lbs to 100 lbs, but they are easy to obtain in all areas.

The unit weighs about 33 pounds and measures 15” in length, 4” in depth, and 24 inches in height. It’s tall and can be tucked away behind a door or other storage area for easy hiding and easy access in a number of locations including behind a door, in a closet, or in a cabinet away from view.

The company offers 24 hours, seven day-a-week customer support so even if your electrician or plumber can’t come in the event of an emergency, you can contact the company for advice and support. The unit also offers a limited 2-year warranty on the heating element.

Pros and Cons

  • Instantly hot water provided from the propane source of heat.
  • Low flow rate of 3.6 gallons per minute cuts down on over usage of water and waste.
  • This unit offers low power usage which can result in more savings overall.
  • Moderately heavy but small footprint for the overall size of the unit.
  • Ideal for small homes with only 1 or 2 people in the residence.
  • Short warranty that only covers the heating element.
  • Needs a separate propane tank which can add up over time to the cost savings you might have seen on your water or electrical billing statement.

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Marey Gas 10L Best for DIYer

Promising to save consumers up to 60% on electricity bills for the water heating portion of your bill, the Marey Gas 10L tankless water heater offers water flow rates of up to 3 gallons per minute. Despite its small size and ability to save you a lot of money, the tankless water heater can support multiple points of use including showers, dish washing, and laundry.

What’s great about this tankless water heater is that it does not require electricity. This is a life saver for homes that experience frequent power outages, especially if you have small children at home.

The unit offers adjustable gas and water controls and uses natural gas to power the unit easily and quickly.

The tankless water heater measures 24 inches high, 14 inches wide and 7 inches deep. It is a little thicker than other models in this review, but because it doesn’t require electricity, it’s a great little number to install in your home or even cottage. What’s more, the unit only weighs about 21 pounds making it easy to move around during installation and easy to move if required.

Like some of the other models of tankless water heaters listed here, the Marey Power Gas 10L can be easily installed by the homeowner in just a matter of hours, depending on how much preparation of the installation site has to be done. The unit does require 2 D-cell batteries to keep the ignitor flame ready for heating on demand.

This manufacturing company offers good customer service support to its customers, but not on a 24-hour basis. It is available Monday through Friday during regular business hours CST. The manufacturer also offers a five year limited warranty on all parts.

Pros and Cons

  • A true do-it-yourself unit.
  • Can support multiple points of drawing water.
  • Lightweight and compact for easy installation.
  • Great money saving option for homes.
  • Offers 50 feet of support from the point of installation to the source of the water.
  • Doesn’t have digital controls, which is disappointing because it is expected in units like this.

Click here to see reviews on Amazon


Camplux 10L – Best Outdoor Tankless Water Heater

The only outdoor tankless water heater in this roundup, the Camplux 10L Outdoor portable water heater is powered by propane and great for the campsite, cottage, hunting cabin and more. It offers anti-freeze protection, flame failure device, and an automatic shut off for power consumption and safety when not in use.

The unit offers a compact and lightweight design measuring 21” high, almost 13” wide, and 8 inches deep. It comes with a number of accessories to help you get the most out of your camping or cabin experience including the complete Camplux tankless water heater system.

This system includes a shower head with a pedestal for storage, premium construction shower hose that measures 5 feet long; a CSA approved gas hose and regulator, a garden hose, a gas inlet connector to attach to your propane tank, and an accessories package that allows you to hang the unit and repair it.

The tankless water heater provides instant hot water thanks to the propane system so you can wash your car, boat, animals, or even use it as an outdoor shower at the camp or in your pool house.

It provides 2.6 gallons of water per minute and offers a unique combustion technology that provides steady heat and reliability anywhere you hook it up. What’s more, you can work the system on a modified 12V amp system for even more options for hot water on the go.

Unfortunately, while this tankless water heater has many benefits and features, the water that comes through the tank should not be used for drinking water, nor is this unit approved for indoor use in a residential home.

Hooking up the Camplux tankless outdoor water heater is as easy as hooking up a propane tank to a barbeque, and can provide hot water seconds after it is hooked up.

Pros and Cons

  • CSA approved for outdoor use.
  • Can be used on a 12V system.
  • Small and lightweight, weighing only 18 pounds.
  • Portable and easy to move around for travel and more.
  • Hooks up to a propane tank in seconds and hot water is instantly accessible for cleaning cars, boats, and more.
  • Good water pressure and flow for easy cleaning of a number of items, including yourself at the cottage or cabin in the woods.
  • Rated for outdoor use only.
  • The hot water is not intended for potable usage.
  • Can be used in colder weather but must be stored indoors for longer periods of cold.

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BOSCH Tronic 3000 Best Under-Sink Tankless Water Heater

Backed by one of the best electronic and appliance brands in the world, the BOSCH Tronic 3000 tankless water heater offers electric power and provides hot water on demand in seconds. It offers easy installation and is small enough to fit under a kitchen or bathroom sink.

The unit provides a 98% efficiency rating and doesn’t waste power when not in use. It can only be operated on a 240V power source, however. The unit is available in several sizes, but they can all be mounted on the wall or under your sinks, depending on the size.

However, despite the size of tankless water heater you choose, all of the units are incredibly lightweight, weighing only 5 pounds and they are all the same size: 6.5″ x 12.25″ x 3″ overall.

Typical usage does not require an additional pressure relief valve, and for many years of enjoyment, the unit should be installed by a professional.

The tankless water heater from BOSCH boasts an energy star rating. And the company does offer a limited warranty and customer service to help with issues or concerns. Before attempting to install the unit yourself, check with the manufacturer to ensure that doesn’t void the warranty, like some other models in this review.

Pros and Cons

  • The unit offers great efficiency ratings.
  • Small and lightweight across all models.
  • Modern design and easily blends in with surroundings.
  • Backed by one of the best brands in the business.
  • Can be installed anywhere from under the cabinets to on the wall.
  • Limited warranty from such a great brand name.
  • Some customers have complained of the hi-temp setting being switched on without warning causing issues with the temperature of the water coming out of the unit.

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SioGreen IR6000 Best for Whole House

The SioGreen IR6000 tankless electric water heater offers 3.6 gallons per minute of water pressure and uses a unique coilless technology and infrared technology to heat the water quickly. The unit offers a corrosion free build and uses less power because only the water you use is heated, rather than having hot water sitting in a traditional tank waiting to be used but needing to be kept hot for days sometimes.

This unit is good for areas that have hard water because it doesn’t produce calcium and limescale deposits the way some other tankless water heaters might. The water heats in seconds using a patented quartz heating element, so the water doesn’t come into contact with metal.

There are a number of models available for residential and commercial use under this brand, but this model is ideal for family homes of 4-5 people. It is also ideal for multiple draws on the system at the same time so more than one shower can be running at a time.

The unit can be installed easily without a lot of interruption to the flow of water. It offers adjustable temperature settings, and it doesn’t require ventilation.

Small and compact measuring 20” x 14” x 6” and weighs about 27 pounds in total. It doesn’t require any batteries, and there is a limited manufacturer’s warranty available for purchase as well.

Pros and Cons

  • Lightweight and small in size.
  • Patented design heats water fast.
  • Offers 3.6 gallons per minute of water pressure.
  • Unique infrared technology for heating water on demand.
  • Offers both commercial and residential applications.
  • Good for moderate sized families.
  • The water can take a few seconds to heat up so it’s not “instantly” hot as promised.
  • The unique design and element use might make it hard for professionals to fix.

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Buying Guide

When it comes to buying a tankless water heater for your home, apartment, cottage, or anywhere else you need a source of hot water; there are a number of things to consider.

The first thing to consider is whether or not you are going to be installing the tankless water heater yourself. Some models won’t honor a manufacturer’s warranty if the homeowner installs the tankless heater themselves. This is an important thing to note because if you have troubles later on, it can be difficult to get the help you need to fix your water heater.

The next thing you need to consider in your purchase of tankless water heaters is how many sources of water do you need to support. For example, if you have 2 or 3 bathrooms in your home and multiple people will be using the showers or sinks at a time. You will need a robust and higher gallon flow water heater to support that kind of use.

This typically means the tankless water heater you choose will be bigger and potentially heavier than lesser flow models, but it’s an important distinction to make.

If you live alone or have a smaller home, you can probably get away with getting a smaller unit. Which will cost you less money up front and potentially overall as you won’t be using as much water as someone who lives with multiple people or has more than one bathroom or shower source.

The third thing you want to think about is whether or not you want a tankless water heater that is electric, runs on propane or runs on natural gas.

If you don’t have access to natural gas in your area, then a number of models in this review will be irrelevant for you. However, most areas these days do have it so you should be fine. Be sure to check your local area to be sure before you buy.

Electric water heaters can save you money overall, and so can propane heaters. But the propane tankless water heaters still require you to purchase propane and make sure you don’t run out. This can mean cold showers in the morning if you forget to get a new supply of propane.

Finally, before you buy a tankless water heater, be sure to see how much voltage you need to run the heater itself. Some models don’t require electricity at all, and this won’t be an issue if you buy those. But if your tankless water heater needs a power source, you will need to ensure that your home is properly wired to support the installation of such a device.

One last thing, if you need a water heater for outdoor use, be sure to purchase a CSA approved tankless water heater for the outdoors. Nine out of the ten models in this review are not meant for outdoor use.

Not only can this void your warranty, but it can create a dangerous situation for you or anyone else using the water heater in a way that was not intended for it to be used. If you are not sure if the water heater you are going to buy is indoor or outdoor, ask for assistance at the location before you buy it.


If you are looking for the best tankless water heater on the market today, go for the Rheem RTGH-95DVLN. We like it because it offers the most robust options for natural gas water heating. Has an excellent warranty, offers a great water flow of 9.5 gallons per minute and is small enough to store anywhere in your home.

When their hot water tanks stop working, many people are turning to tankless water heaters to provide them with the water they need, when they need it, for a fraction of the cost of traditional water heaters.

What’s more, tankless water heaters save homeowners as much as 60% of their electricity bill associated with heating their water supply in a traditional hot water tank. That means that your tankless water heater could pay for itself less than a year.

Shop around, check out the buyer’s guide, know your options, and know your limitations based on your home’s wattage or access to natural gas, and you’ll be on your way to owning a great tankless water heater in no time.