The Best Tankless Water Heater Reviews

(Last Updated On: April 19, 2017)

Hot water on demand; this is what makes tankless hot water heaters so popular and highly in demand. Unlike ordinary water boiler which are inefficient, consume lots of power and have limited hot water storage capacity these heaters are more than efficient! They give you a steady supply of hot water throughout the day without consuming that much of power.

This is because tankless heaters heat water only when you need and want it to instead of wasting electricity storing heated water. It’s no wonder so many people are now turning to, and using tankless water heaters for their showering needs.

With so many models and brands in the market, you should find this buying guide helpful in choosing the best tankless water heater for your household needs! Remember, not all homes are set to work with tankless water boilers and not every heater works very well too!

The main reason people prefer a tankless vs. tank heater is because on an average, a whole-house tankless heating boiler can reduce your electricity bills by 5-50%. It heats water which moves through the system and doesn’t heat and store hot water like storage heaters, thus ensuring you never run out of hot water!

Tankless water heater reviews – Top 6 in 2017

Picture Name Electrical requirements Size Our Rating
 ecosmart-eco-27-electric-tankless-water-heater Review of EcoSmart ECO 27 Electric


27 kw, 240 volt

17 x 17 x 3.5

eccotemp-l5 Review of Eccotemp L5 Portable
11 kw, 240 volt 1.5 GPM 4.4

Review of Rheem RTE 9 Electric


9 kw, 240 volt 3 GPM 4.3

Review of Eccotemp L10 Portable Outdoor


27 kw, 240 volt 2.65 GPM 4.3

Review of Takagi T-KJr2-IN-NG Indoor


27 kw, 240 volt 4.2

Review of Rheem RTE 13 Electric


13 kw, 240 volt 4 GPM

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

pricebuttonHaving a hot shower in cold climates can be difficult for some as water heaters don’t heat up water as expected. However this problem is nothing to worry about with the EcoSmart ECO27 at home.

This device is configured to provide hot water in cold climates and places with high water flow rates. It’s fit for use wherever there is a high demand for water usage as it can heat nearly 3 gallons per minute even at temperatures as low as 37 degrees.

Compact in size, it saves on your valuable storage space. Stylish to look at, the heater is pleasing to the eye. The EcoSmart whole house electric water boiler comes with copper and stainless components which assure the heater’s optimal efficiency and durability while in use and easy replacement if required.


  • Helps you save as much as 50% on your water heating costs
  • Heats water in cold climates and places with high water flow rates
  • Compact size saves space and fits anywhere
  • Pleasing design
  • Energy required for heating water is regulated by its self-modulating flow sensor
  • Outlet water temperature setting is digitally displayed
  • Thermostat automatically resets
  • Can heat nearly 3 gallons of water as low as 37 degrees per minute
  • Fit for use with Jacuzzi tubs and large Roman-style tubs needing more water
  • Easily handles four showers and a sink together without running out of water


  • Many consumers complain the Ecosmart Eco 27 trips AFCI breakers when switched on.

eccotemp-l52. Eccotemp L5 Portable Tankless Water Heater and Outdoor Shower

pricebuttonThe Eccotemp L5 Portable is the answer to the dream you always had of instant hot showers while camping. This portable 1.4GPM runs on a 2 D cell battery ignition, making it perfect for use in campsites, cabins or around your house for washing your car, boat, dog or horse, where electricity is not easily available.

While its optimal operating range is 20-80 PSI, it also works on modified water systems with items like a 12 volt pump. It weighs only 13.8 pounds and requires just 2” clearance from walls, 1’ side to side clearance from anything flammable, 3’ from windows or anything overhanging and 18” from the ground to use.

The Eccotemp tankless propane is easy to set up and use. Just connect to a standard garden hose nozzle and a propane tank, which isn’t included, and the heater produces hot water within seconds. You can choose from variable spray settings and as the heater automatically shuts off after 20 minutes, in case you forget.


  • Perfect for use outdoors in campsites and cabins and around the house for washing pets and vehicles.
  • Ignition triggered by 2 ‘D’ cell batteries, making it great to use off grid and places where electricity is unavailable.
  • Functions with 20-80 PSI of water pressure and minimum flow rate of 0.3 litres per minute
  • Saves water, energy and money
  • Generates more than a gallon of hot water per minute
  • Comes with adapters for attaching to standard garden hose nozzle (excluding propane tank)
  • One-year limited warranty on parts
  • Automatically shuts off after 20 minutes of use


  • The wind outdoors can blow out the pilot to leave you with a cold shower
  • Water gets very hot; painfully hot sometimes.
  • You get either water pressure or hot water and not both. So pressure to be set at low to get hot water.

rheem-rte-9-electric-tankless-water-heater-3-gpm3. Rheem RTE 9 Electric Tankless Water Heater, 3 GPM

pricebuttonThe Rheem RTE 9 is perfect for producing continuous hot water on demand. It fits practically anywhere and comes with an energy efficient compact design. Installation is easy as it fits with any standard ½” water connection.

The Rheem comes with on-unit temperature control LEDs which indicate when the heater is in active and standby mode. Prefect for use in hotels, boats, homes, apartments, restaurants, condos, laboratories, offices and practically anywhere hot water is necessary.


  • Saves energy while providing continuous hot water on demand
  • Fit with a rugged brass/copper heat exchanger
  • On-unit temperature control LEDs indicate when the unit is active and in standby mode
  • Fits anywhere hot water is necessary like hotels, homes, offices and boats
  • Has a minimum activation flow rate of 0.4GPM and a maximum flow rate of 3 GPM
  • Compact in design and quick and easy to install


  • Needs a minimum 50-amp service
  • Not meant for use for the entire house
  • Provides hot water to only one shower and at the most, an additional sink
  • Some consumers complain it doesn’t produce 3GPM but only 1.5 GPM at the most.

eccotemp-l104. Eccotemp L10 Portable Outdoor Tankless Water Heater

pricebuttonThe Ecotemp L10 Portable offers the perfect solution to all your hot water needs. It is conveniently designed to use outdoors at your cabin, Lake Home, RVs, horse washing stalls and wherever you need hot water.

It delivers about 2.65 GPM of hot water, which is enough for two hot water applications running together. As it’s 2 ‘D’ cell battery ignition starts only when water is running, there is no chance of any overheating and is perfect for use in areas with limited electricity and when off grid.

As the L10 tankless waterheater propane comes with standard ½” NPT fittings, it’s easily fitted in with standard fixtures. While its best operating range is 25-80PSI, it also works great on modified water systems like 12v pumps. Comes with 9’ CSA approved gas regulator and hose fitting standard 20lb grill style propane tanks


  • Portable tankless water fit for outdoor hot water use
  • Comes with CSA approved gas regulator and hose, stainless steel rain cap and ½” NPT to garden hose adapter
  • It’s 20 minute automatic safety shutoff timer resets once water stops and then starts again
  • Doesn’t need any electricity as it works on an battery igniter
  • Delivers a maximum of 2.65 GPM of hot water, enough for 1-2 hot water applications


  • Some consumers complain of poor customer support
  • Some consumers complain the heater doesn’t stay lit for longer than 10 seconds
  • Sometimes the regulator’s male part may not screw far enough into the propane tank’s female receptacle for adequate gas flow
  • May catch fire because of internal fittings leaking propane

takagi-t-kjr2-in-ng-indoor-tankless-water-heater5. Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas

pricebuttonThe next time you need to replace your heating boiler, why not go for a tankless waterheater like the Takagi T-KJr2-IN-NG instead of a traditional one? This point of use tankless heater is perfect for bachelors and people who don’t need a lot of water as it’s reasonably priced and its smaller capacity makes it fit to use anywhere as required.

While it does have gas, water and venting requirements to be met for its installation, and this may cost some money, in the long run, it helps you save energy and consequent utility bills. Its wall mounted controller lets you set your desired water temperature and displays both water in and water out temperatures and water flow rate. Just set your desired water temperature and there’s no need of any additional mixing of hot and cold water.


  • Small capacity heater which fits anywhere
  • Enables constant monitoring of temperature through its inlet and outlet thermistors
  • Has a maximum flow rate of 6.6 GPM.
  • Reasonably priced
  • Wall mounted controller facilitates setting of water temperature and displays water in and out temp.


  • Will not drive two showers together unless set at the lowest temperature setting
  • Burner has to be cleaned annually.
  • Heater tends to shut off mid shower
  • Poor customer service

rheem-rte-136. Rheem RTE 13 Electric Tankless Water Heater, 4 GPM

pricebuttonFed up of waiting for hot water to take a bath? With a Rheem RTE 13 you no longer have to wait. This is an instant heater which gives you hot water on demand, and is ideal for use in point-of-use applications.

The Rheem RTE 13 works on a standard 1/2” water connection and has temperature control LEDs which indicate active elements and when on standby mode. Compact in size, it conveniently fits almost anywhere to work with your washing machines, showers and dishwasher.


  • Fit for use anywhere hot water is needed- in homes, condos, hospitals, apartments, restaurants, hotels, boats, offices and laboratories.
  • Temperature control as required
  • LEDs indicate if the heater is in standby and active mode
  • Easy to connect with its standard ½” water connection
  • Great for use with single shower application with its maximum flow rate of 4.0GPM
  • Pays off its initial costs with long-term use
  • Best for single people or couples who don’t use much water
  • Comes with a 10 year warranty
  • Saves money, energy and water


  • Can’t take shower, wash cloths or do dishes together as it reduces the heat
  • Poor customer service
  • Some complain the water temperature tends to fluctuate
  • Not as much water flow as advertised

Factors to look out while buying tankless water heaters

  1. Check the water temperature

Setting the required water temperature in the waterheater is an individual choice. However if you want to maximize your power savings, it’s better if you maintain a lower water temperature.

Then again, too low water temperatures can result in pathogens like Legionella surviving and reaching your water. As all heating boilers, conventional or tankless have to heat water from the original input point, you need to find out what the incoming temperature of the water is in your area before you buy your system. This is because lower temperatures need more energy to heat water to the required degree.

  1. Electric or gas tankless water heater

The conventional heating boilers work either by igniting natural gas or propane or using a fully electric system. It’s easy and better replacing a gas or propane system with a propane powered or tankless gas waterheater.

It’s also possible to replace the old gas system with an electric heater; but you’ll have to expand the replacement system’s electrical input as the electric heaters require more direct electrical current to work.

However replacing a conventional electric heating system with a gas tankless boiler is a complex procedure as you not only have to install gas lines, but also install ventilation systems for the excess heat the systems produce. So it’s not something you can do on your own, but which requires an expert’s help.

  1. Size the tankless water heater based on its hot water production

As tankless water boilers provide continuous hot water, you need to decide what size tankless heating boiler do I need based on its flow and not its capacity. This is because while these heaters never run out of hot water like storage waterheater, they cannot heat water fast enough to serve numerous fixtures at a time.

Tankless water boiler receive BTU (British thermal unit) input and efficiency ratings which determine the heater’s flow rate. A BTU is the amount of energy used to raise a pound of water’s temperature by 1F where higher BTU ratings indicate a higher flow rate.

Gallons per minute or (GPM) determines the heater’s flow rate or the amount of hot water it produces where the cheaper systems have a low GPM of about 1.2 to 6 gallons per minute. While a heater which provides hot water to a single bathroom sink is rated 1.2GPM, 2.6GPM tankless waterheater can handle one shower at a time. A 4GPM model can handle a shower and a sink while a 6GPM heater, 2 showers.

Generally, the water pressure drops off and the water boiler’s temperature falls once the gpm of the heater is reached. This is because these heaters are tankless and so only heat water at input using copper housings and can heat fixtures based on its GPM.

It’s thus better to buy the more expensive systems which max out at 9 gallons per minute or more if you have a large house and family with many fixtures needing hot water. You’ll end up disappointed replacing your conventional heaters with a smaller system.

  1. Flow activation

Tankless heating boilers electronically measure the water flow which automatically turns on the heater. Higher flow requirements mean slower hot water. The initial flow activation is under a gallon per minute, between 0.3 and 0.9 gpm for most heaters. Lower gpm means faster hot water. The water flow is managed and detected by advanced microprocessors in the new hot water boilers.

  1. Location

It’s important that tankless heating boilers be fitted within about 50feet of a power source. This should not be a problem as they can be easily mounted on interior or exterior walls.

Advantages of tankless water heater (Tank vs Tankless)













Besides this, there are many benefits associated to installing these heaters at home and between tank vs. tankless.

  1. Hot water at your comfort and convenience

Tankless waterheater are considered the epitome of comfort and convenience as you just have to push a button to get a continuous supply of hot water. There’s no more scheduling of bathing times for the family or risk of sudden temperature fluctuations due to revolutionary technology and design.

Unlike traditional tanks where available hot water diminishes at one time so that people end up postponing their shower so that more water is heated, tankless heating boilers have sufficient water for everyone. Moreover, these heaters are compact in design, and can be mounted on walls or in corners, and not necessarily need large space like the traditional heaters.

  1. Tough and durable

As tankless devices have an all metallic framework and heavy duty construction, they are a tougher and more durable option to conventional heaters. They are also long-lasting and once installed, you needn’t worry about them for at least 20 years, double the expected lifetime of ordinary heaters.

So investing in tankless water heaters is a plus point while building a new home or while upgrading a house to live in for a long time. Moreover, the presence of a tankless heating boiler proves beneficial, and a strong selling point to homeowners planning to sell their house.

  1. Uses less power

These devices run mainly on gas or electricity, which reduces power consumption a lot. So though the gas versions are faster and more efficient than its electric counterparts, tankless waterheater are on the whole more power efficient and time saving than conventional heating boilers. And as water is heated on demand, not much energy is lost or wasted due to standby heat loss.

  1. Flexible operation

Tankless water heaters have many built-in heat settings and controls which offer greater flexibility for easy regulation of the quantity and temperature of water. Moreover, its compact size means that these heaters are not confined for use only in bathrooms. They can also be installed outdoors to boost the cleaning results of appliances like dishwashers and washing machines.

  1. Saves energy and is then environmentally friendly

As tankless heating boilers save up to 27 -50% of energy because of its power saving and ergonomic design, these heaters are environmentally friendly. Moreover, you are assured of fresh and clean water throughout the day as dirt or other impurities in the heater do not accumulate in it.

  1. Safe to use

These waterheater are safe to use as there’s no risk of any short circuits or gas explosions as they run on a full proof and secure power supply system. Moreover, its insulation covering prevents accidents and its plastic covering protects from any external damages and depreciation. They are especially safe with kids around as its smart sensors cut off the power supply when the machine’s not in use and there’s no risk of spillage with its tankless design.

  1. Longer warranties

Tankless heating boilers generally come with a longer warranty, of about 15 years when compared to the 6 years warranty of traditional boilers. There’s also no worry of water spilling on the floor due to the breakdown of the heater.

  1. Saves money

Though you may have to initially spend more on the cost of tankless heating boiler, you end up saving money in the long run. Unlike traditional heaters which heat and store hot water, only a small amount of water is heated as and when required in waterheater without tanks.

  1. Uses less space

Traditional deices may hold between 40-60 gallons of water and measure 5 feet tall, to thus take up lots of space. However tankless water heaters are only 20-28 inches in size and are thus more compact to be installed in more areas to give more space for other things.

Choosing between gas and electric tankless water heater

Choosing between these two can be easy for people who base their decision based on the power availability at home. It’s when your household can accommodate both types of heating boilers that you have to decide based on other factors. There is no ‘better’ heater between the two; you have to decide based on factors like your household circumstances, how much is a tankless waterheater and your hot water needs and preferences.

  • Cost

The rates of these tankless heating boilers differ drastically where the tankless electric water heaters are cheaper than the gas-powered counterparts. While good quality electric tankless waterheater are available for as cheap as $500, you need to spend as much as $1000 for reputed gas heaters. Moreover, gas heating systems with electronic ignition systems and other additional features cost even more.

  • Installation

Gas heaters are not only expensive to buy, it comes with a higher installation cost. On the contrary, electric tankless water heaters are easier, and thus cheaper to install as they are small and less complex to install.

They fit practically anywhere in the household like under the sink or in closets. However the gas versions are difficult to install as they require ventilation, gas supply and other things which normal houses may not have. This is why you first need to find out if your present venting ducts and gas supply  lines can be used, which unfortunately can’t.

  • Operating costs

Despite its initial costs, gas water heating systems are cheaper to operate than their electric counterparts. This is the main reason for consumers buying them; with the hope of recovering the investment money through reduced operating costs.

However if your locality has limited natural gas supply, it’s operating costs will increase. Moreover, while electricity rates are expected to remain stable, it’s not the same with natural gas, which may increase in the future.

  • Water supply

Gas and electric heaters supply different levels of hot water. While the electric versions can provide as much as 8 gpm, sufficient for the average family, the gas versions can provide a larger supply of hot water. They are thus a better option for homes and buildings needing lots of hot water.

  • Maintenance

While gas heater have to be inspected annually by licensed technicians for its safe and efficient use, electric tankless hot waterheater need no maintenance. At the most, they require some occasional cleaning of the inlet screen filter.

So there’s no ‘better’ tankless water boiler between the two. You need to weigh the pros and cons of both these types of heating boilers before choosing the right one for yourself. You need to consider its installation and tankless hot water heater cost, maintenance costs and of course, how much hot water you and your household require.

However whichever choice you make, tankless water heaters are definitely better than the energy sucking conventional water heaters. They not only save you money, but also reduce the amount of carbon emissions to the environment.

How does a tankless water heater work?

As you know, water heater tankless do not heat and hold water in a tank. They basically heat the water by circulating it through a series of electric coils or burners and then pass the hot water through to the faucet or appliance.

These heaters never run out of hot water unless the demand for water at one end surpasses the unit’s heating capacity. This means while a tankless unit may handle the flow of 2 people taking showers at a time, they may end up in a cool shower if the dishwasher or washing machine is started.

While storage heating boilers deliver water at a set temperature, the temperature of most tankless units depends on the flow and temperature of incoming water. This varies greatly from one area or season to another. The unit’s capacity is thus measured by the number of degrees its temperature increases at a given flow which is expressed as gallons per minute.

It is because of this required response time and heat output that most whole house tankless waterheater units are gas-fired and the smaller, single-fixture unit storing a few gallons of water are usual electric versions.

The gas-fired tankless heating boilers need venting with flues generally larger than those found in conventional gas water heaters. Some units also have power vents wherein gases can be exhausted out through a side wall and are best used for replacing electric waterheater where it’s expensive venting out of the roof.


Vested with all this information, it’s thus easier choosing the right tankless water heater for your home’s hot water needs. You basically have to choose your heating boiler based on its heating capacity, water temperature and if you want a gas or electric unit.

As both have their share of pros and cons, you may find these tankless waterheater reviews with their features, helpful at choosing the best tankless heating boiler. The more tankless hot water heater reviews you go through, the more informed you are at choosing the best waterheater.

The Best Tankless Water Heater Reviews
5 (100%) 3 votes

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