Consumer Reports Tankless Water Heaters.

If you don’t have space for large tanks and are looking for some smart option for heating water, you should look for consumer reports tankless water heaters.

A tankless water heater heats water only when you turn on the faucet. Generally, most of these water heaters use natural gas or propane instead of electricity. The main reason these models are so popular is that they can help you save energy bills.

Since these tankless water heaters do not store water in a large tank and do not need to heat the water before it can be used, you will use less electricity when switching to a tankless water heater. Moreover, its innovative feature like smart control through mobile phone lets you set the temperature of the water and the time. In this technological era, there is no doubt that tankless heaters are better than those with tanks.

The best brand of Tankless Water Heater:

Rinnai Tankless Water Heater:


Rinnai is a well-known brand in the gas water heater industry. They manufacture high-quality tankless propane and gas water heaters for private and commercial facilities.

The Rinnai RUC98iN Ultra series is a small 10-inch thick unit that weighs 6.7 pounds. It has a sleek metallic gray appearance with multiple ventilation options, control buttons, and a digital display on the front.

If you are looking for high-quality gas or propane tankless water heaters for residential or commercial use, the Rinnai series is a good choice. However, its installation is a bit complicated, and it is best to hand it over to a professional plumber.

Rinnai’s high-efficiency tankless water heater models offer the latest technology, convenience, and value for money. Unlike tank heaters that collect rusty deposits, this V75eN compact instant water heater has a longer service life because the water is only heated when needed, saving energy costs. In addition, Rinnai products provide a guarantee of safety and superiority over competitors.

One of the most attractive features of this device is that you can connect to it through an app called Control-R 2.0 and can control this water heater; you can You may be on vacation, and you don’t have to worry about shutting down the system because you can operate it remotely it comes with an application called Control-R 2.0. You can download the app and then control the system, such as timers and scheduling. By taking the time to familiarize yourself with its functions, you can further improve the energy-saving effect through optimized use.

The warranty is also worth mentioning because it is very competitive. For example, the heat exchanger has a 120-month warranty. In addition, 12 months of labor and 60 months of parts. Since you are buying a Rinnai product, you can expect the highest level of reliability. You can expect an average of 20 years of use, and all parts are interchangeable.

The system is well-designed, which means there are not so many shortcomings. Maybe you can say that GPM is only 7.5. However, calculate your estimated flow demand before you start buying a water heater. Therefore, if 7.5 GPM is not enough, you will have to look elsewhere.


  •  Trustworthy.
  • Wireless network ready.
  • Control-R 2.0 application.
  • Leak detection.
  • Factory Warranty for Residential Buildings.


  • Device traffic is a bit low.
Rinnai V65iP Non-Condensing Propane Tankless Water Heater, Indoor Installation, Up to 6.5 GPM
  • Original Design: Tankless hot water heater only heats when necessary to conserve energy; For the latest in non-condensing technology and a cleaner layout that speeds up service and installation, check out our new RE160iP model
  • Never Run Out of Hot Water with this Compact Propane Water Heater: Non-condensing tankless hot water heater from Rinnai is only the size of a small suitcase and fits in a wide variety of spaces, but provides up to 6.5 GPM (5 fixtures at once)
  • Smart, Durable Design: Enhanced scale detection helps prevent serious, long-term damage to unit; Includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively; See Controlr module for WiFi control (not included)
  • Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your tankless water heater; We do not recommend installing a water heater without a technician
  • Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region

Rheem Tankless Water Heater:


Rheem is another leading brand of Consumer reports tankless water heaters, focusing on gas and electrical appliances. One of their most popular products is Rheem RTE 13, a compact device that weighs only 8.5 pounds. It is 7.25 inches wide and 10 inches high.

The device has a gray metal casing and can be easily installed out of the box. You might have studied the replacement options. The temperature using a convenient control Panel with green and red LED indicators. In addition, it has a thermostat dial with nine settings.

RTE 13 can be used in residential and commercial properties to heat water. It has adjustable external digital thermostat control with an LED display (+/- 1-degree accuracy) with durable copper immersion bath, two heating elements, field repairable, automatic adjustment of power control, and also easy to install-includes 1/2 NPT adapter; 1/2 inch pressurized water connection on the side99.8% energy efficiency. The external control adjusts the temperature in steps of 1°F.

Water-saving showerhead-1.5 GPM and thread is easy to replace, easy to install, 54A digital temperature display 13 kW model and the flow rate is up to 3.17 GPM.


  • Instant water heater.
  • Energy-efficient.
  • Easy to installed.


  • Not designed for cold climate.
  • Expensive.
Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
  • External adjustable digital thermostatic control with LED display (+/1 degree accuracy
  • Durable Copper immersion two heating elements, field Serviceable.Self-modulating power control
  • Simple installation – 1/2 NPT adapters included; side 1/2 inch Compression water connections
  • 99.8% energy efficient. External controls to adjust temperature in increments of 1°f. Water-Saver Shower Head – 1.5 GPM
  • Threaded for easy replacement, simple installation, digital temperature display 54 A. 13kW Model Flow Rate: up to 3.17 GPM

EcoSmart Tankless Water Heater:


Eco-Smart instant water heaters are at the forefront of the on-demand hot water industry. They have a stylish design and are easy to install on the wall. They are equipped with patented automatic modulation technology, which can save you up to 50% of energy costs compared with traditional tank water heaters.

The brand is a leading brand of innovative and green energy products. These devices have a high energy efficiency of 99.8%. The other important function is the digital temperature setting. You only need to adjust it once to supply hot water at your favorite temperature every day continuously. The brand provides excellent customer support and a limited lifetime warranty for its always-heated products. It can save up to 50% of water heating costs. The dimensions are 17 high x 17 wide x 3.625T inches with pipe fittings: 3/4″ NPT.

Digital temperature control in a 1-degree unit allows to control hot water; trigger flow rate: 0.3 GPM. The Copper and stainless steel components are designed to improve Efficiently, be durable, and easy to replace with the compact size saves valuable storage space, while the stylish and progressively designed to be pleasing to the eye and the copper and stainless steel components are designed to be efficient, durable, and easy to replace.

EcoSmart model ECO 27 is an instant electric water heater, specially developed for those looking for a powerful heating system for their home. It measures 17 x 17 x 3.625 inches, weighs 11 pounds, and can be easily installed anywhere. However, don’t be fooled by the compact design, as it is a powerful device that can heat almost 3 GPM to 37 °F with an efficiency of 99.8%. So if you live in a northern area where it is too cold, this water heater is perfect for you.

Before purchasing and installing, please make sure that the size of this model is suitable for your hot water and electricity needs. Electrical requirements are 27 kilowatts, 240 volts, requires 40 circuit breakers, 112.5 maximum power (AMP), requires eight wires. Power consumption is are113A.


  • Automatic reset thermostat and patented automatic modulation technology.
  • It can withstand water heating even at 37°F.
  • The heat exchanger consists of three long-life copper tubes.
  • Compact, ergonomic design.


  • Some users have reported errors
EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW - Quantity 1
  • Endless on-Demand Hot Water; Consistent hot water when you need it that never runs out; Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature
  • Save Space; EcoSmart tankless electric water heaters are 90% smaller than traditional tank heaters; may be installed on wall or at point of use; Dimensions 17 x 17 x 3.75 inches 
  • Save Energy; EcoSmart tankless electric water heaters are 99% thermal energy efficient; Only heats water when called unlike a tank heater that maintains water temperature even when not being used. Save up to 50% in water heating costs according to the Department of Energy
  • EcoSmart ECO 27 Sizing; Refer to the sizing map. Requires 3x40 AMP Double Pole Breaker, 27-kilowatt tankless electric water heater ideal for providing hot water for whole home applications; provides between 2.7 and 6.5 gallons-per-minute depending on the inlet water temperature; refer to the sizing guide to select the proper solution
  • Warranty and Certifications; Limited Lifetime Warranty on electronics, exchanger and element; UL-499 certified; ETL Listed

Takagi Tankless Water Heater:


Homeowners who wish to invest in tankless water heaters should pay attention to Takagi tankless water heaters. One of the main characteristics of the brand is its relatively low price. Despite the low price, this device has most of the main functions of other non-instantaneous instant heaters on the market today.

Takagi T-KJr2 is a natural gas water heater, which is very suitable for your home’s instant hot water needs. Moreover, it is very energy-efficient and can save you high electricity bills. The device consumes less energy but provides high-volume hot water when needed. In addition, it has inlet and outlet thermistors, which can monitor the temperature at any time.

The device has a maximum flow rate of 6.6 gallons per minute, more than you need when you use it at home, and runs at 140,000 BTU. However, it is small in size and light in weight. T-H3M provides hot water (directly or indirectly) to the hot water system, using storage tanks, circulation systems, circulating heating systems, floor heating systems, and household and heating applications. T-H3M is a high-efficiency condensing instantaneous water heater, which is very suitable for residential applications. With a gas supply of 120,000 BTU, T-H3M can produce enough hot water for two baths in warm climates and 1.5 baths in colder climates.


  • Unlimited hot water production.
  • This gives you more space for other utilities.
  • Reduce your monthly electricity bill.


  • The acquisition cost and installation cost may be slightly higher.
  • It does not have a high production capacity.
Takagi T-H3M-DV-N Condensing Direct Vent Tankless Water Heater, Natural Gas
  • Inlet, outlet thermistors for constant temperature monitoring
  • Perfect for light residential and radiant heating applications
  • Manufactured in Japan

SioGreen Tankless Water Heater.


SioGreen is the leading brand of instant infrared water heaters. For example, the company company’s SIO18 model is designed for residential and commercial applications. It is very suitable for large households and medium and large commercial facilities with hot water demand of up to 4.4 gallons per minute.

This is a powerful and efficient water heater that uses quartz infrared heating elements to heat water. It is designed for hybrid applications and allows you to use the device to upgrade existing standard water heater installations with water tanks. For example, by integrating this device into a traditional gas or electric tank heater, you can enjoy the benefits of a tankless system.

The infrared heater is designed to use 110 volts or 220 volts and only heat the water you use to high temperatures. This instant tankless electric water heater has automatic power supply technology and manual mode, so you can easily match your power supply with your family’s needs. Press and hold the power button to switch between automatic and manual modes. For example, adjusting the current from 10A to 40A will produce 1.5 kW to 9.0 kW of power, which is suitable for any household application. You can also easily adjust the temperature using the included water flow controller.


  •  Large water heater throughout the house.
  • Excellent liquidity.
  • 8 IR quartz heating elements with a 10-year warranty.
  • The hot water keeps on.
  • Installation is straightforward.
  • Can be installed as a HYBRID with your existing water tank water heater.


  • On standby mode, the digital display will show “4” instead of “SB,” which may confuse new customers.

StiebelEltron Tankless Water Heater:


The digital instant water heater series without instant water heaters demonstrates the company’s passion for innovation and technology. The Tempra Plus model is an excellent example of its technologically advanced tankless water heater system. It has rugged electronic equipment, a unique flow sensor design, advanced flow control, and a convenient hinged cover, allowing users to access the equipment easily.

This energy-saving equipment can save you about 15-20 kWh of energy compared with traditional water tank heating. In addition, it allows you to easily adjust the water temperature through an accessible dial without taking up too much space in your home. As a result, it is one of the most advanced electric water heaters on the market today.

Its stylish design saves space and, at the same time, provides a steady stream of hot water for the entire house without the need for vents. Furthermore, environmental protection equipment saves energy due to the possibility of automatic regulation and electronic control of water flow. The energy-saving monitor will even show how much you have saved on energy costs. The electronic switch activates the water heater and keeps it quiet during operation. The internal copper heating system completes all electrical work with a digital temperature display and preset temperature and memory button.

This specific model is 24 kW, 240 V, requires a minimum recommended power supply of 150 A and provides an outlet temperature of 68 ° to 140 ° F. This 19-pound machine from Germany is one of the best and most advanced models developed by Stiebel Eltron. Depending on the number of kilowatts included, there are many different styles, from Tempra 12 (12 kW) to Tempra 36. Your power supply needs 240 volts and 300 amps to work correctly. Thanks to the digital control screen with Tempra advanced temperature control, Tempra Plus is very simple to operate, and it can always maintain a stable heat level. The installation of the device should be pretty straightforward, mainly because it does not require ventilation, but if household plumbing is not your best choice, please feel free to contact a professional to install it for you.


  • No ventilation is required.
  • Temperature control is digital.
  • It has advanced Tempra temperature control to ensure that you always get the correct
  • temperature, no matter what your needs are.
  • Slim and compact, it fits anywhere in your home.
  • It is cheap and easy to install.


  • If the correct size is not considered, it may malfunction or cause problems.
Stiebel Eltron Tankless Water Heater – Tempra 24 Plus – Electric, On Demand Hot Water, Eco, White, 20.2
  • CONTINUOUS FLOW – Advanced Flow Control patented technology invented by Stiebel Eltron, automatically maintains water temperature for constant comfort. It’ll reduce flow slightly if hot water demand exceeds capacity. Hot showers will never be interrupted again
  • SPACE & ENERGY SAVER – Its small, sleek white design saves space yet still provides endless hot water for your whole house, and no venting is required. Eco friendly unit saves energy with auto-modulation and the ability to electronically control water flow. Savings monitor even shows how much you save on energy costs
  • EASY OPERATION – Electronic switch activates the hot water heater and it’s noise free while in use. Has a digital temperature display and preset temperature and memory buttons, while the interior solid copper heating system does all the power work
  • TEMPRA 24 PLUS – This specific model is 24kW, 240V, requires a min recommended electric service of 150 A, and offers an output water temperature of 68° to 140°F. Check our guides below to compare features of our various Trend and Plus models, each available in different kW levels, Tempra Plus tankless water heaters can be set to limit the maximum hot water temperature to 109°F. This can be important in some installations to prevent the possibility of scalding.
  • WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric tankless water heaters perform with the highest standards for comfort and reliability. Our 7-Year Leakage and 3-Year Parts Warranties are included with purchase

Noritz Tankless Water Heater:


It has a history of more than 60 years in the industry. Noritz launched the first electronically controlled instant water heater in 1981 and continues to lead the development and manufacture of advanced instant water heaters, providing excellent hot water and energy-saving effects. Noritz tankless water heaters offer many benefits to private and commercial users. They are easy to use, environmentally friendly, energy-efficient, reliable, and durable, ensuring you always get fresh, clean water when you need it.

The Noritz Eco-Tough series and NRC661 run on natural gas, with an EF of 0.91. Noritz provides consumers with economical and reliable hot water solutions without the need for water heaters.
NORITZ NR50OD is a 5 gallon per minute outdoor tankless water heater use. The valve kit IK-WV-200-1-XX-LF (required for installation) is sold separately.

Noritz water tankless heaters are designed with sufficient capacity and performance to be used in 1 to 5 bathtubs, such as model NRCP1112, with a water flow rate of 11.1 GPM. In addition, if you need more electricity and hot water, up to 24 devices can be networked through the link system to meet the most demanding applications. Noritz tankless water heaters are designed for use by the whole family. The most miniature model can produce 5.3 GPM and is suitable for families with one or two bathrooms. The largest model with 11.1 GPM water flow is ideal for up to 4 to 5 sanitary units.

Each Noritz tankless water heater uses the least amount of electricity, mainly through direct electric ignition to ignite the gas burner and power the circuit board of the ventilation and control system.


  • Install overheat protection.
  • Low consumption.
  • Affordable and sustainable.
  • No power consumption.
  • Polyester-coated steel is used to protect the elements.


  • No digital temperature display.
  • Owners complain about low buzz.
  • Valve Kit Sold Separately
Noritz NR50ODNG Outdoor Tankless Water Heater, max. 120,000 Btuh, 5.0 Gpm - Natural Gas
  • Endless hot water
  • Ideal for outdoor applications
  • High Efficiency
  • Low Nox

Bosch Tankless Water Heater:


Bosch tankless water heaters provide the best performance, energy efficiency, and environmental protection. The compact design of the Tronic 3000 allows space-saving wall mounting directly under the sink. Because these high-efficiency devices run on electricity and do not store water, there is no ventilation and little maintenance. Tronic 3000 under-counter water heater significantly saves space and energy and is an excellent choice for your residential or light commercial point-of-use applications.

It can be installed in a 360-degree direction, allowing you to place the device in a small space under the counter, enabling flexible and worry-free installation. Due to the need for power, this item will be wired with an Ultra-compact and lightweight design, with an efficiency of up to 98%, no standby heat loss, no temperature or pressure reducing valve. The size is 6.6″ x 12.8″ x 2.9″, making it ideal for light commercial applications such as shopping malls, airports, stadiums, and offices. Due to the current intensity, the product will be wired.


  • You can get hot water immediately.
  • Kettle lasts longer.
  • Your energy costs are lower.
  • You can save space.


  • The temperature may be uneven.
  • Their hot water supply is limited.
Bosch Thermotechnology 7736505867, 3.6kW, Bosch US3-2R Tronic 3000 Electric Tankless Water Heater, 3.6 kW, 6.6" x 12.8" x 2.9", White
  • NEW LOW ACTIVATION FLOW RATE: A new lower activation flow rate of only 0.3 GPM allows for use with newer, low flow faucets
  • ELECTRIC TANKLESS WATER HEATER: 3.6 kW under-sink tankless water heater designed to provide an endless supply of instantaneous hot water to one or more sinks
  • FLEXIBLE INSTALLATION: Can be installed in a 360 degree orientation so you can position the unit in tight under counter spaces for a flexible, worry-free setup. Due to the amperage requirement this item will be hard wired.
  • EFFICIENT DESIGN: Ultra compact and lightweight design with 98% efficiency and no stand-by heat loss plus does not require a temperature or pressure relief valve
  • IDEAL SIZE: Measures 6.6" x 12.8" x 2.9", making it the perfect size for light commercial applications such as shopping malls, airports, stadiums and offices. Due to the amperage requirement this item will be hard wired.

Eccotemp Tankless Water Heater:


EL22-I tankless water heater is the successor to Eccotemp’sEccotemp’s popular EL22 indoor water heater. Although it looks the same as its predecessor at first glance, it has many new features under the hood, an all-black slim glass body, and a large digital temperature display to improve its performance and efficiency.

First of all, it is a fully automatic water heater it will automatically adjust the heating temperature according to the temperature of the water source. This helps reduce heating costs. In addition, it has an excellent flow rate of 6.8 gallons per minute (GPM) and is rated at 140,000 BTU per hour, making it ideal for standard size homes with one or two bathrooms.

The compact size and beautiful design are a far cry from the scary old water heater at best. The black tempered glass looks very beautiful; it has a touch screen control panel, it is delightful to use. This CSA-certified heater also has a built-in antifreeze circuit to ensure that the remaining water in the pipe will not freeze when the temperature drops. EL22-I can use natural gas and liquid propane to operate and can be adapted to the split system. If you have curious children at home, please activate parental controls to lock the touch screen control panel immediately. However, you need to purchase a separate 4-inch vent for the circuit.


  • Compact indoor water heater.
  • Stunning design, black tempered glass housing.
  • Touch screen control panel.
  • Digital temperature display.
  • Parental control.


  •  4″ vents must be purchased separately.

Marey Tankless Water Heater:


It’s the bad boy in the tankless water heater. You can be sure that the device will provide you with appropriately heated water when you need it because it has a power rating of 27 kilowatts and 112.5 amps. Its intelligent technology and digital control panel can automatically adjust the water supply to the required temperature. You only need to set it once, and it will provide you with a steady stream of hot water at any time of the year, winter or summer. In addition, thanks to its patented technology, it can resist sediment and limestone.

Compared with traditional water heaters, using this device can save up to 60% of electricity bills. In addition, it is perfect for families with up to 4 bathrooms. Other important features are durability and nickel-chromium heating elements. It is certified for use in the United States and Canada.

The flow switch activation mechanism ensures that the water pressure required for the heater to operate without interference is shallow. If there are potential problems during the installation process, Marey has one of the best customer service teams globally and can provide quick solutions. For example, a family damaged the heater during the installation process. However, when Marey delivered the substitute in time, they were pleased. Replacement fully illustrates the reliability of the brand.

The 14.6 kW Marey ECO150 unit is ideal for using up to two points simultaneously, increasing the inlet water temperature to 41 °F at a water flow rate of 2.5 GPM. In addition, Marey’sMarey’s eco instant water heater is the only patented heating element with stainless steel water channel developed in Germany on the market. This high-quality component is corrosion-resistant and reduces the formation of hard water due to chlorine and calcium.


  • 1. The perfect mid-range instant domestic water heater.
    2. It can provide a continuous supply of hot water for up to two points simultaneously.
    3. White metal alloy shell.
    4. LCD screen with touch buttons.


  • The heater inlet device should be cleaned regularly to check for large deposits that may reduce efficiency.
Marey ECO150 220V/240V-14.6kW Tankless Water Heater with Smart Technology, Small, White
  • Unit requires 220v~240v and (1) 70 amp double pole breaker. Minimum Activation Rate 0.50 GPM
  • ETL approved
  • Smart technology: easy management and simple adjustments on a LCD panel allows you to program the exact desired water temperature thereby optimizing energy consumption
  • Flow switch activation mechanism allows the unit to produce constant temperatures with as little as . 5Gpm/5Psi
  • Tankless water heaters provide an efficient hot water solution eliminating the stand-by energy consumption of conventional tank units

FAQs What you need to know about tankless water heaters:

1. What is the Price of the water heater?

The Price of water is included the Price of the unit and the installation cost. The Price range from 600-3000 USD dollars depending upon the size and features of the unit.

2. What are the main differences between tank water heaters and tankless water heaters?

The main difference between the two models is that one requires a water tank to store and heat (30 to 120 gallons), while the other does not. In addition, when comparing traditional tanks with non-tank models, there are significant differences in energy-saving and installation.

3. How to clean the water heater?

To drain water heaters, especially water heaters, you must do the following:

  • Turn off the heat.
  • Turn off the valve/power.
  • Turn off the cold water tap.
  • Turn on the hot water tap in the sink.
  • Open the pressure relief valve.
  • Connect the garden hose to the drain.
  • Turn on the faucet and pour out the hot water.
  • Close the nozzle and open the cold water valve.
  • Turn on the tap and rinse with water.
  • Repeat this process until the water becomes clear.

4. Is natural gas and propane the same?

Of course not! Natural gas and propane are two different types of fuels. Natural gas is a fossil fuel extracted from the ground, while propane is extracted during crude oil and petroleum gas refining. Therefore, propane is more expensive than natural gas.

Final Verdict:

Before buying a water heater, the first thing to consider is your family’s expectations for this type of machine. Water heaters will undoubtedly meet the hot water demand, but different families have different expectations. For example, one family may need a water heater that can run three bathrooms simultaneously, and another family may be looking for a water heater to meet the hot water demand of the dishwasher.

But no matter what your expectations are, Takagi sets the standard by providing a variety of water heaters that can meet the needs of different households. For example, if you only need hot water from a single bathroom and kitchen sink, a smaller unit mainly on propane gas may be the perfect solution. In contrast, a more powerful unit provides hot water to meet all the household’s needs. Furthermore, as you may have noticed on these Takagi tankless water heaters, all models have an excellent energy factor, ensuring efficiency and energy saving. Finally, the machine also has various safety devices.

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