Attention homeowners! If you have heard about tankless water heaters but aren’t sure what all the fuss is about, we are here to help. We have reviewed for you our ten top picks, as well as a comprehensive buying guide, so you can determine the right heating solution for your home. Our tankless water heater reviews are sorted in order from lowest to highest price.

Top 10 Tankless Water Heaters

PictureNameRatingPriceReviews
Noritz NRC661-DV-NG5$$$$6
Stiebel Eltron Tempra 24 Plus4.8$$$143
Takagi T-KJr2-IN-NG4.6$$$170
EcoSmart ECO 27 Electric4.3$$$650
Rinnai RL75iN4.2$$$$87
Chronomite SR-20L/240 HTR4.1$12
Rheem RTE 13 Electric3.8$$909
Rheem RTE 9 Electric3.8$272
Marey Power Gas 5L 1.3GPM3.4$26
Eccotemp FVI-12-NG3.3$$116

#1 Chronomite SR-20L/240 HTR SR Series Instant-Flow Tankless Water Heater

Chronomite SR-20L/240 HTR 240-Volt 20-Amp SR Series Instant-Flow Low Flow Tankless Water Heater

The Chronomite SR-20L/240 HTR Tankless Water Heater is a cost-effective and compact electric unit designed for point-of-use installation.

Capacity

The Chronomite SR-20L/240 is designed for point-of-use. Its petite size means it can be installed to give a boost of hot water to any hot water application, from sinks to showers to clothes washers.

Water Pressure

You may notice a minor reduction in water pressure after you install this unit. It is designed for a maximum flow rate of 1.5 gallons per minute.

Temperature

The Chronomite SR-20L/240 can deliver a temperature rise between 33-82 degrees. If you try to achieve the maximum flow rate, the temperature of the water will be noticeably cooler. Microprocessor technology enables you to control the output temperature to avoid scalding.

Installation

Installation of the Chronomite SR-20L/240 can take just minutes, thanks to its simple design and lightweight size.

Power/Gas Requirements

The Chronomite SR-20L/240 is an electric on demand water heater. It draws 20A power and requires 240V.

Affordability

The Chronomite SR-20L/240 is a very budget-friendly purchase.

Verdict

The Chronomite SR-20L/240 HTR Tankless Water Heater is an ideal choice to service a small area. For instance you might have one hot water use that is more remote from your whole-house heater, and it needs just a little boost for better hot water delivery. You can have a big improvement at a small cost, by strategically employing this water heater for maximum effect.

#2 Marey Power Gas 5L 1.3GPM Propane Gas Tankless Water Heater

Marey Power Gas 5L 1.3GPM Propane Gas Tankless Water Heater

The Marey Power 5L is a petite and portable tankless gas water heater that is quite affordable and easy to install.

Capacity

The Marey Power 5L Heater is recommended as a point-of-use unit to service small areas, and particularly recommended for RV’s and campers. It is the only propane-powered unit on this list, making it ideal for camping aficionados.

Water Pressure

The Marey Power 5L Heater delivers up to 1.3 gallons per minute, plenty for handwashing, showering, or light-duty dishwashing.

Temperature

Hot water is available in seconds. The heating element activates by water flow as soon as the faucet is opened.

Installation

The Marey Power 5L Heater is engineered for portability and easy installation. Install it right at the point of use near sinks or showers.

Power/Gas Requirements

The Marey Power 5L Heater is the only one on this list that is powered by propane gas. It discharges exhaust through a flue duct. The ignition switch is powered by D batteries.

Affordability

The Marey Power 5L Heater is very cost-effective for smaller budgets.

Verdict

The Marey Power 5L Propane Gas Tankless Water Heater delivers excellent value for adventurous campers and outdoorsmen.

#3 Rheem RTE 13 Electric Tankless Water Heater

Rheem RTE 13 Electric Tankless Water Heater, 4 GPM

The Rheem RTE 13 Electric Tankless Water Heater is a mighty workhorse in a small package. It is ideal for point-of-use applications, specifically designed with showers in mind.

Capacity

The Rheem RTE 13 is designed for point-of-use applications. You will be most satisfied with the performance when you use it as recommended. Install the compact unit near the tap that most needs the boost from the heater.

Water Pressure

The Rheem RTE 13 can deliver up to 3 gallons per minute at lower temperatures.

Temperature

The Rheem RTE 13 responds quickly when you turn the faucet, heating water within seconds. Water is heated consistently and will last for as long as you have the tap open.

Installation

With such a small unit, installation is very easy in terms of finding the perfect spot. However you should pay attention to the plumbing and electric requirements. You may want to hire a professional if you find yourself in over your head.

Power/Gas Requirements

The Rheem RTE 13 is an electric unit that produces 13 kW. It requires 240V and 60A from a grounded 6 gauge line. You should consider a water-tight junction box and an emergency cutoff, to prevent any mishaps caused by water meeting electricity. In addition, 18 inches of copper piping is recommended on both the input and output to the unit. Flexible piping and quick connectors may seem like an easy and cheap workaround, but they will not be adequate for safe and secure installation.

Affordability

The Rheem RTE 13 has a low price point but will still deliver quality performance.

Verdict

The Rheem RTE 13 Electric Tankless Water Heater is praised by users and reviewers. It delivers good value without busting your budget. Use it where it is most needed and you will have a fine, long-lasting heater.

#4 Eccotemp FVI-12-NG High Capacity Gas Tankless Water Heater

Eccotemp FVI-12-NG High Capacity Gas Tankless Water Heater

The Eccotemp FVI-12-NG is a good, basic machine that is very budget-friendly and is a good choice for small spaces.

Capacity

The Eccotemp FVI-12-NG is a great choice for smaller-demand scenarios. One-bath and low-use locations are ideal, such as cottages and small homes.

Water Pressure

The average flow rate is 3.4 gallons per minute (GPM), up to a maximum of 4 GPM. The activation flow rate is reported to be quite high, meaning it takes a lot of water pressure before the water starts heating. So it would be very valuable to use as a point-of-use for an appliance like a dishwasher or clothes washer.

Temperature

Temperature rises can range from 45-77 degrees. The Eccotemp FVI-12-NG is equipped with a reliable electronic ignition system that is activated by water pressure. Operating the unit is easy, just turn two independent dials on the front of the unit to adjust the temperature and gas.

Installation

The Eccotemp FVI-12-NG is heated by natural gas. The power cord can plug into a standard 120V outlet, in order to power the internal exhaust fan and digital display. The heater comes with a venting kit, so that’s one headache you won’t have during installation.

Power/Gas Requirements

The gas rate is between 25,000-74,500 BTUs which is adequate for smaller scale water requirements.

Affordability

The Eccotemp FVI-12-NG is one of the most economical gas-powered tankless heaters on our list.

Verdict

If you have budget restrictions, or you have a need for a light-duty on demand water heater, the Eccotemp FVI-12-NG will be a good choice for you.

#5 EcoSmart ECO 27 Electric Tankless Water Heater

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

Capacity

The EcoSmart ECO 27 model is a powerful whole-house tankless water heater that functions perfectly well in small or mid-sized homes.

Water Pressure

The EcoSmart ECO 27 model is configured for high flow rates without compromising water temperature. Flow rate ranges between 3-6 gallons per minute, depending on the climate and desired temperature.

Temperature

Temperature rise ranges from 60-100 degrees. The EcoSmart ECO 27 is equipped with proprietary Self Modulating Technology. There are three heating elements, and the ECO 27 automatically activates each in turn as hot water demand is increased. This is obviously more efficient because you have extra power in reserve without calling on it all the time. A digital temperature control allows for precise temperature setting one degree at a time.

Installation

Installation is reported to be quite easy, and handy homeowners might be able to do the work themselves. Since the ECO 27 is electric, no venting is required.

Power/Gas Requirements

Three 40 DP breakers are required. The unit draws 112A. It delivers a max of 27 kW on 240V.

Affordability

The EcoSmart ECO 27 delivers a very good value at a reasonable price point.

Verdict

Depending on your needs, the EcoSmart ECO 27 Electric Tankless Water Heater is the best electric tankless water heater for the price. It will deliver solid and satisfactory performance without breaking the bank.

#6 Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater

Stiebel Eltron Tempra 24 Plus Electric Tankless Whole House Water Heater, 240 V, 24 kW

The Tempra model is the most popular model of tankless water heater from Stiebel Eltron. It can reduce energy consumption by up to 20% when compared to a conventional water heater.

Capacity

The Tempra 24 Plus is recommended for homes with two baths, in warmer climates.

Water Pressure

Tempra Plus models are specially equipped with proprietary Advanced Flow Control, which adjusts the flow rate when you exceed the system’s capacity. The result is a precise and consistent temperature that has been prioritized at the expense of water pressure. So you may experience some fluctuations in water pressure, particularly if there is heavy water use at the time.

Temperature

The temperature rise is 54 degrees, reaching optimum performance at 3 gallons per minute (GPM). The thermostatic temperature control is designed with microprocessor technology. It will enable you to have superior, all day comfort and accurate and reliable heating temperature. The unit modulates the power, inhibiting temperature fluctuations. Use the dial on the front to precisely adjust the water temperature in seconds.

Installation

The compact and sleek shape of the Stiebel Eltron Tempra can fit just about anywhere, and homeowners have found installation quite easy. Since it is electric, no venting is required. The Tempra has completely silent operation, so no matter where it is installed, it won’t disturb the occupants. The Tempra Plus model is quite durable and long-lasting, being designed to resist corrosion.

Power/Gas Requirements

The Tempra 24 Plus has two heating modules, draws 100A, and delivers a maximum of 24 kW on 240V.

Affordability

Stiebel Eltron is a leader in tankless water heaters, and the Tempra Plus is one of their most popular and premium models. But even with superior construction and high-quality design, the price is still quite reasonable.

Verdict

The Tempra is appreciated by consumers and reviewers for its reliable high performance and well-engineered design.

#7 Takagi T-KJr2-IN-NG Indoor Tankless Water Heater

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

This Takagi tankless water heater is an excellent, well-built heater for either whole-house or point-of-use applications.

Capacity

The Takagi T-KJr2 is the smallest model in Takagi’s line of tankless water heaters. However it is still of sufficient capacity for a 3-5 person family. It is best suited to homeowners living in somewhat warmer latitudes. It delivers 140,000 BTU for long-lasting heating.

Water Pressure

Flow rates range between 3.3-6.6 gallons per minute.  Inlet and outlet thermistors provide constant temperature monitoring. By means of water temperature safety controls, the unit automatically shuts off to prevent hazardous overheating.

Temperature

Temperature rise ranges from 35-70 degrees.

Safety

The Takagi T-Kjr2 is equipped with numerous safety features to protect your family. Water temperature safety controls will automatically shut the unit off when they detect overheating. An air fuel sensor checks the operational efficiency of the unit to identify harmful emissions. The Takagi T-Kjr2 also comes with an internal freeze protection system.

Installation

The Takagi T-Kjr2 is sleek and compact, much easier to install than the hulking storage-tank water heaters. Install it anywhere to deliver a boost at point-of-use.

Power/Gas Requirements

The Takagi T-Kjr2 requires 4-Inch category III stainless steel venting to the outdoors. It also requires an 110V electric supply.

Affordability

This is a pricier unit, but you will find it worth it for the high quality components and superior performance of this tankless water heater.

Verdict

Many consumers and reviewers loved the reliable and consistent performance of the Takagi T-Kjr2-IN-NG. It is an excellent mid to high-range tankless heater.

#8 Noritz NRC661-DV-NG Indoor Condensing Direct Tankless Hot Water Heater

Noritz  NRC661-DV-NG  Indoor Condensing Direct Tankless Hot Water Heater 6.6 Gpm-Natural Gas

The Noritz NRC661-DV-NG Tankless Water Heater is an exceptionally well-engineered device. No expense has been spared to include top-shelf components, which will deliver outstanding performance.

Capacity

The Noritz NRC661 is an excellent choice for whole-house heating if you have a small home with 1-2 baths.

Water Pressure

The Noritz NRC661 delivers a superior flow rate of up to 6.6 gallons per minute. Take a shower and run the washer at the same time. You should have no problems.

Temperature

The temperature can be pre-set to between 100-140 degrees. Two heat exchangers provide highly efficient heating capability. An automatic ignition device is activated when you turn the faucet.

Efficiency

The Noritz NRC661 is part of Noritz’s ecoTOUGH(TM) line, providing a lower carbon footprint. Cutting-edge condensing technology means that heat is recaptured from the combustion gases. This heat is then used again by a second heat exchanger, to preheat the incoming water. In addition, this means that the vented emissions are not so hot, which is safer for everyone in proximity.

Extra Features

What puts Noritz at the top of the heap is their attention to details. The NRC661 is equipped with a temperature lockout, flame sensor, overheat prevention, freeze protection, fan rotation detector, and condensate overfill.

Power/Gas Requirements

The Noritz NRC661 is a direct vent model. It consumes 120,000 BTUs. It also requires electricity from a 120V AC power source.

Verdict

The Noritz NRC661-DV-NG Indoor Condensing Direct Tankless Hot Water Heater is absolutely packed with features and extras. It is the best gas tankless water heater in its price range. It is designed with the utmost precision and care to make a truly remarkable heater.

#9 Rinnai RL75iN Natural Gas Tankless Water Heater

Rinnai RL75iN Natural Gas Tankless Water Heater, 7.5 Gallons Per Minute

Rinnai is one of the most well-known suppliers of tankless water heaters on the market. The RL75iN is from their Luxury Series.

Capacity

This Rinnai tankless water heater can easily handle the demands of a home with 2-3 baths.

Water Pressure

Flow rates go up to an amazing 7.5 gallons per minute. Depending in your temperature needs you’ll probably get between 4.3-6 gallons per minute.

Temperature

Temperature rise varies between 50-70 degrees. Available temperatures range from 98-140 degrees. The unit comes with a temperature lock function, to prevent unapproved changes to the temperature control.

Installation & Maintenance

The Rinnai RL75iN does need to vent which could limit the places you can install it. However the venting mechanism is designed to give you more flexibility. The direct sealed combustion vent needs only one port to the outside for venting. In terms of maintenance, the Rinnai RL75iN is very high tech with best-in-class digital controls and easy to read sensor lights and error codes. An enhanced scale detection feature alerts you when it is time to clean lime-scale buildup.

Power/Gas Requirements

The Rinnai RL75iN draws up to 180,000 BTUs and requires a ¾ inch gas pipe. It plugs into a standard 120V outlet. A direct electronic ignition system lights the burner so there is no pilot light.

Affordability

The Rinnai RL75iN is a luxury product which requires a premium up-front investment. However you will make up for the larger cost over time with greater energy efficiency and lower operating costs.

Verdict

The Rinnai RL75iN Tankless Water Heater will deliver unparalleled service and quality. Your family deserves the best.

#10 Bosch Therm 520 HN NG Whole-House Tankless Water Heater

Bosch is a well-respected manufacturer of tankless hot water heaters, consistently garnering great reviews with their reliable and durable appliances. The Bosch Therm 520 HN is a cutting-edge water heater in a class of its own.

Capacity

We recommend the Bosch Therm 520 HN for homes with 1-2 baths.

Water Pressure

The flow rate of the Bosch Therm 520 HN ranges from 3.4-5.2 gallons per minute. The modulating gas valve is designed to optimize a consistent temperature, so at times of higher demand the flow rate may fluctuate a bit.

Temperature

The Bosch Therm 520 HN is designed to deliver a consistent temperature even near the top of its capacity.

Efficiency

The efficient and cutting-edge design are what really put the Bosch Therm 520 HN in a superior class. The model is engineered with patented hydro-power ignition technology. No electricity is required for this unit. That’s right, it does NOT require a power source. A small turbine within the unit generates energy from the flowing water in order to ignite the burner.

Bosch boasts that this unit achieves up to 80% thermal efficiency. And the unique design means that you have a variety of flexible installation options. Also it will continue to work even in case of power outages.

Installation

The Bosch Therm 520 HN does require galvanized B vent for natural draft venting of emissions. This can make it a bit more tricky and complicated to install.

Power/Gas Requirements

The Bosch Therm 520 HN draws about 117,000 BTUs. It connects to a ¾ inch gas pipe. The unit can tolerate a maximum water pressure of 150 psi.

Affordability

Such a high-tech tankless water heater comes at a premium cost. But it has a 20 year life expectancy, and Bosch offers a 15-year warranty.

Verdict

The Bosch Therm 520 HN could represent the future of tankless water heating technology. You will be investing in a long-lasting, durable unit that will service your home for years to come.

Tankless Water Heaters – Comprehensive Buying Guide

Tankless water heaters are also known as on demand water heaters. The water is heated directly when needed, without the use of a storage tank. Therefore a tankless heater provides money savings in energy losses when compared with a traditional storage-tank style water heater. The US Department of Energy estimates that a tankless water heater can be up to 34% more energy efficient.

HOW IT WORKS

When you turn your hot water tap, cold water travels through a pipe and is heated instantaneously. However, flow rates and temperature are inversely proportional. So the higher the flow rate, the more you might discover inconsistencies with the temperature. Lower flow rates allows higher water temperature consistently.

Tankless water heaters can be used independently, as a total replacement for the conventional heater. This type of water heater is called the “whole house” version. However some homeowners might also buy them as a supplementary system to deliver hot water to a remote part of the house, or as a booster for heavy-demand appliances like dishwashers or clothes washers that use a lot of water. This type of heater is known as “point of use”. They are installed to feed right into a high-demand appliance to boost hot water availability.

BENEFITS

Here are the benefits of a tankless water heater. Their lifespan is up to two times as long as a conventional water heater. They require less maintenance and don’t tend to suffer from corrosion or buildup of deposits. They are a terrific option for property owners who are short on space, because they are compact and conveniently wall-mounted. Endless hot water can be available for successive or concurrent uses. And once again, they are more energy-efficient.

SPECIFICATIONS

How do you know what is the best water heater for you?  You should look for a temperature rise between 70-90 degrees. That should give you a total water temperature up to 120-140 degrees. If your ground water is unusually cold, you would want a higher temperature rise. Choose a model with a temperature control to mitigate the risk of scalding water.

Determine the hot water devices in your house that may be running at the same time, and add up their flow rates in gallons per minute (GPM). That number is the flow rate you should look for a water heater. You can expect a flow of about 2-5 GM.

Tankless water heaters have an initial up-front cost premium versus the traditional models.  But they typically have lower operating and maintenance costs, and they have a longer life expectancy – over 20 years! Make sure your heater is securely and professionally installed, and follow the manufacturer’s recommendations for maintenance.

CAUTIONARY TIPS

You should note that water output is limited by the tankless water heater’s flow rate. Typically you can expect a flow of 2-5 gallons per minute, with gas-fired water heaters producing a higher flow rate than an electric-powered heater. This is about half what you will be accustomed to from a standard storage heater. Tankless water heaters may have trouble keeping up with hot water demands in a scenario where you have simultaneous multiple needs for water, like showering while the clothes washer is running.

A tankless water heater that runs off of gas will not show significant energy efficiency if the pilot light is always on. One way around this is to find a model with an intermittent ignition device (IID) rather than a standing pilot light.

INSTALLATION TIPS

An improperly installed tankless water heater will not deliver good performance and may possibly be a safety hazard. We recommend you consult with a professional to go over what your new tankless water heater will need, to see if any retrofits or modifications are needed. You should be prepared to analyze voltage and amperage availability, as well as the condition of your circuit breaker. You should also be prepared to review any plumbing needs or modifications to your water line.

If you will have a gas-powered tankless water heater, review your current gas piping, gas meter, and gas line. While a standard water heater uses about 40,000 BTUs, a tankless water heater can use up to 200,000 BTUs. It has different venting requirements because of the exhaust and carbon monoxide it produces.

Depending in your local municipality, permits may be required for the installation process including any modifications you will be making.

The bottom line: do your research and be prepared. Then buy the tankless water heater that is right for your home, and enjoy the improved energy efficiency and hot water comfort.