- 1 Find the Perfect Option for Your Home in Minutes
- 2 Our Top Gas & Electric Tankless Water Heater Reviews
- 3 Buying Guide: How to Choose the Right One
- 4 Our Favorite Heaters
- 4.1 Takagi T-H3-DV-N Condensing High-Eff Gas Indoor
- 4.2 Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Gas
- 4.3 Takagi T-KJr2-IN Gas Indoor
- 4.4 EcoSmart ECO 27 Electric
- 4.5 EcoSmart ECO 11 Electric
- 4.6 Rheem RTE 9 Electric
- 4.7 EcoSmart ECO 18 Electric
- 4.8 Lotus 3.5kW/120 Volt Electric
- 4.9 Rheem RTE 13 Electric
- 4.10 Bosch Tronic 3000 3.2kW Electric
- 4.11 Bosch T 2.7-Gallon Electric Mini-Tank Under Sink
- 4.12 Atmor AT-900-03 Electric
- 4.13 Eccotemp L5 Portable
- 5 Our Favorite & WHy You Should Get This One
Find the Perfect Option for Your Home in Minutes
We have reviewed our top 13 choices below and also done in-depth reviews by brands, but if you are in a rush:
Here’s our choice:
Takagi T-H3-DV-N Gas (View on Amazon.com)
Installing a tankless water heater in your home can help you save hundreds of dollars or more on your water and gas or electric bills every year. Some designs work perfectly with homes that rely on natural gas, but you’ll also find models that work with traditional electrical systems. The flow per minute rating tells you exactly how much water it can produce in terms of gallons per minute.
Most options feature an exchanger made from a durable form of metal like copper or brass, and many have metal coils inside too. As the water moves across the coils and through the exchanger, it increases the temperature of the water.
With setting controls listed on the heater itself, you can turn the heat up and down or adjust it to the exact temperature that you want.
The best model that we came across is the Takagi T-H3-DV-N (View on Amazon). It works with homes that rely on a type of natural gas for heating like propane.
Though it’s heavier than other similar models, it has a vast temperature range that many will love and a flow rate of approximately 10 gallons every minute.
Our Top Gas & Electric Tankless Water Heater Reviews
Buying Guide: How to Choose the Right One
You no longer need to worry about finding space for a new water heater in your home. As you look at options for sale online, you need to make sure that you find the best one for your home. Consider all the following factors when choosing one.
A traditional water heater has space inside for bringing the water up to temperature. With a tankless design, you don’t have a tank of perfectly heated water at your disposal. Always consider the capacity that it has to ensure that it can meet the needs of your family.
You generally only need a heater with a capacity of more than 55 gallons if your family takes three or more showers, does several loads of laundry and does meal and food prep daily. A heater that can heat up less than 55 gallons during the day is suitable for everyone else.
Flow Per Minute
Consider the flow per minute listed on the box too. This refers to the amount of water that the heater can bring up to a temperature in a single minute. Most models provide up to three gallons or more per minute, which is the perfect amount for doing dishes or taking a shower.
Water heaters with a digital or LCD display on the front are easier to use. You can adjust the temperature of the water and make other changes to the settings with the buttons listed on the front.
While heaters without tanks take up less space than traditional heaters do, you still need to look at its overall size. Many designs now come in compact shapes that are no bigger than an average suitcase. This reduces the amount of work you need to do to install one in your home.
Energy Source – Gas vs Electric
The right water heater for you depends on whether you have electric or gas lines. If you purchase a gas heater and have electric, it will cost more to install it. Make sure that the heater will work with your existing system.
When you take a shower, the water heats up to a temperature of around 105 degrees Fahrenheit. Some prefer taking colder showers, and some enjoy hotter showers. Check the box carefully to see the temperature range the heater can support.
Though not important to all shoppers, some will want to consider the heater’s energy efficiency rating. This refers to how efficient the heater works. Some come with a higher rating from Energy Star that you can see right on the box.
Tank-less water heaters often provide less hot water than more traditional systems do. With the recirculation technology found on some models, though, you’ll always have hot water on hand.
These systems bring in water and keep the water circulating around the coils to bring it up to the perfect temperature. As the water keeps flowing over those hot coils, you’ll have enough water for all your needs.
Our Favorite Heaters
Takagi T-H3-DV-N Condensing High-Eff Gas Indoor
If you have a natural gas heating system in your home, this Takagi is the best option available.
Instead of requiring that you light and relight a pilot light to turn on the water heater and get hot water, you can press a button on the front to turn the water heater on and send hot water to every room in your home. Takagi designed this model for those who need more hot water over an extended period of time.
The best thing about the T-H3-DV-N is that it can provide an almost endless supply of hot water. Whether your whole family takes showers in a row, or you want to do some laundry right after a bath, you’ll have plenty enough water for all those jobs. It has the classic Takagi smaller footprint too, which helps you save some space around your home.
Takagi added some new features to ensure the safety of your home and family. Not only can you feel confident that it won’t catch on fire because of its lack of a pilot light, but you can also rest assured that it won’t release gas emissions that might make your family sick. It meets all the standards to carry a low emissions label and has computerized safety settings.
The amount of hot water it produces depends on the temperature of the ground water in your area. In warmer climates, it can provide enough water for up to four bathrooms, but in colder climates, it can only serve three bathrooms.
This Takagi has a temperature range that you can change from 100 to 180 degrees Fahrenheit. It also has a lower sound rating that some will like. You’ll also like that it has a flow per minute rate of 10 gallons per minute.
Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Gas
Rheem is one of the leading names in the world of home appliances, and this just narrowly missed out on landing the top spot.
It comes in a simple design that includes a metal cabinet that protects the internal components and the Energy Star seal of approval on the front of that cabinet door. Rheem estimates that you can save nearly $200 a year on your energy bills with this model.
As an outdoor model, Rheem designed this model for installation and mounting on any outdoor wall. It comes with an option plug that lets you use it with any 120 V outdoor power source, but you can also hard wire it into your electric system. Hard wiring will usually require some professional help. Rheem recommends hard wiring for outdoor use.
This is the first heater to come with a heat exchanger made entirely from copper. That does a much better job of keeping the water hot and lets you enjoy more hot water right off the bat. A unique film wrap added to the outside helps protect that exchanger and keeps it from rusting.
You’ll also receive a digital remote control that helps you control the temperature of the water and other settings without touching the water heater itself. If the remote stops working, you can easily replace the batteries inside. Use the remote to adjust the settings from inside your house or across your lawn.
This Rheem model has a flow rate of more than six gallons per minute, and its 6.4-gallon flow rate ensures that you always have the exact right amount of water that you need. It also has a degree rise of 35 degrees, which lets you adjust the water temperature up or down based on what you need.
Takagi T-KJr2-IN Gas Indoor
Takagi makes our list a second time with this model, which comes with some of the same features as its more expensive and top-ranked model does. It measures 6.7-inches by 13.8-inches by 20.3-inches, which gives it a more compact size and reduces the amount of space you need to set aside for a water heater. Weighing in at less than 30 pounds, this model is also much more lightweight than some of the others we found.
This Takagi model comes with two certifications. The first is from Energy Star and guarantees that you’ll use less water and save some on your utility bills. Its second certification is a frustration-free certification that ensures you won’t experiences any of the frustrations or hassles with this model that you would with others.
The basic design of this water heater includes heavy-duty couplings at the very bottom. Those couplings make it easy to install the water heater in your home and to shut off the system in case of an emergency. You can typically unscrew each one to stop the flow of water or power.
You might look at energy factors when comparing models, and this Takagi water heater has a high energy factor of up to 0.83. This lets you know that it produces a high level of hot water in comparison to the amount of energy it uses every day.
Takagi added unique components that actually monitor the machine and the temperature of the hot water produced. With other models, you might find that the temperature changes during the day and drops below a level that you would like. These components both regulate and monitor the water to ensure that it remains at the setting you chose to keep you from taking showers that are boiling hot or ice cold.
EcoSmart ECO 27 Electric
EcoSmart makes multiple appearances on our list because its heaters are so efficient and effective, which are just two reasons why the ECO 27 makes this list. The ECO 27 comes loaded with features that can cut your energy bills in half and a digital temperature control that gives you more power over the water temperature.
The ECO 27 has a more modern design than some of the other EcoSmart models do. It comes in a bold black design that features a silver knob in the middle and a digital display at the top. As you adjust the temperature of your water, that display lets you see exactly what you set it to, right down to the very degree.
Though it comes set to a medium temperature setting that many will like, you can adjust that setting with the central knob. Turn the knob to the right when you want to increase the temperature and to the left when you want to decrease it. Keep an eye on the digital display to see when you reach the desired temperature.
If you prefer using Celsius instead of Fahrenheit, simply hold down the silver know while touching the nearby power button as you move the knob back and forth. While it has a temperature range between 80 and 140 degrees Fahrenheit, EcoSmart recommends sticking to a maximum temperature of 110 degrees.
To install the ECO 27 in your home, you need three 40W breakers and 240 volts. Electrical systems with less power cannot support this model and can cause the whole electrical system to overheat. Not only is the ECO 27 compact enough that it won’t take up a lot of space, but it features durable components made from copper and brass that can last for years.
EcoSmart ECO 11 Electric
The last model from EcoSmart to make our list is this ECO 11. Though it only works with electrical systems and not propane systems, it can help you save up to 60% or more on your home’s heating bills. EcoSmart also includes a limited lifetime warranty for those who use this water heater in residential homes.
A common problem that some have is that the lack of tank limits the amount of water they can use at one time. EcoSmart designed this one to provide users with as much water as they might need. It heats the water up the temperature you selected and ensures that the water keeps coming from the tap or faucet.
We also like its ease of use. Unlike other models that feature so many different buttons and knobs that your head might spin, this one has just one button on the very front. Press and hold that knob for three seconds to power on the heater, and hold the button down for three more seconds to turn it off. Rotate the knob to adjust the temperature of the water up and down.
If you worry that the water might come out a little bit hotter than you want, you won’t worry about this model. It features a digital display on the very front that shows you the exact temperature you set. As you move the knob to the right, the display shows that you lowered the temperature, and if you move the knob to the left, the temperature display will increase.
To install the ECO 11 in your home, you must have an electrical panel of 125 amps, a double pole breaker of 60 amps and AWG wire. This ensures that the water heater runs and won’t overheat your electrical system.
Rheem RTE 9 Electric
Rheem will provide you with all the hot water that you need with this RTE 9 . Like other models designed for outdoor use, it has a durable metal cabinet that protects all the important components and wires inside. It also features two simple hook ups located on each side of the box for quickly installing in your home.
One of its best features is its simple design, which includes a knob and some basic lights on the front. Turn that knob from the right to the left to cycle from the lowest temperature setting to a medium setting and then the highest setting. Some may not like that it doesn’t show the exact temperature, though. All you can see is a general setting and not the actual temperature of the water.
A red and green button on the very front also helps you keep an eye on the system. When the green light or button comes on, it indicates that the system is in standby mode. When the red light comes on, the system is active. The water heater usually goes into standby mode when you don’t need or use any hot water.
Rheem added a copper heat exchanger that lasts longer than other types of exchangers. A film added to the surface of the exchanger keeps water from settling around the metal and causing rust to form. The exchanger features some brass components that add to its durability.
With a flow rate of nine gallons of water per minute, this Rheem model provides more than enough water for most homes. You’ll have enough water to take a shower, do some dishes and even wash a load of laundry before the water runs out. Weighing less than eight pounds, it’s also compact enough for most homes.
EcoSmart ECO 18 Electric
With the ECO 18 from EcoSmart, you can switch between Celsius and Fahrenheit in a few seconds. Designed with ease of use in mind, it’s perfect for those who want something basic that still delivers gallons of hot water with each passing minute. You’ll also love its simple design, which anyone in your house can use before hopping in the shower.
That design features a silver know with a digital read out above. It comes set to Fahrenheit, but you can hold down the knob and turn it to either side to see the temperature setting in Celsius degrees instead. After installing it, simply press and hold down the know for three seconds or until the digital display lights up.
That display will then show you the precise temperature you selected. EcoSmart is one of the only companies operating today that will let you adjust the temperature one degree at a time. As you move the knob to the right, the temperature goes up, and when you move the knob to the right, the temperature does down.
Its self-modulating flow technology helps set this model apart from its competitors. That technology looks at the temperature you need and the amount of water you use and will then automatically adjust itself to use less power. This can help you slash your utility bills by as much as 60%.
The ECO 18 also comes with a thermostat that you can automatically reset, which comes in handy if you have a lot of people who like different water temperatures in your home. When you hold down the central button for three seconds, the system automatically resets itself. You can then adjust the knob to select the temperature that best works for you.
EcoSmart includes a limited lifetime warranty on the ECO 18 that covers many of its parts and components. The manufacturer also claims that you can save more than 12 cubic space with this model when compared to others.
Lotus 3.5kW/120 Volt Electric
Despite its small size, this heater can deliver all the hot water that you might need. One reason it ranks so far down is because it’s best suited for warmer climates. Depending on the ground temperature of your water, you may find that this model cannot heat the water to the perfect temperature that you desire.
The basic design includes two couplings for your water and power sources. While it might look easy to install, Lotus recommends that you hire a professional for the job. A licensed contractor can help you decide where to install it in your home and ensures that it works perfectly and provides all the water you need.
Lotus designed this model for single application usage, which means that it cannot provide enough hot water for your whole home. Once the installation is done, you’ll get enough water for washing a load of dishes or doing some prep for an upcoming meal. It provides enough hot water to fill a single sink at a time. You can even hook it up with other Lotus models and those from other manufacturers to supply your whole home with hot water.
Using it is a snap because of a single power button the front. You flip that switch to turn the water heater on and off. This lets you save even more on your energy usage because you do not need to run it all day.
Though it has a degree rise of 45 degrees Fahrenheit, you’ll get the best results when you install it with an aerator on your faucet. This ensures that the water flowing through reaches the maximum temperature that you want. Its smaller design makes it a good choice for recreational vehicles, apartments, and even boats.
Rheem RTE 13 Electric
Enjoy the feel of warm water every time you hop in the shower with this Rheem RTE 13, which you can use with the existing electrical system in your home. Rheem includes a sticker of its logo on the front to remind you of who made it and a warning sticker for contractors. That warning sticker reminds them to turn off the power source before servicing the heater.
Two LED lights on the very front help you keep track of modes. The red light comes on to let you know that it is in active mode, which also lets you know that it has power and has hot water ready for use. The green light turns on when it is in standby mode, which usually occurs when you haven’t used it in a few hours.
Those lights sit inside a small system control panel in the very front. Right beneath those buttons is a knob that lets you increase and decrease the temperature of the water. The lowest temperature is on the very left, but if you turn it to the very right, it will reach the highest temperature setting. As it does not feature a digital display and does not tell you the exact water temperature, you may need to experiment a little to find the setting that is best for your home.
Though it comes with a dependable copper heat exchanger, this model is best for smaller homes and individuals than larger families. It fits in a smaller space and generally provides enough hot water for a single shower, making it a good choice for apartment dwellers. The RTE 13 weighs just over seven pounds and has a lower flow rate that lets you enjoy four gallons of hot water for every minute.
Bosch Tronic 3000 3.2kW Electric
For a model that can supply your bathroom or kitchen sink, you can’t go wrong with the Bosch Tronic 3000. Keep in mind that it has a lower flow rate and lower temperature settings, which means that it won’t work effectively in your laundry room or for taking long showers and baths. You can use this model to have instant hot water for washing dishes, cleaning your hands or for other minor uses around the house, and you can install it with other water heaters too.
One reason some might like the Bosch Tronic 3000 is because it is so easy to install. Using the included instructions, you can install it yourself without calling a contractor for help. It comes in a conveniently compact size that makes it perfect for installing under your kitchen sink or inside a bathroom cabinet.
This is a great option for those who have a smaller water heater that cannot supply the whole house with hot water and those who have larger tank heaters that have a hard time keeping up with the demands of the entire household. It can easily produce water that is hot enough for killing germs and removing bacteria from your hands. It even produces enough hot water for washing dishes and doing meal prep.
You can use this with either 220V breaker or a 208V breaker, but you need an 85% capacity for the larger breaker and a 75% capacity with a smaller breaker. As it weighs five pounds, it also works in commercial buildings like offices and hotels that have private bathrooms. Though it can also meet some of the needs of your household, you may prefer a model that has a higher flow rate as this one only produces 0.5 gallons of water for every minute that it runs.
Bosch T 2.7-Gallon Electric Mini-Tank Under Sink
Bosch is a trustworthy name, but the smaller size of this under sink water heater led to us placing it further down on our list. It is a little more unique than other tankless designs because it comes with a built-in mini-tank. That tank can hold up to 2.7 gallons of hot water.
One of the biggest benefits of this model is that it instantly provides you with hot water when you need it. Instead of waiting for the water to circulate over the coils and reach the right temperature, several gallons of water are ready and waiting when you turn the faucet. You’ll have enough water for washing your face or doing your dishes.
Its convenient size is another reason it made our list. Unlike other models that you must mount in a central location like your basement, this one is so small that it will fit right under your sink or inside a cabinet. That makes it easier for you to do necessary repairs and to change the settings.
The inside features a small tank lined with glass. That glass lining reduces the risk of the tank rusting and does a good job of keeping bacteria out of your water. This simple lining can extend the life of your water heater and give you years of use too.
Installing this Bosch model is simple. As it works with any standard 120 V outlet, you can hook it up to your water line, plug it into a nearby outlet and use it right away. Bosch can also send a technician out to your home to install the water heater for you.
It also comes with its own bracket for fast and easy installation. Use that bracket to install this Bosch water heater under your sink, inside a cabinet or on a shelf.
Atmor AT-900-03 Electric
Get instant water without waiting around with this electric heater from Atmor. Weighing in at well under four pounds, it’s great for residential homes and smaller spaces. Atmore includes a dependable warranty that covers leaks for seven years and covers parts and components for two years.
Two couplings or connections on the bottom serve as the intake valves for both hot and cold water. One valve pulls the cold water in for circulating and heating, and the second valve lets that water move through your pipe once it comes up to temperature. Made from metal, those connections won’t rust, even after years of use.
This model is unique because it also comes with a safety thermal shut off tucked inside. If the water heater detects that it has too much power or that it might overheat, it will automatically turn itself off to prevent the risk of injuries and accidents. It also has a high safety rating and a safety certification from UL Standards.
With measurements of 11.9-inches by 8.7-inches by 4.2-inches, this one is easy to install in almost any area of your home, though you do need to place it close to both a water source and power supply. It weighs a little over four pounds, which won’t add too much weight or pressure to your walls.
As it has a low flow rate of just 0.5 gallons per minute, it’s best for smaller spaces and practical applications like washing dishes or doing kitchen prep work. It’s also safe for use in outdoor spaces and vehicles like a motor home or boat, and Atmor recommends it for use in low-flow sinks. As it requires less electricity than similar models do, you can use it spaces you thought you couldn’t install a heater
Eccotemp L5 Portable
Though this Eccotemp model is by far the cheapest option on our list, it’s a solid little option for those who need one they can use outside. Most models require an electric or gas hook up inside your home and come with a warning against using one outside. As this model uses two D-cell batteries, though, you can safely use it outside.
Perfect for those who spend a lot of time hiking or camping, it’s lightweight enough that you can take it on vacation with you. You can easily connect it to any small or large propane tank to have enough water on hand for showering or cleaning up.
A gas regulator knob on the front lets you adjust the gas flow up to the maximum level or down to the minimum level. This lets you enjoy hotter or cooler water based on your needs.
While it has a limited gallon per minute flow rate, it’s still higher than you might expect. Despite its small size, it can actually produce up to 1.4 gallons per minute. If you need more water, simply use the heater for a longer period of time.
Keep in mind that you will also need to connect this to some type of water source. It works with most faucets, including those found in campgrounds and recreational parks. Use the knob on the front to regulate the water pressure, but remember that it requires at least 20 PSI of water pressure to operate properly.
Eccotemp added a convenient metal carrying handle to the top too. This lets you pick up the water heater and take it with you. It also features a standard shower nozzle that you can use for easy washing. As it has a lower flow rate and smaller size, it ranks lower than most.
Our Favorite & WHy You Should Get This One
While there are a lot of great options on the market today, none can beat or even come close to the Takagi T-H3. Priced a little higher than some on our list, it comes with features and a capacity that others cannot match. It provides an endless stream of hot water just when you need it.
Takagi added new safety features to keep you, your family and your home safe. Those features reduce the risk of both electrical fires and standard fires. While similar models have a pilot light that you must turn on and light before using, this one uses a new design that lacks any type of pilot light.
All it takes is a press of a button for the water heater to come on and send out the water you need. A series of buttons placed across the front panel give you complete access to all its settings, and there is a digital display that helps you keep track of those settings. Use those buttons to turn the temperature up or down.
Designed for use with natural gas lines, it works with propane and other energy sources. It has a lower sound rate than similar designs, which lets you enjoy using it without worrying about hearing loud knocking or banging noises coming from your basement. As you can install it in your home, you can put it in your basement, hallway, crawlspace or another area of your choosing.
The Takagi has an 85-degree temperature range that adjusts from 100 to 185 degrees Fahrenheit. It also has a high rating from Energy Star to help you save on your energy bills and an impressive flow rate that provides you with up to 10 gallons of hot water every minute.