Say goodbye to those bulky, costly, and wasteful tank-type water heaters!
Install a high-efficiency natural gas-fired tankless water heating system and enjoy hot water on demand.
The tankless variation will deliver you hot water when you need it, without an energy-consuming storage tank. It’s also space-saving and lasts much longer than any conventional tanked ones. What’s more, it’s cost-effective. For these reasons, this variation is quickly taking the nation by storm.
Sounds impressive, right?
But which are the best tankless natural gas water heaters to get in 2021?
Here are our expert’s review and buying guide. We’ve listed down 8 top-rated models currently available on the market.
If you plan to purchase one and interest in knowing why we consider these 8 models worthy contenders, keep on reading our tankless natural gas water heater review.
What's in this Guide?
- Comparison Chart
- Best Tankless Natural Gas Water Heater – Updated Reviews in 2021
- 1. Rinnai Tankless Water Heater, V65iN-Natural Gas
- 2. Takagi Tankless Water Heater, T-H3-DV-N
- 3. rheem tankless water heater, Indoor Direct Vent, RTGH-95DVLN
- 4. Noritz Tankless Water Heater, Indoor Condensing, NRC66DVNG
- 5. EZ ultra HE Natural Gas Condensing Tankless Water Heater
- 6. Eccotemp fvi12-NG High Capacity no tank Water Heater
- 7. Eccotemp i12-NG Tankless Water Heater
- 8. Noritz NR50ODNG Outdoor Tankless Water Heater
- No-tank Natural Gas Water Heater- Buying Guide
The following comparison table is for your easy reference.
Best Tankless Natural Gas Water Heater – Updated Reviews in 2021
After 80+ hours of research and testing, we’re comfortable recommending the following 8 models.
We’ve carried out our own test under different environments, climates, and altitudes. In addition to that, we also have considered the convenience, performance and owner satisfaction of these products.
The following is a detailed review of our recommended top 8 models with their pros and cons.
Check this out!
Hope, you’ll be able to find your pick here.
1. Rinnai Tankless Water Heater, V65iN-Natural Gas
If you’re looking for one of the best indoor tankless water heaters to use in your house, then check this Rinnai V65IN out. The unsurpassed quality and performance of this device will meet all of your water heating needs.
Rinnai is the #1 selling gas tankless water heating brand in North America.
Rinnai V65IN might just be one of the best and most convenient heaters on the market. It offers the perfect combination of efficiency, comfort, and value.
It’ll never run out of hot water and leave you in the cold!
This system recirculates hot water through your pipes to get you hot water fast. Thanks to its ThermaCirc360 technology.
The unit uses between 10,300 and 150,000 BTUs of natural gas to deliver endless hot water. It delivers 6.5 gallons of hot water every minute, making it perfect for small to medium homes with 2-bathrooms or less. Notably, its minimum activation rate is 0.4 GPM.
This heater can handle up to 5 fixtures. It delivers water for a washing machine and two showers at the same time, or a washing machine, a dishwasher and one shower, all running at once,
It uses 40% less energy than conventional tanked variation. It also conserves water.
The compact design of this model saves valuable space. It is only the size of a small suitcase. That means you can install it in non-traditional spaces such as crawl space, attic, or even closet.
Conveniently, it offers a minimum 98-degree F and maximum 120-degree F factory preset temperature. What’s more, with Rinnai standard remote, you can adjust the temperature up to 140-degree F.
Moreover, it is compatible with the full line of Rinnai digital controllers.
More conveniently, the R 2.0 mobile app has timers and schedules throughout the day. It allows you to put the device into vacation mode. Plus, the Rinnai service provider can monitor this device’s efficiency and address issues before you experiencing a break in service.
You don’t need to be worried about its safety!
Firstly, the leak detector automatically shuts off water to the system and prevent property damage. Secondly, the enhanced scale detection mechanism lessens the possibility of long-term, serious damage.
Apart from this, it includes a temperature lock that prevents unauthorized or accidental changes in water temperature.
This eco-friendly system meets California and Texas NOx Emissions Standards. In addition, it complies with the 20 ppm NOx emission levels and South Coast Air Quality Management District 14 ng/J.
Rinnai V65IN is a smart investment!
With this premium no-tank water heater, you’ll save–both money and worry–in the long run. The average life expectancy of this model is 20 years. Besides, each part of this device is replicable. So, you can easily swap the parts.
Rinnai provides peace of mind with warranties that surpass the competition!
V65IN offers you a 10-year warranty on heat exchanger, 1 year on labor, and 5 years on parts for home use.
To sum up: the features and high level of performance of this heater would surely make you fall in love with it.
- Perfect for indoor locations
- Wi-Fi Capable
- ENERGY STAR qualified
- Safe to use
- Reliable and long-lasting
- Smart and compact design
- Environmentally friendly
- Generous warranty
- Some users have complained that it takes longer to get the water hot.
2. Takagi Tankless Water Heater, T-H3-DV-N
Hands up if you’re fed up with those smaller no-tank water heaters with lower flow rates.
If you’re looking for a tankless variation for heavier residential usage, then you obviously need Takagi T-H3-DV-N, which is built for the job.
There are plenty of advantages to this unit ranging from its high-efficiency build to an impressive flow rate.
Equipped with innovative water condensing technology and an impressive water flow rate, Takagi T-H3-DV-N is among the top-performing heaters on the market.
It is also well-suited for commercial applications such as beauty salons or small restaurants requiring a steady supply of hot water. All thanks to its commercial-grade copper alloy that it uses for the primary heat exchanger tubing. Notably, it is 25 times better for heat transfer than stainless steel.
What stands out of this condensing high efficiency natural gas indoor tankless water heater?
This unit eliminates the need for an energy-consuming ventilation system. It lends an impressive performance and efficiency level, saves energy, and produces cleaner output by directing condensed steam into drainage outlets. Thanks to its specialized steam condensing technology.
It easily powers multiple appliances and simplifies operation!
With an impressive gas input of maximum 199,000 BTU, the T-H3-DV-N produces sufficient hot water for household with three to four baths.
Compared to electric water heaters, it is needless to say that this model delivers hot water almost immediately. It has a fantastic water flow rate of 10 gallons per minute, which is more than enough for all your hot water needs. In addition to this, this bad boy can pass water smoothly to 10,000 feet in the higher place.
Its reaching temperature range is 100 to 185 degrees Celsius, meaning you rest assured it’ll supply consistently hot water to the dishwasher and washing machine.
Most importantly, the T-H3-DV-N comes with several safety features to ensure it will run seamlessly. It includes an overheating management tool as well as a freeze protection control. What’s great about this product is it has troubleshooting diagnostic codes that are helpful to identify where the problem is in case it breaks down.
You can install it without much hassle. It features power direct vent construction. You can also connect it to various units found in your home.
The durable design of this device makes it perfect to last you for many years to come.
But don’t take our words for it – get this unit for yourself and see what it really can do.
- Environmentally conscious, innovative design
- Perfect for residential and commercial uses
- Slim, minimalist appearance
- Reliable performance
- Anti-frost and anti-leakage protection
- Complies with Ultra-Low NOx regulations
- High efficient water flow rate
- Compact and space-saving
- Advanced safety features
- Straightforward installation
- Highly efficient and durable
- Designed for indoor use only.
3. rheem tankless water heater, Indoor Direct Vent, RTGH-95DVLN
Allow me to shift your attention to this simplest but advanced model that has really made its mark to impress us.
We’re talking about rheem RTGH-95DVLN.
Priced at the higher end of the market, the Rheem RTGH-95DVLN allows you to enjoy the convenience and comfort of continuous hot water on demand. It is great for homes with busy members and homes with luxury bathrooms or simply have a higher than average need for hot water.
For those of our readers who do not know, Rheem is a globally renowned brand name for exceeding the rigorous industry standards for cooling and heating products. It has earned a high level of recognition for reliable and durable water heaters.
It’s worth noting that all the Rheem products are subject to frequent tests. So, they have certification of various third-party testing labs and Government. It ensures all the Rheem water heaters meet rising quality standards.
RTGH-95DVLN can produce 9.5 gallons of water per minute; this unit provides sufficient heated water for a large home.
It comes with a maximum factory preset temperature of 120-degree F and can be raised to 140-degree F with a manual override.
For an indoor-only no-tank natural gas water heating system, the Rheem RTGH-95DVLN is a very energy efficient device at 94%. The stainless-steel casing contributes to its high energy efficiency as well.
You can evaluate much of this unit’s efficiency and safety through its intelligent electronic controls.
With the up and down arrow button of this control, you can easily change the default temperature settings. These controls help monitor efficiency. It also performs self-diagnostics to ensure sustainable usage and long-term safety.
The well-thought design of this product allows you to feel secure, and it is highly unlikely to leak.
It’s certified to function efficiently at up to 9,840 feet elevation above sea level. So, if you live at high altitude, you can still put this model on your list. Thanks to its built-in freeze protection.
RTGH-95DVLN is a Low NOX version water heating system. This means it effectively works to decrease emissions that this unit naturally releases during operation.
Why is it special?
It is designed for direct venting for both the intake and exhaust vents. It contains a two-pipe direct vent that connects up to 5 feet of 2-inch PVC pipe or 38-feet of 3-inch PVC pipe.
By utilizing this two-pipe direct vent system, it activates by a minimum flow rate of 0.40 GPM and operates by 0.26 GPM.
This unit also comes with remote control, 120 V power cord, and a 10 ft. thermostat wire. It offers 12 years warranty on heat exchanger, 5 years on parts, 1 year on labor.
- Designed for larger families
- Convenient design
- Provides a vast level of hot water
- Enhanced energy efficiency and safety
- Self-diagnostic capability
- Low NOx output
- High-altitude capability
- Low-cost operation
- Generous warranty
- Noisy operation
- Expensive, but it’ll save money over time.
4. Noritz Tankless Water Heater, Indoor Condensing, NRC66DVNG
Noritz is a renowned manufacturer for offering a wide range of efficient and qualitative water heating systems over 60 years within Canada and the USA. They focus on the client’s satisfaction with the qualitative, durable, easy to install no-tank water heater.
Noritz NRC66DVNG indoor condensing direct tankless hot water heater is no different. It comes with several features for high performance and easy use. This is especially true when compared to some of the lower-end no-tank units.
High- efficiency delivers constant hot water!
This model is designed to efficiently serve small to medium properties to give you an endless supply of hot water. Conveniently, it allows you to use natural gas as your fuel source.
With the ability to deliver you hot water between 100 and 140 degrees Fahrenheit, you’ll never have to worry about running out of hot water ever again.
The 6.6 GPM flowrate ensures that you’ll get a reasonable amount of water pressure suitable for everyday use.
Not only do all the tankless variations reduce the amount of energy used to heat water. But this is not the case with Noritz NRC66DVNG. This model is specifically designed to be even more efficient.
No need to worry about finding a dedicated space to install or store it!
Measuring in at 6.70 x 13.80 x 23.60 inches, this product is incredibly compact, making it perfect for storing in absolutely any room in your home. You can install it anywhere.
What’s more, this condensing direct water heater can be vented with a schedule3-inch 40/80 PVC pipe and fitting, P or CPVC. Conveniently, different terminations and adapters are available to allow for a wide variety of venting options.
Speaking more, it is designed with a basic temperature control system that comes with a remote thermostat.
Equipped with specialized heat exchanger technology, the NRC66DVNG packs powerful performance into its compact size. The built-in controller also helps you to monitor the actual temperature.
The Energy Star certification and leak-proof construction make it one of the most eco-friendly models available in energy and water consumption.
Noritz offers an impressive 12-year warranty on heat exchangers, 5-year on parts, and 1-year on labor.
- Very cost-effective
- Sleek and compact appearance
- Easy to mount
- Quiet operation
- Low nitrous oxide emissions
- Robust and reliable performance
- Minimal maintenance
- Even though this product is designed to be easier to install, it’s not recommended for inexperienced DIYer.
5. EZ ultra HE Natural Gas Condensing Tankless Water Heater
Ultra HE is one of the newest models of EZ that you would love to have. It offers almost all the features that you may expect from a tankless variation. It eliminates significant amount of stand-by energy loss of your home’s, which will save you money and precious energy.
You can rely on it for hot water!
It is an ultra-low energy profile option for small to mid-sized homes. It can serve two outlets simultaneously.
With a 3.4 GPM flow rate, it can produce adequate water for a single shower and a single kitchen sink at a 45-degree temperature rise.
Conveniently, it can function at water pressure as low as 8 psi and 0.6GPM flow rate. This low water pressure ignition makes it perfect for people living at high altitudes. It’sIt’s also helpful for those users using well water with the older or less powerful pumping system.
Are you ready for the best part?
The easy to understand advanced technology LCD control panel is a useful feature of EZ ultra HE. It allows you to adjust water flow and temperatures easily. Plus, it features various temperature settings that are helpful to choose the right one for your needs.
Additionally, it has two direct vent chamber exhausts. It allows for the most flexible installations. You will only need to drill one hole in your wall. It can be vented vertically or horizontally using 2″ Solid Core Schedule 40 PVC/CPVC.
With this appliance, you’ll enjoy the powerful performance, thanks to its condensing technology and recirculation settings.
By utilizing exhaust gas to reheat inlet water, it significantly reduces both water consumption and lowers energy bills.
A fully automatic function lets this unit fires up and switches off depending on the water flow. If the water supply is interrupted, the gas valve will automatically shut off. All you have to do is choose your preferred temperature on the LCD display. The system will do the rest and ensure the right temperature is achieved.
EZ offers 5-year warranty on the heat exchanger and 1-year limited warranty on parts with this model.
- Advanced Intelligence (AI) design
- Superb combustion performance
- Fully-automatic operation
- High thermal efficiency
- Extremely reliable
- Safe and convenient
- Easy to install and use
- Designed only for small households
6. Eccotemp fvi12-NG High Capacity no tank Water Heater
Next, we have this efficient system from Eccotemp Systems, LLC, an American brand whose mission is to deliver a state of the art no-tank water heating system at an affordable price point.
The FVI-12-NG offers you a lot, especially for the price!
It is not a powerhouse for producing hot water, but if you need hot water for your small household, this can be a perfect choice, especially for the price.
It is an incredibly efficient indoor water heating system designed for smaller homes, vacation cabins, and cottages. It effectively delivers water to homes where more than 1 hot water application is used simultaneously, such as a faucet and a shower.
FVI-12-NG can achieve a maximum flow rate of 3.5 GPM with a 45° Fahrenheit temperature rise.
By utilizing strong gas-powered flame, it instantly heats water as soon as it passes through the heater exchanger. An electronic ignition system ensures that it uses gas only when heating water.
It has manual controls for precise temperature and water-flow adjustment. The two separate knobs at the face of the unit let you regulate the gas pressure and the water temperature separately to an exact setting. Importantly, the easy to read digital temperature display shows the temperature of outgoing water.
Best of all, it activates only when in use, making it an energy saver. Notably, it pulls only 2 watts and 1.07 amps during operation. The included power Ventilation improves its safety and efficiency.
This model comes with everything you need for easy installation. It also includes a 110 volt UL listed power cord and the horizontal stainless steel vent kit.
Furthermore, the compact and space saving design makes it perfect for mounting anywhere. You can mount it to a wall or a vertical space in your home. It is also adaptable to any existing plumbing setup or system.
Finally, the low entry price makes the system affordable for nearly every budget. If you’re looking for an efficient but low-cost option to meet the demands of your small home’s everyday use, the Eccotemp fvi12-NG is definitely worth a second look.
A two-year limited manufacturer warranty covers the heat exchanger and other parts.
- Modern, sleek design
- Compact and space-saving
- Enhanced efficiency and safety
- Energy saving
- Minimal noise output
- Comes ready to install
- Precise adjustment for water temperature and gas
- UL listed electrical components
- Vent kit included
- Pocket-friendly price
- 79% efficiency rating is very low for gas tankless water heaters.
- It doesn’t feature any internal freeze protection.
- You need to flush it every three months to prevent limescale build-up
7. Eccotemp i12-NG Tankless Water Heater
i12-NG is another excellent natural gas no-tank low-cost option on our list. It’s one of the most affordably priced no-tank unit available on the market today. But in fact, it has more to offer.
i12-NG is one of the slimmest models available that makes it an excellent choice for vacation cabins, cottages, and smaller homes.
With an ultra-low energy profile and a modernized appearance of sleek Gorilla black glass casing, this unit blends seamlessly with any home appliances.
This model is perfect for small to medium household where you need hot water for more than one application simultaneously. It is rated at an impressive 3 GPM for a 35 to 40 degree Fahrenheit temperature rise. Besides, it offers a 77-degree F temperature rise when operating at a flow rate of 1.5 GPM.
It offers a novel and innovative approach to home water heaters.
A highly energy-efficient and safe solution!
This system provides some key functionality that makes it both efficient and safe. Firstly, it incorporates an electric ignition system. Ultimately, it is safer and more energy-efficient. It uses only 1.07 amps during operation and 2 watts during idle, making it energy efficient.
Secondly, the fully automatic temperature controls take the guesswork out of selecting the most cost-effective and precise setting. Additionally, a user-friendly LED display shows output temperature as well as GPM flow. The child lock technology ensures it’s ideal for those homes with younger members.
Finally, the UL listed electrical components makes it safer to use.
It’s worth noting that you can use this unit up to 5500 feet in elevation.
Along with your purchase, you’ll get a 120-volt UL listed power cord and a horizontal stainless steel vent kit, ready to install. What’s more, it’s small and flexible enough to install in even the tiniest of spaces.
The manufacturer offers 2 Year Limited Warranty on the heater exchanger.
Overall, it is a top-performing model at this price point.
- Improved revolutionary design
- Sleek and attractive appearance
- Very well made
- Highly efficient
- Low energy consumption
- Fast heat-up time
- Highly affordable
- It’s not designed to handle freezing temperatures well.
8. Noritz NR50ODNG Outdoor Tankless Water Heater
Wrapping up our list is Noritz NR50ODNG tankless water heater for residential outdoor use. This model is designed for wall mounted outdoor installation, perfect to upgrade your lifestyle to continuous hot water when you need it.
It performs flawlessly for an average-sized household with 1 or 2 showerheads.
As a top no-tank natural gas outdoor water heater, the NR50ODNG has a 0.81 energy factor. It features direct ignition that makes it easy to use.
Boasting an impressive amount of gas input of up to 120,000 BTU per hour, this system can meet all the hot water needs required for all small households. It has a flow rate of 0.5 to 5 GPM. That has given this unit high energy efficiency.
Because of the carbon reduction technology, it is very eco-friendly. It has the lowest NOx emission comparing the other models of its class.
It is lightweight and small in size but thoroughly robust in operation. Moreover, the compact design lets you easily install it in a tight space. Being an outdoor unit, it does not require any expensive venting. But it needs space upfront as it vents out from the front.
Of course, the resin-coated PC board protects the unit from all external elements.
With this decent purchase, you’ll get 12 years warranty on the heater along with a 5 years warranty on internal parts. Plus, it offers a 1-year labor warranty.
Combine all of these with its cost-efficiency and pricing; you have the best outdoor tankless natural gas-powered water heater that can satisfy all your requirements.
- Ideal for outdoor applications
- Easy to maintain
- Good quality and reliable
- Lightweight and easy to install
- Least NOx emission
- Relatively quiet operation
- Built to last
- Perfect in the southeastern region of the USA only. So, it won’t work well in the Northern region.
- It does not come with a filtering system. So, you have to purchase it separately.
No-tank Natural Gas Water Heater- Buying Guide
All of these 8 models are excellent in terms of quality, performance, and price. In the end, it is all about getting the right model for the right job.
Still, deciding which of the above-reviewed model is right for you?
There are a whole lot of variables that you need to consider before you shell out your hard-earned money for an NG no-tank water heating system.
This buying guide will help you narrow down the right one for your needs.
If you exactly know what to look for, choosing from the many most efficient models available should be easier than ever!
TEMPERATURE DEGREE RISE IN YOUR AREAS
The average water supply inlet temperature differs based on location. So, an ideal model in the South might not work well in the North. Again, a unit might work at 5500 feet altitude, but not at all at 10000 feet.
So, consider the altitude where you plan to use the system.
YOUR HOT WATER NEEDS AND UNIT’S FLOW RATE
This is by far the most crucial factor to consider when choosing a no-tank model for your home. You’ll need to determine beforehand how many gallons of SIMULTANEOUS HOT WATER you need and how much the system can pump out per minute. This will help you determine the GPM or gallon per minute that you’ll need to meet your needs.
For example, for a load of laundry and two showers, you’ll need a model that is rated to deliver at least 5.5 GPM (1.5+2.0+2.0=5.5) for your area.
Let’s have a look at the estimation
|Appliance||Gallon per minute (approximate)|
|Standard hand sink||0.5|
|Standard shower head||2.0|
|Washing machine||1 to 1.5|
|Kitchen sink||1 to 2|
|Dishwasher||1 to 2|
|Whole home||up to 6|
Check the spec sheet or product information page for your selected model, find the line with your degree rise, and learn how many GPM it will deliver at that degree rise.
Calculate the total GPM you need and compare it to the one you get from the chart.
Don’t forget to check the model’s BTU and make sure it is suitable for you. In general, the larger the house, the more powerful model you will need. Getting the right power requirements will ensure that the system is ideal for your hot water requirements.
An energy-efficient model will deliver you hot water within a short time and thus help you to save your money.
Energy efficiency of a NG model is expressed as EF (energy factor). It refers to the ratio of energy delivered as hot water to the unit’s total energy over 24-hour. EF take into consideration the efficiency of the source of energy to the unit’s standby energy losses plus the energy loss when it cycles on and off. The greater the EF rating, the more energy-efficient the unit is.
We recommend going for a unit that reaches about a minimum 60% efficiency rate.
PRODUCT DIMENSIONS AND COMPATIBILITY
This type of unit doesn’t require much space to install since it has no tank. But you need to be sure you have available space to install this system.
The natural gas-powered unit needs to be installed in locations that have proper ventilation outside. So, you should check its compatibility with your home.
Purchasing an NG on-demand hot water heater is an investment that could last you for 10 to 20 years. This variation comes with different price ranges. However, they are more expensive than their electric counterparts. But, it is just the initial buying cost. They are less costly in the long run.
When purchasing a system, make sure it is of high-quality so that you won’t have to worry about its service life.
We hope this extensive review of the best tankless natural gas water heater was helpful.
In spite of the high upfront cost, when it comes to both long-term utility perspective and cost-effectiveness, any of these 8 models might just be the right option for you.
Armed with this information, you’re just one step away from enjoying an efficient water heater with full confidence that it’s the best, most economical choice for your needs.
You’ll love the convenience and endless savings of these no-tank natural gas variations.
Finally, we really appreciate taking the time to read our post.