10 Best Gas Tankless Water Heaters

As depicted by their name, a gas tankless water heater provides a route to get hot water instantly without the help of storage tanks!

Although initially, a gas tankless water heater will seem like a hefty investment, it’s a proven fact that they save you more costs in the long term.

These costs include energy costs as well as other water costs. So if you end up purchasing a gas tankless water heater, you reap the benefits while spending less.

Additionally, if you use your water heater economically, it saves you a good deal of other costs as well.

However, not all tankless water heater units aim towards energy conservation and picking the right one should be carefully considered.

This is because you might be spending a large amount of money initially, to purchase a water heater that lasts a long time!

And that’s the very reason we’ve accumulated and constructed this ultimate gas tankless water heater guide for you!

By the end of this guide, you’ll know just the right unit to pick out for yourself and why!

DISCLOSURE: We may receive commissions when you click our links and make purchases. However, this does not impact our reviews and comparisons. We try our best to keep things fair and balanced, in order to help you make the best choice for you.

Our Top Pick


Rinnai RL75IN

The Rinnai RL75IN water heaters can be used for immediate on-demand hot water for bathing, cleaning, washing, or laundry!

They especially focus on being the most energy-efficient appliances!

Types Of Gas Tankless Water Heaters

We mentioned earlier about some tankless water heaters having condensing or non-condensing units.

When it comes to tankless gas water heaters, there are several. We’ve explained the different types of gas tankless water heaters below.

Condensing Units

Earlier we mentioned that using a tankless water heater that has a condensing unit will most definitely help in energy savings.

Let us tell you how!

This is because condensing units use a secondary heat exchanger even after the first one. In this way, condensing units are known as the second generation of tankless gas water heaters.

It uses another heat exchanger so that the second one reuses the heat from the exhaust to heat the water further. This in turn helps save energy by up to 90+%.

However, these units may report higher costs if you’re using the condensing unit for less use and time.

Non Condensing Unit

A non-condensing unit can also provide hot water on demand while helping in energy savings.

The non-condensing technology is mostly used in European and Japanese models and is known to save energy by up to 80%.

There is a possibility that these units can get extremely heated. The exhaust attached can get hot which may require you to add additional vents. However, there’s no guarantee that this will maintain energy efficiency.

Condensing Hybrid

Condensing hybrid units come with small-capacity water storage. What this does is that it increases the energy efficiency of your unit by up to 94%.

Condensing hybrids do this by retaining hot water in the tank so that the unit doesn’t lose its efficiency during shorter drawers.

However, make sure you are well-read on your condensing hybrid unit before you get one since they’re a relatively new technology!

Best Gas Tankless Water Heater Comparison

Image PRODUCT/ Features Rating  
Top PickComparing Rinnai RL75IN Rinnai RL75INTemperature Range: 98 – 140 Farenheit
14 x 9.3 x 23 inches
50 pounds
Read Full Review
Budget PickComparing Gasland BE158 Gasland BE158Temperature Range: 93 – 167 Farenheit
Price: $$
Dimensions: 11.8 x 6.1 x 17.3 inches
Weight: 15.44 pounds
Warranty: 1-year
Read Full Review
Most TrustedComparing Noritz NRC661-DV-NG Noritz NRC661-DV-NGTemperature Range: 90 – 140 Farenheit
Price: $$$$
Dimensions: 6.7 x 13.8 x 23.6 inches
Weight: 11.42 pounds
Warranty: 1-year
Read Full Review
Comparing Rinnai RUCS75iN Rinnai RUCS75iNTemperature Range: 120 – 140 Farenheit
22 x 14.5 x 35 inches
63 Pounds
Read Full Review
Comparing Takagi T-H3M-DV-N Takagi T-H3M-DV-NTemperature Range: 99 – 167 Farenheit
Price: $$$
Dimensions: 17.75 x 13.12 x 29.5 inches
Weight: 44 pounds
Warranty: 5 years
Read Full Review
Comparing Camplux Instahot Camplux InstahotTemperature Range: 95 – 149 Farenheit
Price: $$$
Dimensions: 14.37 x 4.72 x 25.39 inches
Weight: 28.7 pounds
Warranty: 1-year
Read Full Review
Comparing FOGATTI FOGATTITemperature Range: 95 – 149 Farenheit
Price: $$$
Dimensions: ‎26.2 x 17.1 x 7.3 inches
Weight: 47.8 pounds
Warranty: 1-year
Read Full Review
Comparing Tengchang 16L Tengchang 16LTemperature Range: 90 – 140 Farenheit
Price: $$
Dimensions: 22.05 x 6.3 x  14.57 inches
Weight: 21 pounds
Warranty: 3 years for parts
Read Full Review
Comparing Rinnai V53DeN Rinnai V53DeNTemperature Range: 115 – 140 Farenheit
Price: $$$
Dimensions: 14 x 19.8 x 7.9 inches
Weight: 29.7 pounds
Warranty: 1-year
Read Full Review
Comparing Eccotemp i12-NG Eccotemp i12-NGTemperature Range: 50 – 140 Farenheit
Price: $$
Dimensions: ‎17 x 29 x 11 inches
Weight: 28.8 pounds
Warranty: 2 years
Read Full Review

Best Gas Tankless Water Heater Review

1. Rinnai RL75IN

review of Rinnai RL75IN

With the Rinnai RL75IN, you never need to worry about running out of hot water again! Rinnai’s gas tankless water heaters provide you with endless hot water while working to reduce energy consumption.

Rinnai’s tankless heaters are proven to be twice as durable compared to other natural gas tank heaters! They help in energy conservation by heating your water only when needed!

Compared to a tank gas water heater, the Rinnai RL75IN gas tankless water heater saves you up to 32% in energy bills and high water costs.

A standout feature of the Rinnai RL75IN is that it uses recirculation technology. This technology gets you unlimited hot water faster!

This Rinnai RL75IN uses the highest advancements to make it easy to use and become accustomed to.  It includes a voice activation feature and can also be connected to the wifi.

Don’t worry about your placement settings because this device uses very little space. Additionally, it is available as both indoor and outdoor units.

With a temperature rise or fall, the Rinnai gas tankless water heater can operate at a flow rate between 7.5 to 9.8!

Enjoy this indoor model by Rinnai with its non-condensing water heaters to save yourself from an extremely high gas bill!

Customer Rating- 4.5 out of 5 stars.

+ Energy-efficient
+ Voice activation feature
+ Space-saving design
+ Twice as durable
Hefty initial investment

2. Gasland BE158 (Budget Pick)

review of Gasland BE158

With the Gasland BE158 gas tankless heaters, you don’t need to set up or wait for a preheating process. Anywhere you install it, you get instant hot water whenever you need it!

By anywhere we mean anywhere because the Gasland water heaters are portable outdoor tankless water heaters.

With providing 1.58 gallons of water per minute, these tankless water heaters are also fully equipped to allow you to adjust the temperature and flow rate.

With only a few minutes needed for installation, this portable tankless gas water heater is designed to be compact and take up less space. Its compact size and lightweight feature make it even more viable as a water heater!

Alongside their lightweight construction, these tankless gas water heaters save up to 11.5% energy. The Gasland BE158 uses a propane water heat exchanger with a burner that uses advanced combustion technology to save gas from being wasted.

Gasland tankless gas water heaters are fit to use according to both US and Canadian standards. They come with multiple safety features.

The anti-freezing protection feature prevents ice from accumulating on the tankless unit. This tankless gas heater also has an over-heating protection feature that works for temperatures over 167 Fahrenheit.

With the Gasland gas tankless heater, the best part is you get all the features of a tank water heater, with energy savings at an incredibly affordable price!

Customer Rating- 4.4 out of 5 stars.

+ Energy-saving features
+ Flame failure unit
+ Excellent customer service
+ Most affordable
Difficult to install indoors

3. Noritz NRC661-DV-NG (Most Trusted)

review of Noritz NRC661-DV-NG

The NRC661-DV-NG is one of the best tankless water heaters by Noritz. This is their most compact designed tankless gas heater. It takes as little space as possible while being an indoor unit.

Since these tankless gas water heaters are for indoor use, they come with a condenser which increases the rate of energy efficiency this unit can perform.

This natural gas tankless water heater is up to 90% energy-efficient with an EF rating of 0.91. This is only possible because this natural gas tankless water heater is also a condensing unit.

This gas-powered unit comes with a built-in controller as well as a highly advanced heat exchanger design.

Noritz introduced one of the first units that focus on energy efficiency while providing one of the largest flow rates. The Noritz NRC661-DV-NG natural gas tankless water heater has a  flow rate of 6.5 gallons per minute.

Don’t worry about the quality guarantee since the Nortiz tankless water heaters have been in the water heater industry for 60 years! They try to provide the same benefits of an electric tankless water heater but use natural gas instead!

Customer Rating- 4.4 out of 5 stars.

+ Small and lightweight
+ Natural gas tankless heater
+ 12-year warranty on heater exchanger
+ Endless supply of hot water
Indoor unit only
The size and weight of the unit may increase due to the condenser

4. Rinnai RUCS75iN

review of Rinnai RUCS75iN

The Rinnai gas tankless water heater is one of our top picks, and the Rinnai RUCS75iN water heaters are also one of their best!

You no longer need to worry about other ways to heat water or having a continuous supply of cold water either!

Get endless hot water for washing, cleaning, showering on demand! The Rinnai RUCS75iN along with their other gas tankless heaters guarantee energy efficiency as well as savings when it comes to energy bills.

Not only do these gas units come in an indoor model, but they are also available as outdoor models! Furthermore, this tankless gas water heater doesn’t fluctuate its flow rate with changes in water temperature.

The RUCS75iN has a flow rate between 6.5-7.5 gallons per minute. Get instant hot water with a consistent flow rate whenever you need it!

As with its other gas water heaters, the Rinnai RUCS75iN ensures and guarantees you durability and quality. They take the time to individually test each water heater and its components before it is sent out to ship!

There’s no doubt that the Rinnai RUCS75iN is one of the best gas tankless water heaters!

Customer Rating- 4.7 out of 5 stars.

+ Space-saving design
+ Extremely energy-efficient
+ Provides energy-saving benefits
+ 1-year limited warranty
Does not include condensing unit

5. Takagi T-H3M-DV-N

review of Takagi T-H3M-DV-N

Takagi natural gas tankless water heaters are manufactured in Japan and guarantee you multiple features in one compact water heater.

The Takagi T-H3M-DV-N is a good tankless water heater since it is highly efficient. These water heaters do this by using natural gas only instead of another electric or a propane water heater model!

These energy optimizations and energy savings have earned the Takagi T-H3M-DV-N water heater an energy star approval and certification.

This is an assurance and guarantees for you since they are very few tankless units on the market that can get an energy star label!

These water heaters come with safety features like an exhaust and safety temperature control as well as an overheat cut-off fuse. It also comes with features to prevent internal freezing as well!

Adding a condensing unit to a gas tankless water heater can help increase its energy efficiency by up to 10% and the Takagi T-H3M-DV-N  uses exactly that!

The great thing about the Takagi tankless gas water heater is its extended warranty time. Most tankless water heaters provide a 1-year warranty period however, the Takagi gas tankless water heaters offer up to 5 years of warranty!

Customer Rating- 4.2 out of 5 stars.

+ Energy-star certified
+ Can be used with any sort of heating system
+ Endless hot water
+ Highly energy-efficient
Hefty initial investment
Slightly heavy

6. Camplux Instashot

review of Camplux Instahot

The Camplux Instashot tankless gas water heaters are natural gas water heaters designed and constructed to look modern and sleek in your home!

With this tankless heater, you don’t have to worry about your hot water supply running out at any time.

The Camplux Instahot tankless gas water heater promises a flow rate of 3.18 gallons of hot water per minute even if 2-3 people are using it at the same time!

This tankless water heater is equipped with a heat exchanger made of copper and is oxygen-free. Additionally, it is up to 89.98% energy-efficient for an immediate hot water demand without wracking up huge bills.

This natural gas tankless water heater comes with 6 safety features all in one gas model! These safety features include a flame failure device,  anti-freezing, and overheating protection.

Furthermore, it includes automatic temperature controls with a child lock safety feature to ensure your safety first!

These tankless gas water heaters go through an easy installation, with all necessary parts for installation being provided with the tankless gas water heater!

Customer Rating- 4.3 out of 5 stars.

+ Available in a propane option as well
+ Sleek modern design
+ Multiple safety features and controls
+ Easy installation
+ Affordable
3.18 GPM may be low if more than 3 people use hot water


review of FOGATTI

The Fogatti tankless water heater is designed to be small and compact so that it can easily fit in compact or crawl spaces.

It is designed to have a modern sleek look which makes it easier to clean and maintain as well as to blend into your home’s decor.

The Fogatti gas tankless water heaters use combustion engines approved by the CSA to meet all safety and operational standards.

The combustion engine is made using European technology that promises extreme energy efficiency as well as energy saving. This leads to saving other costs as well!

The Fogatti tankless water heaters actively focus on the safety of your unit as well as you. Their safety features include anti-dry protecting, ant-freezing, and overheating protection as well as protection against anti-backflow of wind.

This gas water heater comes with smart controls for water temperature regulation to make it easy to use and operate.

Enjoy a never-ending supply of hot water with the Fogatti gas tankless water heaters that are quick and easy to install!

Customer Rating- 4.9 out of 5 stars.

+ Highest customer reviews
+ Small and easy to install
+ Endless hot water supply
+ Helps save up to 40% in energy savings
Suitable as an indoor unit only
Relatively expensive

8. Tengchang 16L

review of Tengchang 16L

Tengchang’s 16L gas tankless water heaters are produced by Japan and are the most suitable for an endless supply of hot water for large families.

The best part about the 16L is that it is designed to fulfill your family’s hot water needs at an extremely affordable price. They provide you with all the features and performance of a normal gas tankless water heater at an affordable price.

Tengchang provides instantly heated water with constant temperature control for easy operation.

Furthermore, the Tengchang water heaters come with safety features as well. These include overheating protection and protection against dry heating.

These tankless water heaters are constructed to be long-lasting but most importantly to save you money in energy savings. The unit automatically powers off when the water is off and also has a touch operation with an LED screen for changing the temperature!

If you’re not sure of your purchase or come across a problem, Tengchang offers you a 3-year warranty as well!

These units make for an easy installation to have them up and running to give you endless hot water in no time!

Customer Rating- 4.4 out of 5 stars.

+ Suitable for large families
+ Extremely affordable
+ 4.2 GPM flowrate
+ 3-year warranty
Indoor unit only

9. Rinnai V53DeN

review of Rinnai V53DeN

The Rinnai V53DeN is another great gas tankless water heater to produce hot water! They come with an energy star label which automatically means you’re getting the best!

Like Rinnai’s other gas tankless water heaters, this tankless gas model also guarantees energy efficiency as well as cost savings!

Rinnai’s water heaters can save you up to 40% energy. Furthermore, they are built to be compact to take up as little space as possible during installation.

These water heaters are highly durable and are worth the initial investment since they last a long time. These models can last between 5-10 years with the proper maintenance.

Some units automatically operate on a low flow rate to access hot water, however, the Rinnai V53DeN has an operating flow rate of 5.3 GPM. With this water heater, you get a consistent heavy stream of hot water.

Rinnai offers a 1-year warranty on the heat exchanger, the parts, and the labor for you to enjoy your hot water experience with ease!

This would make be a great option for your house and family!

Customer Rating- 4.5 out of 5 stars

+ 6 in 1 safety features
+ Easy to install
+ Energy efficient
Outdoor use only

10. Eccotemp i12-NG

review of Eccotemp i12-NG

The Eccotemp i12-NG gas tankless water heater is the best choice for smaller spaces. It can provide instant hot water to small houses, cabins, or cottages.

This gas-run tankless water heater focuses on energy efficiency and only uses gas when needed or demanded. With these features, we can deduce that this energy-conserving unit will result in lower bills at the end of the month.

It has a flow rate of 3GPM but it can provide hot water to several faucets or taps at the same time. Although the water pressure may seem less, it allows for no wastewater!

Although the unit is easy to install, it requires mounting. If you feel like that’s something you’re not up for, you should call a professional for help.

The Eccotemp confirms your safety with multiple features including a safe electronic ignition system as well as a child safety lock.

Moreover, its sleek and modern design makes it easy to blend into your home. The Eccotemp i12-NG comes with an LED screen which makes it easy to display and control the temperature.

Customer Rating- 4.2 out of 5 stars.

+ All items for installation come with the package
+ Highly efficient
+ Affordable
+ Can be mounted anywhere
You will most probably require the help of a professional

What Is A Gas Tankless Water Heater?

Tankless gas water heaters are similar to electric heaters but instead use natural gas to heat water. These water heaters also have no storage tank attached to store hot water.

Tankless gas water heaters are instead connected to your water supply line. This directly heats your water supply to provide hot water through your taps and faucets instantly!

Compared to a tank water heater, where there would be occurrences where you can run out of hot water, tankless water heaters don’t have that feature! You can attain hot water anytime without a delay!

Gas tankless water heaters can supply hot water instantly because these units heat water actively during usage. However, this is dependent on the kind of model you have as well.

Some units can take some time to heat up before supplying hot water, however, some don’t need to.

When it comes to using gas, these tankless water heaters also come with two options to choose between; either natural gas or propane.

A lady doing the dishes using hot water from the faucet with the help of one of the best gas tankless water heater

How Efficient Are Gas Tankless Water Heaters?

Gas tankless water heaters are extremely efficient because when you install these units you don’t have to repeatedly pay for hot water!

As compared to other water appliances like a whole house filtration system, you have to continuously pay for replacements and upkeep. However, gas tankless water heaters don’t.

Alongside this, tankless gas water heaters are constructed and designed to be durable and last a long time. On average if you maintain your tankless gas heater properly, it can last you between 15 to 20 years.

Additionally almost all gas tankless water heaters are designed to be energy efficient and save you costs in electricity and water bills.

These water heaters use gas as their primary fuel source which isn’t expensive. This, as compared to electricity as a heating source would be more expensive since electrical prices often see surges.

Granted the best tankless water heater for you will be a big investment initially, but you also aren’t spending anything afterward for a long time.

In the long term, the correct energy-efficient unit is up to 80%-96% energy efficient. So you can enjoy the prolonged benefits of these water heaters while saving costs!

Advanced ventilation system chart of the best tankless water heater

How To Pick A Gas Tankless Water Heater?

As with anything, there are multiple factors you need to consider before buying a gas tankless water heater.

To make the process easier for you, we’ve accumulated all factors of consideration in this singular buying guide!

Power Input

When it comes to power in a gas tankless water heater, size and power correlate with each other.

You will need a tankless water heater that is big enough to offer hot water to your entire household. You will also need a good water heater that can give you the temperature you want.

In this case, the more power the unit holds, the better.

Flow Rate

The flow rate of a unit will determine how much water you receive.

Your flow rate should be determined by how many devices or appliances you’re using to supply hot water.

If you’re using hot water only with one faucet, a flow rate as low as 1 GPM is good. However, if it’s the opposite, then you’ll need more than a few gallons per minute.

Venting System

Venting is an important part of a heating system to prevent your unit from overheating and letting out hazardous gases.

Most units come with either a power or direct venting system. The former requires an exhaust pipe however the latter requires exhaust and intake pipes.

Energy Factor

Energy factors are especially crucial because this will determine how much energy and consequent costs you will save.

To guarantee make sure you look for an energy star label or a unit with which has an energy-saving capability of up to 90%.

Condensing or Non-Condensing Units

It’s true and proven that condensing units save you more costs and energy. They also save money on installation as well as have a proficient venting system.

On the other hand, non-condensing units are relatively smaller and cheaper and are perfect for outdoor spaces.


It’s beneficial for you that your unit has a proper warranty so the company can help you with a problem or malfunction.

Make sure you get the correct deal for yourself since some companies provide you certain certifications only if you opt for a professional installation from their company.

Safety Features

Before you procure the right unit for yourself, ensure your unit has the proper safety. These include anti-freezing and overheating protection, anti-wind protection, flame failure protection, and automatic on and off!

The Costs To Operate A Gas Tankless Water Heater

Gas tankless water heaters can start from $250 and go up to $3500 to install. Added costs include the costs of venting and other safety measures.

It’ll cost approximately $1200 in labor costs coupled with a gas line that will cost at least $500. Annual maintenance costs can cost you up to $150. With this, you’ll also have to pay a permit fee between $250-$500.

When it comes to the costs of fuel, natural gas can cost you between $150-$500 annually. Propane is available at an annual cost of up to $500 as well.

The installation costs can vary with the unit however installation costs mustn’t steer you away from buying a gas water heater.

It’s important to note that with time, you can save up to $200-$300 per year through updated technologies and saving energy from being wasted.

FAQs on Best Gas Tankless Water Heater Comparison

Is A Gas Tankless Water Heater More Efficient?

Yes, they are! For houses that use up to 41 gallons or less of hot water, gas tankless water heaters are more efficient.
They can be between 25%-35% more energy-efficient than traditional water storage heaters.

Do Gas Tankless Water Heaters Need Electricity?

Gas tankless water heaters need some electricity to operate. Although the primary source is natural gas, these water heaters have an internal PC board that requires electricity to operate.
The PC board includes electronic ignition and an electronic thermostat that needs electricity to function. 

How Long Does A Gas Tankless Water Heater Last?

If you want a definite number, gas tankless water heaters can last for 20 years at least. But on average depending on your unit, a gas tankless water heater can last between 15-20 years.
In addition, these units also have a warranty on their parts and can be exchanged or replaced.

Do I Need To Turn Off The Gas When The Power Goes Out?

Most units turn off automatically when the power goes out. But if your unit doesn’t do that, the gas valve should be turned off for precautionary reasons.
Turning the gas valve off automatically turns off the unit’s furnace for your safety.


Now you know everything about gas tankless water heaters and more. With the detailed informational guide provided above, we aim to clear any questions you may have.

Share The Love

If you find this useful, please let others know by sharing it. 

Share on facebook
Share It
Share on twitter
Tweet Us
Share on pinterest
Pin This