page title icon 10 BEST GAS TANKLESS WATER HEATER | top brands of 2021

Are you on the hunt for the best gas tankless water heater for your home, but cannot decide which one to buy due to excessive available options, then just relax because we are here to serve you. Here we shall provide you with every single detail of some of the best tankless gas water heaters available in the market along with the advantages and disadvantages of buying them.

But before we start this review of best gas water heaters there may be some questions in your mind that need clarification like; why you should buy a gas tankless water heater and not any other tankless water heater? What are the benefits of purchasing a gas tankless water heater? And how does a gas tankless water heater work? So we are here to answer these commonly asked questions.

A gas tankless water heater is better than any other water heater because it offers a better flow rate; it has more capacity to heat water instantly. Secondly, the water heating cost or only fuel cost of tankless gas water heaters are less than the electric tankless water heater. The water heater has gas burners in the unit and when a hot water tap is turned on the cold water through pipes passes the burner chamber; as a result, you get a supply of hot water every time you get an instant supply of hot water.

But how can to select the right gas tankless water heater when a very brand claims to provide the best water heater. We shall assist you in making this difficult task much more comfortable. In our extensive review of the best tankless gas water heaters, you will indeed find the one best water heater for your use.


Given below is the best gas tankless water heater reviews, all you need to do is read the given below details thoroughly and pick the best one.

Image Product Details   Price
backpac GASLAND Outdoors BE158 Brand: GASLAND
Model: BE158
Weight: 15.71 Pounds
Voltage: 3 Volts
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backpac Rinnai V75iN Brand: Rinnai
Model: V75iN
Weight: 45.6 Pounds
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backpac Rinnai RU199iN Brand: Rinnai
Model: RU199iN
Weight: 64 Pounds
Voltage: 120 Volts
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backpac Rinnai RL75IN Brand: Rinnai
Model: RL75iN
Weight: 50 Pounds
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backpac Eccotemp i12-NG Brand: Eccotemp
Model: i12-NG
Weight: 28.8 Pounds
Voltage: 120 volts
Amperage: 12 A
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backpac Rinnai RL Series Brand: Rinnai
43.6 Pounds
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backpac Rheem RTGH-95DVLN Brand: Rheem
Model: RTGH-95DVLN
79 Pounds
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backpac Rinnai RU180iN Brand: Rinnai
Model: RU180iN
Weight: 64 Pounds
Voltage: 120V
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backpac Rinnai RUC98iN Brand: Rinnai
82 Pounds
120 Volts
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backpac EZ Ultra HE Brand: EZ
Ultra HE
31 Pounds
Check Price

1. GASLAND Outdoors BE158
  • Quiet and Efficient
  • Very Budget Friendly
  • Easy Installation
  • Lightweight and Portable
  • No warranty

If you want a tankless gas water heater that is portable and lightweight, then GASLAND BE158 is a viable option. This gas water heater is best for outdoors either you are on vacations in your countryside or camping with your fellows it will serve you will instant supply of hot water, any time any place. It not only facilitates you with hot water but it also saves a lot of your bucks. With its compact size and energy-saving technology, you can save up to 11.5% of energy.

As it is an outdoor portable gas heater, it uses propane as a fuel. No compromise has been made on safety due to its compact size. It ensures the safety of the user with overheating protection, anti-freezing protection and flame failure device. The tankless water heater works quietly and efficiently and reduces maximum noise made by the burning of gases. The installation of the unit takes a few minutes barely. You can easily hang it with the featured hang brackets.

It has a built-in drain plug that discharges all the remaining water from the pipe to prevent freezing. It offers a flow rate of 1.5GPM that is quite extraordinary when talking about a portable, outdoor tankless water heater. A gas tankless water heater with all these exceptional features is available at the lowest price that makes GASLAND BE158 the best tankless gas heater under 200$.

Key Features

  • Flow Rate of 1.5 GPM
  • Anti-Freezing Drain Plug
  • Portable and Lightweight
  • Energy Saving Technology
  • No burning gas noises
  • Over-heating, Anti-freezing Protection
  • Advanced Combustion Technology

2. Rinnai V75iN
  • High Flow Rate
  • 60 Months Parts Warranty
  • ThermaCirc360 Technology For Recirculation of Water
  • Built-in Wi-Fi Module
  • Requires Special Vent Piping

Rinnai has utilized its 100 years’ experience in water heaters manufacturing and has developed a tankless water heater that fulfils all the requirements of any modern-day user. Keeping a close look at the needs of the customer, they have designed a gas tankless water heater that is compact in size but complete in its features.

Rinnai V75iN is a tankless water heater that can compete with any best-selling tankless water heater due to its various features. With an excellent flow rate of 7.5 GPM, this model defeats all other tankless heaters far behind. With such a flow rate, you will never run out of hot water while doing laundry or using a dishwasher. The unit is equipped with ThermaCirc360 technology that keeps the hot water circulating in the pipes, thus saving a lot of water and time. With this innovation, the water that is typically wasted while waiting for hot water is kept.

An additional feature that distinguishes Rinnai V75iN from other top tankless gas water heaters is that it can be controlled with a mobile app. With R-2.0 mobile app you can manage your water heater with your mobile anytime, anywhere. The feature makes it perfect for any modern-day user. Having all these features, the water heater is small in size and can easily be installed. You save in multiple ways if you get the water heater first Energy-saving cost, low maintenance cost, and fewer expenses on installation.

Key Features

  • 7.5GPM Flow Rate
  • Features ThermaCirc360 Technology
  • Compact size 14.04 x 9.27 x 26.90 inches
  • 40% Energy Saving
  • R-2.0 Mobile App Control
  • Wi-Fi Connectivity
  • High Efficiency
  • Available In Natural Gas and Propane Versions

3. Rinnai RU199iN
  • Easy Installation
  • High Efficiency
  • 40 Percent less Energy Consumption
  • Energy Star Qualified
  • Quite Costly

Rinnai is a well-reputed name as the brand produces some high-quality tankless water heaters. Whenever best gas tankless water heaters are listed, all the top positions are occupied by different models of Rinnai. The tankless water heaters this brand manufactures possess some features that many other competent brands do not offer. They fulfil all the requirements of a modern-day user.

Rinnai RU199iN is the best example of it, as it has all the features that are peculiar to this brand with some additional features. If you have been searching for a tankless gas water heater that has the highest flow rate sufficient to supply hot water to the whole house, then Rinnai RU199iN is the perfect option. It has an exceptional flow rate of 11GPM. The water heater will provide you with an endless supply of hot water to multiple fixtures at the same time.

The unit has been equipped with Circ Logic Technology that recirculates hot water in the pipes, and you get an instant supply of hot water each time you turn on the tap. With this advanced technology, not only you save a lot of time must also a lot of water that’s usually being wasted while waiting for hot water to come out of the pipe. You save up to 40 percent more energy than the typical water heater.

The tankless water heater emits less CO2 because of its compact size. Therefore it is more energy-efficient. This tankless water heater model features a compact and sleek design, that’s why it offers indoor installation. Because of all these advanced features, this one of the best tankless gas water heaters has an efficiency of up to 96%. Due to the condensation feature, most of the heat is released through exhaust before being entering the ventilation

Key Features

  •  Features Circ Logic Technology
  • Flow Rate of 11 GPM
  • Efficiency up to 96%
  • Indoor Installation
  • Available both in Natural Gas and Propane
  • Contains Isolation Valves
  • Optional Wi-Fi, R Module
  • Compact Size 18.5 x 11.45 x 31.3 inches
  • Offers Condensation feature
  • Less CO2 Emission

4. Rinnai RL75IN
  • High Flow Rate of 7.5GPM
  • 60 Months Parts Warranty
  • Wi-Fi, R Module
  • Compact Size
  • Quite Heavy

Rinnai is ruling the industry with its premium quality gas tankless water heaters. Not only it offers the best of features, but also these features are being provided without putting any strain to the safety of the unit. All the models are tested in extreme circumstances.

Rinnai RL75iN is just another example of best gas tankless water heater the brand is offering that fulfils requirements of people who love precision and does not want more or less. The best thing about this renowned brand is that it has provided products considering the hot water requirements of every group of people. Rinnai RL75iN has a flow rate of 7.5GPM, enough for an average-sized home with two washrooms, sinks and laundry faucet. You will get an uninterrupted endless supply of hot water each time you open the tap.

There is no long wait of hot water to come out of the tap as the unit features Circ-Tech Technology that recirculates hot water in the pipes. That not only saves a lot of energy but also plenty of water that is typically wasted while waiting for hot water. It has all the also energy star certified that ensures the safety features that been infused in the unit while building.  No doubt it can compete to any best gas tankless water heater.

Key Features

  • 7.5 GPM Flow Rate
  • Circ-Tech Technology
  • Includes Isolation Valves
  • Wi-Fi, R module to connect through a Mobile Application
  • High Thermal Efficiency
  • Compact size 14 x 9.3 x 23 inches

5. Eccotemp i12-NG

  • Sleek Design
  • Compact and Lightweight
  • Very Low Price
  • LED Control Display
  • Features Child Lock
  • Does not work above 2000ft
  • Limited warranty of 2 years

If you are a customer who does not need a water heater with high flow rate and is looking for an instant gas water heater for small house, cottage or to use as an on-point water heater, then Eccotemp i12-NG is a perfect option. Its unique design and colour distinguish the gas water heater from another top-rated water heater.

The water heater has a tempered glass front panel and pitches black colour that adjusts perfectly to the interior of a washroom or a house. The LED Display not only shows the temperature but also the flow rate of the unit. The gas water heater has been rated to provide a flow rate of 3GPM, enough to supply hot water to2 showerheads at a single time. With fully automatic temperature control, the unit becomes much more energy-efficient. Just like the best instant water heater, it only provides hot water when needed, therefore reducing the standby energy consumption.

The maximum-security has been insured with a child lock feature. The feature attracts many parents who are cautious about the well-being of their kids when they are not around. The best tankless gas water heater comes with a horizontal stainless steel vent kit and a power cord. The power cord needs to be plugged in a switch to supply power to the internal exhaust fan and LED Display.

Power Saver Mode enables a user to save a lot of energy as the unit will automatically adjust its power according to the requirement. It also has a significant energy factor that is 79%. All these unique features available at such a low cost makes it the best gas tankless water heater under 500$.

Key Features

  • 3 GPM Flow Rate
  • LED Control Display
  • Indoor Installation
  • Natural Gas Powered
  • Horizontal Stainless Steel Vent Kit
  • Features Child ClockAutomatic Temperature Control
  • Energy Factor of 79%
  • Energy Saving Mode

6. Rinnai RL Series
  • Very Compact Size
  • Budget-Friendly
  • Company’s Warranty
  • Extremely Lightweight as compared to other tankless gas water heaters
  • Does not include Isolation Valve
  • Not Star Energy Certifies

Suppose you are fed up with spending hundreds of dollars on high-cost maintenance of your traditional water heater and want to resolve the issue once for all. Then you must purchase a water heater that comes from a renowned brand. That ensures you the reliability and durability with its high-quality products.

By purchasing the Rinnai tankless water heater, you will be surely satisfied with your decision as they guarantee the 100 per cent of their valuable customers. Although all the series and each model of Rinnai offers the best of features still, you can choose the one product that fulfils your requirements. Rinnai RL Series HE+ is an extension of its RL series.

The most distinguishing features include the endless supply of hot water. The natural gas tankless water heater has a high flow rate of 7.5GPM. With a high-efficiency factor up to 0.82, the water heater saves a lot of the customer’s water heating cost. The unit has been embedded with Circ Logic Technology, with this most advanced technology the hot water recirculates in the pipes that follow your water requirements pattern. As a result, you will get piping hot water each time you turn on a hot water tap. The water heater uses natural gas fuel. And has been designed for outdoor installation

Key Features

  • Flow Rate up to 7.5 GPM
  • Uniform Energy-saving factor up to 0.82
  • Outdoor Installation
  • Less CO2 Emission
  • Up to 40 percent saving on Water Heating Cost
  • Available in Natural Gas and Propane Versions
  • Circ-Logic Technology

7. Rheem RTGH-95DVLN
  • High Flow Rate
  • 94% Efficiency
  • Electronic Controls
  • EZ-Link cable to connect two heating units
  • Hot water takes a litter longer to reach a point of demand

In a very competitive market, some of the brands have set such high standards other brands envy to achieve. Rheem is one of these brands that comes up with such innovations in their products. These products do not only perform well with their most advanced features but also are great to look at because of their sleek and distinctive look.

Rheem RTGH-95DVLN is among the best gas tankless water heater. Let’s discuss its features so that you will know why it deserves to be placed on this list. Most of the customers prefer a tankless water heater that will work as a single water heating unit for the whole house. Because installing many water heaters is not economical as well as they occupy a lot of space. So if you want a tankless gas water heater with more capacity than this model might be the right choice. The water heater has a high flow rate that is 9.8GPM. You will never run out of hot water as it will provide you with an endless supply of hot water as it is capable of supplying hot water to multiple faucets at a time.

The body, as well as the condensing heat exchangers of this water heater, is made of stainless steel. And the unit has a high efficiency of 94%. The gas water heater has been embedded with specially designed intelligent electronic controls that improve its efficiency. One of the best tankless gas water heaters prevents the emission of toxic gasses that ensures its security. The design includes a two-pipe direct vent system that has been specially designed for PVC Pipes. With EZ-Link cable, two heating systems can be connected for higher demands of flow rate.

Key Features

  • 9.8 GPM Flow Rate
  • 94% Efficiency
  • Built-in Electric Blower
  • 2 Pipe Direct Vent System
  • Stainless Steel Condensing Heat Exchangers
  • Freeze Protection up to -30 Degree Fahrenheit
  • Compact Size 18.5 x 9.75 x 27.5 inches
  • No Emission of Toxic Gases
  • Features Intelligent Electronic Controls

8. Rinnai RU180iN
  • High Thermal Efficiency
  • Flow Rate of 10GPM
  • Wi-Fi Connectivity and Mobile App Controlled
  • Energy Star Certification
  • Sometimes Fluctuations of Hot Water

Rinnai, a brand with more than 100 years of trusted quality, has been serving the customers with some of the best tankless water heaters and specifically gas tankless water heaters for years now. They have used their long experience in the industry to build some of the most delicate tankless water heaters. The products they introduce are made using the latest technology and by highly experienced professionals. Each of the brand’s tankless water heater is unbeatable in terms of features, quality and price.

Rinnai RU180iN has been designed after looking deep into the requirements of the user. The one of best tankless water heater has the highest flow rate of 10 GPM that can work as a whole-house heating system of the family with up to 5 members. When you have this unit installed at your home, there is no need to worry about the hot water level drop age because that’s not going to happen.

The water heater features a stainless steel body with a very sophisticated look. The unit is highly efficient due to its Circ-Logic Technology. The hot water recirculates in pipes and adjusts itself according to the hot water requirements of the user. All these features make it one of the best tankless as a water heater.

Key Features

  • 10 GPM Flow Rate
  • Wi-Fi Connectivity
  • Features Circ-Logic Technology
  • Stainless Steel Body
  • Energy Factor 0.92
  • Indoor Installation
  • High Thermal Efficiency
  • Includes Isolation valves

9. Rinnai RUC98iN
  • Compact Size
  • Very less NOx Emission
  • Energy Star Certified
  • High Flow Rate
  • High Maintenance Cost

In this lengthy review of best gas tankless water heater, most of the positions are occupied by Rinnai products as undoubtedly they manufacture the best gas tankless water heaters. Rinnai RUC98iN is one of the newest addition to their long line of tankless gas water heater and has all additional features along with the quality of its last series.

The model uses natural gas as a fuel and offers you an efficiency that is higher than any other gas tankless water heater. The model has an energy factor up to 0.96 that is quite astonishing. If you want a water heater that can offer an endless supply of hot water without any fluctuations and limitations, then Rinnai RUC98iN is the best option. It is a product worth investing for because of its high flow rate that is 9.8 GPM.

The space-saving compact design reflects that this best tankless natural gas water heater has been specially designed for indoors. The water heater has a metallic finish that looks attractive ad catches customers attraction. The model has an option of PVC Venting. The unit ensures security with low NOx emissions. These remarkable feature helps get Rinnai RUC98iN a distinctive position in the list of best natural gas tankless water heaters.

Key Features

  • Space-Saving Compact Design
  • Silver Metallic Finish
  • Flow Rate of 9.8GPM
  • Optional PVC Venting
  • Energy Factor up to 0.96
  • Indoor Installation
  • Exceptional Efficiency up to 95 per cent

10. EZ Ultra HE
  • Automatic Temperature Modulation
  • Fully Automatic Operation
  • Advanced AI Design
  • Very Lightweight
  • Quite Affordable
  • Low Flow Rate of 3.4 GPM

EZ Ultra HE Natural Gas Tankless water heater that has been specially designed keeping in view a typical American home. It has many extraordinary features that demand to place this water heater in a list of top tankless gas water heaters. Let’s discuss some of its unique features.

First of all, the unit features Condensing Technology; the exhaust heat is used to preheat the water in the pipes, thus increasing the efficiency of the company. The water heater has a stainless steel body and tiny in size, best to be installed indoors. The water heater has been extensively tested in American laboratories to meet all the safety standards. The advanced Electronic Control System further adds to the energy savings as being incredibly reliable. It also features fully automatic Temperature Modulation; you will get a constant supply of hot water once the outlet temperature has been set. It can be vented both horizontally and vertically. It has a Key Touch interface, to set temperature and for different settings, with this user-friendly interface operating the tankless water heater has become much more comfortable and more straightforward.

The one of best tankless gas water heaters has been rated for a flow rate up to 3.4GPM at 45 Degree Fahrenheit. The flow rate is ideal for small to average-sized houses. The Advanced AI design of the heating system saves the temperature setting even when the unit is restarted. You get a high thermal efficiency by installing EZ Ultra HE Natural Gas tankless water heater. The unit includes Anti Back Draft Vent.

The water heater is operational even at low water pressure as low as 8psi. And the unit turns off automatically when the supply is interrupted. In short, the best natural tankless water heater offers numerous features that have been designed, keeping in view all the modern-day requirements. And the fascinating quality is that all these features are available at a very budget-friendly price.

Key Features

  • Fully Automatic Temperature Modulation
  • Advanced Electronic Control System
  • Flow Rate of 3.4GPM
  • Includes Anti Back Draft Vent
  • Key Touch Control
  • High Thermal Efficiency
  • Condensing Technology
  • Automatic Gas Adjustment

Ultimate Buyer’s Guide to Buy Best GAS Tankless Water Heater

After reading the extensive review of some of the best gas tankless water heaters, you might have selected the one that fulfills all of your requirements. But before taking any final decision, you must take some factors into consideration to get the best of all. 


Before buying such an expensive product like a gas tankless water heater, you must have a clear idea of your budget. Once the account has been set you can move further and look for the water heater that falls into that category. Then select the one that offers maximum features while being affordable.

Flow Rate (GPM)

Flow Rate is also an essential factor that is entirely defined by your hot water requirements. Either you need a tankless water heater for a huge house, or you need a water heater for your small apartment. Higher the flow rate, more the number of faucets the water heater can supply hot water to and less flow rate means the gas tankless water heater can provide hot water to little taps at a time.

Power Input (BTU)

Power input is the amount of energy that is required to warm up the water. It is measured in BTU. The best gas tankless water heater s the one with auto modulation technology that adjusts the input power automatically according to the requirements of hot water.


A Gas tankless water heater uses two types of gases.

  1. Natural Gas: Most of the best gas water heater uses natural gas as fuel. Natural gas is relatively cheaper than any other fuel used in the water heater. Thus, it offers better energy savings.
  2. Propane: Almost all the best gas tankless water heaters are available in both natural gas and propane versions. Propane is mostly used as a fuel at places where natural gas is not available. But it offers the portability factor. But costs litter more than natural gas.


Gas tankless water heaters work by burning fuel. Toxic gases are produced as a by-product that needs to be vented to escape any mishap. Best gas tankless water heaters have a high quality advanced Ventilating System for smooth performance.

Size The size of the gas water heater must be considered seriously to accommodate the water heater in the given space. Large size gas water cannot be installed indoor thus can cause problems. Always select a tankless gas water heater that has a compact size


What size tankless gas water heater should I buy?

You should buy a tankless water heater that fulfils your requirements. If you have a family with more than two members, it is preferable to buy a water heater with a flow rate 7.5GPM to 10GPM. However, for a small family, you can purchase a water heater with GPM up to 5.

What are the drawbacks of buying a gas tankless water heater?  

The installation and maintenance can cost a lot in case of gas tankless water heaters that are the biggest drawback of these water heaters.

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