[Buyer’s Guide: 2020] Top Five Best Natural Gas Tankless Water Heater Reviews

Best Natural Gas Tankless Water Heater

best natural gas tankless water heatersNatural Gas tankless water heaters have nowadays become more popular as the demand for efficient home appliances increases. Various natural gas tankless water heater brands manufactured by different companies are currently competing in the market. But for the best result, choosing the Best Natural Gas Tankless Water Heater is the most important part. Natural gas tankless heaters usually deliver more consistent temperatures as well as a high volume of water while also managing to use up less energy as compared to the “tank” water heaters. Unlike other conventional units, these heaters are only active when needed thus saving an average of 45% on the consumer’s energy bills.

The best natural gas tankless heater models also provide hot water at once instead of having to pre-heat and store the water. This means that the water will not run out and it can be used concurrently in various areas of the house.

Benefits of a Natural Gas Tankless Water Heater

In case the idea of constantly heating water in a tank sitting in the basement sounds wasteful and inefficient to you, then a natural gas water heater might be the right option for you.

The best natural gas water heaters have always been full of promises. By heating the water only when you require it, the suitcase-sized water heaters could potentially save the homeowners a lot of energy as well as storage space.

In addition, the endless hot water supplies mean no more cold showers in your home. Here are the benefits of a natural gas tankless heater:

  • Natural Gas is Green: Natural gas is cleaner than the petroleum-based fuels. Natural gas emits fewer chemicals associated with smog, greenhouse emissions, and acid rain. The average natural gas tankless heater home emits 46 percent less carbon than the non-gas counterpart. Replacing non-gas tankless heater with the natural gas tankless heater prevents around 3,000 pounds of carbon (IV) dioxide from entering into the atmosphere each year
  • Natural Gas is Efficient: Natural gas reaches the home directly at more than 3 times the efficiency of the non-gas energy. While natural gas tankless heaters provide up to 90 percent usable energy, up to 78 percent of non-gas’ o energy is already wasted by the time it’s delivered to the home. As a result, the natural gas tankless heaters are more efficient to use.
  • Natural Gas is Economical: Natural gas tankless heaters cost up to half the cost to operate as compared to the non-gas counterparts. Homes with the natural gas tankless heaters save an estimated 25 percent on energy costs each month.
  • Natural Gas tankless heaters are reliable: Natural gas is normally delivered to your home through underground pipelines and provides nearly 100 percent reliable services. Homes with natural gas tankless heaters can still use hot water and even cook even when the power goes out.

How To Choose a Best Natural Gas Tankless Water Heater

A natural gas tankless heater can just be the second largest energy user system in your home, after the heating and cooling system.

As a result, it is important to make wise choices when you’re replacing an existing natural gas heater or when purchasing a new gas hot water heater.

Below are the factors to consider when choosing the best natural gas tankless water heater for your home:

Size and CapacityCompatibilityEfficiencyCostsYour hot water needs
The best way of determining the size of the natural gas heater that you want is its “first-hour rating” or the “recovery rate.” This is simply the maximum amount of the hot water that can actually be heated and then supplied within one hour starting with cold water. The first-hour ratings of natural gas heaters normally range from 41 to more than 131. Generally, natural gas heaters have a higher first-hour recovery rate than the electric water heaters that have the same storage capacity. As a result, when you buy a natural gas tankless heater, you should take its size and capacity into consideration so as to get the best heater for your entire home needs. Natural gas storage heaters range in size from 20-80 gallons of capacity.
You should check to see whether your home has access to the natural gas lines before purchasing the natural gas-fuelled heaters. Even if natural gas is available in your home area, it might be quite expensive to add the gas line to your home. Natural gas heaters also have to be installed in locations which can provide proper ventilation to the outside. As a result, before you head to the market to buy a new natural gas tankless heater, you should always think about its compatibility with your home.
The energy efficiency rating of a natural gas heater is normally stated in terms of its EF (energy factor). The EF refers to the ratio of energy delivered as hot water when compared with the total energy that is used by the heater over a 24-hour period. The ratings take the efficiency of the source of energy into consideration that heats the water, the heater’s standby energy losses, as well as the energy lost when the heater cycles on and off. The higher the energy factor, the more energy-efficient the gas hot water heater is.
In order to determine the actual costs of using a natural gas water heater, you should always look at both the buying price of the water heater and its total lifetime operating costs. In most parts places, a natural gas heater can operate for around half the cost of an electric heater although the natural gas heater might cost a little more. Similarly, a natural gas heater with higher efficiency ratings might cost more than a natural gas heater having a lower E F. However, you can save hundreds of dollars over the heater’s lifetime thanks to its lower operating costs.
When buying a natural gas tankless heater, you should always take a clean look at the hot water needs of your home. The “First Hour Rating” (FHR) tells you the amount of hot water that a heater can provide in every hour. The First Hour Rating should match the amount of water which your household requires when you use most hot water every day.

Top 5 Best Natural Gas Tankless Water Heater in 2020

BEST NATURAL GAS TANKLESS WATER HEATERNatural gas tankless heaters are popular since they give the precise amount of hot water that you need. This type of heaters can save your money since you do not end up heating several gallons which just sit in the tank, waiting to be used.

An efficient gas hot water heater will save you considerable amounts of cash. However, the market is home to a wide range of hot water heater models and it’s important to choose the heater that best suits the family’s hot water needs.

#1 Rheem RTGH-95DVLN 9.5 GPM – Indoor Natural Gas Tankless Water Heater

Rheem RTGH 95DVLN Review

Rheem RTGH-95DVLN 9.5 is a top-class water heating solution which runs on natural gas and also provides an unlimited supply of hot water to your whole family. It’s a very simple-to-use natural gas heater which comes with the remote control panel that’s designed for setting the output’s water temperature. You might also use the heater to display the fault codes.


  • Direct vent system: The Rheem heater contains the two-pipe direct vent system that connects up to 5 feet of 2-inch PVC pipe or 35 ft. of 3-inch PVC pipe.
  • Intelligent electronic controls: Rheem RTGH-95DVLN 9.5 has increased safety and efficiency with Intelligent electronic controls. With the up and down arrow buttons, you can change the default temperature setting which is set at 110 degrees F to 120 degrees F.
  • Energy efficiency: Operating at around 199,000BTUs, Rheem RTGH-95DVLN 9.5 is a high-performance natural gas tankless heater. The stainless steel condensing heat exchanger on the heater makes it 94% energy efficient. The Rheem RTGH-95DVLN is also an ENERGY STAR rated natural gas tankless heater.


  • It has been reported that this heater has a short span of life. But that should not throw you away because every product’s lifespan depends on how you use it.

All in all, it is a very good heater. If you have a relatively big house, this heater will work just fine for you.

#2 RINNAI RL94IN 9.4 GPM – Best Natural Gas Tankless Water Heater

Rinnai RL94iN ReviewExperience the never-ending supply of hot water and a sculpted sleek water heater design using the Rinnai RL94iN Heater. Whether you’re building a spacious home or you are just remodeling the older home, it can be used in pairs, individually or in banks of 3 or more so as to supply your entire home’s hot water needs.


  • No additional venting required: The Rinnai RL94iN can be placed in almost any room. it vents outside and has an integrated condensate collector. The natural gas tankless heater also requires no additional venting and it can be installed even in a recessed enclosure where it’s painted or textured so as to match with your home’s exterior for a clean and inconspicuous appearance.
  • Commercial-grade heat exchanger: This Tankless Water Heater also contains the commercial-grade heat exchanger for maximum durability. With this best gas hot water heater, homeowners will get the reliability of the commercial-grade construction as well as an industry-leading warranty of 12 years.
  • EZConnect feature: The heater has an EZConnect feature for connecting two or more units. Three or more units can also be manifold using the MSA control board.
  • Digital temperature control: The heater has Digital temperature control, troubleshooting and monitoring features. Temperature can be monitored and changed with a standard MC-91 controller (included): 98F to 140F.


  • Some users complained that this heater makes a lot of noise. But it is not that big of a deal since it does not affect the efficiency of the heater

This is one of the best natural gas tankless water heaters out in the market. This is the number one choice for many customers and so, you should consider it.

#3 Rheem RTG-64XLN 6.4 GPM Low NOx – Outdoor Tankless Gas Water Heater

Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Natural Gas Tankless Water Heater ReviewRheem RTG is a well-known brand that’s popular worldwide for its eco-friendly, innovative, efficient and budget-friendly water heating solution.


  • 6.4 GPM: The Rheem RTG-64XLN’s output is around 6.4 Gallons per minute. You can get hot water easily for two bathrooms. In addition, you can use it from approximately 10 feet distance and also through remote control.
  • Outdoor heater: The fact that Rheem RTG is an outdoor heater which runs on natural gas simply proves that there shall be no safety risks that are involved when using it. This is a very reliable outdoor tankless water heater.
  • Built-in electric blower: The Rheem RTG has a built-in electric blower for forcing exhaust gas to the outside.
  • Low Nox Version: The heater features a Low Nox Version. That means it emits very little Nox. It makes this heater eco-friendly.


  • Since it is an outdoor heater, it cannot be installed inside the house.

This is an amazing heater. People who need hot water instantly without compromising on energy consumption and the utility bill must have this amazingly efficient tankless water heater.

#4 BOSCH 520 HN NG Therm – Best Natural Gas Tankless Water Heater

Bosch 520 PN Therm Natural Gas Tankless Water Heater ReviewBosch is a well-known natural gas tankless heater brand that comes up with a series of water heaters from time to time.

The Bosch Therm 520 HN NG is a popular tankless water heater that was introduced into the market in 2011. The Bosch Therm 520 HN has the pilot light and also offers a Piezo push-button ignition system.


  • Modulating gas valve: This natural gas tankless heater utilizes the modulating gas valve so as to ensure a constant temperature at different flow rates.
  • No electrical connection required: The Bosch Therm 520 PN has a Piezo ignition system. Therefore, it requires no electrical connection.
  • 5.3 GPM: The Bosch Therm 520 PN has a 5.3 gallons/minute capacity at 35 degrees F rise. It has a minimum activation flow rate of around 0.5 gallons/minute. Therefore, it can provide endless hot water for a single application at a time.


  • It has been reported that some consumers get random shut off. But that is just some technical problem.

The Bosch Therm 520 HN NG is the perfect tankless heater for smaller households and families that only use less than two hot water appliances at a time.

#5 Rheem RTG-95XLN 9.5 GPM Low NOx Outdoor Tankless Natural Gas Water Heater

Rheem RTG-95XLN 9.5 GPM Low NOx Outdoor Tankless Natural Gas Water HeaterRheem is a widely trusted and highly brand for its vast range of water heaters. Similar to Rheem’s other water heaters, the RTG-95XLN Tankless Natural Gas Water Heater is another excellent water heater that accompanies both Rheem’s years of experience and the latest technology to bring us one of the best outdoor tankless water heaters. 

One of the best things about Rheem RTG-95XLN is its 10-year warranty on heating parts and its stainless steel heat exchanger that gives you the option to connect both vents as water demand turns high. Thus you never run out of the supply of hot water. 


9.5 GPM Flow Rate: If you want to install a single tankless water heater for multiple bathrooms and faucets, Rheem RTG-95XLN is an excellent option as it has a large 9.5 gallons per minute water flow rate. The impressive 9.5 GPM means that your family will never run out of hot water supply. Rheem RTG-95XLN 9.5 GPM is also an efficient tankless water heater for commercial use.

Energy Efficient: No matter if you talk about the energy consumption or fuel options, Rheem RTG-95XLN will surely impress you. The unit reaches up to 94%, it emits less carbon dioxide and operates on both propane and natural gas.

Latest Technology: Rheem RTG-95XLN tankless water heater comes with EcoNet smart home technology that enables you to control your water heater remotely via an app. With Rheem RTG-95XLN, you do not have to go out to adjust the gas power and water temperature; you can easily do this via your mobile app. 


  • Complex to install without professional help. So, we would recommend you to hire a professional for proper installation.

All-in-all, Rheem RTG-95XLN tankless water heater is an excellent natural gas outside water heater that is ideal for large families or commercial use.


There are several brands of natural gas heaters to choose from and each brand is slightly different from one another. Some brands specialize in providing Eco-friendly technology while other brands put their main focus on power and efficiency. You should, therefore, be sure that you find the right model which suits all of the needs of the consumer, based on size, design, preference, and price.

Many brands now offer Tankless water heater units with internet connectivity that will allow you to adjust the settings and monitor the usage via a smart device.

Additionally, smart technology allows the unit to detect the source of issues with the system. This information will save you and your plumber time and effort when they show up knowing precisely how to fix the problem. Knowing when to descale is also easier since the smart system alters you at the right time.

However, you should try not to make the decisions solely based on how much money will be deprived of the pocket. When purchasing the best natural gas heater, you should make sure that it will be of high quality and it’s also able to last for many years so that you will not have to worry about the heater for at least one decade or so.
Have a Quick look on the Natural Gas Tankles Water Heaters Comparison Table.

Main Features


Size (lbs)


Max. Flow/Min


18.5"x 9.8"x 27.5"






14"x10" x 23"





14” x 10” x 26”




16.7"x 8.7"x 25.8"






14” x 10” x 26”





Don’t know what to choose for your heater at home? Contact us anytime and we are ready to assist you.