The Best Tankless Gas Water Heater Reviews 2017-09-02T20:21:05+00:00

The Best Tankless Gas Water Heater Reviews

Congratulations on making the decision to consider a tankless water heater for your home and welcome to our Best Tankless Gas Water Heater Reviews Guide. Tankless water heaters have been on the market for many years, however, in the United States and along with the rest of the Western world, tankless water heaters are relatively unknown and generally an uncommon sight in a U.S household. On the contrary, on other continents of the world, tankless water heaters are abundant and a dime a dozen in hotels and homes alike. 

Given the many benefits associated with a tankless water heater, it is surprising that traditional hot water tanks are still the norm in the U.S even though the advantages of a tankless far outweigh those of a traditional hot water tank. Spread the news far and wide! Let’s see more U.S homes with tankless water heaters. The energy cost savings and environmental advantages of tankless water heaters are reason enough to begin the research and consideration of a new tankless water heater purchase. Tankless water heaters are the most environmentally friendly and budget friendly option.

So let’s take a look at our Best Tankless Gas Water Heater Reviews Guide (that’s a mouthful!) and if you have any feedback or would like any additional information, please don’t hesitate to contact us!  

Tankless Water Heater Considerations

Incoming Water Temperature

Incoming water temperature is an essential factor when considering a tankless water heater. If you live in the northern states of the U.S, your groundwater temperature is going to be much cooler than the southern states. The average person, however, typically showers with a water temperature of approximately 105°. A tankless water heater will need to heat the incoming water at a greater rate and work harder if you live in northern states because your groundwater temperature will be much lower than the southern states. It’s worth noting that gas tankless water heaters do have a greater heating capacity. For northern state residents, a gas tankless water heater is likely to be a better option for you.

Use the below chart to identify the approximate groundwater temperature in your region.

Incoming Water Temperature

Tankless Water Heater Considerations

Household Water Flow

Use the chart below to identify how many gallons per minute your water appliances will likely use on average.

Gallons Per Minute Chart

Your overall water use will depend on how many occupants are living in your household and what appliances may be used at the same time. The volume of water that a tankless water heater is required to heat is measured in gallons per minute (GPM). A one or two person household will need a smaller tankless water heater; whereas a 4 person family household will require a whole house tankless water heater which on average heats 6.5 gallons per minute.

Tankless Water Heater Considerations

Available Utility Services

Utility Services Available

First of all you need to know the available utility services in your area. A tankless propane water heater or natural gas water heater may not be an option for you if gas is not available. If you are limited to only the electric tankless heater variety, click here for our comprehensive electric tankless water heater reviews guide. If gas is an option for your household, continue reading for more information on the best tankless gas water heater.

Pros and Cons of a Tankless Gas Water Heater


  • Higher heating capacity than electric

  • Less expensive than electricity

  • Eliminates the possibility of flooding from ruptured or rusted out water tanks

  • Environmentally friendly; only the amount of water necessary at any particular moment is heated

  • Can be wall mounted, floor mounted, installed under your sink essentially taking up less room than a traditional water tank

  • High efficiency and reduced energy costs with no standby heat loss


  • Proper ventilation is required

  • More maintenance required than electric tankless heaters

Takagi Tankless Water Heater Review (T-KJr2-IN-NG)


Temperature range: 65-145°F

Water Flow Rate: up to 6.6gpm

Vent Type: direct vent 4″

Water Connection: 3/4″

Weight: 38lbs

Dimensions: 20 x 13.75 x 7.75

Water Pressure range: 150psi

Warranty: 15 yr limited heat exchanger, 5 yr limited parts residential use


Amongst the most well known tankless water heater brands, Takagi is a market leader and have been developing innovative and high quality tankless water heaters since 1952. Over half a century of product excellence and innovation has created a brand reputation so valuable that you know that reliability and quality will be a key feature if you purchase a Takagi gas tankless water heater.

The Takagi t kjr 2 is a compact, fully modulating, non-condensing, gas powered tankless water heater suitable for residential purposes and is powerful enough to heat up to two bathrooms in warmer climates where the incoming water temperature is warmer.

All Takagi tankless water heaters come with standard superior safety features including and internal freeze protection system (for protection in sub-freezing conditions), air fuel ration (AFR) sensor to monitor and maintain proper combustion, hi-limit switch to ensure that the water temperature does not exceed safe levels and an overheat cut off fuse to ensure that there are no breaches in the heat exchanger drum.

Rinnai RL75iN Natural Gas Tankless Water Heater Review


Temperature Range: 98° – 160°

Water Flow Rate Temperature range: 7.5 gpm

Vent Type: direct vent 3/4″

Weight: 46lbs

Dimensions: 14 x 9.3 x 23″

Warranty: 12 yr limited heat exchanger, 5 yr limited parts, 1 yr labor for residential installations


The Rinnai direct vent heater is a large, powerful unit designed to heat two to three fixtures at once.  This means that you can run two showers and a dishwasher simultaneously.

Innovation is a key feature of the Rinnai water heater and The RL75in has been designed with a sophisticated and advanced temperature controller that not only indicates the outgoing water temperature and flow rate but also alerts the user of errors in the water heater through diagnostic codes. The temperature controller is built into the front panel allowing you to quickly identify the problem and address it.  Problems can include scale build up in the heat exchanger, air supply blockage and an over temperature warning. The installation manual provides a list of the error codes displayed, a description of the error and a solution to the problem.

It is important that you undertake regular maintenance to ensure that you maximize your gas tankless water heater’s lifespan. This requires flushing of the heat exchanger and manual draining of the water heater at least once per year. Check out the you tube videos for further information on the Rinnai Water Heater.

Summary: The Rinnai Water Heater is slightly above average in cost, however you are getting an energy efficient, highly innovative, long-lasting product built by a very reputable brand which will save you money in the long term.  The Rinnai Tankless Water Heater is considered by many one of the best natural gas tankless water heaters on the market. 

Note: if you wish to find out more about propane tankless heaters, click here to see our guide on Rinnai propane tankless water heater reviews

What is the best tankless water heater?

Navien NPE 240A Tankless Gas Water Heater


Water Flow Rate:  up to 11.2 gpm

Vent Type: Forced Draft Direct Vent

Weight: 82lb

Dimensions: 13.2 x 17.3 x 27.4 “

Warranty: 5-15yr limited heat exchanger, 5 yr limited parts, 1 yr labor for residential installations

Energy: Natural Gas/Propane Gas

BTU: 19,900-199,900


The Navien NPE 240A brings you the latest in innovative tankless water heater technology and design with advanced condensing efficiency and cutting edge energy efficiency. The Navien Tankless Heater has been constructed with two stainless steel heat exchangers; the benefit of which is the longer life expectancy as stainless steel is far more resistant to corrosion and erosion in comparison to copper heat exchangers.

The Navien Water Heater produces low NOx emissions which is far kinder to the environment and in compliance with SCAQMD 1146.2 – the standard put in place to reduce NOx emissions from natural gas fired water heaters. Additionally, the metal fiber burner is designed to deliver a consistent air/gas mixture to improve combustion efficiency.

The Navien tankless water heater employs superior preheating technology and intelligently recognizes hot water usage patterns to provide hot water when required. The NPE model can also be converted from natural gas to propane.

A stand-out feature of the Navien On Demand Hot Water Heater is the sophisticated Front Panel Command Center. Consisting of a user friendly interface with soft touch pad, it provides self-diagnostics allowing you to swiftly identify any problems and can display the water temperature in either °F  °C.

Summary: What is the best gas tankless water heater? The Navien Tankless Water Heater npe 240a is a superior product with advanced energy efficiency and high quality features.  This gas tankless water heater ranks as one of our best rated gas water heaters available on the market in 2017! 

Rheem RTGH 84dvln Gas Tankless Water Heater


Water Flow Rate:  up to 8.4 gpm

Vent Type: Forced Draft Direct Vent

Weight: 78lb

Dimensions: 9.8 x 18.5 x 27.5”

Warranty: 5yr limited heat exchanger, 5 yr limited parts, 1 yr labor for residential installations

Energy: Natural Gas

BTU: 199, 000 BTU/h


The Rheem RTG 84DVN tankless water heater is a high performing, innovative unit from the Rheem Prestige Series. The sleek and compact design of the Rheem RTG 84 DVLN is a huge space saver and anaesthetically pleasing on the eye. You needn’t attempt to install your unit inconspicuously as it will complement your surrounding décor.

The Rheem condensing hot water heater features freeze protection up to -30°F, built-in condensate neutralizer, high altitude capability (up to 9, 840ft above sea level) and low flow fixture compatible.

If one unit is insufficient for your household, Rheem has developed an EZ-Link cable to connect two tankless units together to operate as one to satisfy higher demand applications. However, the Rheem RTGH 84 is not only for residential use, it can be used in settings where multiple units are required such as hotels, restaurants, schools and hospitals. MIC-6 and MIC-185 manifold control boards are available to manifold up to 20 units if required.

The intelligent digital display shows the temperature setting and maintenance codes as part of the self-diagnostic system, alerting you to any errors within the device. A digital remote control and 120volt power cord is included with the unit.

Summary: The Rheem professional prestige series 84 direct vent indoor tankless water heater is an exceptional space saver, energy saver and most importantly a fantastic cost saver!

Check out the you tube video below for more information on the Rheem RTG 84 DVLN gas tankless water heater.

Rinnai ruc98in Review


Water Flow Rate:  up to 8.4 gpm

Vent Type: Forced Draft Direct Vent

Weight: 78lb

Dimensions: 9.8 x 18.5 x 27.5”

Warranty: 5yr limited heat exchanger, 5 yr limited parts, 1 yr labor for residential installations

Energy: Natural Gas

BTU: 199, 000 BTU/h

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