Best Gas Tankless Water Heater 2019 ? [ Choosing the Right Water Heater ]

Reasons to Select Tankless water heater Gas 

If you are looking for a powerful water heater, you are likely to be reading this article because of gas If you are looking for a powerful water heater you are likely to be reading this article because gas Tankless water heaters are more potent in generating hot water in no time than electric water heaters. The Best Gas Tankless Water Heater is supposed to have - 

  • Easy installation.
  • Low NOX emission compliance with industry standard A proper venting system that will not require you to buy many extra things for Gas tankless water heater becoming workable.
  • A low BTU requirement in compare to temperature BTU ratio-guaranteeing for low energy consumption.
  • Dual-energy slots-gas/propane operated and provision for battery operation.
  • High GPM –More force in less time for multiple applications to run simultaneously.
  • Copper or stainless heating exchanger-that has higher heat convertibility and quickly warms up.
  • The best propane tankless water heater also adds extra features like –High altitude compatible, recirculation pump for instant hot water.
  • A good energy efficiency factor and industry peer’s energy certification, ie, Energy Star.
  • Safety lock features along with the digital display for temperature control.

I must have miss one or two points let us find them out then go through the details of some industry’s best tankless gas water heaters.

Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water heater

Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water heater is a mid-efficiency outdoor Gas tankless water heater. It has made its position in the league of Best tankless gas water heater through its lowest activation rate of .26gpm in the industry and All-copper heat exchanger. It is mildly efficient with 81 % EF.

It has a remarkable feature of reducing your water pressure to the extent where the temperature reaches the set temperature of the heater. This will help a home to save 1100 gallon water every year. It has an easy installation feature for the DIY experts.

I am a fan of their display unit, apart from temperature setting. This digital display shows maintenance codes. It has intelligent Self-diagnostic system that will preemptively insinuate the user via digital display about the forthcoming error. Gives you time to find the problem and solution before it finally stops working.

It has Guardian OFW™ overheat film wrap purpose of this wrap is to monitor a temperature of the heat exchanger shuts the unit down when it goes beyond a safe heat.

Rheem RTG-64XLN Tankless Natural Gas Water heater

It is an outdoor unit with Freeze protection to -30°F, making intransigent to survive in extreme weather. It needs 11,000 - 150,000 BTU at maximum. It works for two showers and a faucet to run at a time with the excellent flow of water.

It is a medium capacity water heater it gives 6.4 GPM at 35° F rise and 5.6 GPM at 45° F rise. In case you need an industry’s best tankless gas water heaters that can also function at 8,400 ft. Above sea level. Rheem RTG-64XLN 6.4 GPM Low NOx Outdoor Tankless Natural Gas Water heater is hugely environment-friendly with ultra-low NOx burner that meets SCAQMD rule of 1146.2. Also, it is certified by AHRI, CANDA CSA, USA CSA, LEED POINTS, NSF the list has many more significant names.

Rinnai RL75iN Natural Gas Tankless Water Heater

Rinnai RL75iN Natural Gas Tankless Water Heater is a Gas tankless water heater for average homes. Some call it best tankless gas water heaters for mobile homes. Because like the essential feature of best natural gas tankless water heaters; it complies with all the necessary environmental legislation. It conforms to low NOX emission levels. It is an Energy stared unit. Enhanced scale detection has made it safe and free of long-term damage. Also, the feature of Temperature lock function gives you provision to prevent your group from unauthorized changes to water temperature which could otherwise lead to accidents.

Dimensions are super convenient 14 x 9.3 x 23 inches weigh 50 pounds. It comes with a 12-Year Warranty on Heat Exchanger, 5 Year warranty on Parts, 1 Year warranty on labor in case of residential Installations. It runs on natural gas and propane. You will need a hanger to hang it outside, and necessary pipes for venting.

It has been designed in a way that you can use it for the parlor, food van, a medium office or other commercial purposes. It has a digital scale of 98°F - 140°F (37°C - 60°C) for residential purpose and 98°F - 160°F (37°C - 71°C) for Commercial usage.

Rinnai RL75iN Natural Gas Tankless Water Heaters

Rinnai RL75iN Natural Gas Tankless Water Heater gives the maximum output of 7.5 GPM at 120 degrees. Also At 4.3 GPM, it gives rise to 70°F at 6.0 GPM it gives rise to 50° Temperature, so it is ideal for moderate t cold temperature regions.

It needs .4 GPM to activate the flow sensitive ignition. If you have a big home you may consider buying more than one unit because through the journey by pipe from far end to the different bathrooms; water will hold off a bit. It is ideal for a medium home with 4 to 6 people.

Navien NPE-240-A Tankless Gas Water Heater

This one is new, Navien has many tankless units, but I chose to review this as it provides some extraordinary features in a single system that can easily win the title of the best propane tankless water heater; like double heating condensing unit.
It has Dual stainless steel heat exchangers. These heat exchangers are highly resistant to corrosion and erosion. In some aspects, they are even better than the copper heat exchangers. Because of less corrosion and no mineral pile up, it gives longer life. Navien NPE-240-A Tankless Gas Water Heater has a built-in recirculation system this means no more cold water sandwich problem.

NPE models have an option of easy convertibility from NG to LP. It has a provision to convert multiple systems (up to 16 units) into one by joining them through active link cascade system, and you won’t need another control board for controlling the temperature. It has an optional remote control the option you search for ease of use. The digital monitor on its face let you change the F to C, set temperature, displays temperature with water flow rate, shows the status of cascade operation.

Navien tankless water heater reviews

If you read Navien tankless water heater reviews can know that it has a superior venting system with 2” venting option another 3” vents are usable up to 150 with standard 2 x 3” adapters. Energy conscious people would be happy to learn that it has a new metal fiber burner. This burner delivers a consistent air, gas mixture this improves combustion efficiency.

The result is ultimately less acid rain and less greenhouse effect. Apart from greenhouse effect redemption it also complies with SCAQMD strict NOx emissions standard. Because of its advanced features is comfortably usable in –homes, hotels, beauty shops, hospitals, restaurants, schools, health centers, and more. It has a small size with 13.2 x 17.3 x 27.4 inches dimension and 15 years warranty on heat exchanger, five years warranty on parts however due to the warranty clauses DIYers would be out of luck, and the warranty will be void if not installed by professionals. In my words, this is the best tankless water heater gas that has all the features anyone can look for.

EZ 101 Tankless Water Heater

EZ 101 Tankless Water Heater is one of the best gas tankless water heater on the go. You can install it as a point of useful purpose in your garden, garage, kitchen, bathroom faucet. It has an aesthetic design making it unobtrusive for your interior or exterior views. It does not have a pilot light so it will save battery life. People call it camping model, the workshop model because of its portability.

Another proof EZ 101 Tankless Water Heater is it can easily cope with rocky water flow. It is workable with 15 PSI water pressure. In case you live at high altitude or have an old or weak pumping unit with low water pressure this unit will easily blend in.

EZ 101 Tankless Water Heater - Propane LPG - Portable - Battery Powered Ignition

Installation is straightforward and not associated with the red flag clause of without professional help the installation will void warranty clause. This low water pressure accommodating unit it has a rate of water flow of 1.6 gallons per minute. The group comes with a Shower Head and a hose. It has a 20-minute safety timer, so it is ok if you forget to use it and turn off because like automatic ignition it turns off automatically thus the risk of carbon-monoxide poisoning also reduces (in case it is improperly ventilated). For colder inlet water it has a winter-summer switch and double proportional valves making the temperature range more full.

If you are buying it be sure you use it only outdoor because gas-fired EZ 101 Tankless Water Heater needs unconfined space of 2050 cubic feet as a room for combustion air. For a non-fluctuating water pressure, you can depend upon pressure regulator (externally installed in supply line) thus stable water flow irrespective of how rocky the supply line is will be guaranteed.

In case you are wondering what EZ stands for than manufacturer spells it as - it easy to use, easy to install, and easy on the pocket! So it an amply good value choice after all.

How to install a Tankless gas water heater?

To install a tankless water heater gas, it requires to have an outside vent, the connection of 120V electric circuit & a gas line with the valve. The gas meter should be upgraded because it may not have enough capacity to supply gas to other areas of home use. Better to employ a gas company to check gas meter & supply line.Tankless gas water heater Installation process as below in common.

1. Turn off the main water supply line. Disconnect the water pipeline from the old water heater. Then disconnect the heat source of the water heater from the electric socket. For a gas heater, please ensure that the gas supply valve is closed.

2. After the water heater is completely detached, dispose of it as per the laws of your living area. Then get the new one at your side. Get necessary hardware as per the manufacturer’s instruction manual as well.

3. Locate a position on the wall to set up the tankless water heater & be confirm that your wall has enough support to handle the weight of your new water heater.

4. As this is a gas fueled water heater, you need to install ventilation ducting because tankless gas water heaters need larger steel flue.

5. Now water supply line should be connected & gas supply pipe also should be connected to the new water heater. Turn on the gas pipe valve to keep the gas flow towards the radiator.

6. You need to check manufacturers manual to know the process of lighting up the pilot on the gas water heater.

7. Now you can enjoy this instant water heater solution as per your need. Check manufacturer’s manual also at the installation stage. As you know safety first.

How many GPM for tankless water heater?

How many GPM is required for your tankless water heater it depends on the consumption of water at your place. Determining the GPM of water heater can be a bit confusing. We will put this as simple as possible.

The concept is, you need to find out in how many areas you may need to use hot water at the same time. Maybe for the kitchen, shower, dishwasher, washing m/c at the same time & number of shower heads also important for determining GPM. These areas hot water usage general information as below-

Kitchen sink -                      1.5 GPM             -110°F

Dishwasher-                       1.5 GPM             -110°F

Washing Machine-            2 GPM                -120°F

Shower-head (1) -              2.5 GPM             -110°F

All these functions if happen simultaneously then your Tankless heater require around 7.5 GPM with produced heat rise of at least 60 degrees which is average temperature (Total number of temperature/number of GPM). These hot water usage functions will happen at the same time, or not that decision is yours. Now you have a basic concept.

What are the advantages & disadvantages of a tankless water heater?


  • Tankless water heater never runs out of the water. Just turn on the hot water tap & you will get water instantly on demand.
  • It takes less space because there is no extra tank. A small area is enough to adjust this machine.
  • It uses almost 30% less energy than a tank water heater. So your lot of money will be saved.
  • A tankless unit lasts around 20-25 years. Much more than a tank water heater.
  • Safety is better in the case of a tankless water heater because it only functions only when warm water is required. However, storage type heaters permanently stay on to keep the water hot.


  • Although Tankless heater saves much cost in the long term, the initial value is expensive. Its price is almost twice than a storage type water heater.
  • Also, there is an initial cost coming at the installation stage. Retrofitting a home for a tankless heater is complicated which might require a skilled plumber. A professional plumber charges avg. $75 hourly to do this type of job.
  • The water softener should be installed if there is the availability of hard water.
  • To maintain a tankless machine you need to flush & descale it on a yearly basis.

You need to choose the location of your new tankless water heater considering all this advantages & disadvantages. Don’t forget to prioritize your safety first.


A Gas Tankless water heater has its own benefits & drawbacks, but the most important thing is safety & comfort which this machine can provide. It only operates only when hot water is required. So there is less risk of hot water leakage. Now you are supposed to be educated enough on what type of Tankless water heater you should choose. All the best for your future new asset.

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