Rheem RTG-64XLN Tankless Natural Gas Water Heater Reviews

Are you looking for one of the industry’s best gas water heater? Are you cost conscious and have more interest for eco friendly gadgets? Then you can look into the details of Rheem RTG-64XLN Tankless Natural Gas Water heater. This tankless gas fired water heater is popular for it state of art technology of copper heat exchanger and 84% energy efficiency. Comes with multiple remote controls and serves 3 bathrooms and a kitchen faucet at a time. Another thing that you may take into special consideration there is only one negative review about the unit and the product rating gives it 4.5 out of 5 among 49 total reviews in Amazon.

Rheem RTG-64XLN Tankless Natural Gas Water heater

Features of Rheem RTG-64XLN Outdoor Natural Gas Tankless Water Heater

Meet the high standard of eco friendly appliance

Rheem RTG-64XLN is phrased as an extremely environment friendly and one of the best tankless water heater. It conforms to the high standard of Ultra Low NOx burner and meets SCAQMD rule 1146.2 requirements. In our language that is meeting the standard set for the reduction of nitrogen oxides from gas-fired fan-type residential furnaces. These gas fired furnaces are typically used for comfort heating in home or at sales outlet for both commercial and residential use. Meeting this standard ensures your gas fired tankless water heater is emitting very nominal nitrogen oxides thus gaining the credit an environmental friendly appliance.

Has a better technology to heat water

It uses copper heat exchanger, unlike many heaters that uses stain less heat exchanger. Stainless heat exchangers are also good and efficient but using a copper heat exchanger gives 40 time faster heat transfer. Rheem is giving 82% efficient copper heat exchanger with the model Rheem RTG-64XLN and this is happening for the first time in this industry. So you are going to experience an improved performance for sure.

Remote control and additional remote control

We are undoubtedly active in our work and in chores but that do not mean we do not appreciate a little luxury of not moving to the heater in middle of washing clothes or having a bath to control the temperature. Yes we all enjoy that little comfort that extra savings of energy. Rheem has captured the demand and introduced remote control for these purposes. Also additional bath remote controls are available for other family members at distance from heater to control the heat. How cool is that!

Safety first

Best tankless gas water heater reviews gauge over Rheem RTG-64XLN for their smart technology. The heater has a built-in self-diagnostic program; it displays maintenance codes whenever something goes wrong. When an error is detected in the thankless unit, an error code is displayed on the digital controller. You will get a manual explaining these codes with the heater, so you can check it for quick reference and troubleshooting issues and may solve it yourself.

Space saving

With 14 x 10 x 26 inches dimension it is very compact and space saving. So you no longer need to worry where to hang it or hide it. This will eat up 1/5th of the space of a traditional heater making more room for other purposes.

Endless hot water

This unit is capable to support 3 faucets at a time. It generally happens very rarely at a home that 3 people take bath and one use the dish washer simultaneously. Even if such incident occur, Rheem RTG-64XLN 6.4 GPM Tankless Natural Gas Water heater can support it with 6.4 gallon water per minute.


  • It has 0.26 GPM minimum flow rate, 0.40 GPM minimum activation flow rate.
  • It is capable for High-altitude - up to 9,840 ft. elevation above sea level.
  • Eco friendly -Consumes very less gas.
  • Warranty is 5 years on the parts and labor charges, 12 years limited warranty on heat exchanger.
  • Has an Overheat film wrap (OFW) to protect the heat exchanger.
  • Has automatic shut off option to prevent accidents.

Cons with solution

Cold water when vent goes wrong

It is designed for outdoor wall mounting, because it needs lot of venting power. If anything goes wrong very soon you will be left with cold water


When installing it outside by you or by a plumber be sure to remove any barricade that may be distracting the exhausting process. It is OK to make necessary shelter for the unit in order to protect the vent pipes from freezing but you also need to make sure there is enough space for exhausting air to go away and keeps the heater functioning.

Does not provide hot water instantly

This tankless gas fired water heater is good for all purposes residential or commercial however on opening the faucet a few gallons are wasted as it does not provide hot water instantly.


About the instant heating thing all tankless water heater has flow sensing meter that ignite the burner and heat the water only after sensing a minimum flow. For Rheem RTG-64XLN 6.4 GPM Tankless Natural Gas Water heater the minimum activation flow rate is 0.40 GPM it is very low and most cases your flow is much higher than it.

Frequently Asked Questions

  • Q- Is this tankless unit not suitable for indoor installation?
  • Ans- It is a Medium-Efficiency Tankless Outdoor Water Heater that is what mentioned in the style of Amazon guide, so you can hang it at your garage with a duct system to let the fume go away or any outdoor place nearer to indoor faucets. It is not an indoor type.
  • Q- What is the minimum flow rate for this unit?
  • Ans- The unit has a minimum GPM of 0.26 so even when all of the capacity is being used up by multiple purposes you will receive hot water at a rate of 0.26 GPM.
  • Q- What electrical configuration us needed for installation?
  • Ans- This gas fired tankless heater needs 120V AC, plug or Hard-Wired, however the 120 volt plug is not included with the model.


People used to say “You use it, you know it” but at today’s digital world we put more faith on reviews before making the final call. As per reviews of Amazon only 1 out of 49 users had something ill to talk about it. So if you have a home with 3 bathroom and dishwasher /washing machine with a medium to high need of hot water, and planning to buy an outdoor tankless gas fired water heater that comes with great warranty conditions and an easy installation process I would say-go for Rheem RTG-64XLN Tankless Natural Gas Water heater.

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