Top 10 Best Rheem Tankless Water Heaters Reviews 2021

Consumers prefer tankless water heaters for their ability to last longer compared to tanked heaters. They also go a long way towards reducing your gas bills. Investing in the right tankless heater for your home’s needs is the only way to get the full range of benefits. That said, Rheem is one of the most reliable manufacturers and provides tankless heaters that guarantee a continuous supply of hot water.

10. Rheem RTX-04 120V Residential Tankless Heater

Rheem RTX 04 120V Residential Tankless Heater

The first thing you will notice about the Rheem RTX-04 is its stylish appearance. Its design incorporates high-quality, immersion heating elements that are corrosion resistant. The digital temperature control allows you for one-degree increments or decrements from 80 to140 degrees Fahrenheit. This heater is equipped with one heating element that operates at 120volts.


  • 99.8% heating efficiency
  • Robust copper immersion heating elements
  • Threaded at the end for easy installation and replacement
  • Digital temperature display

9. Rheem RTX-18 240V Tankless Heater

Rheem RTX 18 240V Tankless Heater

Like all RTX heaters, this one comes with two durable copper immersion heating elements that are field serviceable. The external digital thermostat control has an LED display for clear visibility and offers a +/-1 degree accuracy. Threading allows for easy installation, replacement of parts as well as a digital temperature display. Also, the bottom ¾ inch NPT water connections make installation easier.


  • Advanced self-modulation
  • External digital thermostat control with LED display
  • Installation is simple
  • Two heating chambers

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8. Rheem RTX-13 240V Electric Tankless Heater

Rheem RTX 13 240V Electric Tankless Heater

This is a tankless water heater loved for its compact design, energy-efficient system, and top performance. The heater is Energy Star certified and can heat up to four gallons of water in a minute. It also features the patented Rheem energy-efficient system, which goes a long way towards reducing your energy bills. The on-unit temperature offers nine different heating levels and an LED display that indicates the active elements. Other features include 1/2 –in water connection and copper heat exchanger.


  • Quick heating under one minute despite its small size
  • Easy to install and use
  • Compact star
  • Energy-star certified

7. Rheem RTG-84DVLN 8.4 Tankless Heater

Rheem RTG 84DVLN 8.4 Tankless Heater

If you are in the market for a natural gas unit, the Rheem RTG-84DVLN will prove a worthy investment. Among its range of inciting features is a flow of 8.4 gallons of water depending on how warm you need your water to be and where you live. The heater requires about11000-180000 BTUs of heat, which again depends on where you live. At 54 pounds of weight, this unit isn’t as compatible as other heaters on the list. The low NOx system allows for indoor installation.


  • Remote control to increase or decrease temperature setting by 20 degrees Fahrenheit
  • The flow rate of 8.4 gallons per minute
  • Easy to install and use
  • Special low NOx system for indoor installation


6. Rheem RTE-27 Electric Tankless Water Heater

Rheem RTE 27 Electric Tankless Water Heater

Many benefits and tons of great features come with the Rheem RTE-27. For starters, it is Energy Star certified and has on-unit temperature control. The rugged brass/copper heat exchanger increases reliability and durability. This unit can heat up to 5.0 gallons of water per minute, which is expected given its size. LEDs do a great job of indicating the active elements and standby mode, while the compact design saves on space.


  • Produces up to five gallons of water per minute
  • Rugged brass/copper heat exchanger
  • Great for mid-sized homes


5. Rheem RTE-7 2.5 GPM Electric Tankless Heater

Rheem RTE 7 2.5 GPM Electric Tankless Heater

Areas that require hot water in small doses will benefit a great deal from the Rheem RTE-7. This heater is perfect for rural areas and RVs. It only weighs 6.2 pounds and can heat up to 1.5 gallons of water per minute. Like other models on this list, it is energy star certified and has an LED indicator that shows the unit’s status. The analog temperature control helps with the modulation of power.


  • Great for small homes
  • Comes with LED indicator
  • Energy-star certified
  • Compact size


4. Rheem RTG-64XLN 6.4 GPM Tankless Heater

Rheem RTG 64XLN 6.4 GPM Tankless Heater

This is another natural gas unit and offers a good flow of 6.4 gallons of water per minute. That’s more than enough to handle several showers at the same time. It requires about 150,000 BTUs and has a high-efficiency rating of 0.82. At 54 pounds, mounting this heater on the exteriors and walls shouldn’t be that hard. Another notable feature is the special low NOx function that eradicates the need for complicated venting systems.


  • Low NOx function reduces harmful emissions
  • Can serve multiple bathrooms and kitchens simultaneously
  • Temperature wire and remote control included


3. Rheem RTGH-95DVLN 9.5 GPM Tankless Heater

Rheem RTGH 95DVLN 9.5 GPM Tankless Heater

This tankless water heater is packed with various great features, including a flow rate of 9.5 gallons, which is quite high compared to what other models offer. That’s more than enough to serve multiple kitchens and bathrooms at the same time. It requires up 199,000 BTUs, which you will be happy to know that the heater has a high energy efficiency rating of 94% though high. The unit weighs 80 pounds and features a low NOx function that prevents harmful emissions.


  • High energy efficiency rating of 94%
  • Energy-star certified
  • Low NOx function
  • Easy to install
  • Available in both propane and natural gas


2. Rheem RTE-9 3 GPM Electric Tankless Heater

Rheem RTE 9 3 GPM Electric Tankless Heater
This tankless heater lives to Rheem’s standards by providing a continuous supply of hot water. Its plethora of features include an external temperature control that allows for customization. There are a standby mode and LEDs that do a great job of indicating the unit’s active elements. The copper and brass heat exchanger is a welcome feature that allows for increased durability and is backed by a ten-year warranty.


  • Easy to install
  • Its small size makes the unit a space saver
  • External temperature control modulates heat exchange


1. Rheem RTE-13 Electric Tankless Water Heater


Rheem RTE 13 Electric Tankless Water Heater

This will prove investment if you are looking for something suitable for on-point applications. It is designed for single shower applications and can provide up to four gallons of water per minute. This 13kw 240W tankless heater comes with a modulating power control with nine settings that allow for customization. The contents are housed inside a metal box with a grey finish, and 0.5” connections pipe water in/out of the unit.


  • Energy star rated
  • Rugged brass and copper heat exchanger
  • Modulating power
  • Great for single shower applications