Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

(10 customer reviews)

Price: $509.99

ON/OFF Dial Control with adjustable digital temperature display
Self-modulating power control
24kW Model Flow Rate: up to 5.9 GPM for RTEX-24
Bottom 3/4″ NPT water connections
On demand, consistent and continuous hot water

SKU: B01MS9DVEE Categories: , Tag:
Brand Rheem



Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

Rheem Residential Tankless Water Heater

Rheem 240V 3 Heating Chambers RTEX-24

Professional Classic tankless electric water heaters offer continuous hot water quick and on demand for single point-of-use or multiple applications.

Performance Features

  • On demand, continuous hot water
  • Compact and stylish with digital temperature control in increments of 1°F ranging from 80°F to 140°F
  • 99.8% Energy efficient
  • Robust copper immersion heating elements with brass top increases durability and are threaded for easy replacement
  • Simple Installation
  • Digital temperature display

Rheem Residential Tankless Water Heater Applications

  • Standard Hand Sink – 0.5 GPM
  • Washing Machine – 1 to 1.5 GPM
  • Kitchen Sink – 1 to 2 GPM
  • Dishwasher – 1 to 2 GPM
  • Water-Saver Shower Head – 1.5 GPM
  • Standard Shower Head – 2.0 GPM
  • Bath Tub – = 4 GPM
  • Whole-Home – up to 6 GPM

Average Gallons Per Minute (GPM) based on 2010 Plumbing Standards.

Unique Features
  • External Digital Thermostatic Control with LED display (+/- 1 degree accuracy)
  • Most advanced self-modulation, adjust power to meet hot water demand
  • Durable Copper Immersion three heating elements, field serviceable
  • Simple Installation – Bottom 3/4″NPT water connections

Additional information


Part Number


Item Weight

17.8 pounds

Product Dimensions

18.25 x 3.5 x 17.63 inches


Item model number


Is Discontinued By Manufacturer









240 volts

Installation Method

Wall Mount

Item Package Quantity


Maximum Pressure

150 Pound per Square Inch


Inside; Professional

Included Components

Fittings, Aerators

Batteries Included?


Batteries Required?




Date First Available

January 19, 2017

10 reviews for Rheem RTEX-24 24kW 240V Electric Tankless Water Heater, Gray

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    Norman Ryan

    Disconnected traditional 50 gal., drained and reconnected the tankless, including wiring (3) 8/3 wire 40 amp breakers in less than 3 hours.

    1 product
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    works great,, Rheem’s customer support very helpful

    1 product
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    Virginia Barton

    This heater works really well. One of the previous reviewers complained of lights dimming when it came on. I have noticed no power issues. It takes 10 or 15 seconds longer to get full hot water because it has to heat up from being completely cold. Other than that, I can’t tell any difference from the old tank unit.

    1 product
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    Not much for writing reviews, but feel compelled to do so now. We needed a new water heater, as ours was 20 years old. After much research on on-demand water heaters, we decided to go with the Rheem water heater. Our previous tank was a Rheem and it performed it’s job well for all those years. Installation of the tankless system was time consuming as circuit breakers, wiring, and plumbing supply lines all had to be replaced. The system initially did not work. No hot water and temperature indicator light not illuminating. This is where tech support earns their five stars and the Rheem system subsequently earned it’s five stars. Winston was the tech support guy that helped us through this. He walked us through trouble shooting the product, determined what the problem was and next-day shipped the replacement parts to us. Our home address was not registering for shipping and he was very diligent about finding a way to get us the replacement parts ASAP. Meanwhile, Winston continued to help troubleshoot the problem, even after replacement parts were ordered and on their way. The troubleshooting proved fruitful and we suddenly had HOT hot water in no time flat. To top it off, we were told to keep the already-shipped replacement parts as spare parts in the event of the system not working/needing replacement parts. Can’t thank tech support enough, the on demand hot water heater is out-performing our old tanked system (which we ourselves installed upon building the home) and we love taking SUPER hot showers now.

    1 product
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    Paul Lewis

    Very small space required to mount, work’s great excellent response time.Have had no problems at all.

    1 product
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    Amazon Customer

    Its a great water heater, we have 3 showers, 5 sinks and the dishwasher and it gives us continuous hot water. Also super easy to install thanks to the fact that the instruction manual is very thorough.

    1 product
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    R.J. L.

    Save money💲Really hot water for as long as you want to shower.Make sure you get the right size for your needs. I bought this model after reading everything I could about tankless waterheater and decided on this one. Perfect for our house.12/25/20 updateHad to go back to a tank. One element went out after another. Then the controller board. Easier and less expensive to go back to the tank.

    1 product
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    Wills AmaZONE

    This is my Third Rheem on my third rental. I’ve done american hot water heaters and Bosch. Stick with Rheem.

    1 product
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    James T. Consler

    Replaced a 50 gallon hot water tank and have not noticed any difference in our hot water. Still waiting for an electric bill to compare costs; but as of now it was the right decision. I did not rate tech support as we have not used that service yet. I would recommend this product.

    1 product
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    Red Burch

    So far fantastic. Limitless hot water. Relatively easy installation. Wife thrilled with long showers. Needs a reduced inline from 34 to 12 inch so heater can keep up. Well worth the money.

    1 product
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