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Availability:
In Stock.
Arrives
Tuesday, Sep 8
Style: Whole Home, 24 kw
Features
- 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
Description
The Professional Classic Tankless Electric RTEX-24 240V is engineered to provide continuous hot water on demand, making it ideal for both single point- of-use and multiple applications, with a remarkable flow rate of 5.9 GPM. Its compact design is up to 93% smaller than traditional electric water heaters, allowing for significant space savings, while its energy-efficient operation eliminates standby heat loss when installed near the point-of-use. See performance guide for average expectations in your region based on ground water temperature and application usage. 3 x 40 AMP Double Pole Breakers Required. 200 AMP Household service recommended. Ensure your home can accomodate the power supply and that enough space is available in your breaker panel for this unit.
Brand: Rheem
Capacity: 5.9 gallons
Power Source: Corded Electric
Product Dimensions: 17.63"W x 18.25"H
Special Feature: LED Display
Power Source: Corded Electric
Special Features: LED Display
Wattage: 24 KW
Voltage: 240 volts
Flow Rate: 5.9 gpm
Maximum Temperature: 140 °F
Heat Output: 24 KW
Efficiency: 99.8% Energy efficient
Maximum Pressure: 150
Mount Type: Wall
Maximum Pressure: 150 psi
Capacity: 5.9 gallons
Item Dimensions W x H: 17.63"W x 18.25"H
Item Weight: 17.8 pounds
Item Depth: 3.5 inches
Material Type: Stainless Steel
Brand Name: Rheem
Model Number: RTEX-24
Number of Items: 1
Unit Count: 1 Count
Manufacturer: Rheem
Manufacturer Warranty Description: Limited lifetime warranty
UPC: 020352685397
Global Trade Identification Number: 97
Included Components: Fittings, Aerators
Item Type Name: Water Heater
Manufacturer Part Number: RTEX-24
Color: Gray
Style Name: Whole Home, 24 kw
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Sep 8
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Style: Whole Home, 24 kw
There are many factors to consider before buying an electric tankless heater. By far the most important -- at least for me -- is whether the ground water temperature in your area is consistently warm enough to give the water heater a chance to succeed. I live in North Central Florida where the groundwater temperature is a rock-solid 72F (~22C) year-round. This is the ideal setup for tankless electrics; if you are far north this heater will likely fall short at the exact worst time, i.e. when it's winter and you could really use a nice, hot shower. I recommend looking closely at the map provided on Rheem's website and product pages to determine if this product is right for you. Second caveat, if you have a natural gas hookup, it is worth researching whether a gas-powered unit would be more efficient and/or less costly. There are considerations beyond this, of course, but those are the key ones that will determine whether you will be a happy camper or have cold water poured on those dreams of long, hot showers. If you're still considering after reading the above, then the short of it is (drumroll) ... I'm very satisfied and fully recommend making the jump to tankless! Here's the long-winded version: There is about 25- to 30-feet of pipe to travel between the water heater and the showerhead in my bathroom, and it takes about 25 seconds (well, 22.93 ... yes, I used a stopwatch) for the shower water to reach max temp. I did not use a stopwatch on my tank heater, but I'd guestimate it takes about 10 seconds longer for the tankless to deliver hot water than the tank unit it replaced. The main benefit, again, is that the tankless will continue to deliver hot water indefinitely while the tank is finite -- so, no more playing beat the clock and if you get in the water and realize you forgot your razor or something. The temperature coming out of the showerhead lines up with the temperature on the digital display for the main shower. There is a slight, but noticeable (I'd say 2F-4F/1C-2C) drop from the maximum temperature for the shower furthest away from the water heater. There is enough overhead that you can crank it a few degrees higher -- just be sure your shower handle can settle on something that won't scald you if you go above the recommended! I can also verify that the throughput on the model I bought (24 kW) is enough to handle two showers running at the same as well as start a load of laundry on hot -- I'm sure it could handle more, but there's not a scenario I can imagine where I would need it to. All in all, the flow is as good or better than the water heater it replaced. The dimensions listed on the product page are accurate. As far as your monthly bill, this hasn't made a significant impact although it may in the future. Here's some data from my most recent utility bill compared to the same month last year. Keep in mind the following figures are the daily averages listed on my bill for the whole home, not just the heater, although it is the only major appliance we have replaced over the past 12 months. April 2025 = 33.90 kWh electric and 0.06 KGA water (whole-home daily average) April 2024 = 31.34 kWh electric and 0.03 KGA water (whole-home daily average) Based on the above info (and the prior two months), it's essentially a wash -- we're using more power but only because we're taking longer showers because we can actually enjoy the heat now rather than worrying whether we're leaving enough water for everyone else! I'm sure that our water usage will level out once the novelty wears off, but that might be a while :) Now for the elephant in the room: Installation. If you can't say right now, with confidence and without any further research, whether you could get away with a DIY install, I'll answer the question for you: No, you can't. The plumbing end of the equation is easy -- the only hard part was ditching the tank unit. Beyond that, all you will need is a few fittings and a little pipe to hook it all up, plus the proper hardware to secure it to the wall. Any homeowner who would be comfortable ripping out a vanity sink/faucet and installing a new one should be able to do this portion themselves. The electrical hookup is another story. First, you will need 200-amp service to make this viable; if you don't, save yourself the headache. Second, depending on the distance between your electrical box and your water heater, you may need to have an auxiliary breaker box installed, as we did. Just as water temperatures vary regionally, so do electrician's rates. In our area we paid $850 to have a licensed electrician and his journeyman knock it out -- it took them about three hours and that includes the cost of the pictured auxiliary box. I would expect that rate to be higher in major metros but hopefully it gives a ballpark for what you can expect to pay beyond the sticker price.
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Reviewed in the United States on May 27, 2025 by 2LiveDrew
Style: Whole Home, 24 kw
I’ve had this over a year now and it’s still working perfectly! I just did my first cleaning and it was very easy to descale/clean ! Plus now I have so much more space in my utility room!
Reviewed in the United States on July 29, 2026 by Cherie Jarvis
Style: Whole Home, 24 kw
I replaced a 55 gallon hot water tank with this unit, I bought a little larger unit than what the ratings said I needed to be safe. Make sure you check your electrical panel to make sure you have room for 3 x 40 double pole 40 amp circuit breakers. I didn’t have enough room, had to add a sub panel plus had to run 9 x 8 gauge wires the unit requires. I’m pretty handy, but asked a certified electrician to help me with the pre wiring. To be honest, I would have been afraid to try and do this myself even with all my experience. Installation was pretty simple after you have the wiring installed. Use 1 inch piping from your electrical panel to the tankless electrical unit or you won’t be able to pull the nine 8 gauge wires through the pipe. I also suggest having an electrical panel with a main breaker so you don’t have to shut the whole house down for the final install. Additionally i installed a surge protector to hopefully protect the unit from power surges which appears to have delicate electronics inside. We’ve only had this unit in operation for 4 days so far, but the water is really hot, have had no issues at this point and I love the added space gained without having the tank. Time will tell if we save 50% on energy, but from all my research it makes sense even with us living in a warm climate. There are several tankless unit manufacturers with great ratings, I went with Rheem because if I have an issue, they are based in the USA and hopefully that means English speaking in my time zone….. Hope my review is helpful to you. Update: it’s been 7 months, still works great, very happy with this decision even though I can say I’ve seen significant energy savings
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Reviewed in the United States on May 6, 2025 by Amazon Customer
Style: Whole Home, 24 kw
I received my brand new Rheem RTEX-24 tankless water heater and after paying a serviceman to install it (pluming and electrical) we find out that the electronic module that controls the temperature is broken. So I have a useless unit up on my wall and no hot water in my house. I contacted Amazon service support and the solution was return it for exchange or refund. That would be nice except the unit is fully installed (pluming and electrical) up on my wall. I do not recommend this product. Don't waste your time or money. Bad quality control = a useless product and a bad experience for the customer.
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Reviewed in the United States on February 19, 2026 by LAB
Style: Whole Home, 24 kw
Good Equipment, installed almost a year ago and my electric bill dropped about 90.00 dollars per month.
Reviewed in the United States on July 27, 2026 by Rafael C.
Style: Whole Home, 24 kw
It calls for 3/220 electrical wire. It’s an over kill for my little house. I didn’t know it when I bought it just to much power as the ole people say over kill. To BIG. I didn’t know what o was buying
Reviewed in the United States on June 10, 2026 by Tonya Martin
Style: Whole Home, 24 kw
works great!
Reviewed in the United States on July 29, 2026 by Raq
Style: Whole Home, 24 kw
This is working perfectly, the installation was not difficult although i had a professional installed it,
Reviewed in the United States on July 12, 2026 by candelario