Rheem RTEX-18 18kW, 4.4 GPM 18kW 240V Tankless Electric Water Heater
Available offers (2)
Price history by offer
Volatility: MediumFeatures
- Self-modulating power control
- Wall mounting
- On demand continuous hot water
- Energy efficient operation
- Digital temperature display
General specs
- Brand: Rheem
- Model: RTEX-18
- Seller: Retailer
- ID: B01MR7Z39V
- Voltage: 240 Volts
- Wattage: 18000 watts
- Dimensions: 14.5"W x 18.25"H
- efficiency: 99.8%
- Heat Output: 18 Kilowatts
- Item Weight: 14.78 pounds
- Mounting Type: Wall
- Maximum Flow Rate: 4.4 Gallons Per Minute
- Maximum Temperature: 140 Degrees Fahrenheit
- First listed by seller: March 24, 2025
If you are interested in more details, you can find full information on the seller's page.
Price History for seller Retailer
Shipping options
United States
Imagine never running out of hot water—ever. The Rheem RTEX-18 tankless electric water heater keeps the warmth coming, whether you're sudsing up in the shower or tackling a mountain of dishes. (And yes, it can handle your whole house if that's what you're after.)
Here's the kicker: it's smart enough to dial down the power when you don't need it, slashing your water heating bill by up to 50%. Who knew being energy efficient could feel so good?
Gone are the days of that hulking water heater hogging space. This little guy is 90% smaller than the old tanks, fitting snugly under sinks or wherever you've got a spare nook. Talk about a space saver!
Want to tweak the temp just so? The external digital control with its LED display lets you adjust with precision—down to the very degree. Because sometimes, 'lukewarm' just won't cut it.
And let's not forget the nitty-gritty: durable copper heating elements and straightforward 3/4 inch NPT connections mean installation is a breeze. No PhD in plumbing required.
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Rheem RTEX-18 Gray
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| Brand | Rheem | HNK | EcoSmart | GE | BOSCH | Rinnai |
| Model | RTEX-18 | D3548A11 | ECO 11 | GE06P08BAR | ES2.5 | V53DeP |
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| Price | €381.98 | €124.57 | €177.97 | €219.56 | €201.11 | €593.99 |
| Seller | Retailer | Retailer | Retailer | Retailer | Retailer | Retailer |
| Update | May 17, 2026 | Mar 21, 2026 | Apr 27, 2026 | Mar 21, 2026 | Apr 11, 2026 | May 15, 2026 |
| Voltage | 240 Volts | 110 Volts | 120 Volts | 120 Volts (DC) | ||
| Wattage | 18000 watts | 3500 watts | 1440 watts | |||
| efficiency | 99.8% | 98% | High | |||
| Heat Output | 18 Kilowatts | 140 Degrees Fahrenheit | 2.5 Gallons | 81 Kilowatts | ||
| Item Weight | 14.78 pounds | 4.29 pounds | 33 pounds | |||
| Mounting Type | Wall | Wall | Wall or Floor | Wall | Wall | |
| Maximum Flow Rate | 4.4 Gallons Per Minute | 1.9 Liters Per Minute | 5.3 Gallons Per Minute | |||
| Maximum Temperature | 140 Degrees Fahrenheit | 131 Degrees Fahrenheit | 140 Degrees Fahrenheit | 140 Degrees Fahrenheit | ||
| Is Electric | Yes | Yes | No | |||
| Product Dimensions | 9.13"W x 7.59"H | 17.25"W x 17.75"H | 13.75"W x 13.75"H | 13"W x 30"H | ||
Rheem RTEX-18 Gray
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