--- product_id: 273292299 title: "Rheem 18kW 240V Tankless Electric Water Heater" brand: "rheem" price: "€ 1261.58" currency: EUR in_stock: true reviews_count: 5 category: "Rheem" url: https://www.desertcart.hr/products/273292299-rheem-18kw-240v-tankless-electric-water-heater store_origin: HR region: Croatia --- # 18kW high power output 4.4 GPM flow rate ±1°C precision LED thermostat Rheem 18kW 240V Tankless Electric Water Heater **Brand:** rheem **Price:** € 1261.58 **Availability:** ✅ In Stock ## Summary > 🔥 Endless Hot Water, Zero Waste ⚡ ## Quick Answers - **What is this?** Rheem 18kW 240V Tankless Electric Water Heater by rheem - **How much does it cost?** € 1261.58 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/273292299-rheem-18kw-240v-tankless-electric-water-heater) ## Best For - rheem enthusiasts ## Why This Product - Trusted rheem brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Compact Space-Saver:** 90% smaller than traditional tanks, this sleek wall-mounted unit fits discreetly under sinks or tight spaces—maximize your living area. - • **Continuous Hot Water Flow:** Delivers up to 4.4 gallons per minute, providing endless hot water for single or multiple point-of-use applications without interruption. - • **Energy-Smart Self-Modulation:** Advanced self-modulating tech dynamically adjusts power to your exact hot water needs, slashing energy waste by up to 50%. - • **Precision Temperature Control:** External digital thermostat with LED display ensures perfect hot water every time, down to ±1°C accuracy. - • **Effortless Installation & Maintenance:** Threaded 3/4 inch NPT water connections and field-serviceable copper heating elements make setup and upkeep a breeze. ## Overview The Rheem 18kW 240V Tankless Electric Water Heater offers a powerful, energy-efficient solution for whole-home or single-shower hot water needs. Featuring precise digital temperature control, advanced self-modulating technology, and a compact design that saves space, it delivers up to 4.4 GPM of continuous hot water while reducing energy consumption by up to 50%. Easy to install and maintain with durable copper heating elements, this unit is perfect for modern homes seeking smart, sustainable comfort. ## Description This tankless electric water heater is ideal for mid-range whole-home applications. This unit is ideal for single shower applications in the Midwest. The Rheem Performance tankless electric water heaters offer a continuous, endless supply of hot water. A lower kilowatt unit can provide hot water on demand for single or multiple point-of-use applications while a higher kilowatt unit could provide hot water for a whole house depending on the inlet ground water temperature. Tankless electric water heaters save space, save energy, save money, and require no venting. The sleek, compact size, 90 percent smaller than a tank, allows you to save space and place the unit wherever you want, including under a sink. Tankless units only draw energy when hot water is flowing, while traditional tanks are constantly drawing energy to keep the water in the tank at the desired temperature. Rheem's self-modulating technology can save Up to 50 percent on your water heating bill. Review: Works well. - So far this has worked well saves on electricity takes maybe 30 seconds to heat up and then I jump into the shower. Review: Great product! - This works awesome for our needs - doesn't take all the space of a regular water heater. We turned it into a little storage closet! ## 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 two heating elements, field Serviceable. Flow Rate- up to 4.4 GPM - Simple installation – bottom 3/4 inch NPT water connections - Threaded for easy replacement, simple installation, digital temperature display ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B01MR7Z39V | | Best Sellers Rank | 482,377 in DIY & Tools ( See Top 100 in DIY & Tools ) 1,390 in Water Heaters & Parts | | Brand | Rheem | | Capacity | 18 gallons | | Colour | Silver | | Country of Origin | China | | Customer Reviews | 4.2 out of 5 stars 2,034 Reviews | | Efficiency | 99.8% | | Flow Rate | 4.4 Gallons Per Minute | | Global Trade Identification Number | 00020352685335 | | Heat Output | 18 Kilowatts | | Included Components | Fittings, Aerators | | Is Electric | Yes | | Item Depth | 14.5 inches | | Item Dimensions W x H | 36.8W x 46.4H centimetres | | Item Type Name | Water Heater | | Item Weight | 14.78 Pounds | | Manufacturer | Rheem | | Material | Stainless Steel | | Maximum Pressure | 150 | | Maximum Temperature | 140 Degrees Fahrenheit | | Model Number | RTEX-18 | | Mount Type | Wall | | Part Number | RTEX-18 | | Power source | AC Power | | Product dimensions | 36.8W x 46.4H centimetres | | Special Features | LED Display | | Special feature | LED Display | | Style | Whole Home, 18 kw | | UPC | 020352685335 | | Unit Count | 1.0 count | | Voltage | 240 Volts | | Wattage | 18000 watts | ## Product Details - **Brand:** Rheem - **Capacity:** 18 gallons - **Power source:** AC Power - **Product dimensions:** 36.8W x 46.4H centimetres - **Special feature:** LED Display ## Images ![Rheem 18kW 240V Tankless Electric Water Heater - Image 1](https://m.media-amazon.com/images/I/91J18WlAKqL.jpg) ![Rheem 18kW 240V Tankless Electric Water Heater - Image 2](https://m.media-amazon.com/images/I/91+--nit2uL.jpg) ![Rheem 18kW 240V Tankless Electric Water Heater - Image 3](https://m.media-amazon.com/images/I/81+NX7Lb71L.jpg) ![Rheem 18kW 240V Tankless Electric Water Heater - Image 4](https://m.media-amazon.com/images/I/616uuS+hD9L.jpg) ![Rheem 18kW 240V Tankless Electric Water Heater - Image 5](https://m.media-amazon.com/images/I/71LH0jtHwnL.jpg) ## Questions & Answers **Q: will this supply two showers, washer and dishwasher for two people? (1000 sf house)** A: Hello- Sizing an electric tankless is very difficult. I always recommend that you call Rheem at 800-432-8373 to get a suggestion. I want to say this will only keep up with ONLY 1 source of hot water at any one given time. That being said, the RTEX-18 performance ( @240V )- 1.5GPM - 82degree rise 2.0GPM - 62degree rise 2.5GPM - 49degree rise 3.0GPM - 41degree rise So.... what it can keep up with all depends on: -the temp of water coming into the house -the flow rate of each faucet/shower head/washing machine/source of hot water -outlet temp desired I hope this helped :) Ben **Q: How many amps** A: Paperwork says it requires four 40 amp breakers or two DP 40 amp breakers. Max draw of 75 amps. **Q: Rheem rtex-18 be big enough to heat water in my shop to wash my hands and perhaps take a shower in kansas city, mo?** A: Yes you could even go with the unit rtex-15 one smaller if that's it. Good luck **Q: how many breakers and what amp.** A: The RTEX-18 (240 Volt) requires (2) 40 amp breakers and 8 AWG wire. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Works well. *by D***Y on 22 April 2026* So far this has worked well saves on electricity takes maybe 30 seconds to heat up and then I jump into the shower. ### ⭐⭐⭐⭐⭐ Great product! *by L***K on 26 May 2026* This works awesome for our needs - doesn't take all the space of a regular water heater. We turned it into a little storage closet! ### ⭐⭐⭐⭐⭐ Buen producto *by J***V on 8 December 2023* Bastante cumplidor aun para lo que yo esperaba ya que solo requiero una cantidad relativamente baja de agua caliente y da bastante mas de lo esperado, totalmente recomendable ## Frequently Bought Together - Rheem 18kW 240V Tankless Electric Water Heater, Gray - HYDRO MASTER Tankless Water Heater Service Valve Kit with Pressure Relief Valve 3/4-Inch IPS Isolator Clean Brass - 3/4 Inch IPS Isolator Tankless Water Heater Service Valve Kit with Pressure Relief Valve, Clean Brass, 3/4 Inch Service Installation Valve for rheem,rinai,ecosmart,navien,noritz,takagi,bosch --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.hr/products/273292299-rheem-18kw-240v-tankless-electric-water-heater](https://www.desertcart.hr/products/273292299-rheem-18kw-240v-tankless-electric-water-heater) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-07-25*