Performance 18 kW 3.51 GPM 240-Volt Self-Modulating Electric Tankless Water Heater
- Electric tankless water heater provides consistent hot water
- Energy and cost savings of up to 34% in whole-home installations
- Tankless water heater requires 2 x 40 AMP. double pole breakers
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Product Details
About This Product
Get hot water for your space with this Performance Self-Modulating Tankless Electric Water Heater. This energy-efficient tankless water heater delivers an endless hot water supply and consistent temperature with a self-modulating technology that adjusts energy based on your hot water needs. With the electronic thermostatic temperature, you can easily read the incoming water temperature and control it in one-degree increments. Point-of-use installation and compact size makes this Performance tankless water heater a convenient choice.
Highlights
- Energy and cost savings: heats water only when it is needed for savings of up to 50% on water heating costs when used in a point-of-use application or 34% when used as a whole-home solution
- Instant, continuous hot water: instantly provides ample hot water for up to 2 showers and 2 faucets (review selection guide below to confirm this water heater will provide the hot water needed based on your geographic location)
- Space savings: small, compact design fits perfectly in tight places like under cabinets and sinks
- Great investment and value: energy cost savings and a 5-year heat exchanger and 1-year parts limited warranty
- Easy to adjust: electronic temperature control adjustable in 1-degree increments from 80-140 degrees F with easy-to-read display (Celsius and Fahrenheit compatible)
- Easy installation: compatible with 3/4 in. water connectors for flex hose installation and no venting or T and P valve required for Easy installation (professional installation recommended)
- Easy to maintain: durable, easy-to-replace heating elements
- A reliable hot water solution from Rheem, the global leader in water heating
- Before purchase and installation, please verify that you have the proper electrical requirements for your chosen heater
- ETL Listed to UL-499 and CAN/CSA-C22.2 No. 64
- Check out our buying guide on water heaters
- What tankless water heater is right for you?
- Click here for more information on Electronic Recycling Programs
- Return Policy
- California residentssee Prop 65 WARNINGS
Product Information
Specifications
Dimensions: H 18 in, W 14.5 in, D 3.5 in
Dimensions
Kilowatt | 18 |
|---|---|
Product Depth (in.) | 3.5 in |
Product Height (in.) | 18 in |
Product Width (in.) | 14.5 in |
Water Connection Size (in.) | 3/4 in NPT |
Water Connection Size (in.) | 3/4 |
Details
Amperage (A) | 75 A |
|---|---|
Application Type | Residential |
First Hour of Delivery (gallons/hr) | 211 |
Flow Rate @ 35°F Rise (gallons/min) | 3.51 gal (US)/min |
Flow Rate @ 45° Rise (gallons/min) | 2.73 gal (US)/min |
Indoor/Outdoor | Indoor |
Maximum Flow Rate (gallons per minute) | 3.51 |
Number of Showers | 1-2 |
Product Weight (lb.) | 11 lb |
Required Volt Connection | 240 volt |
Returnable | 90-Day |
Uniform Energy Factor | 0 |
Water Heater Features | Wall Mounted |
Water Heater Type | Electric |
Wattage (watts) | 18000 W |
Warranty / Certifications
Certifications and Listings | CSA Listed, ETL Listed, UL Listed |
|---|---|
Part Warranty | 1 Year |
Questions & Answers
What is the size of the breaker
Hi Julio, The RETEX‑27 requires three 40‑amp double‑pole breakers, not a single breaker. Derius
How big is the electrical opening in the bottom?
Hi Tony, The electrical opening is ½‑inch trade size. Derius
Why is my water no longer getting hot
Hi Ben, Based on the information you provided, for technical assistance and troubleshooting on your water heater, please call 866-279-4566 between the hours of 7 A.M. and 7 P.M. CST. Derius
Does this unit work with a dual 30amp single pole breaker?
Hi Rudy, Based on the information you provided, the correct hookup is one 60 A double‑pole breaker. Derius
Does this unit work with a dual 60amp dual pole breaker?
Hi Rudy, The RETEX‑13 (13 kW, 240 V) does not use a dual 60 A breaker. Correct hookup is one 60 A double‑pole breaker. Derius
What if I only have one 40 amp double pole breaker?
Hi Lynn, The RETEX‑18 requires two separate 40 A double‑pole breakers (total 80 A at 240 V). If you only have one 40 A breaker: It is not sufficient, the unit will be underpowered, trip the breaker, and void warranty. Derius
Can you mount this water heater on outside wall
Hi, No. The RETEX‑18 (Performance 18 kW Electric Tankless) is indoor‑only per manufacturer specs. Derius
How quickly does the water reach the set temperature
Hi, The RETEX‑13 delivers hot water at the set temperature within a few seconds of opening the tap. The limiting factor is flow rate vs. temperature rise, not time, it heats on demand, not by waiting for a tank to warm up. Derius
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Customer Reviews
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Thank you for sharing your feedback. We’re glad to hear the installation was easy and that the unit is working so well for your apartment. It’s great that the water heats quickly and keeps up even when you’re running other appliances. We appreciate you taking the time to leave a review.
Derius
Thank you for sharing your feedback. We’re glad to hear the installation went smoothly and that the unit is performing so well for you. It’s great to know you’re happy with the hot water output. We appreciate you taking the time to leave a review.
Derius
Thank you for sharing your feedback, we’re glad to hear the unit was easy to install and operate, and that it’s been working great so far. We appreciate you taking the time to leave a review.
Derius
Thank you for taking the time to share your experience! We’re glad to hear the installation went smoothly with the proper electrical setup and that the unit is meeting the hot water demands of your home. It’s great to know it’s providing plenty of hot water for your household needs—including multiple bathrooms and appliances. We appreciate your feedback and thank you for choosing our product!
Moneke
Thank you for taking the time to share your experience, and we’re very sorry to hear about the ongoing temperature fluctuation issues you’ve dealt with over the past two years. Sudden shifts from hot to cold—or spikes to unsafe temperatures—are extremely frustrating, and this is certainly not the performance we want our customers to experience.
We also apologize for any difficulty you had reaching support. You deserve timely assistance, and we regret that this was not your experience.
Based on your description, there may be a control, sensor, or mixing-related issue that needs further diagnosis, and we would appreciate the opportunity to help address it. If you haven’t already, please contact our Technical Support Team directly at 866‑279‑4566 so we can review the unit’s behavior with you and determine the correct next steps.
Your feedback is important, and we want to ensure you receive the support needed to restore safe, consistent operation.
Thank you again for bringing this to our attention.
Moneke
Thank you for taking the time to share your experience. We’re very sorry to hear that your water heater has not met your expectations, especially after investing in a second unit and taking extra steps with maintenance and filtration. We understand how frustrating it is to experience repeated interruptions to your hot water supply.
Your feedback is important, and we appreciate you highlighting your challenges so we can continue improving our products and support.
If you’re open to it, we’d be glad to learn more about what happened so we can better understand the situation and help prevent similar experiences for future customers. In any case, we truly appreciate your honesty and the time you took to share your review.
Thank you again for your feedback.
Moneke
Loading Recommendations
Compare Key Features
Product Snapshot | |||
|---|---|---|---|
Ideal for homeowners looking for on-demand hot water, making showers and faucet use easier and more efficient. | Ideal for homeowners looking for an energy-efficient water heater, making hot water readily available while saving money on utility bills. This tankless model offers endless hot water on demand. | Ideal for homeowners looking for an energy-efficient water heater , making hot water delivery easier and more efficient . This tankless water heater provides endless hot water on demand , saving energy and money .. | Ideal for apartments, condos, and townhomes, this compact heater provides endless hot water on demand. |
Flow Rate | |||
3.51 GPM | 3.75 GPM | 3.75 GPM | 5.27 GPM |
Power Output | |||
18 kW | 19.2 kW | 19.2 kW | 27 kW |
Temperature Control | |||
Electronic temperature control adjustable in 1-degree increments from 80-140 degrees F | 68 to 140°F (20-60°C) | 68 to 140°F | Digital thermostatic temperature control in 1-degree increments |
Maximum Temperature | |||
140 F | 140 F | 140 F | 140 F |
Smart Connectivity | |||
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