Rheem RTEX-36 Review: Unlock Superior Heating Performance

Rheem RTEX-36

Last updated on May 5th, 2024 at 03:57 am

Looking into a reliable water heating solution for your home? Rheem, a brand synonymous with quality, offers the Rheem RTEX-36—a 36kW Electric Tankless Water Heater that might just be what you need.

This model belongs to the professional classic series and is designed to provide continuous hot water on demand, ensuring that you never have to endure an unexpected cold shower again.

With the inherent benefits of going tankless like energy savings, endless hot water, and a compact size, the RTEX-36 has caught our attention. The flexibility of easy temperature adjustments and the peace of mind that comes with robust whole-house heating capabilities make it an attractive option for those looking to upgrade their home’s hot water system.

While this model is praised for its power and efficiency, it’s also worth considering the electrical requirements and ensuring your home is ready for the installation. It’s equipped with ingenious features such as self-modulation to only use energy when heating is needed.

However, it’s important to assess whether the flow rate matches your expectations for simultaneous usage across multiple fixtures.

Bottom Line

The Rheem RTEX-36 is a tankless water heater that could be the upgrade your home needs for a steady supply of hot water at a single point of use.

With a glowing customer rating and high-quality features, it’s poised to deliver reliable performance.

Feeling ready for that consistently warm and comforting shower experience? Click here to purchase the Rheem RTEX-36 and enjoy the benefits of going tankless today!

Rheem RTEX-36 36kW Electric Tankless Water Heater Overview

When considering a solution for your hot water needs, the RTEX-36 could be a game-changer. This electric tankless water heater has whole-house multiple applications performance features, can be a major upgrade from traditional models.

It comes with an External Digital Thermostatic Control with LED display (+/- 1 degree accuracy), most advanced self-modulation, adjust power to meet hot water demand. It has 4 durable copper immersion heating elements and field serviceable simple installation.

With a 36,000-watt output and a flow activation as low as 0.3 gallons per minute, you’re looking at efficient water heating that activates only when needed. This not only conserves energy but also provides you with hot water on demand.

The stainless steel body increases durability

You’ll appreciate the precise temperature control, adjustable in increments, allowing you to find the perfect temperature between 59 and 140 degrees Fahrenheit. Even with a usage as high as 6.0 gallons per minute, you’ll notice a reasonable temperature rise, assuring that your comfort is not compromised even when multiple outlets are in use.

Rheem’s reputation is reflected in the performance of the RTEX-36, and with no batteries required, it presents a straightforward, user-friendly experience. Since its launch in mid-2018, users have rated it highly, appreciating its reliability and ease of installation.

Keep in mind that a 240V electrical supply is a must and professional installation is recommended to ensure safety and optimal functioning.

Key Features and Benefits

Your quest for a steady supply of hot water could end with the RTEX-36, which boasts a substantial 36kW of heating power running on 240 volts, making it a workhorse for indoor water heating needs. Its self-modulating flow sensor technology ensures you get hot water when you need it, adjusting the energy input based on how much you draw.

One standout feature is the external adjustable digital thermostatic control with an LED display. The digital temperature control lets you fine-tune the water temperature, giving you the precision that can be critical for both comfort and various household tasks. Moreover, the simplicity of the control means you can adjust temperature with ease.

Its bottom 3/4 inch NPT connections might sound technical, but they’re really about providing hassle-free compatibility with standard plumbing setups. As a safety measure, the RTEX-36 incorporates advanced features to prevent overheating and to ensure stable operation.

All in all, the combination of effective flow control, reliable safety mechanisms, and precise temperature adjustments make this water heater a noteworthy addition to your home appliances, one that doesn’t forget to deliver that reliability Rheem is known for.

Without the need for batteries and with its compact size, the RTEX-36 integrates into your living space without any extra fuss.

Installation Process

Embarking on the installation journey for the Rheem RTEX-36 tankless water heater might seem like a task best left to professionals, but with the proper guidance and safety precautions, it can also be a manageable DIY project for those familiar with basic electrical and plumbing work.

Firstly, ensure your electrical system can handle a 36 kW load and has a 150 A circuit breaker. This sometimes requires an upgrade by a certified electrician if your current setup isn’t sufficient.

When you’re ready to install, shut off the main water supply and power. Next, mount the unit on the wall, ensuring it’s level. The water connections require attention to detail; use quality pipe thread compound or tape to prevent leaks on the 3/4 in. NPT connections.

Electrical connections are next, follow the manual carefully or consider a professional, especially if you’re unsure about handling a 240V wiring task.

Lastly, set the desired temperature using the external control. The adjustable range between 59-140 degrees F allows tailoring to your specific needs.

While the process is straightforward for those with experience, don’t hesitate to call in a licensed plumber or electrician if any of these steps are outside your comfort zone. Safety comes first—better to invest in professional help than compromise your household’s well-being.

Energy Efficiency and Savings

When considering an electric water heater like the RTEX-36, energy efficiency is a valuable asset that translates directly into savings for you. This model’s tankless design means it only heats water on demand, eliminating the standby energy loss common with traditional tank heaters.

Its efficiency is rooted in the ability to provide hot water without the need to maintain a large reservoir at a constant temperature.

The unit’s self-modulating power technology draws energy precisely when it’s needed, based on your water usage, which can lead to significant reductions in electricity consumption.

With its substantial wattage, you might think it’s a power-hungry device, but in reality, the RTEX-36’s performance is optimized to use energy only when required, offering you more control over your electricity bills.

Moreover, the adjustable temperature control lets you pinpoint the exact heat level for your needs, preventing overuse of energy. By using just the right amount of power to reach your desired temperature, you avoid the inefficiency of overheating water, further contributing to lower energy usage and cost savings over time.

Pros and Cons

When considering the Rheem RTEX-36, it’s essential to weigh what works in your favor and what may not. This high-powered, electric tankless water heater promises efficiency and convenience, but let’s take a closer look at the specifics.


  • Endless Hot Water: You’ll enjoy a constant supply of hot water, perfect for families or when you have guests over.
  • Saves Space: Its compact design frees up valuable space in your home.
  • Energy Efficient: Since it’s tankless, it only heats water when you need it, which could lead to savings on your electricity bill.
  • User-Friendly: The external adjustable temperature control allows you to easily set your desired water temperature.
  • Reliable Brand: Rheem is well-known for its quality and customer service, giving you peace of mind with your purchase.


  • Initial Cost: The upfront price may be higher compared to traditional water heaters.
  • Professional Installation Recommended: You may need a professional to install it properly, adding to the initial cost.
  • Limited Ratings Total: With only a couple of ratings, it’s tougher to gauge long-term reliability from users’ experiences.

Remember, what seems like a drawback to some may be inconsequential to others. It’s all about what fits your lifestyle and home the best.

Comparisons With Other Rheem Models

Exploring the Rheem lineup, you’ll notice the RTEX-36 stands out for its robust heating capability suitable for a whole-house setup. When measuring it up to its siblings, like the Rheem RTEX-18 or RTEX-24, it’s evident that the RTEX-36 provides a higher wattage, translating to a more powerful performance in larger homes or where the demand for hot water is greater.

However, this extra power comes with considerations. The RTEX-36 requires a significant electrical capacity—150 amps, to be precise—something not all homes are equipped for. In contrast, models such as the RTEX-18 might be more suitable for your current electrical infrastructure and still offer consistent hot water for a small to medium-sized home.

While all electric models from Rheem, including the RTEX-36, are celebrated for their efficiency, installation simplicity, and temperature control, you should weigh up the RTEX-36’s potential energy consumption against that of lower wattage models, especially if your hot water usage isn’t exceedingly high. Your choice hinges upon the balance between demand, installation feasibility, and the readiness to invest in the necessary electrical upgrades.

Customer Reviews and Feedback

You’ll find that the feedback on the Rheem RTEX-36 is quite limited yet remarkably positive. Users seem to appreciate its efficiency and how it seamlessly delivers hot water on demand. There’s a sense of satisfaction expressed regarding the temperature control, which allows for precise adjustments, ensuring you get the perfect temperature every time.

While the ratings are few, they come from actual users, indicating that this electric tankless water heater lives up to its promises of providing sufficient and consistent hot water. The brand, Rheem, carries a reputation for quality, and it seems the RTEX-36 is no exception, despite the small number of reviews.

Bear in mind that due to the limited number of reviews, you might want to consider other sources or wait for more feedback to get a comprehensive understanding of the product. It’s always prudent to look for a pattern in customer experiences before making a final decision for purchasing tankless water heaters.

If you are living in Singapore and planning to invest in this water heater, be sure to take note of your shipping address as there is no free shipping available.


Exploring the strengths and caveats of the RTEX-36, it’s evident that this Rheem tankless water heater is tailored for those seeking efficiency and consistent performance.

It simplifies life with its external adjustable temperature control and streamlines installation with its bottom 3/4 inch NPT connections. Although detailed pricing is not discussed here, its cost fits well within the expectations for its features and build quality.

Moreover, a solid warranty backs your investment, giving you peace of mind. The unanimous five-star rating further echoes the product’s reliability and customer satisfaction. While there are no reviews to directly quote, the high ratings suggest that users are finding it to be a dependable and proficient choice for their homes.

Always consider your specific needs and compatibility with your home setup, but if you’re in the market for tankless electric water heaters, the RTEX-36 presents itself as a robust contender.

Useful Resources

Rheem RTEX-36 Specification Sheet

Rheem RTEX-36 Energy Guide


  • Edmund Yeo

    🌱 I'm passionate about sustainable living and renewable energy, and I'm thrilled to share my journey towards a greener, brighter future with you. Join me as I explore the latest innovations, eco-friendly lifestyle tips, and inspiring stories from the forefront of the green energy revolution. Note: This website uses affiliate links which may earn a commission for purchases made at no additional cost to you.

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