Are you fed up of paying heavy electricity bills? Well, there is a likelihood that your current water heater is using up too much electricity. This is because not all tankless water heaters are designed to work efficiently and to conserve electricity. If this is true, there is an immediate need to look at alternate options. 

In this regard, one product that has specifically gained a lot of attention is the Rheem RTEX-18. To give you a deeper insight into this tankless water heater, we have penned down this review with great precaution and honesty. Hopefully, it will help you in making an informed decision. 

An overview of the Rheem RTEX-18

Rheem RTEX_18

Rheem RTEX 18

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The RTEX-18 is a durable investment that is designed to last long and to work with great efficiency. Apart from being powerful, it also has a range of features that make it a true all-rounder.

The first thing that strikes one’s eye is the appearance of Rheem RTEX-18. This tankless water heater looks absolutely stunning with that sleek silver finish. In all honestly, it gives off a very high-end look even though it is quite an affordable investment. 

So, regardless of where you choose to install this water heater, it is bound to reflect some elegance. 

Featuring an LED display with a very responsive thermostatic control, the RTEX-18 is able to adjust the water’s temperature to an accuracy of 1-degree. However, the temperature limit is ranged in between 80 to 145 Fahrenheit. 

Typically, many tankless water heaters (especially the low-end ones) are unable to maintain constant water temperature during their operation. However, with the Rheem RTEX-18, that is not the case. It features a very efficient self-modulating technology which prevents the water from getting heated more than the desired temperature. This ensures that the out-going water is comfortable enough for washing at all times.

When it comes to tankless water heaters, the quality of the heater itself is incredibly important. Since the heating element is the main part of a water heater, it must be long-lasting. Otherwise, if the heating element goes haywire, the entire system would shut-down. This is an on-going problem with many low-end water heaters (as their heating elements stop working after a few months). 

However, significant care has been put into the RTEX-18 in this regard. This unit packs a very efficient heating element that has a brass top. These are also threaded well for maximum heat transfer. With that, they heat the water up pretty fast. Though, in an unlikely case where the heating element does stop working, it is easily repairable. Hence, even in the worst case scenario, you will not have to replace the entire unit (though the likelihood of the heating element to stop working is extremely low).

One incredible feature of this water heater is that it is able to manage a flow rate of 2.0 gallons per minute. Though, anything greater than this will significantly reduce its performance (after all, it is a tankless water heater and is not designed for lengthy operations).

Lastly, the RTEX-18 comes with a 5 years warranty which is simply a reflection of its unmatched quantity. After all, low-end products never provide such lengthy warranties. This shows that the brand is confident enough that in all likelihood, your unit will last long.

Are there any downsides? 

Indeed, no product is perfect and we believe that you are well aware of that. Based on our research, we have come across a few downsides to it. 

Firstly, if you are not adept at the installation process, you will need professional help. In comparison to other heaters, this tankless water heater is slightly difficult to install. Hence, professional installation help is going to cost you a bit higher. 

Furthermore, the unit will not immediately provide you hot water. Sometimes, you may have to wait up to 30 seconds for the hot water to start flowing. While this is not a big issue for most people, the wait can sometimes be annoying. 

Sometimes, the thermostat can have slight inaccuracies, such as fluctuation of temperature. So, the water may not heat exactly up to the temperature that you have specified or, it may heat up just a little more than that. Such fluctuations are random. Though, they are not a concern for most people. 

With that, there is a slight risk of flickering too. We believe that all of these downsides are rather manageable, and are not something that one cannot handle.

What are the pros and cons?

As a summary of the information discussed above, take a look at the pros and cons mentioned below. 

  Pros of RTEX-18 

  • Sleek design 
  • Digital thermostat control
  • Heating accuracy of up to 1 degrees
  • Wide temperature range (80 – 140F) 
  • Threaded heating elements allow easy replacement
  • 99.8% efficient
  • 5 years warranty 
  • Long-lasting 

  Cons of RTEX-18 

  • Expensive installation
  • Takes up to 30 seconds to heat sometimes
  • Slight risk of flickering is present 
  • Temperature fluctuations are a common issue 

What do the customers say? 

Based on the customer reviews on the internet, the Rheem RTEX-18 is a solid product. Some customers, however, complain that their unit had temperature fluctuations after 1-2 years of usage. We have found that it is a common issue with this water heater albeit it is a manageable one. 

With that, some customers also complain that the wait-time increases indefinitely up to 1 minute after a long time of usage. This is a common issue with many water heaters, which persists due to an old heating element. 

Luckily enough, the RTEX-18 features a threaded heating element which can easily be taken out and replaced with a new one. 

 Final Verdict 

To conclude it all, we believe that the Rheem RTEX-18 is a solid choice for your kitchen or bathroom. Though, it is a tankless water heater with a capacity of 2.0 gallons per minute. So, do not expect it to give the same performance for heavier applications. 

Overall, this tankless water heater is worthy of investment and is going to serve you for a long time. In an unlikely instance where the unit stops working, you can always make use of that 5–year warranty. All in all, it is a reliable option that anybody can put faith in.

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Rheem RTEX 18 tankless water heater
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Rheem RTEX 18