Rheem RTEX 11 & RTEX 13 Reviews (Best Point-of-Use Models)

The most affordable tankless water heater that fits in your budget. These two are beginner models that come in 2.68 & 3.17 GPM flow rates.

Some brands are too expensive to be popular; some lack the efficiency to stay on the market for long; some are genuinely good products that just don't catch on.

Rheem is a brand that defies all of these expectations. Not only do they sell solid, inexpensive products, but their tankless water heaters can also cut your energy consumption in half.

But which Rheem product is right for you?

Which will best suit your needs as a homeowner?

Rheem RTEX 11 & RTEX 13 Reviews

Let's take a look at two Rheem electric tankless water heaters.

Rheem RTEX 11

Rheem RTEX 13


Here are the models we'll be comparing today:

  • Rheem RTEX 11 Electric Tankless Water Heater, 2.68 GPM
  • Rheem RTEX 13 Electric Tankless Water Heater, 3.17 GPM

As you can see, you could almost call them twins, but with the 13 having a slightly higher flow rate (GPM). They have the same basic functions, and they're even the same size. So when choosing between these products, the technical details and cost differential are probably what will make your decision.


Both the RTEX 11 and the RTEX 13 are electric units, meaning they work through a system of internal sensors and heat exchangers rather than firing up a live flame. This is great for homeowners who don't have natural or propane gas and who don't want to deal with complicated ventilation systems.

One drawback of these electric units is their lower flow rates.  They might not meet all of your hot water needs if you live in a large home or require "simultaneous usage" of hot water appliances.

In fact, both the RTEX 11 and the RTEX 13 are what's called "point of use" units, meaning they should be installed directly at or near the faucet where you want the hot water. You may have to install several of these units around the house to fulfill all of your needs.

Heat Output and Flow

Both the RTEX 11 and the RTEX 13 can comfortably offer water as cool as 80°F and as hot as 140°F. This is excellent news for residential buyers who wish to very temperatures at different locations! It should be noted that 100°F is more than enough to kill germs and bacteria.

In terms of flow, customers do report that your GPM rate will depend on how hot you want your water and how cool the water is coming into your house before it's heated. 

The higher the temperature demands, the less your GPM. So that's something to consider if the flow rate is a deciding factor in your purchase.

In better news, flow delays are quite small with Rheem. This isn't a unit where you have to wait 60+ seconds for the water to come flowing out of the tap. You'll get hot water instantly and for as long as you require it.


Depending on the circuitry of your home and the tools you already have on hand, you might need to purchase a few supplies for installation:

  • Conductor wire
  • Double pole amp breaker
  • Conduits
  • Connectors
  • Junction boxes

The good news is that despite all their parts, both the RTEX 11 and the RTEX 13 are relatively simple to install.

A Rheem technician can do it in a matter of hours, and this is the recommended method so you don't void your warranty, but even if you're going at it as a DIY project, you shouldn't face many difficulties.

General Use

I always advise my customers to look at the pros and cons of an item before they take the plunge and actually buy it. It's just smart shopping. Here are a few advantages/disadvantages of the RTEX 11 and RTEX 13:


  • Simple interface
  • Small units that are easy to install and operate
  • Less expensive than other electric heating units. 


  • 1 unit is not suited for a whole house. 
  • "Point of use" units may require multiple purchases

Customer Reviews

Customers love the RTEX 11 and the RTEX 13. Rheem is a popular brand for a reason, and that reason is that they create sturdy, long-lasting products that work as advertised.

In terms of which model you should buy for yourself, it really depends on your likes and dislikes in a heating unit.

The RTEX 11 is less expensive, but according to customer reviews, it also offers fewer savings on the whole.

The RTEX 13 has a higher flow rate, but on the flip side, customers report that its flow delays are slightly longer.

What functions and features are most important to you?

What's the bottom line?

If you're looking for a no-fuss, point-of-use tankless water heater, you can stop your search with the Rheem RTEX 11 or the Rheem RTEX 13. Not only are they inexpensive, easy-to-use units, but they're also fantastic for energy savings and living a greener life.

Check out the Rheem product pages on Amazon to learn more!

  1. Hi:

    We have a hunting shack in northern Wisconsin near Minocqua. We want to install a liquid propane shower system and we have no electricity. We were going to buy a Marey unit of either 4.3 or 3.1 gpm. We were told at Home Depot that Marey does not ship the units to northern tier states.

    So we are inquiring about a Rheem liquid propane unit that ;you could recommend that would fulfill our needs. Our water is stored in a 150 gallon tank located in our rafters so the water in the tank is not from a well and is close to room temp at about 65 degrees. We need the unit to supply water for a lightly used shower and hot and cold water facet, also used lightly.

  2. […] Read detailed review on Rheem RTE 9/RTE 13​ […]

  3. […] really do not need a Bosch, go for other brands. We highly recommend the Ecosmart ECO 27, Rheem RTE 13, Takagi T​kJr2 and the Stiebel Eltron Tempra […]

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