Discover Why a Rheem Tankless Water Heater Should Be Your Next Water Heater + 7 Reviews!

A Rheem Tankless Water Heater is your one-stop go-to for a seamless, hot water solution in the dead of winter. Their line of tankless water heaters are light-weight, convenient, hassle-free, and easy-to-install anywhere in your home or office building. The smart and compact design gives you the advantage of being able to fix the water heater even in a small space without too much hassle.

 The highly-convenient and affordable Rheem tankless water heater not only turns cold water to hot water, but also cuts your electricity bills and saves energy due to its advanced technology. Moreover, it can reduce water waste as they’re equipped with a built-in flush valves system through which water supply can be instantly controlled.  

Rheem’s Global Reach

Established in 1925 in Emeryville CA by two brothers, Rheem is one of the top-ranking technical solutions providers in North America. By providing quality services and premium products, Rheem has built its reputation for close to 100 years with its heating, cooling, water heating, swimming pool, sauna, spas, domestic use, home improvement appliances, industrial heating/cooling systems, and commercial refrigerating solutions.

Rheem offers you the best technological solutions for all your commercial, industrial, or residential needs at affordable prices. From automotive products to industrial and household applications, Rheem has captured the technological aspect of almost all kinds of products including electrical and thermal control systems, power equipment, heat exchangers, boilers, tankless water heaters, mini-split systems, furnaces, oil furnaces, solar water heaters, heat pumps, cooling coils and more categories.

Rheem tankless water heaters are not only economical and flexible, they can be implemented for all kinds of users including industrial, commercial, or residential applications. Due to their advanced tankless water heating system, they can also eliminate any standby electric losses, saving you money and being as energy-efficient as possible.

Rheem can connect you with a “Pro Partner” which is an installer that the company recommends for all their installations and service calls. 

A Little About Rheem Tankless Water Heaters

Looking for a convenient and affordable tankless water heating solution so that you can take a hot bath in the winter season without any trouble? Rheem brings you the best quality tankless water heater with the latest water heating technology which is light-years ahead of the traditional storage heaters.

Without the need to wait hours until the your storage tank water heater is able to heat up a new batch of water using conventional electric water heaters, Rheem tankless water heaters provide an instant and steady flow of hot water for the whole building.

Rheem offers a wide range of tankless water heaters; each of which comes with unique features, and flexible installation and control systems. These heaters have the ability to be portable, if that’s a quality you need them to be, and come in different sizes allowing you to change locations of the installation, depending on the space available.

You can also equip these tankless water heaters with your geothermal system, water-source system, or air-source system according to your needs and requirements. With the advanced water heating technology, they can precisely control the temperature of the water and provide an endless stream of hot water for the whole building on demand.

Moreover, the electrical or gas ignition system is designed such that it doesn’t cause any issue to the rest of the machine. With built-in flush valves, water supply can be easily controlled to ensure no water wastage.

Furthermore, the water connections in the heaters are built externally for easy plug-in and plug-out options.

Rheem Tankless Water Heater Reviews

Rheem provides high-quality consumer goods that cater almost everything from your house appliances to commercial control systems. Because of its advanced technologies and super-class installation and maintenance services, Rheem has become a globally recognized brand.

Rheem Tankless Water heaters and boilers are both energy-efficient and cost-efficient. Their compact designs are both space-saving and aesthetically pleasing. You can instantly get hot water supply exactly where it’s needed.

However, we always put ears to our customers’ reviews and suggestions. That’s how we cater to their issues and problems with any of our products.

Below are some of the pros and cons of our Rheem tankless water heater range that have been created based on the comments received from the buyers. The Rheem tankless water heater reviews would assist you better in deciding which heater to purchase based on your needs and requirements.

Rheem 240V Heating Chamber RTEX-13 is known for its versatility and convenience of use. The main and most sought after feature of this Rheem electric tankless water heater is its adjustable digital thermostatic control with a highly efficient LED display.

The internal structure of this heater is made up of durable copper immersion heating coils that adjust their power on their own so the unit is a self-modulating system.

This electric tankless water heater is ideal for those looking for a single point of use electric unit that’s able to be used for quick and unlimited water supply for a hot bath, or in the kitchen or offices.

You can also regulate its temperature according to your requirements so there’s no need to worry if your kids want like hot water bath’s but usually the hot water is too hot for them to enjoy.




Rheem’s RTEX-24 are popular because of their durability, they have a long life span and for the amount of water they provide the house with, they can fit almost anywhere.

This Rheem tankless electric water heater has copper immersion heating elements with a brass top that provides a strong and durable structure and like most Rheem’s this unit is not insanely difficult to install, although, a professional plumber is always recommended when doing this sort of install. 

High water consumption in your house? Don’t worry, the Rheem RTEX-24 should have you covered, although, some owners have mentioned that you should pay attention to the GPM chart to ensure your needed Gallons Per Minute usage won’t have you needing more hot water when you need.

As this is an electric tankless heater it may cost you more money to run than gas tankless water heaters, but the unit is very energy-efficient with a 99.5% efficiency rating.  

Equipped with the most advanced self-modulation system to provide continuous hot water to the whole house the Rheem RTEX-24 is stylish with a clean design. If you decide to move the unit up from the basement where your replaced storage tank water heater was residing, this unit won’t stick out and ruin your interior design skills. 

The most standout feature of this ENERGY STAR certified model is that it’s able to provide different GPM to different applications. It can provide 0.5 GPM to standard hand sink, 1 to 1.5 GPM to the washing machine, 1 to 2 GPM to the kitchen sink, 1 to 2 GPM to the dishwasher, 1.5 GPM to a water saver shower head, 2 GPM to the standard shower head, 4 GPM to tub, and up to 6 GPM to the whole house.

This multiple application system saves not only water, but it is budget-friendly, time-saving, and energy-efficient.




This  Rheem tankless gas water heater is somewhat unique because it is a direct vent unit. This gives you the capability of being able to install it almost anywhere in your home, as long as you can vent it outside. Conversely, a power vented tankless gas water heater would have to be installed in a room that receives adequate air flow.  

The Rheem RTGH series of tankless water heaters are optimized to provide high-efficiency while using low-cost fuel e.g, natural gas. 

Using smart Econet technology makes it useful and popular even more among all the people who are replacing their old storage tank water heating systems with this Rheem tankless gas water heater. The structure is made up of a stainless steel condensing heat exchanger to provide high output of hot water up to 9.5 GPM(!!!). This technology is able to save up to 1,100 gallons per year for domestic use as it regulates the water flow in the pipes when the temperature reaches set limits.

If you’re in the market for a new whole house water heater, this Rheem gas tankless water heater should definitely make your list of considered models. 




For those of you who are looking for a Rheem propane tankless water heater, this is an economical, space and energy-saving option for you to consider. This Rheem RTG series unit has ultra-low NOx, which means it meets low nitrogen oxide emission standards(a good thing).

Having copper heat exchangers and smart Econet technology makes this unit popular among consumers who want to control this Rheem propane tankless water heater’s temperature via Econet mobile app.

A key feature of this Rheem propane tankless water heater is its water-saving setting that’s able to provide the temperature you’re looking for at each location which can save a homeowner up to 1,100 gallons per year.

Apart from domestic use, it offers the best industrial low flow activation, the minimum flow rate is 0.26-GPM while the minimum activation flow rate is 0.4-GPM.

It’s also Recirculation Pump Kit-Ready which if installed would provide you with faster hot water supplies, saving you 12,000 gallons per year!




Although electric tankless water heaters are traditionally more energy-efficient than their gas tankless water heater counterparts, this high-efficient gas model has a UEF (Universal Energy Factor) of 93%, while an average gas model has an energy-efficiency of 80-85%. 

In colder climates home owners tend to enjoy their water heaters being gas energy supplied units to run for a few reasons, primarily due to gas being a cheaper commodity than electric. This model will allow these homeowners to accomplish this goal. 

Equipped with the Econet feature which allows owners to control the tankless water heater from an app, this unit will also alert you if there is a water leak issue. There’s also a programmable time-based activation which makes it super secure for all those who want a versatile temperature range for all points of usage.

The intelligent and smart technology makes it highly efficient in terms of energy and water saving properties. It has the best industrial low flow activation which means you can get as low as 0.26 GPM minimum flow rate to meet your low water consumption requirements. Minimum flow activation rate is 0.4 GPM.

This highly-efficient tankless water heater is good for family’s looking to lower their utility bill and enjoy instant hot water anytime and anywhere in the home. 




This Rheem tankless gas water heater is fully optimized to provide on-demand hot water to wherever you require it in your home. Having a built-in recirculation system makes it super easy and fast to tap the hot water instantly. 

As it saves cost, time, and water wastage, many people replace their existing storage tank water heaters with this ENERGY STAR certified model. The highest capacity of 11-GPM makes it highly desirable and it can provide a non-stop supply of hot water to 4 bathrooms! 

Providing a continuous, comfortable, and instant supply of hot water makes it one of the best Rheem tankless gas water heaters that on the market.




This medium-efficient Rheem outdoor tankless water heater is designed for outdoor install which may benefit or hinder your needs and desires. While this may assist with space in your home, this is not a small unit (but it’s a tankless so how big can it really be??), but if you live in climates where the temperature has a history of dropping you may want to consider a different unit. 

The Rheem RTG-95XLN-1 does provide continuous hot water at the point of use even while being installed outside.

Like all Rheem tankless units made after 2010, the EcoNet mobile app will assist you with controlling the tankless water heater from your phone, which is a luxury we have all become accustomed to these days. You will need to purchase and install the Tankless EcoNet Accessory Kit to take advantage of the mobile connectivity. 

There’s a water savings setting, that if you take a little bit of time during install, will assist you in saving up to 1,100 gallons of wasted water a year. 

This unit also provides you with the best industrial low flow activation, 0.26 GPM minimum flow rate, and 0.4 GPM minimum activation flow rate. You can safely and economically enjoy hot water even when your need is minimal at the tap or appliance.  

This Rheem tankless water heater is also recirculation pump kit ready which could help you save 12,000 gallons of water a year by providing continuous hot water.




Rheem tankless water heater troubleshooting

You must know all the basics of Rheem tankless water heaters so that you can diagnose if any problem happens in your system. Knowing the basics can ease the process of troubleshooting for you. There are many things that can be easily handled just by reading the manual thoroughly. You can also claim your warranty from Rheem as it offers 10 to 12 years of warranty on many of its parts. Read the manual completely before you get your tankless heater installed and get yourself equipped with the necessary knowledge.

Rheem Tankless Water Heater Problems

Not everything is 100% perfect. Sometimes, the most durable and efficient product also shows a lack of performance due to any internal or external problem. Though Rheem takes utmost care in manufacturing their tankless water heaters, the units can at times act up. 

Many owners note that when they didn’t have a certified professional hook their unit up, and a mishap occurs, that Rheem seems less inclined to honor any warranties or give any refunds. This is understandable as the company does state that units should be installed by certified plumbers and instructions should be followed properly.

Owners have noted that the following issues may occur with the occasional  Rheem Tankless Water Heaters:

  • Water gets too hot or just the opposite, water doesn’t heat at all
  • Water heater doesn’t turn on
  • Pilot ignition issue
  • Clogging or scaling issue of the heating coil
  • Fluctuations in the temperature on the dial
  • Flame-intensity issues

 Any of the above-mentioned issues can happen due to non-professional installation, poor electricity connection, or no maintenance at all for a long time. Usually, Rheem’s customer-care professionals are always ready to fix an issue as efficiently as possible.

Troubleshooting Rheem Electric tankless water heaters depend on the problems you face. Some of the basic issues can be easily resolved by just following the instructions on the manual that comes with the package.

Rheem also provides a warranty for maintenance and repairing of tankless water heaters depending on the part(s) creating the issue. Have any issues? Give Rheem’s customer-care line, 1-866-720-2076, to get some assistance! 

Rheem Tankless Water Heater Manual

Every Rheem tankless water heater should have a manual in the packaging. a complete manual in its packaging. If for some reason your box was empty reach out to Rheem if you need a hardcopy, or you may be able to find your manual here

Rheem Tankless Water Heater Warranty

Rheem wants satisfied customers and to assist with ensuring this provides a owners with either 10 to 12-year warranties. As mentioned in the article, please make sure you have a professional plumber installing these units, and make sure they are following the instructions properly to make sure Rheem honors the warranty. 


1. How to reset Rheem tankless water heater?

Rheem provides a high technological user experience to its consumers. The digital panel is designed in a way that you only need to turn off the power switch and press it for a few seconds. Then when you turn it on, press the reset button and all done.

2. How to install a Rheem tankless water heater?

There is no doubt that Rheem tankless water heaters are highly user-friendly and easy to understand and install. Rheem, however, recommends that the installation should be done by a licensed contractor to provide plumbing services. A professional can properly the heater, plumbing, gas, electrical connections, and venting system. This will also ensure the warranty is valid. 

3. How to adjust the temperature on Rheem tankless water heater?

All the Rheem tankless water heaters are provided with a thermostatic digital panel. Depending on the type you can also use a remote control device to change and control the temperature degree by degree. It gives you an advantage over the traditional dial control method.