Brand Comparison

Rheem Water Heater Reviews

In these Rheem water heater reviews, we take a look at this brand, their models and type of water heaters to help you choose the best heater.

by Josh Mitchell

If you are looking for the best water heater to replace your current, older unit, there are plenty of options out there. Not only will you find a lot of brands to choose from, but also a lot of different models. 

How do you know which is the best option for your family’s hot water needs?

In this Rheem water heater review, we will examine this well known brand, their models and type of water heaters and compare them to other known brands. Read on to find out if Rheem has your next water heater. 

Like most manufacturing companies at the turn of the 20th century, Rheem was producing steel goods.

However, it wasn't until the 1930s that the water heater division began to form. Not long after, the Rheem name started to grow in both popularity and production. 

Rheem Company History

Acquiring other smaller companies, divisions and taking a larger piece of the pie, Rheem established itself as one of the highest quality water heater companies in the world. In the 50s, Rheem developed glass lining and copper shells for the water heater tanks adding durability and longevity to their arsenal. 

Boasting a 10-year warranty and durable construction, Rheem doubled in size and was able to buy out the water heater division of Ruud. Now with a larger production capability and access to commercial products, Rheem expanded distribution. They also began production of the Richmond water heater line for the DIY installers. 

Today, the company continues to grow and expand. While the HVAC side of the house may be more popular and recognized, the water heater division is larger and still running at full production capacity. 

Types Of Rheem Water Heaters 

Rheem water heater range

Rheem produces all types of water heater styles, but their largest focus is on the newer tankless models. They still offer tanked models, of course, and are also expanding into alternate power sources. Let’s take a closer look. 


Gas water heaters are efficient, offer even heating, and simple to install. With Rheem, you will find tanked and tankless gas water heaters as well as high and mid-efficiency models. The combination boilers are also gas-powered with adapters to make all versions run on natural gas or propane. 


The electric models are highly efficient and offer a low cost installation. Almost all models are Energy Star rated, too. The largest selection of tankless water heaters is found in the Rheem electric water heater side of the house. This includes the compact, under cabinet, and point of use model styles, as well.  

Indirect & Alternative Power Sources 

Boilers and indirect heating models are also available. You will find that Rheem is also venturing into alternative and green production with solar-powered water heaters, hybrid water heaters, and combination boilers. 

Rheem has also developed a water heater booster that delivers more power and water flow than your average water heater and can effectively double the output (40% increase) of your heater with a simple add-on. 

Why Choose Rheem Water Heaters? 

Rheem knows a thing or two about heating water.

For almost 100 years, they have led innovations and developed new products to make hot water in our homes more effective, efficient, and sustainable. 

Award-Winning Innovations 

With innovations like copper lining, glass lining and water heater boosters, it is no wonder Rheem is at the top of the game when it comes to new ideas and tools. 

Unlike some other innovative ideas, Rheem's research and development team come up with ideas that are easy to implement and actually useful to the consumer. 

Rheem residential hot water heater

Wide Variety of Products 

Rheem may not be the biggest name in the game, but they are one of the most widespread. Offering water heater types, styles, and additions in a wide variety of products, you are sure to find what you need at all times.  

Energy Star Certified 

Reliable and durable is one thing, but being able to save you money and lower operational costs is another. Rheem water heaters are highly efficient, and most models are Energy Star certified. By lowering the amount of power needed to operate at full capacity, you save money over the long term with energy-efficient models.  


Green is the new black. Going green and being eco-friendly has led Rheem to be a leader in alternative power sourced water heaters. From propane and kerosene adapters to solar-powered water heaters, Rheem has an answer for any fuel type currently available. 

Durability Features 

Stronger tanks, durable tubing, piping, and electrical connections make the affordable Rheem water heaters some of the most durable on the market. It is for this reason that they can offer you extended warranties and stand behind their products longer than most other brands out there. 

Unique Features of Rheem Hot Water Heaters 

Rheem can claim to be innovative and industry advanced because they have the proof to back it up. What do they offer that makes their product stand out? Let’s take a look. 

Guardian System 

For gas-fueled heaters, one of the dangers is vapors and fumes of combustible materials or chemicals getting into the piping and drawing the flame outside of the unit. With the Guardian System, Rheem prevents this from happening. Additional flame barriers and check valves, as well as a host of sensors, prevent the flames from leaving the internal combustion chamber. 

Flexible Venting System 

Many gas water heaters offer you a single venting option. Rheem gives you three. Power venting, power-direct venting, or atmospheric venting with a powered damper are available for most gas-fueled water heaters. 

Stainless Steel Elements 

Water corrodes metal, and the use of stainless steel should be something everyone does. However, this isn't the case. Rheem, though, uses stainless steel components to help minimize corrosion. 

Dual Anode Rod System 

Most water tanks will have a single anode rod. These are metal rods that extend into the water tank to attract minerals and corrosion, so the tank stays intact. With many Rheem models, you will find a dual rod system that doubles the corrosion fighting capabilities.  

Digital Temperature Controller 

Where other brands use analog turn dial thermometers, Rheem utilizes digital components and allows you to check the temperature and make changes on a digital readout. 

Eco Net Capability 

Certain water heater models are a part of the Rheem Eco Net family. These products use special sensors and connect wirelessly to a mobile app and each other. You can check your entire eco net system with one glance, change settings and make service calls at any time. 

High Altitude Installations 

There are two high altitude tankless options (6560 and 9840 feet) and a 10,000-foot high altitude tanked option available from Rheem. No other brand offers high-altitude specialized water heaters, and the difference is clear. 

Low NOx Emissions 

Almost every Rheem gas-fueled water heater is rated for Low NOx emissions. For the models that are not, they are rated for ultra-low NOx emissions. This standard of care and quality for low emission standards, sadly, does not extend through all other brands. 

Rheem Hot Water Heater Reviews

Rheem water heaters are built from the ground up to include new industry standards and next-level innovations. They build in two primary categories, Professional and Performance. There are a few extras, though, that may surprise you. 

Rheem Professional Series 

The Professional series, including Professional Platinum, extends through the entire range of Rheem water heaters. You will find tanks, gas and electric as well as tankless electric and condensing models. It is also here that you will find the solar options too. 

The professional series is harder to find in retail stores and online and are still mostly sold through installers and contractors. However, they hold a higher UEF rating (up to 0.93) across the board, and all models are Energy Star rated. 

There are over a dozen to choose from in capacities ranging from 35 to 80 gallons for the gas-fueled models. Electric tanked models are the same, with a wider range of capacities up to 120 gallons. 

The tankless models are the Rheem specialty, though, and where the company has the most considerable focus. With about 2-dozen total models to choose from, they offer the most extensive range of tankless water heaters in the industry. 

With both indoor and outdoor models as well as condensing, electric, and solar-powered units, you won't find a wider range, more efficient, or more durable tankless water heater anywhere. 

The Professional series also has the highest warranty extending to at least 10 years. With two notable exceptions (further below), the Professional Series is the one to look for when making your choice. 



30 to 120 Gal 

Power Source 

Gas, Electric, Solar, Indirect, Boiler 

Heating Efficiency 

15000 to 135000 BTU Input 

First Hour Output 

Up to 340 gallons 

Flow Rate 

Up to 327 Gallons Per Minute 


Stainless steel construction 

Safety Features 

Thermal protection, auto-shutoff, leak detection 


Up to 10 years 

Rheem Performance Series 

For those looking to save a little money and still get a Rheem quality water heater, the Performance Series is what you want. These models also span the gamut of Rheem’s offerings and come in tanks and tankless designs, both gas and electric styles. 

The gas models come in a range of 20 to 90 gallon capacities, while the electric models extend to 110 gallons. 

rheem performance series water heater

They also have specific models for manufactured homes, low clearance installs, and high-demand systems. 

The point-of-use and on-demand models give you instant hot water at a single faucet or tap and can be installed under a cabinet or in a crawl space. Ideal for those that like a hot beverage first thing and don't want to wait on the stove. 

With the Performance series, you will lose some efficiency, and the overall UEF rating falls to between .54 and .70 UEF across the board. However, this is still enough for Low NOx emissions and higher energy efficiency ratings than some other brands.  



20 to 120 Gal 

Power Source 

Gas, Electric, Solar, Indirect, Boiler 

Heating Efficiency 

15000 to 135000 BTU Input 

First Hour Output 

Up to 310 gallons 

Flow Rate 

Up to 295 Gallons Per Minute 


Stainless steel construction 

Safety Features 

Thermal protection, auto-shutoff, leak detection 


Up to 8 years 

Rheem New and Innovative 

Rheem has two models that no other brand can offer. The Gladiator and the Marathon are two new models Rheem is excited about. 

The Rheem Gladiator is a part of the Eco Net family and comes with the service already installed. It also features more sensors and protection systems than any other water heater, including multi-point leak detection that limits leakage to no more than 20 ounces during auto shut-off. 

With the Gladiator, you can also select operational modes, including vacation and away modes, set the water temperature with an app, and instantly know the status of the system at any time, from anywhere. 

The Gladiator is currently available at Home Depot and online. 

The second major release from Rheem is the Rheem Marathon. This is a new style of water heater that features a high-performance plastic shell warrantied for life. The warranty is based on installation location as well, meaning you can sell or transfer your home, and the warranty stays intact. 

With a patented insulation process no-seam liner and tough jacket, the Marathon is the most durable water heater tank ever made. It is lightweight, easy to install, and has a lower service or repair cost than other models in the industry. 

Further, the Marathon is protected against dry firing, available in 30 to 100 gallon capacities, and will last for generations to come. 

Comparisons With Other Hot Water Heater Brands 

Rheem has long been considered a mid to high-end brand, but how do they compare to other well known brands in the industry? We compare Rheem to AO Smith, Bradford White, Richmond, and State to find out. 

Rheem Vs AO Smith 

AO Smith is a premium brand second only to Bradford White in some categories. Compared to Rheem, though, they are a step up in quality and durability. The warranty coverage is about the same, but Rheem wins in terms of initial costs all the way around. 

Whether you go professional installation or the DIY route, Rheem will cost less to get put in place. Rheem has excellent energy efficiency, too, but AO Smith has slightly better. This means that in the long run, over the life span of the water heater, AO Smith will save you more on your energy and gas bills. 

When it comes to replacement parts and service calls, Rheem is also slightly less expensive. But, due to the extreme build and durability of AO Smith units, there are fewer needs for repairs and service calls in the first place. 

Rheem Vs Bradford White 

Bradford White water heaters are the premium brand of the industry. Long considered the gold standard of water heaters, Bradford White uses only the best materials at any cost. Their models are all expertly crafted and sold only through whole sellers. 

It is also known that to get a Bradford White warranty, the unit must be professionally installed. While some consumers don't mind, the higher initial cost of the unit plus the need for pro installation is a turn-off. This is where Rheem comes through. They have lines that are DIY friendly. 

Rheem also has a similar warranty structure and duration without the professional installation requirement. The water heaters are also similar in capability and capacity. However, Rheem has a larger share of the tankless market right now. 

If you are looking for the absolute best of the best and don’t mind paying more for it, Bradford White is probably your answer. If you are handy with tools and don’t mind saving a bit of cash, Rheem has a solution for you that will fit your needs. 

Rheem Vs Richmond 

Richmond started as Rheem’s DIY answer, selling direct to consumers and adding water heater to the homeowner’s list of can-dos. This happened at a time when HVAC and water heaters were all professional installations only. 

Today, though, with more technically inclined homeowners, Rheem also sells their primary brand direct to consumers. Richmond is a Rheem brand and holds standard to their expectations, but is still considered a budget brand. 

This means that while Rheem controls the parts and durability of Richmond units, they aren't as high quality, as energy-efficient, or as long-lasting as the ones with the Rheem name on the label. 

Rheem Vs State 

State, much like Richmond, is a child company. This time, though, under the AO Smith name. State is a different type of company, though, still manufacturing and producing their own lines, just in AO Smith factories and with AO Smith parts now. 

State also boasts one of the largest productions of electric water heater models, with over 100 different units currently being made. Rheem pales in comparison to the sheer number of units that State puts out but maintains a slight edge in quality and durability. 

The rest of the comparison aspects such as cost, warranty, energy efficiency, and performance are about equal. The choice comes down to the model you like best or the one that has the features and options you desire most. 

Where To Buy Rheem Water Heaters? 

Rheem water heaters are sold through retail outlets of Home Depot, on the Home Depot website, and through their storefront on Amazon. You will also find them through wholesale with approved contractors. 

You can head to the Rheem website and enter your zip code to get a base idea of which contractors sell Rheem water heaters. However, we have partnered with Networx, a leading brand that pairs consumers with contractors in their local area. 

Installation Of Rheem Hot Water System 

plumbing installing rheem water heater

Installing a Rheem tankless water heater or a tanked model isn't restricted to professionals. However, professional installation is highly recommended, especially with natural gas-fueled models. 

With proper electrical and gas line experience and knowledge, a professional will not only help you maintain your Rheem warranty, but most will offer their own warranty for labor and repairs if needed. 

Networx is a brand that vets and lists local contractors. All of the results from the free app below will show you licensed contractors with great reviews, highly recommended, and proper background checks already completed. Give it a try now and get your Rheem water heater installed the right way. 

Rheem Water Heater Maintenance 

Care and maintenance of your Rheem water heater are clearly outlined in your owner's manual. If you need a new copy, you can contact Rheem for a download link, or simply look online. Manuals Library, for example, offers free access to over 1200 Rheem water heater manuals. 

Some of the most common issues with water heaters will depend on the fuel type. Electrical water heaters won’t have gas pilot light issues, for example. The chart below offers suggestions to the most common issues with Rheem water heaters. 

rheem troubleshooting




No hot water 

Pilot light is out, fuel supply is shut off 

Check breakers and gas valves to ensure power is supplied to the unit. Ensure pilot light is lit (gas models). 

Water takes long time to heat up 

Cold weather 

If your water is hot but takes a while to reach temp it is generally due to poorly insulated piping during winter.  

Pilot will not stay lit when button released 

Defective thermocouple 

Replace thermocouple 

Pilot light will not light 

Gas is off, gas tube clogged 

Ensure gas is turned on and valve is open. If no flame ever develops, the tubes may be clogged and should be cleared or replaced. 

Rheem Water Heater Warranty Information 

Rheem water heaters have various warranties based on the type, style, and size of the system. It will also depend on your location as well as how the unit is installed. In most cases, the warranty coverage is about 10 years. 

Some lower-end and smaller models will see warranties around the 6-year mark, while tankless models can reach 15 years of coverage. 

To begin the warranty, you will need to register your serial number. You can find your model and serial number on your sales invoice or on the unit itself. There will be a rating plate located at the top of the warning list stickers affixed to the front of the unit. 

Once you have your serial number, enter it on the registration page of the Rheem website to enroll. The full warranty, coverage terms, and duration will all be listed for your specific model once registered. 

You will also need your serial and model numbers to apply and qualify for any tax credits or energy rebates that may be offered in your area. 

Rheem Water Heater Replacement Parts 

Common replacement parts are readily available for Rheem units at most local hardware stores, Home Depot stores, or online through Home Depot websites or Amazon. Depending on the model and serial number, you can find parts to replace just about anything. 

The most common and DIY friendly, though, are fairly inexpensive and quick to change out as long as you know what you are doing. If you are ever in doubt, call a professional, especially if your unit is still under warranty. 

The thermocouple, for example, is one part that can easily burn out or become charred and fail. Without this unit, the pilot light will not stay lit, and you won't have any hot water. However, a quick 20 minute change out of a new one, and you are good to go. You may also find that the gas valve is at fault. 

Upper thermostats and lower thermostats can also go out. Usually, it is an internal sensor or worn contact that causes the failure, but a few screws are all that is needed to ensure your water temperature is where it needs to be. 

A gas model pilot assembly and magnesium anode rod are a more involved replacement but still shouldn't pose much issue for a confident DIYer. Both are straightforward, if not time-consuming, replacements. 

People Also Ask (FAQs)

How do you drain a Rheem water heater? 

To drain a water heater, you need to cut off power at the circuit breaker and the gas valves. Turn the water inlet bib off to stop water flow into the tank. Connect a garden hose to the lower bib and run it to a nearby drain or outside.

Once the hose is secure, open the drain valve and allow the water to empty from the tank. Once completed, reverse your steps and allow the water to fill the tank for at least 5 seconds before you relight the pilot or switch the circuit breakers back on. 

How do you reset a Rheem water heater? 

The Rheem thermostats are equipped with a reset switch on the upper and lower marks. Remove the two front panels on the Rheem water heater and located the red push-button reset switch, and depress them to ensure they are switched on so the thermostats will work and allow the system to operate. 

How old is my Rheem water heater? 

Like most water heater manufacturers, the serial number of the unit will have the date of manufacturer encoded within it. In Rheem models, you want to look at the first r digits of the 10-digit serial number. The first two numbers are the month the unit was made, and the 3rd and 4th numbers represent the year.  

How do you turn on the Rheem water heater? 

Once wired and filled with water, tested for leaks and stability, you can turn on an electric Rheem water heater by turning on the circuit breaker that controls the water heater wiring. 

How do you light the Rheem heater pilot? 

After your water heater is installed, set up, and filled, the gas valve needs to be turned on and allowed a few seconds to run. Press the ignite button on the Piezo ignition and hold for a few seconds. The pilot light will come on, and once the flame is steady, you can release the button. 

How do you wire a Rheem electric water heater? 

When running wire, you need to know if the water heater is a 10-2 (black and white or red) or a 10-3 (black and white and red) wiring.

When you run the wiring from the circuit breaker, connect the leads to the correct color wire, black lead to black wire, white to red or white (on a 10-2), and white to white and red to red (on a 10-3).  

How much is a Rheem water heater? 

The actual cost of a Rheem water heater will depend on which one of over 100 models you choose to buy. The cost will also depend on where you buy, where you are located, and how you plan to install the unit. On average, the DIY tanked models will range between $300 and $800, depending on their capacity. 

How do you adjust the Rheem water heater temperature? 

Open the two thermostat plate covers to expose the thermostats. On analog models, you need to turn the dials clockwise to increase the temperature or clockwise to decrease.

On digital models, press the up arrow key to increase and the down arrow key to decrease. Note that both thermostats must be set to the same temperature. 


Rheem water heaters come in all shapes, sizes, and capacities. Whether you need a full-sized multi-family model or a space-saving, on-demand, or under-counter model, Rheem has them. 

The brand is known for quality and durability and holds some of the highest warranties in the industry. While they are considered a mid-range brand, the water heaters are durable, reliable, and affordable. Whether you go natural gas, electric or alternative, you won’t regret your purchase. 

Josh enjoys researching, testing and diving into home improvement & DIY products. He has a passion for tools, learning new skills and fixing the everyday problems that arise around the house.