Rinnai vs Rheem: Which Gas Tankless Water Heater Takes the Lead

Gas tankless water heaters have become popular among homeowners regarding efficient and on-demand hot water supply. Among the leading manufacturers in this space, Rinnai and Rheem are two prominent brands that have gained recognition for their innovative and reliable products.

If you’re in the market for a gas tankless water heater, you may be torn between these two industry giants. In this review, we aim to settle the debate and determine which brand takes the lead: Rinnai or Rheem.

By delving into their features, performance, energy efficiency, and overall value, we will provide you with a comprehensive analysis to assist you in making an informed decision. So, let’s dive in and explore the key factors that set Rinnai and Rheem apart in gas tankless water heaters.

After hearing a lot about it, you finally decide to go with a tankless heater. Energy saving, endless hot water and small size are really attractive. But you can’t choose between two leading companies: Rinna and Rheem.

You can’t go wrong if you buy, but when dealing with different things in comparing Rinnai vs Rheem, one of the warmers is the best choice. I will review the full versions of Rinna and Rheem and see how they compare. I would focus on cost, capacity and performance as the main deciding factors. So let’s go!

Top Choice Rheem RTGH-95DVLN Rheem RTG-95XLN-1 Rinnai RUC98iN Tankless

Rinnai RL94eN Tankless

Rinnai RL94EN

Rheem RTG-95XLN-1 Rinnai RUC98iN

Rinnai vs Rheem | An Overview

Both models are on the market for tankless water heaters. Both offer excellent engineering and great performance and are leading the way in innovation and technology behind tankless systems. As I said at the beginning, you can only go right with any model if you buy the right device for your needs.

When you read the negative reviews on any model produced, most are from people who didn’t evaluate their needs properly and bought the wrong one.

Keep that in mind as you read. Wondering how Rinnai compares to Noritz? Check out this article to find out.

Whole House Tankless Water Heater

Top Choice

Rinnai RUC98iN (9.8 GPM) Tankless Water Heater

Rinnai RUC98iN

Rheem RTGH-95DVLN (9.5 GPM) Tankless Water Heater

Rheem RTG-95XLN-1


These two models will cover your water needs for an entire house with a family of about 5 people. At almost 10 GPM, you can run several devices at the same time and not see the water flow. run away. Here are more details on how they compare.

details compare rinnai vs rheem


  • Has Wi-Fi capability to connect your smartphone for things like adjusting the temperature and receiving maintenance notifications.
  • The 12-year warranty on the transformer is generous and assures you that it will last you a long time. Long enough to pay for itself in years.


  • With a built-in condensate neutralizer, you won’t have to worry about adding a separate unit to deal with acidic water or special drains.
  • The self-diagnosis process will let you know of any potential problems with the team and let you know if there are any installation problems.


It’s a tough call. Both give GPM a good edge, but Rinnai beats Rheem in this category. These units are sold individually, and Rheem has a lower entry price.

If you like convenience, the Wi-Fi capability of the Rinnai RUC98iN is good to have, especially if you run a smart home. It comes with the best warranty (12 years for the heater, five years for its parts, ten years for the heater, and one year for the Rheem parts).

Rheem vs Rinnai: Outside Natural Gas Models

Top Choice

Rinnai RUC98iN (9.8 GPM) Tankless Water Heater

Rinnai RUC98iN

Rheem RTGH-95DVLN (9.5 GPM) Tankless Water Heater

Rheem RTG-95XLN-1


This is another close as these two tankless outdoor systems give you similar functionality.

tankless performance


  • With Circ Logic, you can set up a hot water reset that will make the hot water ready for you to have hot water immediately without adding a separate pump. It can be programmed only to heat water in line when you need it most to reduce waste.
  • The included remote valves save you a little money in two ways. The first is that you don’t need to spend money to buy and install them separately; it means that you can do the water every year and sprinkle it yourself, so you don’t have to pay a plumber.


  • Installation can be a little more expensive because it fits ½ inch gas lines while Rinnai requires ¾ inch.
  • There is no cold water sandwich with Rheem, and you cannot get a recirculation pump to heat the water as it has a Hot Start program so that the heater is ready to heat water for a few moments after you stop. The water. You will have continuous hot water if you want to turn it on again.


Again, you get two high-quality flashlights here that feature great technological advancements for comfort and ease of use.

But there is a price difference. You pay a few hundred dollars more for the Rinnai up front. However, the Rinnai species are known for their longevity, often lasting up to 20 years. So, in the end, you will save money on the Rinnai models.

I recommend the Rinnai on this one as it is ready for upgrades and maintenance without any headaches to set it up.

Ways Rheem Beats Rinnai

I stop the comparison there because the other models are different from each other to put head to head.

I point out that Rinnai doesn’t have water heaters, and Rheem has many. Rheem offers a complete line of electric heaters that range from small spaces for one or two applications to complete the entire home. So you have more options with Rheem for your needs than with Rinnai.

Another important factor here is the price. Rinnai makes the most expensive tankless heaters, so that you can save money with Rheem. Installation is also cheaper for Rheem than for Rinnai.

Where Rinnai Beats Rheem

You can’t find a better brand for tankless heaters for efficiency, capacity and performance.

Yes, they cost more than other models in the same class, but you get reliable technology and more features. If you like bells and whistles, like connecting to Alexa and getting updates right on your phone, WiFi will love it.

You can add other features, such as the recirculation pump that is already connected. You’ll get the highest gallons per minute (GPM) of any other brand except Navien, so if you live in a cold climate or have a large family with high water demands, you’ll want to make sure Rinnai meets your needs.

How to Know What Water Heater You Need

Here is a detailed explanation of the differences between Rinnai and Rheem heaters. But at the end of the day, you must evaluate your needs. Here are some things you should consider before deciding which one to buy:

Water Demand

Since tankless water heaters do not store water, you must calculate how much water you use regularly.

This number is called GPM or gallons per minute. It’s not hard to figure out, but I have a chart below that will give you the average GPM of your home water fixture to make it easier.

Take a few days to figure out when multiple devices are running simultaneously. See if this is a one-time program or if you want these tools to run simultaneously.

Water Demand

It doesn’t matter if you use 100 gallons of water a day. Only how much you spend at a time is important. When you have this number, you must determine the tankless heating you need for your GPM.

Inside or Outside

You have many options for installing your hot water tank. They offer a lot of storage space because they take up less space. On top of that, you can choose indoor or outdoor models to expand your reach further.

You need to think carefully about where to install your water heater because you can’t put an indoor model outside. There are many reasons to use a tankless outdoor heater, but you’ll want to live in an urban area where you don’t have many hot weather days. Although most outdoor tankless heaters are insulated, if it’s always cold where you live, it will affect the efficiency of your unit.

To understand where and how to install a water heater without a tank, check out this article highlighting the requirements that may affect your decision.

Fuel Source

This will be fine for most people because they can choose between gas, propane or electricity to heat water.

Others may have certain limitations. Product X is the best thing to buy, but if it works only on gas without a gas line, you need an electric model, so confirmation does not mean anything.

That’s why I will analyze units in one section so that you can make an informed decision. The age of your home can also affect the type you can buy, as some older homes have small gas lines incompatible with tankless water heaters. This increases installation costs and negates savings from not going tank by tank system.

Final Verdict

These are two heavy hitters and for a good reason. Overall, Rinnai is the better brand, but most people will get what they want with Rheem and spend less money. If you are worried about long-term care, I would go with Rinnai. They have a good reputation for having long-lasting water heaters and better capacity than Rheem. The good thing is that you will get a good water heater regardless of your chosen brand.