Rinnai vs. Navien Water Heater: Which One is Better? A Side-by-Side Comparison

It's no secret that Navien and Rinnai are prominent brands in the home appliance industry, particularly when it comes to manufacturing top-quality water heaters.
Rinnai vs. Navien Water Heater: Which One is Better?

Rinnai has ruled for a long time as an industry leader, while Navien gives tough competition with its lineup of budget-friendly, high-performance gas appliances, including water heaters.

Rinnai and Navien are both well-known brands in the hot water heater industry. This comprehensive comparison will evaluate both brands’ features and performance to determine which is better. By considering factors such as energy efficiency, reliability, and customer satisfaction, we aim to provide you with valuable insights to help you make an informed decision when choosing between Rinnai and Navien water heaters.

So, in this article, we will conduct a thorough comparison between Navien and Rinnai. Here, our main focus will be on tankless water heaters—a product category that provided both brands with a lot of recognition.

Rinnai Origin

Rinnai is a Japanese multinational company recognized as the number-one-selling brand of tankless water heaters in the United States. Although famous for producing and selling cutting-edge and power-efficient energy tanks, they also manufacture other gas appliances for residential and commercial use, including boilers, stoves, fireplaces, etc.

What gives Rinnai a competitive edge in this field is its dedication to constant improvement and staying at the forefront of technology. They focus on creating efficient, durable products and incorporating the latest advancements in the industry. That’s why it has achieved a huge reputation and even won multiple awards as the best brand in different categories.

Navien Origin

Navien is also recognized as a leader in condensing technology and is a popular choice for homeowners and businesses in North America. It is one of the leading brands in manufacturing and selling tankless water heaters and other gas appliances for residential and commercial applications. 

Like Rinnai, Navien also belongs to the same continent that originated in 1978 in South Korea. Since its founding, this brand has been the epitome of condensing technology and successfully manufacturing highly efficient, energy-saving, and environmentally friendly gas appliances, including tankless water heaters. 

Navien products often come equipped with advanced features, such as built-in recirculation pumps for instant hot water, intuitive controls for easy navigation and adjustment, and features that enhance installation and setup processes. 

Rinnai vs. Navien

Let’s now compare both brands and their products based on the most important aspects and features that they are known for delivering.

Durability and Longevity

Durability and longevity indicate a product’s ability to last longer by withstanding wear, damage, or deterioration over a significant amount of time. Thereby, the products earn a reputation for being long-lasting. 

Based on the user’s experience, Rinnai has a slight edge over Navien as the more durable appliance. While Rinnai has a slightly better rating in durability, the difference is not very significant; many users tend to be influenced by the strong brand reputation of Rinnai. 


To gain a better perspective about which brand has better longevity and durability, we need to look at their materials and warranty periods. However, both products use high-quality components and materials that are resistant to corrosion, scale buildup, and wear. Most Navien and Rinnai tankless water heaters use stainless steel to make heat exchangers, which is considered a crucial addition.

Additionally, both brands prioritize using venting materials known for their corrosion resistance, heat tolerance, and durability. While Rinnai offers 2″ PVC, CPVC, and PP venting options, Navien expands its options with PVC, CPVC, and rigid polypropylene. With regard to the materials, both Navien and Rinnai strive to utilize premium materials that guarantee their long-lasting durability.


Now, given that both brands utilize high-quality materials in their product construction, the determining factor may come down to the extent of their warranty coverage. Throughout the discussion so far, we have seen that Rinnai has a better reputation and user support as a more durable product. 

However, Navien provides more extended warranties on its water heaters, including a 15-year warranty for the heat exchanger, five years for parts, and one year for reasonable labor.

Whereas the Rinnai tankless water heaters offer five years of warranty for all the parts and ten or more years of warranty for heat exchangers. Navien has an edge over Rinnai for offering extended warranties for their product, especially water heaters.


How the appliance of each brand performs matters the most to the users. If a product with exceptional built quality fails to perform up to the mark, the users will not have a good impression of it. 

Now, we will compare Navien and Rinnai based on the performance of their tankless water heater. That’s why we have chosen some vital performance metrics to evaluate relative advantages and strengths. 

Energy-Saving Capabilities

Energy-saving capabilities or energy efficiency is how effectively a water heating unit can transmit the energy needed to produce hot water while minimizing energy loss as waste heat. When selecting a water heater, energy efficiency is important because it directly affects your energy bills and environmental impact.

Both Navien and Rinnai leverage advanced technology to manufacture energy-efficient tankless water heaters. Navien integrates condensing technology into their tankless water heater, which makes their appliance an even greater energy saver. 

On the other hand, Rinnai’s tankless water heaters come with copper heat exchangers and other advanced technologies designed to optimize heat exchange efficiency and accelerate the water heating process.

So, both Navien and Rinnai water heaters strive to present top-tier energy-efficient water heaters. Some of the latest Navien and Rinnai tankless water heater models have energy efficiency above 90%, with Rinnai edging out Navien with a slightly higher efficiency rate.

Heating Capacity

Heating capacity is a vital parameter when it comes to evaluating the performance and suitability of a water heater, especially tankless water heaters. In a nutshell, the heating capacity of a product gives you a straightforward insight into which water heater can deliver a higher quantity of hot water within a particular time.

When evaluating Navien and Rinnai with regard to heating capacity, we may look at available water heaters with the highest BTU. For your kind information, British Thermal Units (BTUs) is the unit to measure the heating capacity. 

Navien’s top-of-the-line model, Navien NPE-240A2 ultra-high efficiency condensing water heater,  offers a heating capacity that spans from 13,300 to 199,900 BTU/h.

On the other hand, the Rinnai RU199iN model is one of the highest BTU models, with a heating capacity of 199,000 BTU/h. It is described as a “Super High Efficiency Plus” tankless water heater. This model is compact, easy to install, and suitable for indoor locations.

While it is clear that the maximum heating capacity input of both Navien and Rinnai’s tankless water heater is more or less similar, there’s a slight edge in favor of Rinnai. Their system’s performance is slightly higher than Navien’s. 

Flow Rate

Flow rate is another parameter to consider when evaluating the performance of Navien and Rinnai’s water heaters. Essentially, it measures the hot water flow from the unit to various fixtures and appliances in your home. 

Flow rate is typically measured in gallons per minute (GPM) or liters per minute (LPM). It indicates the volume of hot water that the tankless water heater can generate and deliver at a specific temperature rise.

Flow rate is important because it determines whether a water heater can meet the demand for hot water in your household at any given time or not. When purchasing a water heater, you need to seriously consider this feature.

When comparing Navien and Rinnai, it’s worth noting that Rinnai offers products with a wide range of flow rate options to accommodate various household sizes and hot water demands. Wondering why? 

Up to this point, the maximum flow rate of a Navien tankless water heater is 11.2 GPM, represented by the Navien NPE-240A2. 

On the flip side, the highest flow rate achieved by a Rinnai tankless water heater is 9.8 GPM  by the Rinnai RUR98eP Tankless Water Heater. These water heaters are often suitable for outdoor use.


Considering the price, Navien is more affordable than Rinnai, and even for some products, the Navien installers charge significantly lower prices than Rinnai. However, the additional price of Rinnai often comes with high energy efficiency, features, and advanced technology. With the strong reputation Rinnai has, they are pretty confident about the higher price compared to the features and quality of their product. 

In this situation, we suggest considering a comprehensive comparison of features, energy efficiency (which contributes to long-term savings), as well as warranty terms.

Product Lineup 

Rinnai has been leading the market for longer than Navien; therefore, they have a more extensive product lineup encompassing a variety of models with cutting-edge features. They offer a wider selection of tankless water heaters suitable for a range of applications compared to Navien. Despite this, Navien remains a strong player in the market with its variety of models, often excelling in offering budget-conscious products.

Use of Technology

Both brands employ the best technology to meet user expectations and ensure the best user experience. They have pioneered their own cutting-edge high-efficiency heating technology to ensure that their products attain superior levels of energy efficiency.  

Also, both of the brands successfully incorporated a built-in recirculation pump, which eliminates any delay and ensures that your hot water is readily available whenever you need it. Rinnai also utilizes Smart-Circ Technology in this matter to deliver better and quicker output.

Moreover, many Navien models are made with a patented built-in buffer tank technology, which controls temperature fluctuation and provides a more consistent and comfortable hot water supply. On the other hand, Rinnai tankless water heaters include built-in freeze protection to safeguard the unit during cold weather conditions.

So both brands go above and beyond in utilizing the most advanced technologies to manufacture premium quality water heaters.

Which One is Better? 

Deciding which brand is better is totally up to personal preference. If you look at the discussions above, you’ll find that both Navien and Rinnai are very close when it comes to delivering high efficiency, which helps you save money in the long term. 

In terms of heating capacity, Rinnai is slightly better than Navien. Currently, Navien offers a tankless water heater with the highest flow rate between the two. When you consider the product price and installation cost, Navien comes out ahead. These are just general points, and it’s ultimately up to you to choose the one that suits your needs best.


When it comes to performance and overall quality, there aren’t any significant distinctions that set these two brands apart. Navien holds certain advantages in areas like pricing and flow rate, while Rinnai excels in aspects such as heating capacity and brand reputation. 

Moreover, in terms of efficiency and leveraging the best technology, both brands remain closely matched, maintaining a neck-and-neck competition.

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