Comparing Efficiency and Performance: Rinnai vs. Navien

Rinnai and Navien are well-known residential and commercial water heating systems brands. Both companies have established a reputation for producing high-quality and innovative products, making them popular among homeowners, contractors, and businesses. This brief overview will compare Rinnai and Navien, highlighting their key features and helping you decide when selecting a water heater.

Rinnai, founded in Japan in 1920, has become a global leader in tankless water heaters. With a commitment to energy efficiency and sustainability, Rinnai offers a wide range of products to deliver endless hot water while minimizing waste. Rinnai’s tankless water heaters are known for their compact size, efficient operation, and precise temperature control. They incorporate advanced technologies like condensing heat exchangers and modulating burners, resulting in significant energy savings and reduced greenhouse gas emissions.

On the other hand, Navien, established in South Korea in 1978, has rapidly gained recognition for its innovative condensing tankless water heaters and combi-boilers. Navien focuses on providing highly efficient and reliable systems that combine heating and hot water functions in a single unit. Their products feature advanced condensing technology, stainless steel heat exchangers, and intelligent controls, ensuring optimal performance and energy efficiency. Navien’s commitment to green technology has earned them several awards and certifications for eco-friendly designs.

When comparing Rinnai and Navien, both brands offer excellent energy efficiency and reliable performance. However, there are some factors to consider when choosing between them. Rinnai’s extensive experience and global presence have established them as a trusted brand, while Navien’s rapid rise in popularity reflects its dedication to cutting-edge technology. Additionally, specific models, features, and installation requirements may vary, so it’s crucial to consult with a professional or refer to the manufacturer’s specifications to determine the best fit for your needs.

Rinnai Water Heater

Rinnai Tankless Water Heater
Rinnai RU199iP
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If you want tankless heating from industry over a century old, Rinnai is the way to go. They have been offering some of the best plumbing products and equipment since the 1920s and have a reputation that is older than Navien. While being around for over 100 years gives Rinnai an edge in terms of experience and modernity, they could be better. Rinnai also uses only fuel for heating without a water tank.

Navien water heater

Although Navien hasn’t been around for over a century, they’re almost 45 years old and certainly not the new kids on the block. Navien offers both gas and electric heating without hot water and is quickly becoming one of the most popular water heating options. Like Rinnai, Navien has won many awards and accolades for tankless water heaters. Navien also works exclusively for various boilers and water heaters, while Rinnai manufactures heating and cooling equipment and heating systems.

Consider when making your decision. 

The models are similar in many aspects, and there is only sometimes a clear winner.


The first thing most people will consider when choosing a water heater is cost. Unfortunately, due to the quality and performance of Rinnai and Navien hot water tanks, they will not be cheap.

These two brands produce a variety of tankless water heaters with a price range between $600 and $2,000, not including the installation fee. You can choose between a high-end option with more features and high output or a low-end option with a small second. In the end, you will pay the same price for each option.


A gallon per minute (GPM) is the standard measure for measuring the amount of water a generator can produce. The higher the number of GPM, the higher the efficiency of the water heater will be, which means more water where you need it when you need it there. Again, both Rinnai and Navien make tankless water heaters with maximum outputs between 11 and 11.2 GPM. Generally, the higher the GPM, the more expensive and inefficient the heater. However, the two types are very similar in this respect.


Priced differently, energy efficiency is top of mind for many when choosing a tankless water heater. Because these machines always provide unlimited hot water, people don’t think about how much they use. Therefore, choosing the best option is a good way to save money.

Rinnai and Navien tankless water heaters are Energy Star certified and efficient. However, Navient’s tankless water heaters perform better than Rinnai’s. Navien’s range of models has an efficiency rating of up to 96%, while Rinnai’s range reaches 93%. However, higher efficiency usually means lower heating capacity. So while Rinnai water heaters are less efficient, they can produce hotter water than most Navien models. In the end, however, the performance and temperature of the water heaters are worth it.

 Difficulty installing

Due to the high cost of tankless heaters, many wonder if they can install them themselves. Installing your water heater will save you money, but you must have moderate sailing skills before attempting it. When it comes to installation problems, Navien is the clear winner. Their water heaters are much simpler and easier to install than Rinnai tank water heaters. For example, Navien water heaters have a special system for easy installation, while Rinnia water heaters do not include this product.

Longevity and warranty

The last thing you want is to have your tankless water heater repaired or replaced, which means a lot of work over time. Although both brands produce reliable products in hot water, Rinnai gets a slight edge in this category. Rinnai water heaters are known to last at least 20 years, which is above the mark for Navien water heaters. The Rinnai breed also has fewer problems and maintenance needs than the Navien, which usually starts having issues around age 10. In terms of warranty, however, Navien comes with a small advantage. Here’s how they rank three types of contracts: labour, parts and heat exchangers.

Labour Warranty Coverage

  • Navien and Rinnai both offer a one-year warranty for labour issues.

Parts Warranty Coverage

  • Navien and Rinnai offer a five-year warranty on all parts and components besides the heat exchanger.

Heat Exchanger Warranty Coverage

  • Navien offers a 15-year warranty on the heat exchanger, while Rinnai only offers a 12-year one.

 Rinnai has an advantage over Navien.

Now that we have a detailed explanation and comparison of these two models let’s see the summary of how Rinnai is better than Navien.


Rinnai wins on durability. Rinnai tankless water heaters last up to five years longer than Navien water heaters.

Heating Capacity

Rinnai’s exclusively gas-powered water heaters have a higher heating capacity.

Customer Support

One of the biggest complaints against Navien is their subpar customer support. While Rinnai doesn’t necessarily go above and beyond the call of duty, they have adequate customer support.

Operating Noise

Rinnai tankless water heaters are quieter during operation than Navien.

Navien has an advantage over Rinnai.

On the contrary, let’s look at Navien’s advantages over Rinnai.


Navien tankless water heaters are slightly more efficient than Rinnai models.

Installation Difficulty

Navien water heaters are much easier to DIY and install than Rinnai models.


The labour and part warranties for either brand are identical, except for the heat exchanger, where Navien offers three more years of contract than Rinnai.


Some of Navien’s electric tankless water heaters are more eco-friendly than Rinnai models.

Best Rinnai Tankless Water Heaters

Rinnai RU199iN

Rinnai RUCS65IP

Rinnai V65iP

Rinnai RU199iP Rinnai RUCS65IP Rinnai V65iP


Frequently Asked Questions

Which tankless water heater is reliable?

Rinnai tankless heaters last longer than Navien water heaters. However, durable and reliable materials are used to make water heaters and last for about 15-20 years.

Are Navien tankless water heaters worth it in terms of performance?

If you are looking for efficiency, durability and great value for money, Navien water heaters are worth the price you will pay. They provide unlimited hot water on demand and are more efficient than traditional water heaters.

Which is better, Rheem or Navien?

Although tankless water heater models are good, Rheem is slightly better than Navien. Rheem tankless heaters are generally more expensive than Navien and last longer, making them a favourite among many.

Final Thoughts 

Whether you rely on a Navien or a tankless Rinnai heater, you will have a large section. The two brands are out of whack in some ways, but they ultimately declare a clear winner. Rinnai has the edge in durability, heating capacity, customer support and noise, while Navien wins in environmental friendliness, efficiency, warranty and installation.

The best way to choose between these two types is to look at the benefits of each and decide which one is most important to you.