Best Rinnai Water Heaters
Reviews & Buying Tips
(updated 2017)

Explore, review and buy the most energy efficient and Energy Star Rinnai water heaters for residential potable water heating and light commercial applications.

See the reviews of the popular Rinnai tankless water heaters from V, RL, RU, RUCS, RUS, RUC and RUR series and boilers, with and without condensing technology, using natural and propane gas. Check the specs, online prices and reviews of the top sellers to shop with confidence, or fix the problem with the provided error code and the troubleshooting guide.

Rinnai water heaters - Buying tips

Rinnai tankless water heater indoorRinnai tankless indoor

Rinnai water heaters are small and compact tankless appliances that are using the latest innovative technology, providing an endless supply of hot water to one or multiple fixtures simultaneously, utilizing natural gas or propane. The small size with the dimensions of approximately 19"x 26"x 10" makes it perfect for wall installation either indoor or outdoor, freeing up the floor space for other use.

The state-of-the-art design brings more interaction between the unit and users, allowing Wi-Fi connection and remote monitoring and control, by using the smartphones.

The quality of Rinnai water heaters and gas boilers is already confirmed by its users and in the "Most Popular Products" magazine, a builder magazine where Rinnai has been voted #1 of all HVAC manufacturers.

Top selling models

Where to buy Rinnai?

Here is the list of the best selling Rinnai gas models found online, where the most praised features include high quality, long life, less waste, low gas emission, flexible installation, lots of power and small size.

Rinnai tankless water heater price is between $600 and $2300, while the cost for the installation varies from a few hundred to over a thousand.

 Features and benefits

High efficiency

Major benefits that one homeowner can get when using Rinnai tankless water heaters are reliability, on demand and almost instant and endless hot water supply, up to 40% energy savings, and high energy efficiency that ranges from 82% to over 90% found in condensing models, RU, RUC, and RUR series. The highest energy factor of 0.96 is found on models RUC90i, RUC80i, RU90, and RU80.

Water flow

Hot water is delivered to the fixture fast, at the consistent and accurate temperature, with very small fluctuation in the water temperature. Some models have the Circ-Logic recirculation program that cycles an external pump for better comfort and higher efficiency.

More advanced models such as tankless and condensing models from RUR series utilize recirculation technology and have the built-in pump and thermal bypass valve, with the dedicated recirculation line mode so the users wait and waste less. The highest water flow of the single unit is 9.8 GPM, found on RUR98, RUC98, and RU98.

Digital controller

And with the use of a 24-hr programmable digital controller, the user can schedule more than one operations during the day to meet different usage patterns, while providing enough hot water at any fixture and at any point of time.

Venting options

With the direct vent sealed combustion and flexible installation options, you can install Rinnai water heater almost on any inside or outside wall. And for more flexibility and faster installation, water heaters from the RUR and RUC series, for example, include one concentric and dual venting PVC/CPVC option on the same model.

Environment-friendly design

Superior advantages are making Rinnai tankless water heaters a world leader in the heating systems: they are "green" as they operate with the reduced energy and water consumption, NOx and CO2 emission and with such a long life of 20 years, reducing waste on the landfills.

Actual performance life of gas burners and other heater elements greatly depends on proper installation, quality, usage rates, environmental conditions, and maintenance.

Best advanced models to buy

Rinnai RUR98eRinnai RUR98e

The best Rinnai water heaters are coming from RUC and RUR models from Ultra series, a series that utilize a condensing technology and ultra Low NOx operation.

From the RUC series, buy RUC98i model, the largest and most advanced water heater - where the temperature controller is integrated into the front panel for convenience. This indoor unit, with the high water flow rate of 9.8 GPM, can provide sufficient amount of hot water to up to four bathrooms easily. The ability to modulate power from 15,200 to 199,000 Btu and pre-heat water with the secondary heat exchanger, ensures RUC98i to operate with the reduced energy losses than standard non-condensing or tank-type while providing great energy and money savings.

The same applies to RUR98i model, the largest from RUR group, but capable to provide hot water much faster, increasing the comfort to its users. This is possible as the unit has the built-in pump and thermal bypass valve, with the dedicated recirculation line mode.  As opposed to RUC model, RUR98 is available for outdoor installation also. Energy factor of 0.95 is something that will make RUR98 a good buy.

Top affordable models to buy

Condensing water heaters are the best from Rinnai, but also the most expensive. And that is why we have selected the top affordable Rinnai models to buy, so the homeowners who are on a budget can also enjoy all the benefits of the tankless technology.

Rinnai RL75, for example, even not being Energy Star is still a good buy as it has a high energy factor of over 0.80, the maximum gas input of 180,000 Btu and water flow of 7.5 GPM, which is enough for homes with up to 3 showers working at the same time. This is an environment-friendly unit with the ultra-low NOx gas combustion. And for faster hot water delivery, its recirculation compatibility makes it a great choice.

Another good affordable model to buy is Rinnai V65 from Value series, smaller than the previous one but still equipped with quality features and providing decent comfort for less. This one is recommended for smaller homes and where up to two showers are used simultaneously. It is available for indoor and outdoor installation.

Model selection

  • RUR series (RUR98i/e)
  • RUC series (RUC98i, RUC90i, RUC80i)
  • RU series (RU98e, RU90e, RU80e)
  • RUCS/RUS series (RUCS75i, RUS75e, RUCS65i, RUS64e)
  • RL series (RL94i/e, RLX94i, RL75i/e)
  • V series (V94i/e, V94xi, V75i/e, V65i/e, V53e)

(note: i - indoor, e - outdoor)

Pros and Cons


  • A great number of models to choose from, with different sizes and design.
  • Never run out of hot water.
  • All Rinnai models are used for the whole house and point of use residential and commercial heating.
  • Condensing models come with the ultra efficiency.
  • Consistent supply of hot water.
  • Up to 12-year limited warranty on the heat exchanger, for residential use.
  • Up to 5-year warranty on Rinnai replacement parts.
  • There is no pilot light, ignition is electronic and automatic.
  • The noise level is low.
  • Unnoticeable cold water sandwiches due to the modulating gas burner and capability to work with the recirculating pump.
  • Takes little space, it saves the wall and floor space - makes the installation easier.
  • Some indoor models have the digital temperature controller built-in, while others have the controller supplied.
  • Simplified problem diagnostics through displayed error codes.
  • Every part is replaceable.
  • Environment-friendly design with the ultra-low NOx gas emission.


  • For some consumers, it takes several minutes to have hot water running. (We say: it depends on how far your point-of-use is), for others no real increase in time to get hot water, when comparing to tank-type heaters.
  • LC code can be seen often, due to calcium issue and hard water. (Recommendation is to buy a water treatment system or flush the unit periodically).
  • Expensive to buy the condensing model (non-condensing are more affordable).
  • Hard to install.
  • Professional installation is expensive.

Conclusion: Based on hundreds of reviews of Rinnai tankless water heaters we have seen, there are many happy customers with positive feedback. When comparing Rinnai vs. Rheem, Noritz, Takagi or Bosch, such as in this article Noritz vs.Takagi vs. Rinnai comparison you will see that Rinnai quality is often superior in providing an "endless comfort and performance".

History of Rinnai water heaters

Rinnai water heaters are distributed by Rinnai Corporation owned by Rinnai Japan. The business was founded in the 1920s and in the early 1930s this Japanese manufacturing giant started producing gas appliances. Distribution started operating in North American in 1974 and in 2001 a new state-of-the-art distribution, research, and training facility opened in Peachtree City, Georgia.

Related articles

Rinnai RUR - Review of RUR98i and RUR98e
Rinnai RUC
Rinnai RU
Rinnai V
Rinnai boilers
Rinnai model comparison
Rinnai condensing models review
Rinnai error codes guide and troubleshooting
10 Reasons to buy Rinnai RUR98

Review Rinnai. Ask about Rinnai.

User Reviews and Questions

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