Rinnai RUR98 
Tankless Water Heaters
Review and Buying Tips

A review of Rinnai RUR98 tankless water heaters for indoor and outdoor use, benefits and advantages.

Explore the most advanced features, technologies, and specs, including the ThermCirc360, Circ-Logic system, condensing technology, ultra-high energy efficiency, ultra-low NOx emission other money-saving and environment-friendly features.

Rinnai RUR98i and RUR98e are tankless and condensing water heaters from the Sensei SE+ series, a series with the top of line features, specs, and state-of-the-art technology.

RUR98 models are designed for ultra-efficient, on-demand water heating, an endless supply of hot water, and significant reduction of greenhouse gases, making it Eco-friendly and an Energy Star unit. They are used in domestic hot water applications and are not recommended for installations in hydronic heating applications.

With their sleek and modern metallic look, Rinnai RUR98 heaters are perfect for indoor installations, making them very attractive to the customers. Due to their high-quality casings, they can last longer, even when installed outdoors.


Models review

Rinnai RUR98 tankless water heaterRinnai RUR98

Rinnai RUR98 models are built for indoor and outdoor installation, using either natural gas or propane:

  • Rinnai RUR98iN – an indoor model powered by natural gas
  • Rinnai RUR98eN – an outdoor model powered by natural gas
  • Rinnai RUR98iP – an indoor model powered by propane gas
  • Rinnai RUR98eP – an outdoor model powered by propane gas

(available on Amazon.com)

Feature review

High power and water flow – low pollution

Rinnai RUR98 tankless water heaters come with a powerful and eco-friendly gas burner that can operate with power ranging from 15,200 to 199,000 BTU. RUR98 models can work as the point-of-use units where a small amount of hot water is needed or as the whole-house unit when there is high demand. As the units are equipped with the modulating gas valve, the heater can automatically adjust the power when it is required.

When working with the maximum gas input, the RUR98 model can provide up to 9.8 GPM of hot water, reaching the temperature of 140 F - making it ideal for up to four-bath homes in both residential and commercial applications. They are also certified for installation in mobile homes.

Water heaters are equipped with thermal bypass technology, so by using the built-in circulation pump, bypass line, and valve, it is now possible to have hot water delivered faster without using the dedicated recirculation line.

Faster water delivery with recirculation

Rinnai RUR series is the only group of tankless water heaters with the ThermaCirc360 recirculation technology. The built-in recirculation pump and its recirculation system ensure faster hot water delivery, with or without the dedicated recirculation line and no matter the plumbing configuration. If there is a dedicated return line in the house, a recirculation pump will move the water from the heater through the return line and back.

In homes where the dedicated line is hard to install, the crossover mode becomes possible due to the ThermaCirc360 technology. The maximum lengths of the recirculation pipes are 400 feet for ¾" diameter and 100 feet for ½" pipe diameter.

Also, with the Rinnai Circ-Logic technology, you can even establish the water delivery pattern to your liking and user habits. Faster hot water delivery reduces the number of user complaints, making it more convenient, comfortable, and due to increased efficiency, there will be less waste in energy and water.

Smart technology

The best of Rinnai also brings the most advanced features in electronics. The electronic control board and provided temperature controller ensure better accuracy, stable operation, control, monitoring, and diagnostics, making troubleshooting easier and quicker.

All the models are Wi-Fi ready, and with the use of the Control-R 2.0 mobile app and your smartphone or tablet, you will have access to timers and schedules and be able remotely to control the unit. You can even give access to a dealer or technician to diagnose the heater remotely, also check the performance for the best comfort and convenience.

In addition to the advanced features from above, the Rinnai RUR98 can use voice activation control, with over 20 voice commands to run the operation.

Related: High-end model - Rinnai RUR199

Flexible venting system

An indoor model RUR98i is the direct vent model that can use concentric or twin-pipe vents to remove the products of combustion out, with the horizontal and vertical termination. The vent pipe can be made of PP, PVC, or CPVC material.

The outdoor model RUR98e is ventless; no venting pipe is needed as there is a venting slot located at the front of the unit that is used for the exhaust. This is what makes Rinnai RUR98 models unique - both concentric and PVC/CPVC venting options are found on the same indoor model, resulting in greater flexibility and faster installation.

Easy maintenance and installation

Isolation valves are included with the RUR98 series and are recommended for installation, making the maintenance and service easier. The valves should be installed on both the hot and cold water side so you can disconnect the heater from the plumbing system if planning to flush the heat exchanger or service other parts.

Contact a licensed plumber for professional installation.

Small and compact size

The small size of 22" x 34" x 14.5" and weight of approx. 72 lbs. makes them, like other tankless units from this manufacturer, easy to handle and install on the wall.

Safety elements

  • Flame rod - flame failure
  • Combustion fan rpm check
  • Boiling protection
  • Over-current glass fuse
  • Thermal fuse
  • Automatic frost protection
  • Remaining flame - OHS


  • Energy factor: 0.92- 0.95 makes it Energy Star compliant
  • Power: 15,200-199,000 BTU
  • Hot water flow: 0.26-9.8 GPM
  • Number of baths: 3-6
  • Temperature: 98-140 F
  • High altitude operation: up to 10,200 ft.
  • Vent lengths: up to 65 feet concentric type and up to 45 feet for twin-pipe PVC/CPVC
  • Gas line size: 3/4" and 1/2" gas line compatible
  • Waterline size: 3/4"
  • Dimensions: 22" x 34" x 14.5"
  • Estimated yearly costs: $417 when using propane; $172 when using natural gas (depends on the use and rates)
  • Weight: 72 pounds
  • Warranty: 12 years on heat exchangers in residential applications; 5 years in commercial applications; 5 years on parts

Related: Low-cost model - Rinnai RL94

Buy a Rinnai RUR98 if you would like to save in the long run, have a large house and family, and would like to enjoy the latest available gadgets and flexibility one tankless water heater offers. The ultra-efficiency saves energy, recirculation saves time and water, and ultra-low NOx gas emission reduces pollution.