Rinnai RUR Water Heaters 
Review and Buying Tips
(updated 2017)

Find out how homeowners can benefit from buying a Rinnai tankless water heater from RUR series and using in residential or light commercial applications. Explore the latest advanced features and see how Rinnai RUR line of tankless water heaters compares to other models. Models reviewed: Rinnai RUR98i and RUR98e.

Rinnai RUR tankless water heaterRinnai RUR

Rinnai tankless RUR water heaters are recommended for new homes and homes that need an upgrade, and where the old tank-type or less efficient unit couldn't keep up with the hot water demand of the growing family.

With the Rinnai RUR water heater, homeowners will enjoy all the benefits from such an advanced unit; never run out of hot water, have plenty of hot water delivered fast to multiple showers, large baths, even hot tubs. All this, plus great energy and money savings, remotely monitored and controlled by the smartphone and installed the mobile app.

Models and features review

Rinnai RUR water heaters, Energy Star and the largest models from this manufacturer, are available for purchase since 2014.

Model RUR98i is designed for indoor installation utilizing a direct vent system, while model RUR98e is a ventless outdoor unit.

Both models are powered by natural and propane gas, utilizing tankless and condensing technology.

Ultra-efficient heating

Tankless means that hot water is generated on demand - no water storage tank, as the units are equipped with two heat exchangers, where the secondary uses heat from the flue gases to preheat cold incoming water. This is what makes the unit operate in condensing mode, resulting in ultra-high efficiency and lower exhaust temperature.

ThermaCirc360 recirculation

What makes Rinnai RUR series unique is its compliance with the ThermaCirc360 - water heating recirculation technology, so even if there is no dedicated return line, hot water is delivered fast - instantaneous, so there is no wasted time and energy. The ThermaCirc360 features the bypass technology, internal pump, Circ-Logic recirculation technology, timer, and thermal bypass valve.

This feature ensures faster hot water delivery throughout the home, with the significantly reduced wait time for hot water, enhanced convenience and comfort. It also reduces energy consumption and greenhouse emission.

Digital controller

With the provided 24-h digital controller and its programming option, even more energy can be saved, as the hot water usage can be scheduled 24 hours, 7 days a week.

Great power and low pollution

Rinnai RUR Ultra series water heaters with its ultra-low NOx gas burner, can produce maximum power of 199,000 Btu and deliver plenty of hot water - up to  9.8 GPM, which makes them great for up to 4-bath homes.

Thanks to the modulating gas valve the power can be reduced from 199,000 Btu to low 15,200 Btu and water flow rate to 0.26 GPM, which is excellent for small jobs, such as shaving or face washing.

Temperature controller

With the included controller, the temperature of the hot water can be adjusted from the minimum 98 F to the maximum 140 F, in residential applications.

The temperature controller is built into the front panel of the indoor water heater RUR98i, and except the temperature control, it is also beneficial for problem diagnostics, as it displays the error codes for easy troubleshooting.

Flexible venting

Rinnai RUR98i model is a direct vent unit that has the concentric vent and twin pipe PVC/CPVC configuration on the same indoor model providing greater flexibility that other Rinnai models. The outdoor unit RUR98e is ventless that uses the fresh outside air for combustion and where it releases the products of combustion.

Features highlights

  • Maximum energy factor of 0.95 and Energy Star approval ensures great energy savings and reduced NOx emission.
  • Compatible with ThermaCirc360 allowing recirculation with or without the dedicated return line.
  • More venting options on the same unit by using the concentric PP and dual PVC/CPVC.
  • Easily adapts to existing plumbing with or without the dedicated return line.
  • The digital controller is included in both models. With the time and duration adjustment of the circulation system operation, the energy savings are maximized.
  • Ultra Low NOx emission, thanks to the green condensing technology.
  • Safety features include; flame rod, boiling protection, combustion fan rpm check, thermal fuse, frost protection, OHS and over-current protection.
  • Standard gas and water connections of 3/4".
  • Warranty; 12 years on heat exchanger and 5 years on parts.


Models / Specs RUR98i RUR98e
Gas input (BTU) 15,200-199,000 15,200-199,000
Water flow (GPM) 0.26-9.8 0.26-9.8
Energy factor 0.95 0.95
Activation rate (GPM) 0.4 0.4
Temp. settings (F) 98-140 98-140
Energy consumption (Watts) 205 201
Noise level (dBA) 41 52
Max. vent length (ft) 65 N/A
Altitude height (ft) 10,200 10,200
Size (inch) 18.5 x 31 x 10 18.5 x 28 x 10
Weight (lbs) 72.8 72.8


Rinnai RUR tankless water heater is a great buy and can be purchased online for a decent price. Due to the small and compact design, RUR models save on space, can be easily installed and maintain, while providing endless hot water in continuous supply, fast and with less energy and water waste. These gas appliances are ultra efficient and green, also smart to modify the power based on the needs, diagnose the problem where the error codes are used for easy troubleshooting.

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