Navien NR and NR-A Tankless Water Heaters: Review and Buying Tips

Navien NR condensing boilerNavien NR tankless water heater (photo: amazon)

Navien tankless water heaters from NR (A) series: NR-180, NR-210, and NR-240 are ultra-efficiency units that utilize condensing technology for continuous, on-demand potable water and space heating. This review covers two types, NR-A with the recirculation feature and NR that is without.

Navien NR tankless water heaters: Models review

The Navien manufacturer offers three sizes of tankless water heaters for residential applications, either talking about NR or NR-A series; NR-180 and NR-180A, NR-210 and NR-210A, NR-240 and NR-240A.

With the use of the modulating gas burner, Navien water heaters can work in the power range from the minimum of 15,000 BTU to a maximum of 199,900 BTU/hr and provide the maximum flow rate of 11 GPM, which is ideal for larger homes with more than three bathrooms. There is a cascading arrangement for high-demanding homes that combines water heaters into one system, either NR-A or NR models.

The Navien NR-A series is the same as the "non-A" group, but with the addition of the circulation pump and mini-buffer tank. NR-A models can be used for both domestic hot water and space heating, while the NR is just for potable water.

If you have ever experienced "cold-water sandwiching" during the shower or couldn't get a trickle of warm water, the "A" series is a water heater model you should look for. Thanks to the ComfortFlow technology, the heaters do not require a minimum flow rate to operate, and water temperature fluctuation is minimized. NR models are not equipped with the circulation pump but can utilize the external pump, provide recirculation, and connect to the storage tank.

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Features review

  • Two stainless steel heat exchangers; primary as the main and the other secondary as condensing.
  • Two microprocessors for accurate and steady temperatures, optimal gas combustion, and increased overall safety.
  • Air Pressure and Gas Pressure sensors provide stable combustion and optimal performance regardless of gas pressure fluctuation, vent length, and even in harsh weather conditions.
  • Direct or non-direct venting for indoor models with the use of the electric fan and no venting required for outdoor models.
  • Built-in remote controller for temperature adjustment and error code display.
  • Multi-system for cascading set-up and increased hot water flow.
  • Recirculation mode for faster hot water delivery.
  • Use of natural gas or, with the correct conversion kit, propane gas.
  • Safety features: freeze protection, flame sensor, water and exhaust high limit switch, CO monitoring, and ignition operation detector.
  • Eco Pre-mixed Burner for low NOx emission and its three-phase combustion improves the longevity and performance.
  • Warranty of 15 years on heat exchangers.


Models / Specs NR-180(A) NR-210(A) NR-240(A)
Gas input (BTU) 15,000-150,000 17,000-180,000 17,000-199,000
Water flow (GPM)
(@30 F temp.rise)
8.3 10 11
Energy Factor 0.94-0.97 0.94-0.97 0.95-0.97
Temp. settings (F) 98-140 98-140 98-140
Energy consumption (Watts) 200 200 200
Weight (lbs) 67/77(A) 77/86(A) 77/86(A)
Max. vent length (ft) 100 100 100

As you can see from the above, Navien tankless water heaters from the NR and NR-A series are solid units that provide great benefits to its users; endless and on-demand hot water supply, comfortable showers, inexpensive venting, eco-friendly solution, space-saving design, long warranty, quality, low operating costs, and much more.

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