Noritz NR71 
Tankless Water Heaters 
Review and Buying Tips

Review of the main features and benefits of Noritz NR71 tankless water heaters. When should you buy a Noritz water heater from NR71 series? 

Noritz water heaters from NR71 series (old N-0631S) are designed as tankless units for an endless and continuous hot water supply. NR71 water heaters heat water on demand and can supply up to three bathrooms or smaller and middle size homes.

Tankless technology allows Noritz NR71 great flexibility so that they can be installed almost anywhere. They are wall mounted with the forced and sealed combustion making them ideal for kitchen or bathroom installation and where the point of service is.


Models review

NR71 series consists of two models: Noritz NR71-SV model that can be installed either inside (with the correct venting) or outside, and model

Noritz NR71-OD, which can be installed outside only. NR71-SV model, when used as an indoor model, is using a stainless steel pipe for horizontal or vertical venting, while the outdoor model has the horizontal vent built into the unit. They are made for residential, and some commercial applications but are not built for recreation vehicles and boats.


Capacity and power

Both Noritz NR71 water heaters are designed to provide a maximum power of 180,000 Btu per hour and water flow of 7.1 gallons per minute (at 35 F temperature rise), which makes them ideal for supplying hot water up to three applications at the same time.

If you need just a trickle of water, for face washing or shaving, NR71 models can lower the water flow to its minimum of 0.5 GPM, where power, thanks to the modulating burner, will also be reduced to its minimum of 25,000 Btu/hr.

Single powerful burner

These models come with one single burner which is not only very efficient but provides a stable water temperature while reducing the emission of greenhouse gases.

Efficient heating

Direct electronic ignition is the standard equipment, so no more waste of energy through the pilot light. It also contributes to keeping the energy factor high, which is above 0.82.

Self-diagnostic system

If something is wrong with the unit, self-diagnostic computer system shows the error message (11, 90, 99...) on the remote control (not supplied with the unit), and based on the code you can easily troubleshoot the problem. If not using the remote control, check for flashing on the unit as the error is displayed on the lamp.

Remote control

Also, if using the remote control it is easy to change the temperature of the outgoing hot water, and there are 12 options where the minimum temperature is 100 F while the maximum is 160 F.

Safety features

    Both indoor and outdoor NR71 models are equipped with the safety features to protect the water heater, you and your home:
  • Flame rod
  • Automatic overheat protection system - Thermal fuse
  • Overheat prevention system
  • Freeze protection to - 30 F for an indoor and -4 F for outdoor models. This applies to the heater's internal plumbing.
  • Lighting protection device
  • Fan rotation detector
  • Safety lock-out system to protect from scalding temperatures
  • Resin coated PC board protect the elements and makes them durable


NR71 tankless water heaters used for residential water heating, come with the 12-year limited warranty on the heat exchanger, 5 years on other components and one year on labor.


Noritz NR71 water heaters are, with the tankless technology, ideal for homes with up to three bathrooms or to supply three applications with hot water simultaneously. Being an Energy Star compliant, NR71 models provide lower water heating costs and rebates from utility companies, including government grants. Both models are made of the strong materials which make them very durable and reliable.


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