Noritz tankless water heaters, N-0631S (NR71) and N-0531S (NR66) series that we are going to review here are gas appliances using either natural or propane gas, recommended for smaller and middle size homes, as they produce enough hot water for up to 3 applications working at the same time.
Even without high class dual
flame burner and commercial grade heat
exchanger as other models, Noritz tankless water heaters N-0631S
models are equipped with a powerful high performance single flame
burner that allows them to be and EnergyStar
With 12 options you can adjust the output hot water
100 and 160 F (38 C - 71 C ). Factory set on 110 F (43 C) Noritz on
demand models are designed to prevent scalding water and burns.
For the most residential applications, like dishwashing or shower,
recommended hot water temperature is below 120 F (49 C).
Temperature of the exhaust gases is high and
as there is a lot of
moisture they tend to produce an acid compound that can
flue. That is the reason for installing a stainless steel
Efficiency level is 83% for both natural gas and LP
Single flame burner
Modulating gas valve for automatically burner output adjustment
Turbo Flow system for high demand applications
Self diagnostic on board computer system, great for troubleshooting and repairs
Suitable for installations up to 4500 ft or 1.5 km above sea level
Thermal fuse provides an automatic protection from overheating
Freeze-prevention heater works automatically if power is provided
Lightning prevention device
Fan rotation detector
Resin coated PC board for element protection
Automatic air regulator monitors an internal temperature
Isolation valves with pressure relief valve - allows easy flushing and full diagnostic testing.
ScaleShield is Noritz brand water softener protects from lime and mineral build up.
Recess box for N-0631S-OD (NR71-OD) and N-0531S-OD (NR66-OD) models only
Outdoor vent cap for N-0631S (NR71) and N-0531S (NR66) models
Remote controller outdoor junction box, necessary when installing outdoor
High elevation adjustment
On demand water heaters, N-0631S (NR71) series, with a maximum power of 180,000 BTU and with the capacity range from 0.5-7.1 GPM, are ideal for one to three bathroom homes. They can be easily installed indoor and outdoor. When installing inside, you can run vent either horizontally or vertically.
Sufficient air supply is required and since models are power vented, products of combustion are extracted out through the vent pipe while the inside air is sucked in through the perforated front cover.
N-0631S-OD (NR71-OD) and N-0631S (NR71-SV), for outdoor installation, are using horizontal vent that is built into the water heater so there is no requirement for any venting elements. The outside air is used for combustion (exhaust and air intake slots are located on the front cover).
For N-0631S (NR71) models only, if there is any problem with a water heater, the error code will show up on the lamp.
Noritz water heaters N-0531S (NR66) models, because of its small size, max. capacity of 6.6 gallons of hot water and 140,000 BTU per hour are perfect for apartments, condominiums and townhouses that are using up to 2 showers.
(Photos courtesy of Noritz)