Navien NR-180(A) Operation & Installation Manual page 66

Safety Instructions:
This Navien Water Heater is factory set at 120°F (NP Series: 140°F )
for your safety and comfort. Increasing the set temperature
increases the risk of accidental scalding. Consult the chart below
before you decide to adjust the set temperature.
Households with small children, disabled, or elderly persons may require
120°F or lower temperature setting to prevent contact with "HOT" water.
Water temperatures over 125°F can cause severe burns instantly or death
from scalds. If the proposed water heater outlet temperature is above
125°F, a thermostatically controlled mixing valve or temperature limiting
valve should be considered to reduce the risk of scalding.
Contact a licensed plumber or the local plumbing authority for further
information.
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