Navien NHB Series, Installation & Operation Manual

Page: 8 / 135

8 About the Boiler
General Specifications
Item NFB-301C NFB-399C
Dimensions 25.1 in (W) × 22.3 in (D) × 32.8 in (H)
Boiler Weight 243 lb (110 kg) 278 lb (126 kg)
Boiler Weight with Water 307 lb (139 kg) 371 lb (168 kg)
Installation Type Indoor Wall-Hung
Venting Type Forced Draft Direct Vent
Ignition Electronic Ignition
Natural Gas Supply Pressure (from source) 3.5 in–10.5 in WC
Propane Gas Supply Pressure (from source) 8.0 in–13.5 in WC
Natural Gas Manifold Pressure -0.06 to -0.87 in WC -0.03 to -1.85 in WC
Propane Gas Manifold Pressure -0.01 to -0.92 in WC -0.01 to -0.90 in WC
Gas Connection Size 3 /
4
in NPT
Power Supply
Main Supply 120 V AC, 60 Hz
Maximum Power
Consumption
Less than 12 amperes
Materials
Casing Cold-rolled carbon steel
Heat Exchangers Stainless Steel
Venting
Exhaust
3 in or 4 in PVC, CPVC, approved polypropylene, approved stainless steel
3 in or 4 in Special Gas Vent Type BH (Class III, A/B/C)
Intake
3 in or 4 in PVC, CPVC, polypropylene, stainless steel
3 in or 4 in Special Gas Vent Type BH (Class III, A/B/C)
Vent Clearance 0 in to combustibles
Safety Devices
Flame Rod, APS, Ignition Operation Detector
Water Temperature High Limit Switch, Exhaust Temperature High Limit Sensor, Water
Pressure Sensor
Temperature Setting Range
Item Temperature Setting Range Remarks
Space Heating
Supply 77–194°F (25-90°C) Actual supply and return temperatures vary
depending on the selected outdoor reset
curve.
Return 68–158°F (20-70°C)
Note
For more information about the space heating temperature setting range, refer to “11.5.2 Setting the Space Heating Operation” on
page 93.