Navien NCB-180, Service Manual, Page: 15 / 149

12 NCB Service Manual Version 1.0

This boiler has been approved for use in the USA
and Canada only.
Using the boiler in any other country will void the
manufacturer’s warranty.

Should overheating occur or the gas supply fail to
shut off, turn off the manual gas valve to the
appliance.

Do not use this appliance if any part has been
under water.
Immediately call a qualified service technician to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
2. Product Information
2.1 Product Information
Navien features the NCB Series gas boiler with a built-in
Circulation Pump and Air vent. This appliance is fully
modulating and provides central heating and domestic hot
water. Depending on the heat capacity, each model is divided
into three types; 180, 210 and 240.
Model
Maximum
Space Heating
Input
Maximum
DHW
INPUT
NCB-180 80,000 Btu/h 150,000 Btu/h
NCB-210 100,000 Btu/h 180,000 Btu/h
NCB-240 120,000 Btu/h 199,900 Btu/h
The appliance always gives priority to DHW supply.
Navien features the NCB Series boiler with a built-in Circulation
pump and 3-Way valve assembly, Flow sensor, DHW plate heat
exchanger and safety valve(or relief valve). A separate heating
expansion vessel is required.
Internal freeze protection and an electronic control unit are
incorporated within the boiler. Any standalone room
thermostat or set of contacts be used with boiler.