Navien NCB-150E Service Manual page 17

Pressure Relief Valve Adapter
Fan & Motor
Dual Venturi
High Limit Switch
Air Pipe
Gas Pipe
APS
Air Vent
Circulation Pump
3-Way Valve
Space Heating Supply
Space Heating Return
16 NCB-E Service Manual
Ignition Transformer
Premix Burner
Primary Heat Exchanger
Secondary Heat
Exchanger
Pressure Sensor
(LWCO)
Gas Valve
Flow Sensor
DHW Inlet Filter
(with built-in flow
restrictor)
DHW Inlet
DHW Outlet
Version 1.4