Primary Heat Exchanger - Navien NCB-150E Service Manual

4.9.11 Primary Heat Exchanger

Part
Function
Failure Event
Effects
Error Code
Diagnostic
74 NCB-E Service Manual
1. Main part for heat transfer from the burner.
2. There are multiple paths of water pipes on the heat exchanger surface as well as inside the
combustion chamber which minimizes the heat loss.
1. Water and/or exhaust gas leakage through a crack.
2. Improper heat transfer can cause the water in the heat exchanger to boil due to possible scale
formation.
1. Exhaust gas leakage.
2. Excessive heating of the water that produces boiling noises.
E016, E030, E047
1. Visual inspection: Check if there is a crack on the surface of heat exchanger.
2. Sound inspection: Check if boiling occurs inside the unit.
Check Point
Version 1.4