Navien NHB-150 Service Manual

74 NHB Service Manual
Version 1.0
4.9.10 Primary Heat Exchanger
Part Check Point
Function
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.
Failure Event
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.
Effects
1. Exhaust gas leakage.
2. Excessive heating of the water that produces boiling noises.
Error Code E016, E030, E047
Diagnostic
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.
Color / Number of wires N / A

Navien NHB-150 Specifications

General

Model	NHB-150
Category	Boiler
Maximum Input	150, 000 BTU/h
AFUE	95%
Vent Type	Direct Vent
Fuel Type	Natural Gas or Propane
Min. Input (NG)	15, 000 BTU/h
Min. Input (LP)	15, 000 BTU/h
Voltage	120 V
Water Connection Size	1 inch NPT
Gas Connection Size	3/4 inch NPT
Vent Diameter	3"