Navien NHB-055 Service Manual

100 NHB Service Manual
Version 1.0
5.2.7 046Error
Error occurrence conditions and check items
Is heat exchanger
thermistor normally
operating?
Is resistance within
normal range?
(refer to page 67)
Replace heat exchanger
thermistor.
Check connector
( #7 and #8 of CN 13)
1 step: Flushing, Clean Filter
2 step: Try to restart
3 step: Replace PCB
Yes
Yes
No
No
5.2.8 047Error
Error occurrence conditions and check items
Is exhaust thermistor
operating normally?
Check connector
(#1 and #2 of CN13)
Replace exhaust thermistor
Resistance between #9 and #10 of CN13
is from 2kΩ to 300kΩ at normal condition.
(see page 63-64 for Wiring Diagram)
No
Yes

Navien NHB-055 Specifications

General

Brand	Navien
Model	NHB-055
Category	Boiler
Language	English

Summary

Safety Information

Safety Definitions

Defines key safety terms used throughout the manual.

Safety Symbols

Explains the meaning of hazard symbols like Danger, Warning, Caution.

Safety Precautions

Lists essential safety measures to prevent hazards.

Product Information

Components

Identifies the main components of the boiler with a diagram.

Technical Data

General Specifications

Provides key operational and physical specifications for the models.

System Details

Setting the DIP Switches

Measuring the Inlet Gas Pressure

Details the procedure and importance of checking gas pressure.

Gas Conversion

Provides instructions for converting the boiler from natural gas to propane.

The Front Panel

Electrical Diagnostic Point & Wiring Diagram

Key Components Description

Troubleshooting

Error code classification

Lists error codes, their levels, functions, and recommended actions.

Troubleshooting guide by symptom

Offers solutions for common operational issues based on observed symptoms.

Replacement of Parts

Replacement Procedure

Components Replacement Instructions

Components Diagram and Part List

Heat Exchanger and Waterway Assembly

Combustion Parts Assembly

Inspection and Maintenance Schedule

Annual Servicing