Navien NCB-240 User Manual

Navien America, Inc.
20 Goodyear lrvine, CA 92618 TEL +949-420-0420 FAX +949-420-0430 www.navienamerica.com
Getting Service
If your NCB boiler requires service, you have several options for getting service:
●
Contact Technical Support at 1-800-519-8794 or on the website: www.navienamerica.com. For
warranty service, always contact Technical Support first.
●
Contact the technician or professional who installed your boiler.
●
Contact a licensed professional for the affected system (for example, a plumber or electrician).
When you contact Technical Support, please have the following information at hand:
●
Model number
●
Serial number
●
Date purchased
●
Installation location and type
●
Error code, if any appears on the front panel display.
Combination Boiler
Installation & Operation
Manual
Version: 1.00(Oct. 02. 2013)

Navien NCB-240 Specifications

General

Fuel Type	Natural Gas or Propane
AFUE	95%
Energy Star Certified	Yes
Voltage	120V
Max Input	199, 900 BTU/h
Vent Type	Direct Vent
DHW Flow Rate	4.5 GPM @ 77°F rise
Type	Condensing Combi Boiler
Warranty	15 years heat exchanger, 5 years parts

Summary

Getting Service

Model and Safety Overview

Critical Operation Warnings

Highlights immediate dangers and critical warnings for safe operation.

Massachusetts Installation Requirements

Carbon Monoxide Detector Installation

Mandatory installation requirements for carbon monoxide detectors.

Required Signage

Details on the mandatory signage for vent terminals.

General Safety Information and Symbols

Gas Leak Safety Procedures

Step-by-step procedures to follow if a gas leak is detected.

Flammable Product Precautions

Guidelines for avoiding flammable products near the boiler.

Boiler Operation and System Safety

Boiler Operation Warnings

Critical warnings about operating the boiler with covers open, improper venting, and wet hands.

Burn Prevention and Water Temperature Safety

Preventing Burns

Guidelines for safe water temperature settings to prevent scalding injuries.

About the Boiler

Included Components

Lists all items included in the boiler packaging.

Boiler Specifications

Space Heating Ratings

Technical data for space heating input, capacity, and AFUE ratings.

General and Temperature Specifications

Temperature Setting Ranges

Specifies the temperature ranges for DHW and space heating.

Boiler Components Overview

Boiler Dimensions and Connections

Supply Connection Details

Lists and illustrates the various supply connection types and sizes.

Boiler Rating Plate Information

Installing the Boiler

Selecting an Installation Location

Factors to consider when choosing a suitable location for the boiler.

Installation Location Details

Installation Clearances

Required minimum clearances around the boiler for installation.

Mounting the Boiler to the Wall

System Piping Installation

Space Heating System Piping

Steps for installing the space heating system piping.

Space Heating System Essentials

Low Water Cut Off (LWCO) Device

Information on the internal and external LWCO devices.

Piping System Components

Pressure Relief Valve Installation

Instructions for installing the pressure relief valve on the heating system.

Domestic Hot Water (DHW) System

DHW Scald Hazard

Information on the risk of scalding from hot water.

DHW System Components

Flow Restrictor Installation

Instructions for installing the flow restrictor for proper water flow.

DHW Safety and Condensate Drain

Condensate Drain Connection

Instructions for connecting the condensate drain line.

System Water Fill Connections

Built-in Water Fill Connection

Using the boiler's auto-feeding water connection.

Water System Testing and Application Examples

Water System Testing

Steps to perform a fill test on the installed water system.

System Air Removal and Zoning

Air Removal Strategies

Ensuring proper removal of air from the boiler and system.

Zone System Configuration

Zone System with Circulators

Diagram and explanation for a zone system using circulators.

Air Handler System Integration

Air Handler System Diagram

Illustration of a system application with an air handler.

Connecting the Gas Supply

Gas Supply Connection Safety

Critical warnings about gas type, pressure, and professional installation.

Gas Supply Installation Details

Gas Pipe Sizing Tables

Tables for determining appropriate gas pipe sizes based on length and capacity.

Gas Pressure and Capacity

Measuring Inlet Gas Pressure

Procedure for measuring the boiler's inlet gas pressure.

Venting the Boiler

Venting Safety Warnings

Critical warnings about improper venting and carbon monoxide risks.

Vent Pipe Specifications

Selecting Vent Types

Information on direct venting and requirements for different vent materials.

Vent Pipe Materials and Length Measurement

Measuring Vent Length

Guidelines for calculating maximum vent length and elbow equivalencies.

Vent Termination and Examples

Vent Termination Guidelines

Clearances and considerations for vent termination locations.

Non-Direct Venting Installation

Single Pipe Non-Direct Venting

Details on preventing back drafting with single pipe non-direct venting.

Setting the DIP Switches

PCB DIP Switch Settings

Configuration options for DIP switches on the main circuit board.

Front Panel DIP Switch Configuration

Front Panel DIP Switch 1 Settings

Settings for temperature unit, well pump, and high altitude.

Connecting the Power Supply

Power Supply Connection Safety

Critical safety warnings regarding electrical connections.

Installation Checklist

Operating the Boiler

Turning Boiler On and Off

Procedure for powering the boiler on and off using the power button.

Adjusting Boiler Temperatures

Space Heating Temperature Adjustment

Steps to adjust the space heating supply and return temperatures.

DHW Temperature and Information Display

Viewing Basic Boiler Information

How to access and view basic operating information on the display.

Boiler Modes and Parameters

Setting System Parameters

Instructions for entering Special Parameter mode and changing settings.

Outdoor Reset Control Configuration

Outdoor Reset Control Mode Setup

Steps to enable and configure the Outdoor Reset Control mode.

Outdoor Reset Temperature Settings

Heat Load Types Explained

Description of different heat load types for outdoor reset.

Heating Performance Settings

Max Heat Capacity for Space Heating

Configuring the maximum heat capacity for space heating.

Pump and Cycling Control

Pump Freeze Protection Setting

Setting the temperature to activate pump freeze protection.

DHW and Pump Operation Settings

DHW Wait Time Setting

Setting the wait time for DHW supply mode.

Supply and Return Temperature Limits

Supply Absolute MAX Temperature

Setting the maximum absolute supply temperature.

Supply and Return Temperature Minimums

Return Absolute MIN Temperature

Setting the minimum absolute return temperature.

Boiler Initialization and Reset

Resetting the Boiler

Steps to reset the boiler to resolve error messages.

Appendix: Gas Conversion

Gas Conversion Tools

List of tools necessary for performing the gas conversion.

Wiring Diagram

Ladder Diagram

Component Assembly Diagrams

Case Assembly Diagram

Diagram and parts list for the boiler case assembly.

Burner Assembly Diagram

Waterway Assembly Diagram

Fan (Gas) Assembly Diagram

Outdoor Temperature Sensor Installation

Sensor Installation Procedure

Step-by-step instructions for installing the outdoor temperature sensor.

Outdoor Reset Control Features

Outdoor Reset Control Operation

How the Outdoor Reset Control enhances efficiency and performance.