Bosch AQUA STAR 250SX LP - User Manual

MODEL 250SX NG and 250SX LP
Temperature Modulated with Electronic Ignition
Suitable for heating potable water only
Not approved for space heating purposes
(Intended for variable flow applications with multiple tapping points)
250 SX NG
250 SX LP
6 720 607 057 (04.05) JS
Warning: If the information in this manual is not
followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
Do not store or use gasoline or other flammable
vapor and liquids in the vicinity of this or any other
appliance.
Improper installation, adjustment, alteration,
service or maintenance can cause injury or
property damage. Refer to this manual. For
assistance or additional information consult a
qualified installer, service agency or the gas
supplier.
In the Commonwealth of Massachusetts this
product must be installed by a licensed plumber or
gas fitter.
Upon completion of the installation, these
instructions should be handed to the user of the
appliance for future reference.
What to do if you smell gas
• Close gas valve. Open windows.
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any
phone in your building.
• If you cannot reach your gas supplier, call the fire
department.
• Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions
• Installation and service must be performed by a
qualified installer, service agency or the gas supplier.

Summary

BOSCH Aqua Star Water Heater Introduction

Gas Leak Safety Procedures

Immediate actions for gas leaks, including shutting off the valve, opening windows, and contacting authorities.

Critical Safety Warnings and Precautions

Electrical Safety and Gas Leak Response

Emphasizes electrical grounding, shock hazards, and safe practices when smelling gas.

Flammable Vapor Hazards and General Cautions

Warnings about flammable liquids, FCC rules, and general cautions for safe use.

Installation Dimensions and Clearances

Minimum Installation Clearances

Specifies the required clearances around the appliance for safe installation.

Safe Operation and Installation Location

General Safe Operation Rules

Outlines essential guidelines for safe installation and daily operation.

Selecting the Proper Installation Location

Guidance on choosing an appropriate location considering combustion air and venting.

Installation Requirements and Clearances

Combustion Air Supply Requirements

Explains the importance and methods for providing adequate combustion air.

Venting System Requirements

Exhaust Venting Installation

Crucial guidelines for properly venting exhaust gases using sealed stainless steel pipe.

Venting Options and Specifications

Venting Configurations and Pipe Types

Vent System Installation Details

Exhaust and Combustion Air Piping Connections

Venting System Layouts

Room Sealed (Twin Pipe) System Diagram

Open Combustion (Single Pipe) System Diagram

Vent Terminator Placement Guidelines

Recommended Vent Terminator Locations

Table detailing minimum distances for vent terminators relative to openings and structures.

Condensate Management and Vent Support

Condensate Trap Installation Procedures

Gas Piping and Connections

Gas Line Sizing Principles

Guidelines for determining the correct gas supply pipe size based on BTU and length.

Gas Line Sizing Charts

Natural Gas Piping Capacity Tables

LP Gas Piping Capacity Tables

Gas Supply and High Altitude Operation

Recommended Gas Line Sizing

High Altitude Performance Adjustments

Water Connections and Safety Valve

Connecting Water Inlet and Outlet

Pressure Relief Valve (PRV) Installation

Guidance on correctly installing the pressure relief valve for safety compliance.

Operation and Electrical Safety

Electrical Connections and Grounding

Requirements for connecting the unit to a 120VAC circuit and ensuring proper grounding.

Initial Operation and Lighting Procedures

Basic Operation and Temperature Control

Adjusting Water Temperature Settings

Water Temperature Setting and Performance Charts

Modulating Water Temperature Control

Maintenance and Troubleshooting Introduction

Annual Maintenance Checks

Troubleshooting: Burner Ignition Issues

Addresses common causes and solutions when the burner fails to ignite.

Troubleshooting Common Operational Problems

Low Water Flow and Temperature Issues

Temperature Fluctuations and Noise Diagnosis

Error Code Troubleshooting Guide

Diagnostic Error Codes and Solutions

A table listing error codes, their causes, and recommended troubleshooting steps.

Electrical System Overview

Electrical Diagram and Component Identification

Functional Operation Logic

Appliance Operation Flowchart

CO2 Adjustment and Measurement Procedure

Measuring CO2 Levels

Steps for a technician to measure CO2 levels using an analyzer.

Adjusting Air-Gas Mixture for CO2

Instructions on how to adjust the air-gas mixture to achieve optimal CO2 levels.

CO2 Adjustment Fine-Tuning

Screw Adjustment for CO2 Levels

Warranty Information and Claims

Limited Warranty Terms and Coverage

Bosch AQUA STAR 250SX LP Specifications