Bosch 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.

Bosch 250SX LP Specifications

General

Brand	Bosch
Model	250SX LP
Category	Water Heater
Language	English

Summary

Warning and Safety

General Safety Guidelines

Gas Leak Emergency Procedure

Critical steps to follow immediately if a gas leak is detected.

Appliance Details

Technical Specifications

Dimensions and Installation Clearances

Specifies appliance dimensions and required clearances for safe installation.

General Installation and Safety Rules

Covers general rules, proper location selection, and safe operation guidelines.

Mounting and Combustion Air

Instructions for mounting the heater and details on combustion air needs.

Venting Requirements and Options

Explains venting procedures, requirements, and available configurations.

Gas Piping and Connections

Instructions for correctly and safely connecting the gas supply.

Gas Line Sizing and Pressure Measurement

Water Connections and PRV Installation

Steps for connecting water lines and installing the pressure relief valve.

Electrical Connections

Safety guidelines for connecting the electrical power supply.

Initial Operating Instructions

Pre-Operation Safety Warnings

Crucial safety warnings and instructions to review before operating the unit.

Lighting and Operation

Operation Instructions

Setting Water Temperature

Troubleshooting

Burner Ignition Issues

Addresses problems related to the burner failing to ignite when hot water is used.

Low Water Flow or Pressure Problems

Diagnoses and solutions for issues caused by insufficient water flow or pressure.

Hot Water Temperature Fluctuations

Explains causes and solutions for unstable hot water temperatures.

Error Code Troubleshooting

Electrical Diagram

Electrical Schematic

250 SX Functional Scheme

Operational Logic Flowchart

Special Adjustment for Measuring and Adjusting CO2 Levels

CO2 Measurement and Adjustment

Twelve Year Limited Warranty

Warranty Coverage and Claims