Bosch KBR21-3 User Manual

Installation and Service Instructions for Contractors
Residential Gas Condensing Boiler
Greenstar FS/Combi FS
6720810590-00.2Wo
WARNING:
Improper installation, set-up, modification, operation or
maintenance of the heating system can cause personal injury and
property damage.
Follow these instructions precisely.
If you require assistance or further information, contact a trained
and certified installer or the gas supply company.
WARNING:
The operating instructions are part of the technical documents that
must be handed over to the owner or operator of the heating
system.
Explain to the owner or operator how to use the heating system
using the operating instructions. Make sure that they are familiar
with all required information for the safe and proper operation of
the heating system.
NOTICE:
In Massachusetts, this appliance must be installed by a licensed
plumber or gas fitter.
These instructions are available in English and French.
Please keep these instructions for future reference.
Warranty information available at www.bosch-climate.us
Annual service is required
KBR16-3. |KBR21-3. |KBR28-3. |KBR35-3. |KBR42-3. |KWB28-3. |KWB35-3. |KWB42-3.
6720810590 (2015/05) CA/US

Bosch KBR21-3 Specifications

General

Brand	Bosch
Model	KBR21-3
Category	Boiler
Language	English

Summary

Key to Symbols and Safety Instructions

General Safety Instructions

Provides essential safety guidelines for boiler operation and installation.

Information About the Appliance

Electrical Wiring Heating Boiler KBR..-3A

Illustrates the electrical connections for the KBR heating boiler model.

Electrical Wiring Combi Boiler KWB..-3A

Shows the electrical wiring diagram for the KWB combi boiler model.

Technical Data

Technical Data Heating Boiler KBR 16-3

Presents detailed specifications for the KBR 16-3 heating boiler.

Regulations

Compliance with Standards and Regulations

Outlines applicable standards and regulatory requirements for installation.

Additional Regulations for Installation in Massachusetts

Lists specific installation requirements mandated for Massachusetts.

Installation

Installation and Operation

Covers general guidelines for installing and operating the heating system.

Installing a Low Water Cut Off (LWCO)

Details the procedure for installing a low water cut-off device.

Connecting Flue Gas Accessories

Instructions for connecting various flue gas system components.

Installation of the Exhaust and Air Intake System

Covers the proper installation of the exhaust and air intake system for safe operation.

Vent and Combustion Air Pipe Lengths

Provides guidelines on maximum pipe lengths for venting and combustion air.

Making the Electrical Connections

Electrical Connections in the Junction Boxes

Details how to make connections within the appliance's junction boxes.

Connecting an External Heating Zone Pump or DHW Recirculation Pump

Step-by-step guide for wiring external pumps to the boiler.

DHW Tank Loading Pump or 3-Way Valve with Spring Return (Only Heating Boiler KBR..-3A)

Wiring instructions for DHW tank pumps or 3-way valves on KBR..-3A models.

Connecting Mains Power Supply

Instructions for connecting the main power supply to the appliance.

Connecting the LWCO Device

Procedure for connecting the Low Water Cut Off (LWCO) device.

Commissioning

Before Operating the Appliance

Pre-commissioning checks and system preparation steps.

Setting Up Space Heating

Guidance on adjusting settings for optimal space heating performance.

Programming the FW 200 Heating Control Unit (Optional Accessory)

Instructions for programming the optional FW 200 heating control unit.

FW 200 Outdoor Reset Heating Control Quick Start (Optional Accessory)

Basic programming guide for the FW 200 outdoor reset control.

KWB..-3A Appliances (Combi Boilers): Setting the DHW Temperature

How to set the domestic hot water temperature on KWB..-3A combi boilers.

KBR..-3A Appliances (Heating Boiler) with DHW Tank: Thermal Disinfection

Procedure for performing thermal disinfection of the DHW system.

Heatronic Boiler Control Settings

First Service Level (Press and Hold the Service Button Until It Lights Up)

Accessing and navigating the first level of service functions.

Second Service Level (At First Service Level, Service Button Lights Up, Press ECO Button and Key Pad Lock Button Simultaneously Until 8.A Appears)

First Service Level

Second Service Level

Gas Type Conversion

Converting to a Different Gas Type

Procedure for converting the appliance to a different gas type.

Setting the Gas-Air Ratio (CO2 or O2)

How to adjust the gas-air mixture for optimal combustion.

Flue Gas Test

Emissions Test Button

Measuring CO Content of Flue Gas

Inspection and Maintenance

Calling Up the Latest Fault (Service Function 6.A)

Burner Servicing

Heat Exchanger Block Inspection and Cleaning

Checklist for Annual Inspection and Maintenance

A comprehensive checklist for performing annual service.

Faults

Troubleshooting

General troubleshooting steps for common issues and safety precautions.

Faults That Are Shown on the Display

Check Sensor Values

Supply Temperature Sensor, External Supply Temperature Sensor, DHW Tank Temperature Sensor, DHW Temperature Sensor

Commissioning Log for the Appliance

Spare Parts