Bosch ZBR 35-3 A NG User Manual

6721822579 (2021/01) US/CA
Installation and Service Instructions for Contractors
Residential Gas Condensing Boiler
Greenstar
0010004900-002
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.
These instructions are available in English and French.
Please keep these instructions for future reference.
ZBR 21-3 A... | ZBR 28-3 A... | ZBR 35-3 A... | ZBR 42-3 A... | ZWB 28-3 A... | ZWB 35-3 A... |
ZWB 42-3 A...

Bosch ZBR 35-3 A NG Specifications

General

Type	Condensing Boiler
Nominal heat output	35 kW
Fuel Type	Natural Gas
Water Pressure	1.0 - 3.0 bar
Weight	Approx. 45 kg

Summary

Explanation of Symbols and Safety Instructions

General Safety Instructions

Provides critical safety procedures for gas leaks, flue gas, and general appliance operation.

Product Description

Product Dimensions and Minimum Clearances

Provides graphical and numerical data for physical dimensions and required clearances.

Electrical Wiring ZBR...-3A

Electrical Wiring ZWB...-3A

Regulations

Compliance with Standards and Regulations

Details compliance with national, local codes, and specific standards like ANSI Z21.13/CSA4.9.

Operating Limits of the Boiler

Notes on Installation and Operation

Notes on Installation and Operation

Mounting the Appliance

Installing the Low Water Cut Off (LWCO)

Connecting Flue Gas Accessories

Explains how to attach vent flanges, flue gas adapters, and options for venting systems.

Installation of the Exhaust and Air Intake System

Details requirements for exhaust/air intake installation, including safety notices and direct vent systems.

Vent and Combustion Air Pipe Lengths

Electrical Connection

General Notes

Covers electrical safety, grounding, circuit breakers, and wiring requirements.

Electrical Connections in the Junction Box (120 VAC)

Connecting the LWCO Device

Commissioning

Before Operating the Appliance

Lists essential steps before powering on, including water filling, purging, and gas verification.

Switch on Heat

ZBR...-3A Appliances (Heating Boilers) with DHW Tank: Setting the DHW Temperature

Explains how to set the domestic hot water temperature for ZBR...-3A models.

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

Explains how to set the domestic hot water temperature for ZWB...-3A models.

Setting Frost Protection

Details how to set frost protection for both the heating system and DHW tank.

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

Heatronic Boiler Control Settings

Guideline to Service Functions

Overview of the Service Functions

Description of the Service Functions

Gas Adjustment

Converting to a Different Gas Type

Instructions and warnings for converting the appliance between natural gas and LPG.

Checking and Setting the Gas-Air Ratio (CO2 or O2), if Required

Details the procedure for checking and adjusting the gas-air mixture using flue gas analysis.

Dynamic Gas Pressure Test Port

Flue Gas Test

Measuring CO Content of Flue Gas

Guides the measurement of CO levels in flue gas and safety limits.

Inspection and Maintenance

Description of Various Steps

Lists and briefly describes multiple maintenance procedures for the boiler.

Burner Servicing

Details the procedure for servicing the burner, including cover removal and cleaning.

Heat Exchanger Block Inspection and Cleaning

Provides steps for inspecting and cleaning the heat exchanger block using specific tools.

Maintenance and Inspection Checklist

A checklist to guide technicians through the service and maintenance procedure.

Faults

Troubleshooting

Provides general advice on troubleshooting, safety, and handling faults.

Faults That Are Shown on the Display

A table listing fault codes displayed on the unit and their corresponding elimination procedures.

Faults That Are Not Shown on the Display

Lists common faults that do not trigger a display code and their remedies.

Check Sensor Values

Provides resistance tables for various sensors to check their functionality.