Bosch ZWB 35-3 A NG User Manual

Faults
73
Greenstar – 6721822579 (2021/01)
17 Faults
17.1 Troubleshooting
DANGER
Explosion!
▶ Close the gas cock prior to working on the gas train.
▶ Check for gas leaks after carrying out work on the gas train.
DANGER
Risk of flue gas poisoning.
▶ Check for leaks after carrying out work on the venting system.
DANGER
Risk of electric shock!
▶ Always disconnect the appliance from the mains power before
performing any work. Always disconnect the appliance from the
mains power before performing any work.
Take measures to prevent accidental reconnection.
WARNING
Danger of scalding!
Hot water can scald.
▶ Drain the appliance before working on components that are water
filled.
NOTICE
Risk of system damage from freezing!
The heating system can freeze up in cold weather if it has been disabled
by a fault shutdown.
▶ Rectify the fault immediately and restart the heating system.
▶ If this is not possible, protect your heating system from freezing by
draining the heating system and hot water pipes at the lowest point.
NOTICE
The Heatronic boiler control can be damaged by leaking water.
▶ Cover the Heatronic prior to work on water filled components.
The Heatronic boiler control monitors all safety and control components.
If a fault arises during operation, an audible warning tone sounds.
Press a button to mute the warning sound.
The display indicates a fault code (e.g. ) and the reset button flashes.
If the reset button is flashing:
▶ press the reset button and hold it until appears on the display.
The appliance starts up again and the current supply temperature is
displayed.
If the reset button is not flashing:
▶ Switch the appliance OFF and ON again.
The appliance starts up again and the current supply temperature is
displayed.
An overview of the faults can be found on page 74.
An overview of the status codes can be found on page 72.
If the fault persists:
▶ Check the PCB and replace if required. Adjust the service functions
in accordance with the commissioning report ( page 78).

Bosch ZWB 35-3 A NG Specifications

General

Brand	Bosch
Model	ZWB 35-3 A NG
Category	Boiler
Language	English

Summary

Symbols, Safety, and Product Overview

General Safety Instructions

Crucial safety guidelines and procedures for installation and operation.

Scope of Delivery and Product Details

Lists included components and describes boiler features, layouts, and specifications.

Regulations, Installation Examples, and Operation Notes

Regulations and Installation Examples

Covers compliance with codes, operating limits, and installation scenarios.

Installation and Operation Guidelines

Key notes for system setup, water, antifreeze, and component maintenance.

Electrical Connection and Commissioning

Electrical Connection Procedures

Safety, Heatronic wiring, junction box connections, and accessory wiring.

Commissioning Steps and DHW Temperature Adjustment

Pre-operation checks, startup, and setting domestic hot water temperatures.

Boiler Control Settings, Gas Adjustment, and Flue Gas Testing

Heatronic Boiler Control Settings

Navigating service menus, setting operating modes, and understanding service functions.

Gas Adjustment and Flue Gas Testing

Procedures for gas conversion, combustion optimization, and emissions measurement.

Inspection, Maintenance, and Faults

Inspection and Maintenance Procedures

Detailed steps for routine service, component checks, and cleaning.

Display Readings, Fault Codes, and Troubleshooting

Interpreting display information, resolving errors, and checking sensor data.

Commissioning Log

Appliance Commissioning Record

A form for documenting installation and service details.