Bosch Zwb283 Manual

							Operating Instructions
Residential Gas Condensing Boiler
Greenstar
6 720 806 992-00-1O
ZBR16/21/28/35/42-3A... | ZWB28/35/42-3A...
6 720 806 993 (2013/03) CA/US 
						

							2 | Contents
6 720 806 993 (2013/03) Greenstar
Contents
1 Key to symbols and safety instructions   . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
1.1 Key to symbols   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
1.2 Safety instructions   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
2 Information about the appliance  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
2.1 Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
2.2 Proper use  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
2.3 Overview of boiler types  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
3 Preparing the appliance for operation   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
3.1 Checking the boiler water pressure  . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
3.2 Topping up the heating system water   . . . . . . . . . . . . . . . . . . . . . . . . .   9
4 Operation   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10
4.1 Overview of controls  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   12
4.2 Switching the appliance ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . .   14
4.3 Turning the space heating ON   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   14
4.4 Programming the heating control unit  . . . . . . . . . . . . . . . . . . . . . . . .   16
4.5 ZBR..-3A appliances with DHW tank: 
Setting the DHW temperature   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4.6 ZWB..-3A appliances (combi boilers): 
Setting the DHW temperature   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.7 Setting manual summer mode  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   19
4.8 Setting frost protection   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   20
4.9 Activating the key pad lock  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   21
4.10 Display codes   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   22
5 Thermal disinfection   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   22 
						

							Contents | 3
6 720 806 993 (2013/03)Greenstar
6 Energy saving tips  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   24
7 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   26
8 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   27
9 Environmental responsibility/disposal   . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
10 Quick reference  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
Index   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   30 
						

							4 | Key to symbols and safety instructions
6 720 806 993 (2013/03) Greenstar
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
Keywords at the start of a warning indicate the type and seriousness of the ensuing 
risk if measures to prevent the risk are not taken. The following keywords are defined 
and can be used in this document:
•NOTICE indicates that property damage may occur.
•CAUTION indicates that personal injury may occur.
•WARNING indicates that severe personal injury may occur.
•DANGER indicates that severe personal injury or death may occur.
Important information
Additional symbols
Warnings in this document are identified by a warning triangle 
printed against a grey background.
Important information for the proper use of the boiler is also 
provided in this manual. You will find the information with a 
symbol shown on the left and bordered by horizontal lines above 
and below the text.
SymbolExplanation
▶ Sequence of steps
  Cross-reference to other points in this document or to other documents
• Listing/list entry
– Listing/list entry (2nd level)
Table 1   
						

							Key to symbols and safety instructions | 5
6 720 806 993 (2013/03)Greenstar
1.2 Safety instructions
General information
This manual is available in English and French.
▶ Keep this manual for future use.
▶ Observe the safety instructions of this manual before putting the heating 
appliance into operation.
If the information in this manual is not followed exactly, a fire or explosion may result 
causing property damage, personal injury or loss of life.
▶ Do not store or use gasoline or other flammable vapors and liquids in the vicinity 
of this or any other appliance.
▶ What to do if you smell gas
– Do not try to light any appliance.
– Do not touch any electrical switch; do not use any phone in your building.
– Immediately call your gas supplier from a neighbor’s phone. Follow the gas 
supplier’s instructions.
– If you cannot reach your gas supplier, call the fire department.
▶ Installation and service must be performed by a trained and certified heating 
contractor, service agency or the gas supplier.
If you smell gas
▶ Turn off the gas cock ( page 12).
▶ Open windows and doors.
▶ Do not operate any electrical switches.
▶ Extinguish all open flames.
▶From outside the building, call gas utility company and a trained and certified 
heating contractor.
If you smell flue gas
▶ Switch OFF the appliance ( page 14).
▶ Open windows and doors.
▶ Inform a trained and certified heating contractor. 
						

							6 | Key to symbols and safety instructions
6 720 806 993 (2013/03) Greenstar
For appliances operating on room air: Danger of flue gas poisoning if supply of 
combustion air is insufficient
▶ Safeguard supply of combustion air.
▶ Do not cover or reduce the size of ventilation openings in doors, windows and 
walls.
▶ Safeguard sufficient supply of combustion air also for appliances installed at a 
later date, e.g. kitchen exhaust fans, clothes dryers, and air conditioning units 
with vent to the outside.
▶ Never operate the appliance if the supply of combustion air is insufficient.
Danger of explosion of flammable gases.
▶ Only employ a trained and certified contractor to carry out work on the gas train.
Risk of scalding
▶ If running at DHW temperatures above 104 °F (40 °C) ask a trained and certified 
heating contractor to install a tempering valve to prevent scalding.
▶ When the thermal disinfection function is enabled, DHW temperatures above 
140 °F (60 °C) can occur.
Risk of damage due to operator error
Operator errors can result in personal injury and damage to property.
▶ Ensure that children never operate this appliance unsupervised or play with it.
▶ Ensure that only people who know to operate this appliance correctly have access 
to it.
Installation, conversion
Only have the appliance installed or modified by a trained and certified heating 
contractor.
Never modify any parts that carry flue gas.
Never close the outlet of safety valves. Water may be expelled from any safety valve 
during heat-up.
Inspection and maintenance
The operator is responsible for safety and environmental compliance of the heating 
system. 
						

							Information about the appliance | 7
6 720 806 993 (2013/03)Greenstar
Sign a maintenance and inspection contract with a trained and certified contractor, 
covering an annual inspection and demand-dependent maintenance. This 
guarantees high efficiency and environmentally sound combustion.
Explosive and easily combustible materials
Never use or store easily combustible materials (paper, thinners, paints, etc.) near 
the appliance.
Combustion air / room air
To prevent corrosion, keep the supply of combustion air / room air free of corrosive 
substances (e.g. halogenated hydrocarbons that contain chlorine or fluorine 
compounds).
Overheating of the appliance
Should overheating occur or the gas supply fail to shut off, do not turn off or 
disconnect the electrical supply to the pump. Instead, shut off the gas supply at a 
location outside of the appliance.
In case of water damage
Do not use this boiler if any part has been under water. Immediately call a trained and 
certified service technician to inspect the boiler and to replace any part of the control 
system and any gas control which has been under water.
2 Information about the appliance
2.1 Certifications
This product has been tested and certified for the US and the 
Canadian market and complies with all applicable standards 
required for the US and the Canadian market.
2.2 Proper use
The appliance may only be installed in closed loop hot water central heating systems.
Any other purpose is considered improper use. Any resulting damage is excluded 
from the manufacturer's warranty. 
						

							8 | Preparing the appliance for operation
6 720 806 993 (2013/03) Greenstar
The commercial and industrial use of the appliance for generating process heat is not 
permitted.
2.3 Overview of boiler types
Z Central heating appliance
W DHW heating
B Condensing technology
R Constant temperature control
16…42  Output up to 54,600 / 71,600 / 95,500 / 119,400 / 143,300 BTU/hr
(16 / 21 / 28 / 35 / 42 kW)
-3 Version
A Fan-supported appliance 
3 Preparing the appliance for operation
▶ If existing, open the heating supply valve and the heating return valve.
▶ If existing, open the cold water valve and the DHW valve.
▶ When using ZBR..-3A appliances with DHW tank, open a DHW tap until water runs 
out.
▶ Open the gas cock.
▶ Open the control panel cover.
Greenstar ZBR16-3A
ZBR21-3A
ZBR28-3A
ZBR35-3A
ZBR42-3A
ZWB28-3A
ZWB35-3A
ZWB42-3A
Table 2   
						

							Preparing the appliance for operation | 9
6 720 806 993 (2013/03)Greenstar
3.1 Checking the boiler water pressure
The standard boiler water pressure is 14.5 - 21.75 psi (1 - 1.5 bar).
Should a higher boiler water pressure be required, refer to a trained and certified 
heating contractor.
Fig. 1  
3.2 Topping up the heating system water
Topping up the heating system water is different on every system. Therefore, you 
should ask a trained and certified heating contractor to show you how it is done.
Maximum pressure of 30 psi (2.07 bar) at maximum heating water temperature 
must not be exceeded (safety valve will spill).
6 720 641 934-04.2O
1
02
3
4
bar psi1530
45 
						

							10 | Operation
6 720 806 993 (2013/03) Greenstar
4 Operation
These operating instructions apply only to the boiler. 
Depending on the heating control unit used, some functions may vary.
The following options for controlling the heating system are available:
• Outdoor reset control unit ( page 16, Fig. 6) installed in the boiler ( page 12, 
[19])
• Outdoor reset control unit mounted on the wall
• Room thermostat
• Outdoor reset with room influence (room thermostat)
• Third party system control unit
Therefore, please read the operating instructions for the heating 
control unit used.