Bosch ZBR16-3A User manual

Operating Instructions
Residential Gas Condensing Boiler
Greenstar
6 720 806 992-00-1O
ZBR16/21/28/35/42-3A... | ZWB28/35/42-3A...
6 720 818 061 (2015/11) CA/US

2| Contents
6 720 818 061 (2015/11)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
6 720 818 061 (2015/11) 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
6 720 818 061 (2015/11)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.
Symbol Explanation
▶ 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
6 720 818 061 (2015/11) 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
6 720 818 061 (2015/11)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
6 720 818 061 (2015/11) 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
6 720 818 061 (2015/11)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
6 720 818 061 (2015/11) 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
0
2
3
4
bar
psi
15
3045

10 | Operation
6 720 818 061 (2015/11)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:
• Room thermostat
• RRC Room thermostat with outdoor reset
• Third party system control unit
Therefore, please read the operating instructions for the heating
control unit used.

Operation | 11
6 720 818 061 (2015/11) Greenstar
Fig. 2
Page 29 contains a quick reference. You can fold this outward and
keep these operating instructions in the control panel cover.
6 720 614 235-04.1O
max
1
2
34
5
6

12 | Operation
6 720 818 061 (2015/11)Greenstar
4.1 Overview of controls
Fig. 3
1 2 3 4 5 6 7 8
10
9
11
12
14
15
1718 13
6 720 641 934-01.3O
16
eco
reset

Operation | 13
6 720 818 061 (2015/11) Greenstar
[1] Emission test button for contractors (see installation instructions)
[2] Service button for contractors (see installation instructions)
[3] Burner ON indicator lamp
[4] ON/OFF switch
[5] Key pad lock
[6] ECO button
[7] Reset button
[8] Display
[9] Boiler water pressure gauge
[10] DHW thermostat
[11] Safety relief valve discharge hose
[12] Condensate drain hose
[13] Heating return pipe
[14] Cold water pipe - combi boiler only
[15] Gas pipe
[16] DHW pipe - combi boiler only
[17] Supply pipe
[18] Boiler high limit dial

14 | Operation
6 720 818 061 (2015/11)Greenstar
4.2 Switching the appliance ON/OFF
Startup
▶ Switch the appliance ON using the ON/OFF switch.
The display shows the supply temperature.
Fig. 4
Shutdown
▶ Switch the appliance OFF using the ON/OFF switch.
The diplay goes out.
▶ If the appliance is taken out of service for a longer period: Observe frost
protection (Section 4.8).
4.3 Turning the space heating ON
The maximum supply temperature can be set from 95 °F (35 °C) up to approx.
194 °F (90 °C). The current supply temperature is shown on the display.
If the display shows in alternation with the supply temperature,
the appliance operates at its lowest output for 15 minutes per the
initial startup sequence.
With radiant floor heating, limit the maximum permissible supply
temperature.
max
1
2
34
5
6
6 720 613 896-05.1O

Operation | 15
6 720 818 061 (2015/11) Greenstar
▶ Adjusting the supply temperature with the boiler high limit dial :
– Radiant floor heating: e.g. setting 3(approx. 122 °F (50 °C))
– Panel or cast iron radiator heating: setting 6(approx. 167 °F (75 °C))
– Heating with supply temperatures up to 194 °F (90 °C): setting max
Fig. 5
The burner ON indicator lamp lights up if the burner is operating.
Boiler high limit
dial
Typical supply
temperatures Sample application
1 approx. 95 °F (35 °C) Frost protection
2 approx. 109 °F (43 °C)
3 approx. 122 °F (50 °C) Radiant floor heating system
4 approx. 140 °F (60 °C)
5 approx. 153 °F (67 °C)
6 approx. 167 °F (75 °C) Radiator heating system
max approx. 194 °F (90 °C) Convector heating
Table 3 Typical supply temperatures
eco
reset
6 720 641 933-53.1O
max
1
2
34
5
6
max
1
2
34
e
6
min

16 | Operation
6 720 818 061 (2015/11)Greenstar
4.4 Programming the heating control unit
4.5 ZBR..-3A appliances with DHW tank:
Setting the DHW temperature
▶ Set the DHW temperature on the DHW thermostat .
The set DHW temperature flashes on the display for 30 seconds.
Fig. 6
Observe the operating instructions for the heating control unit
included in the scope of delivery. There you can read:
▶ How to set the operating mode
▶ How to adjust the room temperature
▶ How to heat economically and save energy
DANGER: Danger of scalding!
▶ In normal operation, it is recommended to limit the DHW
temperature to 122 °F (50 °C) to limit the risk of scalding.
▶ Only set temperatures up to 158 °F (70 °C) for thermal
disinfection (page 22).
6 720 641 933-54.1O
max
1
2
34
5
6
reset
eco
max
1
2
34
e
6

Operation | 17
6 720 818 061 (2015/11) Greenstar
If there is reason for concern for contamination from bacteria such as
legionella, consider setting the DHW thermostat to at least “e”
(131 °F (55 °C)).
This setting ensures an economical and comfortable DHW
generation. Consult your local water department or municipality for
further information.
DHW thermostat Typical DHW temperatures
min approx. 59 °F (15 °C)
e approx. 131 °F (55 °C)
max approx. 158 °F (70 °C)
Table 4
Always set the DHW temperature as low as possible. A lower setting
on the thermostat means a higher rate of energy savings.
Furthermore, higher DHW temperatures result in increased limescale
deposits and thereby may impair the function of the appliance (e.g.
longer times for heating up or lower output).

18 | Operation
6 720 818 061 (2015/11)Greenstar
ECO button
Pressing and holding the ECO button until it lights up switches between Comfort
mode and Economy mode.
•Comfort mode, ECO button is not lit (default setting)
In Comfort mode, the DHW tank has priority. The DHW tank is heated to the set
temperature first. Then the appliance switches to central heating mode.
•Economy mode, ECO button lit
In Economy mode, the appliance alternates between central heating mode and
DHW mode.
4.6 ZWB..-3A appliances (combi boilers):
Setting the DHW temperature
▶ Set the DHW temperature on the DHW thermostat .
The set DHW temperature flashes on the display for 30 seconds.
Fig. 7
DHW thermostat Typical DHW temperatures
min approx. 104 °F (40 °C)
e approx. 122 °F (50 °C)
max approx. 140 °F (60 °C)
Table 5
6 720 641 933-55.1O
max
1
2
34
5
6
reset
eco
max
1
2
34
e
6

Operation | 19
6 720 818 061 (2015/11) Greenstar
ECO button
Pressing and holding the ECO button until it lights up switches between Comfort
mode and Economy mode.
•Comfort mode (default setting)
The appliance is continually maintained at the set temperature. Consequently,
DHW draws are immediate, however the appliance may run even if no DHW is
being drawn.
•Economy mode, ECO button lights up
– DHW is only generated when DHW is drawn.
–On demand: Quickly open and close a DHW tap to signal the appliance to heat
to the selected temperature. After a short wait DHW will be available.
4.7 Setting manual summer mode
In summer mode or warm weather shut down (WWSD), the heating zone pump and
consequently central heating are switched off. DHW generation remains active
following the DHW program.
▶ Make a note of the setting of the boiler high limit dial .
The DHW on demand signal allows maximum gas and water savings.
NOTICE: Heating system at risk of freezing. In manual summer
mode, only the appliance is protected from freezing.
▶ Observe frost protection measures where there is a risk of
freezing (page 20).

20 | Operation
6 720 818 061 (2015/11)Greenstar
▶ Turn the boiler high limit dial counterclockwise to .
Fig. 8
For further information, see the operating instructions for the heating control unit
included in the scope of delivery.
4.8 Setting frost protection
Frost protection of the heating system:
▶ Leave the appliance switched ON; turn the boiler high limit dial at least to
position 1.
Fig. 9
For further information, see the operating instructions for the heating control unit
included in the scope of delivery.
Alternatively if you prefer switching the appliance OFF:
▶ Ask a trained and certified heating contractor to mix anti-freeze (see installation
instructions) into the heating water. All DHW pipes and DHW tank must be
completely drained.
6 720 641 933-82.1O
eco
reset
max
1
2
3
5
6
maxmin
1
2
34
e
6
eco
reset
max
1
2
3
5
6
max
1
2
34
e
6
6 720 641 933-68.1O
min