Bosch Condens 8300i W User manual

6721841534 (2022/05) AU/NZ
Operation Manual
Wall mounted gas condensing boiler
Condens 8300i W
GC8300iW 25 P | GC8300iW 35 P

Table of contents
Condens 8300i W – 6721841534 (2022/05)
2
Table of contents
1 Explanation of symbols and safety instructions . . . . . . . . . . . 3
1.1 Explanation of symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 3
2 Product Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Declaration of conformity . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Information about your product on the Internet. . . . . . . 4
2.3 DHW functions (domestic hot water) . . . . . . . . . . . . . . . 4
2.4 Display of energy data . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1 Turn unit on/off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Display overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3 Display readings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4 Heating key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.4.1 Setting the maximum heating water temperature . . . . . 6
3.4.2 Setting summer mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.5 DHW key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5.1 Set DHW temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5.2 Switch off DHW heating. . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.6 eco key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4 Thermal disinfection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 Tips on saving energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6 Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.1 Reset faults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8 Environmental protection and disposal . . . . . . . . . . . . . . . . . 10
9 Technical terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Explanation of symbols and safety instructions
3
Condens 8300i W – 6721841534 (2022/05)
1 Explanation of symbols and safety instructions
1.1 Explanation of symbols
Warnings
In warnings, signal words at the beginning of a warning are used to
indicate the type and seriousness of the ensuing risk if measures for
minimizing danger are not taken.
The following signal words are defined and canbe used inthis document:
DANGER
DANGER indicates that severe or life-threatening personal injury will
occur.
WARNING
WARNING indicates that severe to life-threatening personal injury may
occur.
CAUTION
CAUTION indicates that minor to medium personal injury may occur.
NOTICE
NOTICE indicates that material damage may occur.
Important information
The info symbol indicates important information where there is no risk to
people or property.
1.2 General safety instructions
HNotices for the target group
These operating instructions are intended for the heating system
operator.
All instructions must be observed. Failure to comply with instructions
may result in material damage and personal injury, including danger to
life.
▶ Read and retain the operating instructions (heat source, heating
controller, etc.) prior to operation.
▶ Observe the safety instructions and warnings.
HDetermined use
The product may only be used in a domestic situation for the heating of
central heating water and for DHW heating in closed-loop DHW and
heating systems.
Any other use is considered inappropriate. Any damage that may result
from misuse is excluded from liability.
This appliance is not suitable to be used as a pool heater.
HIf you smell gas
A gas leak could potentially cause an explosion. If you smell gas, observe
the following rules.
▶ Prevent flames or sparks:
– Do not smoke, do not use a lighter or strike matches.
– Do not operate any electrical switches or unplug any equipment.
– Do not use the telephone or ring doorbells.
▶ Turn off the gas supply at the main shut-off valve or at the gas meter.
▶ Open windows and doors.
▶ Warn your neighbours and leave the building.
▶ Prevent anyone from entering the building.
▶ Move well away from the building: call the emergency services and
the gas supplier.
HDanger to life from poisoning by flue gas
There is a danger to life from escaping flue gas.
▶Never modify any parts through which flue gas is routed.
If flues are damaged or leaking, or if you smell flue gas, observe the
following rules.
▶ Switch off the heat source.
▶ Open doors and windows
▶ Warn your neighbours and leave the building immediately.
▶ Prevent third parties from entering the building.
▶ Notify an approved contractor.
▶ Have any defects rectified.
HDanger to life from carbon monoxide
Carbon monoxide (CO) is a poisonous gas, which arises during the
incomplete combustion of fossil fuels such as oil, gas or solid fuels.
Dangers arise, if carbon monoxide escapes from the heating system due
to a fault or a leak and collects unnoticed in enclosed spaces.
You can neither see, taste nor smell carbon monoxide.
To avoid danger from carbon monoxide:
▶ Have the heating system inspected and serviced regularly by an
approved contractor.
▶ Use a CO detector, which gives an alarm in good time if CO escapes.
▶ If you suspect a CO leak:
– Warn your neighbours and leave the building immediately.
– Call an approved contractor.
– Have any defects rectified.
HInspection, cleaning and maintenance
The user is responsible for ensuring the heating system is safe and
environmentally compatible.
Non-existent or improper inspection, cleaning and maintenance may
result in personal injury, including danger to life or material damage.
We recommend that you enter into a contract covering an annual
inspection and responsive cleaning and maintenance with an approved
contractor.
▶ Have work carried out only by an approved contractor.
▶ Have the heating system inspected by an approved contractor at least
once a year.
▶ Have any required cleaning or maintenance work carried out
immediately.
▶ Have any defects in the heating system remedied immediately,
independent of the annual inspection.
HConversion and repairs
Improper modifications to the heat source or other parts of the heating
system can result in personal injury and/or material damage.
▶ Have work carried out only by an approved contractor.
▶ Never remove the casing of the heat source.
▶ Never carry out any modifications to the heat source or to other parts
of the heating system.
▶ Never close the outlet of the pressure relief valves. Heating systems
with DHW cylinder: During heat-up, water can escape from the
pressure relief valve of the DHW cylinder.

Product Information
Condens 8300i W – 6721841534 (2022/05)
4
HOpen flue operation
The installation location must be adequately ventilated, if the heat
source draws its combustion air from the room.
▶ Never cover or reduce the size of ventilation openings in doors,
windows and walls.
▶ Consult a contractor to ensure that ventilation requirements are met:
– If structural modifications are made (e.g. replacing windows and
doors)
– If devices with an air discharge to the outside are subsequently
installed (e.g. extractor fans, kitchen fans or air conditioning
units).
HCombustion air/ambient air
The air in the installation location must be free of flammable or
chemically aggressive substances.
▶ Do not store or use any flammable or explosive materials (paper,
petrol, thinners, paints, etc.) in the vicinity of the heat source.
▶ Do not store or use any corrosive substances (solvents, adhesives,
chlorinated cleaning agents, etc.) in the vicinity of the heat source.
HFrost damage
If the heating system is not in a frost-proof room and is not in operation,
it may freeze up when exposed to frost. In summer mode or if heating
mode is blocked, only the device frost protection remains active.
▶ Leave the heating system switched on at all times whenever possible,
and set the flow temperature to at least 30 °C,
-or-
▶ Have a competent person drain the heating system and DHW
pipework at the lowest point.
-or-
▶ Have a competent person mix antifreeze into the heating water and
drain the DHW circuit.
▶ Check every two years whether the minimum frost protection is still
ensured.
HSafety of electrical devices for domestic use and similar
purposes
The following requirements apply in accordance with EN 60335-1 in
order to prevent hazards from occurring when using electrical
appliances:
“This appliance can be used by children of 8 years and older, as well as
by people with reduced physical, sensory or mental capabilities or
lacking in experience and knowledge, if they are supervised and have
been given instruction in the safe use of the appliance and understand
the resulting dangers. Children shall not play with the appliance.
Cleaning and user maintenance must not be performed by children
without supervision.”
“If the power cable is damaged, it must be replaced by the manufacturer,
its customer service department or a similarly qualified person, so that
risks are avoided.”
2ProductInformation
2.1 Declaration of conformity
The design and operating characteristics of this product comply with the
European and national requirements.
The CE marking declares that the product complies with all the
applicable EU legislation, which is stipulated by attaching this
marking.
The complete text of the Declaration of Conformity is available on the
Internet: www.bosch-climate.com.au.
2.2 Information about your product on the Internet
We want to actively provide you with suitable information about your
product relevant to your situation. We therefore recommend you use the
information provided on our web pages. You can find the Internet
address on the back of these instructions.
2.3 DHW functions (domestic hot water)
All the DHW functions described are only active when the DHW cylinder
is active.
2.4 Display of energy data
Energy data displayed at a connected accessory, e.g. control unit
(remote control) is based on an estimate using the internal appliance
data.
Many factors affect the energy consumption in real life conditions. This
means that the energy data displayed may deviate from the values
displayed by an energy meter.
These values only serve to visualise the energy consumption and to
perform relative comparisons on different days/weeks/months.
They are not suitable to be used as the basis for billing.

Operation
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Condens 8300i W – 6721841534 (2022/05)
3Operation
These operating instructions describe the operation of the wall mounted
gas condensing boiler. Depending on the heating controller, the
operation of several functions may deviate from the description.
Observe the operating instructions for the heating controller used.
3.1 Turn unit on/off
Fig. 1 On/Off-switch
Switching on
▶ Switch the appliance ON using the ON/OFF switch.
When and the flow temperature appear alternately on the display,
the device remains in heating mode at the lowest heat output for
15 minutes to fill the condensate trap in the device.
Stop
NOTICE
Risk of damage to the system from frost!
The heating system can freeze up after a prolonged period (e.g. during a
power failure, switching off the power supply, faulty fuel supply, boiler
fault etc.).
▶ Ensure that the heating system is in constant use (particularly when
there is a risk of frost).
The anti-seizing function is not active when the device is switched off.
The anti-seizing function prevents the heating pump and the 3-way valve
from seizing up following long periods of inactivity.
▶ Switch off the device using the On/Off switch (Fig 1).
3.2 Display overview
Fig. 2 Control Panel
[1] Display
[2] and keys
[3] dkey
[4] ok/heating pressure key
[5] eco key
[6] DHW key
[7] Heating key
0010034884-001
0010021505-001
reset
eco
5 sec
ok
1
2
3
5
6
7
4

Operation
Condens 8300i W – 6721841534 (2022/05)
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3.3 Display readings
Fig. 3 Display readings
[1] Digital output
[2] Heating Mode
[3] Error display
[4] Burner operation
[5] Internet connection
[6] Wireless connection
[7] Chimney sweep mode (for service technician only)
[8] Service mode
[9] ECO mode active
[10] DHW heating
3.4 Heating key
3.4.1 Setting the maximum heating water temperature
The temperature of the heating water is adjusted via the flow
temperature.
With underfloor heating systems observe the maximum permissible flow
temperature.
▶ Press the Heating key (.
The set flow temperature flashes.
▶ Press the (Tab. 1), key or to set the desired maximum flow
temperature.
The setting is applied after 5 s or after pressing the OK key.
Table 1 Maximum flow temperature
3.4.2 Setting summer mode
The heating pump and consequently the heating are switched off in
summer mode. The DHW supply and the power supply for the control
system remain active.
Summer mode setting:
▶ Press the Heating key (.
▶ Press the key until appears on the display.
The setting is applied after 5 s or after pressing the OK key. The
display shows ].
Switch off summer mode:
▶ Press the Heating key (.
▶ Press key to set the required maximum flow temperature.
The setting is applied after 5 s or after pressing the OK key. The
display shows (.
Further notices can be found in the operating instructions for the heating
control.
0010016015-004
10 9
21 3 4 5 6
8 7
Supply temperature Application example
Approx. 50 °C Underfloor heating system
Approx. 75 °C Radiator heating system
Approx. 82 °C Convector heating system

Thermal disinfection
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Condens 8300i W – 6721841534 (2022/05)
3.5 DHW key
3.5.1 Set DHW temperature
WARNING
Hot water can cause severe scalding!
▶ Bear in mind the risk of scalding when changing the maximum DHW
temperature.
▶ Press the DHW key *.
The set DHW temperature is displayed.
▶ Press the or key to set the required DHW temperature
The setting is applied after 5 s or after pressing the OK key.
Measures for hard water
To protect against increased limescale and resulting service work:
If the water is calcareous with a hard hardness range (≥ 15°dH / 27°fH/
2.7 mmol/l)
▶ Set the DHW temperature to less than 55 °C.
3.5.2 Switch off DHW heating
▶ Press the DHW key *.
▶ Press the key until appears on the display.
The setting is applied after 5 s or after pressing the OK key. The
display shows [.
3.6 eco key
Comfort mode (no eco appears in the display)
In comfort mode, the DHW cylinder is reheated when the temperature
differential is 5 K (5 °C) or more.
ECO mode
In ECO mode, the DHW cylinder is reheated when the temperature
differential is 10 K (10 °C) or more.
▶ To set ECO mode, press the eco key.
eco appears on the display.
▶ To return to comfort mode, press the eco key.
eco goes out on the display.
For maximum gas and DHW saving:
▶ Briefly open and close the DHW tap.
The water is heated once to the set temperature.
4 Thermal disinfection
To prevent hot water from becoming contaminated by bacteria such as
legionella, we recommend thermal disinfection after long downtimes.
You can program a heating controller with hot water control to perform
thermal disinfection. Alternately, you can have a contractor carry out
thermal disinfection.
CAUTION
Risk of scalding.
During thermal disinfection, discharging unmixed hot water can cause
serious scalding.
▶ Only use the maximum adjustable hot water temperature for thermal
disinfection.
▶ Inform occupants of the premises of the risk of scalding.
▶ Perform thermal disinfection outside of the normal operating times.
▶ Do not discharge DHW unmixed.
Proper thermal disinfection involves the DHW system including the
draw-off points.
▶ Set the thermal disinfection in the hot water program of the heating
controller (heating controller operating instructions).
▶ Close DHW draw-off points.
▶ Enable continuous operation of any DHW circulation pump that may
be installed.
▶ Once the maximum temperature is reached, open the DHW draw-off
points one by one, starting from the nearest and ending in the
farthest, and draw off DHW until hot water at 70 °C has been
discharging for 3 minutes.
▶ Restore the original settings.

Tips on saving energy
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5 Tips on saving energy
Economy heating
The device is designed for low energy consumption and low environment
pollution but with a high degree of comfort. The fuel supply to the burner
is regulated according to the heat energy demand of the home. If the heat
energy demand is lower, the device continues to operate with a small
flame. Experts refer to this process as modulating control. The
modulating control keeps the temperature fluctuations low and
distributes heat uniformly inside the rooms. This may mean that
although the device is in operation for a longer period of time, it actually
consumes less fuel than a device that is constantly being switched on
and off.
Heating controls
To optimise the performance of the heating system, we recommend
using a room temperature-dependent controller or weather-
compensated control unit and thermostatic valves as heating controls.
Thermostats
Fully open the thermostatic valves to reach the required room
temperature. Increase the required room temperature at the control unit
if the temperature is not reached after a prolonged period.
Floor heating
Never set the flow temperature higher than the maximum flow
temperature recommended by the manufacturer. We recommend using
a weather-compensated control unit.
Ventilating
Close the thermostatic valves when ventilating, and fully open the
windows for a short time. Never leave windows slightly open during
ventilation. Otherwise heat will always be drawn out of the room without
noticeably improving the ambient air.
Hot water
Always set the DHW temperature as low as possible. Choosing a low
setting at the temperature controller means significant energy savings.
In addition, high DHW temperatures result in increased calcification and
thus impair the function of the device (e.g. longer heat-up times or lower
draw-off volume).
Circulating pump
Set the DHW circulation pump, if installed, using a time program which is
customised to suit your individual requirements (such as morning,
midday or evening).
6Faults
6.1 Reset faults
The symbol Hindicates that a fault has occurred. The cause of the fault
is displayed in encoded form (e.g. fault code 228).
Repeated attempts to reset a fault can lead to the appliance being locked
for safety reasons (fault code 2980). This lock can only be removed by a
qualified professional or the customer service after the cause of the fault
has been determined and remedied on site.
▶ Switch off the appliance and switch it on again.
-or-
▶ Reset the fault on the appliance.
As soon as the fault is no longer displayed, the appliance returns into
operation.
If the fault is still displayed:
▶ To ensure system safety, call a qualified professional or the customer
service immediately.
▶ Inform them of the fault code and the appliance data.
▶ Arrange an on-site appointment and have the cause of the fault
determined and remedied immediately.
Table 2 Appliance data to be passed on in the event of a fault
Appliance data
Appliance name
Serial number
Date of commissioning
System installer

Maintenance
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Condens 8300i W – 6721841534 (2022/05)
7 Maintenance
HInspection, cleaning and maintenance
The user is responsible for ensuring the heating system is safe and
environmentally compatible.
Non-existent or improper inspection, cleaning and maintenance may
result in personal injury, including danger to life or material damage.
We recommend that you enter into a contract covering an annual
inspection and responsive cleaning and maintenance with an approved
contractor.
▶ Have work carried out only by an approved contractor.
▶ Have the heating system inspected by an approvedcontractor at least
once a year.
▶ Have any required cleaning or maintenance work carried out
immediately.
▶ Have any defects in the heating system remedied immediately,
independent of the annual inspection.
Cleaning the casing
Never use aggressive or corrosive cleaning agents.
▶ Wipe the casing with a damp cloth.
Check the operating pressure of the heating system
The standard operating pressure is 1 - 2 bar.
Should a higher operating pressure be required, ask your contractor.
▶ Press the ok key.
The operating pressure is shown in the display.
Fault display: System pressure too low
If the system pressure in the heating system falls below the minimum
pressure that has been set, the display shows the message LoPr => L0.X
bar. The system pressure is too low.
▶ Fill the heating system.
If the system pressure in the heating system drops below 0.3 bar, the
display shows the message LoPr alternating with the operating
pressure. The heating system is then blocked.
▶ Fill the heating system.
Topping up the heating water
Topping up the heating water is different on every heating system. You
should therefore ask your specialist to show you how it is done.
NOTICE
Material damage due to thermal stresses!
When topping up a hot boiler with cold heating water, thermal stresses
can lead to cracking due to internal stress.
▶ Only fill the heating system when cold. Maximum flow temperature
40 °C.
Maximum pressure of 3 bar at maximum heating water temperature
must not be exceeded (pressure relief valve will open).
Bleeding radiators
If radiators heat up at different rates:
▶Bleedradiators.
Checking and refill the heat transfer fluid of the solar thermal
system
Heat transfer fluid may only be topped up by an expert.
▶ Have the frost protection of the heat transfer fluid checked annually.
▶ Have the corrosion protection (pH value) of the heat transfer fluid
checked every 2 years.
The maximum pressure of 6 bar with solar thermal system at maximum
temperature must not be exceeded (pressure relief valve opens).

Environmental protection and disposal
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10
8 Environmental protection and disposal
Environmental protection is a fundamental corporate strategy of the
Bosch Group.
The quality of our products, their economy and environmental safety are
all of equal importance to us and all environmental protection legislation
and regulations are strictly observed.
We use the best possible technology and materials for protecting the
environment taking account of economic considerations.
Packaging
Where packaging is concerned, we participate in country-specific
recycling processes that ensure optimum recycling.
All of our packaging materials are environmentally compatible and can be
recycled.
Used appliances
Used appliances contain valuable materials that can be recycled.
The various assemblies can be easily dismantled. Synthetic materials are
marked accordingly. Assemblies can therefore be sorted by composition
and passed on for recycling or disposal.
Old electrical and electronic appliances
This symbol means that the product must not be disposed
of with other waste, and instead must be taken to the waste
collection points for treatment, collection, recycling and
disposal.
The symbol is valid in countries where waste electrical and
electronic equipment regulations apply, e.g. "European Directive 2012/
19/EC on old electronic and electrical appliances". These regulations
define the framework for the return and recycling of old electronic
appliances that apply in each country.
As electronic devices may contain hazardous substances, it needs to be
recycled responsibly in order to minimize any potential harm to the
environment and human health. Furthermore, recycling of electronic
scrap helps preserve natural resources.
For additional information on the environmentally compatible disposal
of old electrical and electronic appliances, please contact the relevant
local authorities, your household waste disposal service or the retailer
where you purchased the product.
You can find more information here:
www.weee.bosch-thermotechnology.com/
Batteries
Batteries must not be disposed together with your household waste.
Used batteries must be disposed of in local collection systems.
9Technicalterms
Wall mounted condensing boiler
The wall mounted condensing boiler does not just use the heat which
arises as the measureable temperature of the products of combustion,
but also the heat from the water vapour. This means that the wall
mounted condensing boiler has a particularly high efficiency.
Instantaneous water heater principle
The water is heated as it flows through the appliance. The maximum
draw-off rate is quickly available, i.e. without long waiting times or
interruptions for the heat-up process.
Operating pressure
The operating pressure is the pressure in the heating system.
Heating controller
The heating controller ensures the automatic control of the flow
temperature depending on the outside temperature (for weather-
compensated controllers) or of the room temperature in conjunction
with a time program.
CH return
The heating return is the pipework that returns the heating water at a
lower temperature from the heating surfaces to the appliance.
Heating flow connection
The heating flow is the pipework that supplies the heating water at a
higher temperature from the appliance to the heating surfaces.
Heating water
The heating water is the water used to fill the heating system.
Thermostatic valve
Thermostatic valves are mechanical temperature controllers that enable
a lower or higher heating water flow rate subject to ambient temperature
in order to maintain a constant temperature.
Siphon
The siphon is a stench trap for draining water that exits a pressure relief
valve.
Flow temperature
Flow temperature is the temperature with which the heated heating
water flows from the appliance to the radiators, underfloor heating
circuits, etc.

Robert Bosch (Australia) Pty Ltd
Thermotechnology Division
1555 Centre Road
Clayton Victoria 3168
Australia
Phone: [phone]
Fax: [phone]
www.bosch-climate.com.au
New Zealand
Phone: [phone]
Fax: [phone]
www.bosch-climate.co.nz