Bosch OptiFlow Professional GWH12 1 CTD E23 User manual

Operating Manual
Room sealed gas continuous flow water heaters
OptiFlow Professional
6720808879-00.1V
GWH12/16/20 1 CTD E23/31 F5 L
6 720 813 939 (2016/05) AU
Read installation manual prior to installation of this appliance!
Read user manual before putting this unit in operation!
Observe the warnings in the manuals!
The installation location must meet the requirements for sufficient ventilation!
Installation by an authorised person only!

6 720 813 939 (2016/05) OptiFlow Professional
2 | Index
Index
1 Key to symbols and safety instructions . . . . . . . . . . 3
1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Safety Information . . . . . . . . . . . . . . . . . . . . . 3
2 Product details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 EC Declaration of Conformity . . . . . . . . . . . . 4
2.2 Type overview . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 Included Items . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4 Rating plate . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Description of appliance . . . . . . . . . . . . . . . . 5
2.6 Accessory . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.7 Appliance layout . . . . . . . . . . . . . . . . . . . . . . 6
3 Operation instructions . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Digital display - description . . . . . . . . . . . . . 7
3.2 Before first use of the appliance . . . . . . . . . . 7
3.3 Switching the appliance on/off . . . . . . . . . . . 7
3.4 Temperature control . . . . . . . . . . . . . . . . . . . 7
3.5 Programming button . . . . . . . . . . . . . . . . . . . 8
3.6 Draining the appliance . . . . . . . . . . . . . . . . . 8
3.7 Error codes . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.8 Cleaning the front of the appliance . . . . . . . 8
4Maintenance
(only by authorised service technicians) . . . . . . . . .8
5 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Environmental considerations . . . . . . . . . . . . . . . . . 11
7 Water quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8 Warranty details . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6 720 813 939 (2016/05)OptiFlow Professional
Key to symbols and safety instructions | 3
1 Key to symbols and safety instructions
1.1 Key to symbols
Warnings
The following keywords are defined and used in this document:
•NOTICE indicates a situation that could result in damage to
property or equipment.
•CAUTION indicates a situation that could result in minor to
medium injury.
•WARNING indicates a situation that could result in severe
injury or death.
•DANGER indicates a situation that will result in severe
injury or death.
Important information
Additional symbols
1.2 Safety Information
If you smell gas
A gas leak could potentially cause an explosion. If you smell gas,
observe the following rules.
▶ Avoid producing 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.
▶ Stay well away from the building: call the emergency
services and the gas supplier.
If you notice dark combustion gases or sooting:
▶ Isolate the gas supply to the heater.
▶ Notify an authorised technician.
Installation, assembly, and modifications
Installation, assembly, and modifications to the heater must
only be performed by an authorised technician.
Maintenance
▶ The water heater is required to have a service and safety
inspection every two years.
▶ The installer is responsible for the safety and
environmental compatibility of the installation.
▶ The owner/user is responsible for keeping the area around
the water heater free from debris.
▶ Safe access to inspect and service the water heater is the
responsibility of the property owner.
▶ Use only genuine Bosch spare parts.
Explosive and flammable material
▶ Do not store or use flammable material (paper, spray cans,
solvents, paints, etc) near the heater.
Combustion air and surrounding air
▶ The combustion air and surrounding air must be free from
corrosive substances.
▶ Do not spray aerosols or use chemicals around the heater
unless heater is disconnected from the power supply.
Risk of damage due to user error
User errors can result in injury and damage to property.
▶ Ensure that children never play with or operate this
appliance.
▶ Ensure that only personnel who can operate this appliance
correctly have access to it.
▶ Refer to the operating and user instructions before
adjusting the water heater.
To be installed and serviced only by an authorised person
The authorised installer is responsible for:
• Correct installation and commissioning of this appliance.
• Ensuring the appliance performs to the specifications
stated on the rating label.
Warnings in this document are identified by a
warning triangle printed against a grey
background.
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.
This symbol indicates important information
where there is no risk to people or property.
Symbol Explanation
▶ Step in an action sequence
Cross-reference to another part of the document
•Listentry
– List entry (second level)
Table 1

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4 | Product details
• Demonstrating the operation of the appliance to the
customer before leaving.
• Handing these instructions to customer.
THIS APPLIANCE IS NOT SUITABLE FOR POOL OR SPA POOL
APPLICATIONS.
HANDING THE OPERATING INSTRUCTIONS TO THE
CUSTOMER.
NOT SUITABLE FOR COMMERCIAL BOOSTING OF A WARM
WATER RECIRCULATION SYSTEM
Regulations
All local by-laws and regulations pertaining to installation and
use of gas appliances must be observed.
This appliance must be installed in accordance with the
manufacturers installation instructions, AS/NZS5601, AS/
NZS3500, and all Local Building & Gas fitting regulations.
The appliance must not be installed outdoors. The appliance is
approved for indoor installation only. Do not install this
appliance with any modification or alteration.
Failure to install this appliance in accordance with these
installation instructions will void the warranty and may create
an unsafe situation.
Safety of electrical appliances 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
must 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.”
2 Product details
2.1 EC Declaration of Conformity
The appliance has been tested and certified to Australian
Standards.
2.2 Type overview
[GWH]Gas continuous flow water heater
[12] Capacity (l/min)
[1] Generation
[CT] Thermostatic
[D] Digital user interface
[E] Electric ignition
[23] Appliance set for natural gas
[31] Appliance set for Universal LP gas
[F5] Tight chamber
[L] Locked water temperature adjustment
Model GWH12/16/20 1 CTD E23/31 F5 L...
Table 2
GWH 12 1CTDE23 F5 L
GWH 12 1CTDE31 F5 L
GWH 16 1CTDE23 F5 L
GWH 16 1CTDE31 F5 L
GWH 20 1CTDE23 F5 L
GWH 20 1CTDE31 F5 L
Table 3

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Product details | 5
2.3 Included Items
• Gas continuous flow water heater
• Fixing bracket
• Appliance documentation
2.4 Rating plate
The rating plate is located on the outside of the appliance, on
the bottom.
The rating plate specifies the performance of the appliance,
approval and serial numbers.
2.5 Description of appliance
• Room sealed wall-mounted appliance for internal
installation.
• Multifunctional display panel
• Suitable for Natural Gas or Universal LPG
• Electronic ignition
• Water flow sensor
•Watervalve
• Temperature sensors for monitoring the temperature of the
incoming and outgoing water of the appliance.
•Safetydevices:
–Flamesensorrod
–Thermalfuse
– Hot water temperature sensor
– Electronic control unit
– Air temperature sensor
• Electrical connection: 230 V, 50 Hz
• Frost protection device.
2.6 Accessory
•Flueaccessories
• Remote control (optional).

6 720 813 939 (2016/05) OptiFlow Professional
6 | Product details
2.7 Appliance layout
Fig. 1
[1] Heat exchanger
[2] Flame sensor rod
[3] Burner
[4] Air pressure test point
[5] Fan
[6] Air temperature sensor
[7] Thermal fuse
[8] Hot water temperature sensor
[9] Hot water outlet
[10] Power cord and plug
[11] Combustion gas collector
[12] Frost protection device
[13] Ignition electrode
[14] Burner pressure test point
[15] Water flow sensor and Water valve
[16] Electronic control unit
[17] Cold water temperature sensor
[18] Gas valve
[19] Cold water inlet
[20] Gas pressure test point
[21] Gas inlet

6 720 813 939 (2016/05)OptiFlow Professional
Operation instructions | 7
3Operationinstructions
3.1 Digital display - description
Fig. 2 Digital display
[1] ON/OFF button
[2] Programming button
[3] LCD panel
[4] Temperature increase button
[5] Temperature decrease button
3.2 Before first use of the appliance
▶ Check that the type of gas indicated on the rating plate is
the same as the gas to which the appliance is connected.
▶ Plug in the appliance to the electrical socket and switch on.
▶ Open the gas isolation valve of the installation.
▶ Open the water isolation valve of the installation.
3.3 Switching the appliance on/off
Switching on the appliance
▶ Press the button .
The screen cover shows the selected water temperature.
Fig. 3
Switching the appliance off
▶ Press the button .
3.4 Temperature control
▶ Press the buttons or until you reach the desired
temperature.
Fig. 4
Open all the water and gas valves.
CAUTION: Hot surface!
The front of the appliance may reach high
temperatures.
CAUTION:
▶ The initial start-up of the water heater
must be done by an authorised installer
who will hand the customer the
operating instructions.
By default, the heating temperature of the
water is:
55°C preset appliances: 55°C
50°C compliant appliances: 50°C
The temperature indicated on the LCD
display matches the pre-selected
temperature.

6 720 813 939 (2016/05) OptiFlow Professional
8 | Maintenance (only by authorised service technicians)
By selecting the temperature and only turning on the hot tap,
energy and water consumption can be reduced.
3.5 Programming button
Setting the water temperature
Fig. 5
▶ Press the buttons or to select the desired
temperature.
▶ Press the button for 3 seconds to set the
temperature.
When the display stops flashing, the temperature is set in the
memory.
Selecting the preset temperature
To select the preset temperature.
▶ Press the button for 1 second.
The display will show the preset temperature and will supply
water at that temperature.
3.6 Draining the appliance
If draining the appliance is required, the following process
should be followed:
▶ Shut off the cold water isolation valve on the cold water
inlet off the appliance.
▶ Open a hot water tap.
▶ Remove the connection to the cold water pipe.
▶ Empty all the water contained inside the appliance.
3.7 Error codes
See table 4 on page 9.
Resetting the appliance
Some error codes may be solved by resetting the appliance:
▶ Press the button for 3 seconds.
3.8 Cleaning the front of the appliance
▶ Only clean the front of the appliance with a cloth and
detergent with water.
4 Maintenance (only by authorised service
technicians)
To guarantee that the consumption of gas and the emission of
exhaust gas are maintained at the best values, we recommend
that the appliance be inspected every two years and if
necessary, maintenance works be carried out.
▶ Your appliance should only be attended to by a Bosch
service agent. Call for service contract details: AU 1300 30
70 37, NZ 0800 54 33 52.
CAUTION:
The temperature indication on the display is
approximate, always confirm with your hand
before bathing children or old people.
NOTICE:
Not draining the appliance when a freezing risk
exists may damage components of the
appliance.
Beforehand place a container below the
appliance to collect all the water that comes
out of the appliance.
Turning off the power to the appliance will
disable the frost protection circuit. If switching
of power is required, the appliance MUST be
drained.
Do not use corrosive and/or abrasive
detergents.
Maintenance must only be performed by an
authorised service technician.

6 720 813 939 (2016/05)OptiFlow Professional
Troubleshooting | 9
5Troubleshooting
Fitting, maintenance and repair must only be carried out by authorised technicians. The following table describes the possible
solutions.
Display Description Possible solution
A0 Cold and hot water temperature sensor damaged. ▶ Check temperature sensor and associated
connections.
▶ If the problem persists, call an authorised
service technician.
A1 Temperature inside the water heater housing is high
(heat exchanger calcified or sooted).
▶ The appliance automatically regulates its
performance to avoid overheating.
▶ If the problem persists, call an authorised
service technician.
A4 Faulty air temperature sensor. ▶ Call an authorised service technician.
A7 Faulty hot water outlet temperature sensor. ▶ Check temperature sensor and associated
connections.
▶ If the problem persists, call an authorised
service technician.
A9 Hot water outlet temperature sensor is not fitted
properly.
Low incoming gas pressure.
▶ Check temperature sensor and associated
connections.
▶ If the problem persists, call an authorised
service technician.
C7 Faulty fan. ▶ Check if the fan is properly connected to
ECU.
▶ If the problem persists, call an authorised
service technician.
CA Water flow above maximum specified value. ▶ Check incoming water pressure.
▶ Install a pressure limiting valve if necessary.
CF
C1
Blocked flue gas outlet.
Air flow insufficient for start-up.
▶ Remove dirt or any other impediment from
the flue terminal and/or pipe.
▶ Close and open a hot water tap.
▶ If the problem persists, call an authorised
service technician.
E0 Failure of control module ▶ Unplug the electrical connection for 10
seconds.
▶ Reconnect and restart the appliance.
▶ If the problem persists, call an authorised
service technician.
E1 Hot water temperature sensor detects overheating. ▶ Let the appliance cool and try again.
▶ If the problem persists, call an authorised
service technician.
Table 4

6 720 813 939 (2016/05) OptiFlow Professional
10 | Troubleshooting
E2 Faulty inlet water temperature sensor. ▶ Check temperature sensor and associated
connections.
▶ If the problem persists, call an authorised
service technician.
E4 Air temperature sensor detects overheating (leaking
combustion products inside the combustion
chamber).
▶ Switch off at the power point and remove
the plug from the electrical socket.
▶ Do not try to Restart the appliance.
▶ Call a service agent immediately.
E9 Activated thermal fuse. ▶ Call an authorised service technician.
EA Flame not detected. ▶ Check that the gas to the appliance has not
been turned off.
▶ Unplug the electrical connection for 10
seconds.
▶ Reconnect and restart the appliance.
▶ If the problem persists, call an authorised
service technician.
EE Modulating solenoid valve disconnected. ▶ Check solenoid connections.
▶ If the problem persists, call an authorised
service technician.
EF Wrong gas connected. ▶ Call an authorised service technician.
F7 A flame is detected although the appliance is
switched off.
▶ Unplug the electrical connection for 10
seconds.
▶ Reconnect and restart the appliance.
▶ If the problem persists, call an authorised
service technician.
F9 Safety solenoid valve disconnected. ▶ Call an authorised service technician.
FA Fault in the gas control valve. ▶ Call an authorised service technician.
FC Buttons stuck in a “pressed” position for more than
30 seconds.
▶ Release the button.
▶ If the problem persists, call an authorised
service technician.
With indication,
but without existence of
solar thermal system.
The temperature selected is lower than the minimum
power that the appliance supplies.
High incoming water temperatures, or low flow rate
can create this occurrence.
▶ Increase the hot water flow.
-or-
▶ Select a higher temperature.
▶ If the problem persists:
▶ Call an authorised service technician.
With indication
and water temperature
low.
Appliance is making a resonance noise (vibration). ▶ Call an authorised service technician.
Display Description Possible solution
Table 4