Bosch WR 11 G Series Technical Document

Installation Manual and Operating Instructions
Gas Instantaneous Water Heater
WR 11/14/18 .G...
6 720 607 529 (2016/04) ZA
Read installation manual prior to installation of this unit!
Read user manual before putting this unit in operation!
Observe the warnings in the manuals!
The installation room must fulfill the ventilation requirements!
Installation by an authorised person only!

6 720 607 529 (2016/04)
2 | Table of contents
Table of contents
1 Key to symbols and safety instructions . . . . . . . . . . 3
1.1 Key to symbols . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Safety Instructions . . . . . . . . . . . . . . . . . . . . 3
2 Technical Characteristics and Dimensions . . . . . . . 5
2.1 Explanation of Model Code . . . . . . . . . . . . . . 5
2.2 Accessories (Included with appliance) . . . . 5
2.3 Description of the heater . . . . . . . . . . . . . . . 5
2.4 Type overview . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Special accessories . . . . . . . . . . . . . . . . . . . . 5
2.6 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.7 Electrical diagram . . . . . . . . . . . . . . . . . . . . . 7
2.8 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.9 Technical characteristics . . . . . . . . . . . . . . . 8
3 Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Before starting up the heater . . . . . . . . . . . . 9
3.2 Turning the heater on and off . . . . . . . . . . . . 9
3.3 Water flow . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Power adjustment . . . . . . . . . . . . . . . . . . . . 10
3.5 Temperature/flow adjustment . . . . . . . . . . 10
3.6 Purge the appliance . . . . . . . . . . . . . . . . . . 10
3.7 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4 Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5 Installation (must be carried out only by qualified
technicians) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1 Important information . . . . . . . . . . . . . . . . . 11
5.2 Selection of the place of installation . . . . . 11
5.3 Heater mounting . . . . . . . . . . . . . . . . . . . . . 12
5.4 Water connection . . . . . . . . . . . . . . . . . . . . 12
5.5 Hydrogenerator operation . . . . . . . . . . . . . 12
5.6 Gas connection . . . . . . . . . . . . . . . . . . . . . . 13
5.7 Inlet/exhaust pipe installation . . . . . . . . . . 13
5.8 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6 Adjustments (must be carried out only by qualified
technicians) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Factory regulations . . . . . . . . . . . . . . . . . . . 14
6.2 Pressure adjustment . . . . . . . . . . . . . . . . . . 14
6.3 Conversion to a different type of gas . . . . . 15
7 Maintenance (must be carried out only by qualified
technicians) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
7.1 Periodic maintenance work . . . . . . . . . . . . 16
7.2 Startup after maintenance work . . . . . . . . 16
7.3 Flue gas safety device . . . . . . . . . . . . . . . . . 16
8 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9 Environment / disposal . . . . . . . . . . . . . . . . . . . . . . . 18
10 Warranty Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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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 can be used in this
document:
•NOTICE indicates a situation that could resultin 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 Instructions
If there is a smell of gas:
▶ Close the gas valve.
▶ Open windows.
▶ Do not operate any electrical appliances or switches (on/
off).
▶Extinguishanynakedflames.
▶ Phone the gas company or an authorized technician from a
safe distance.
If there is a smell of burnt gases:
▶ Disconnect the appliance.
▶ Open doors and windows.
▶ Inform an installation company.
Burn-back (fire in burner tube or chamber)
▶ In the event of a burn-back, where the flame burns back to
the injector, immediately turn off the gas supply at the
control valve on the panel.
▶ After ensuring the flame is extinguished, wait for one
minute and re-light the appliance in the normal manner.
▶ Should the appliance again burn back, close the control
valve and call a service technician.
▶ Do not use the appliance again until the service technician
has declared that it is safe to do so.
Fitting, modifications
▶ The fitting and modification of the installation of the
appliance must be carried out only by an authorized
technician.
▶ The installation ofthe water heater may only be carried out
by a registered installer and that such installations shall
comply with the requirements of SANS 10087-1.
▶ The pipes carrying burnt gases must not be modified.
▶ Do not close or reduce air circulation holes.
Maintenance
▶ We reccomend to have the system regularly serviced in
order to ensure that it functions reliably and safely.
▶ The installer is responsible for the safety and
environmental compatibility of the installation.
▶ The appliance should be serviced annually.
▶ Only original spare parts must be used.
Explosive and inflammable materials
▶ Inflammable materials (paper, solvents, ink, etc.) should
not be stored near the appliance.
Combustion air and ambient air
▶ To avoid corrosion, combustion air and ambient air should
be free of aggressive substances (for example halogenated
hydrocarbons containing chlorine and fluoride
composites).
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
• List entry
– List entry (second level)
Table 1

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4 | Key to symbols and safety instructions
Important information for the user
▶ This appliance may only be installed by a registered LP Gas
installer.
▶ All registered installers are issued with a card carrying their
registration number.
▶ Ask to be shown the card before allowing the installation
work to commence and make a note of the Installer QCC
number. Upon completion of the installation, the installer is
required to explain the operational details of the appliance
together with the safety instructions. You will be asked to
sign acceptance of the installation and be provided with a
completion certificate. You should only sign foracceptance
of the installation when the installation is completed to your
satisfaction.Note that your invoice is required in the event
that you wish make a guarantee claim.
Important information for the installer
▶ This appliance may only be installed by a LP gas installer
registered with the Liquefied Petroleum Gas Association of
Southern Africa.
▶ The appliance must be installed in accordance with the
requirements of SANS 10087-1 and any fire department
regulations and/or local by laws applicable to the area. If in
doubt check with the relevant authority before undertaking
the installation.
▶ Upon completion of the installation you are required to fully
explain and demonstrate to the user the operational details
and safety practices applicable to the appliance and the
installation.
Client information
▶ Inform the client about the function and operation of the
appliance.
▶ Caution clients against performing modifications or repairs
themselves.
Risk of damage due to operator error
Operator errors can result in personal injury and material
damage.
▶ Ensure that children never operate this appliance
unsupervised or play with it.
▶ Ensure that only personnel who can operate this appliance
correctly have access to it.

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Technical Characteristics and Dimensions | 5
2 Technical Characteristics and Dimensions
2.1 Explanation of Model Code
[W] Gas Water Heater
[R] Proportional power adjustment
[11] Capacity (l/min)
[G] Electronic ignition powered by hydrodynamic generator
[23] Indicator number of natural gas H
[31] Indicator number of LPG
[S...] Country code
The code number indicates the gas group according to EN 437:
2.2 Accessories (Included with appliance)
•Gaswaterheater,
• Attachment elements,
• Installation accessories,
• Heater documentation.
2.3 Description of the heater
Operating convenience, as the heater is ready to operate by
simply pressing a switch.
• Heater for wall-mounting,
• Ignitionbyelectronicdevice triggeredwhenthewatervalve
opens,
• Great savings in comparison with conventional heaters,
due to the possibility of power adjustment and no
permanent pilot flame,
• Hydrodynamic generator produces the necessary
electrical power for ignition and appliance monitoring,
• Natural gas/LPG burner,
• Semi-permanent pilot burner which only functions during
the period between the opening of the water valve and the
ignition of the main burner,
• Heat exchanger in copper without tin/lead covering,
• Water valve in fibreglass-reinforced polyamide, 100%
recyclable,
• Automatic adjustment of the water flow by means of a
device which permits a constant flow to be maintained in
spite of variable pressure supplies,
• Gas flow adjustment proportional to the water flow to
maintain a constant high temperature.
•Safetydevices:
– Ionisation probe to check for accidental extinction of
the burner flame,
– Flue gas safetydevice which turns off the heater in case
of inadequate combusted gas evacuation conditions,
– Temperature limiter which prevents overheating of the
heat exchanger.
2.4 Type overview
The type plate is located at the bottom left of the appliance.
There you will find details of appliance output, model number,
approval data and the serial number.
2.5 Special accessories
• Conversion kit from natural gas to butane/propane.
WR11 G 23
31
S....
WR14 G 23
31
S....
WR18 G 23
31
S....
Table 2
Identification
Code
Wobbe Index (Ws)
(15 °C)
Gas type
23 12,7-15,2 kWh/m3Natural Gas - Group H
31 20,2-21,3 kWh/m3LPG - Group B/P
Table 3

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6 | Technical Characteristics and Dimensions
2.6 Dimensions
Fig. 1
[1] Front cover
[2] Hole for fixing to wall
[3] Observation window
[4] Temperature control
[5] Led failure indicator
[6] ON/OFF switch
[7] Led indicator for burner status
[8] Output control
[9] Gas connection
[10] Flue socket
[11] Draught diverter with flue gas monitor
[12] Heat exchanger
[13] Automatic gas valve
[14] Igniter unit
[15] Water valve
Dimensions (mm) A B C D E F G H (Ø)
Natural
gas
LPG
WR11G 310 580 228 112,5 463 60 25 1/2” 1/2”
WR14G 350 655 228 132,5 510 95 30 1/2” 1/2”
WR18G 425 655 334 132,5 540 65 30 1/2” 1/2”
Table 4 Dimensions

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Technical Characteristics and Dimensions | 7
2.7 Electrical diagram
Fig. 2 Electrical diagram
[1] Servo valve (normally open)
[2] Diaphragm valve
[3] Main valve (normally closed)
[4] Ionisation detector
[5] Igniter electrode
[6] Flue gas safety device
[7] Temperature limiter
[8] Igniter unit
[9] LED failure indicator
[10] LED indicator for burner status
[11] ON/OFF switch
[12] Hydrogenerator
2.8 Function
This gas heater is equipped with automatic electronic ignition
which simplifies its operation.
▶ To do so, just turn on the switch (Fig. 3).
After this procedure, automatic ignition occurs whenever a hot
water tap is opened. First, the pilot burner is lit and
approximately four seconds afterwards the main burner. The
pilot burner flame is then extinguished after a short period of
time.
This is a way of saving a great amount of energy as the pilot
burner only operates for the minimum necessary time to ignite
the main burner, in contrast to conventional systems which
operate permanently.
If this happens:
▶ Close and open the hot water tap to repeat the ignition
process until all the air has been purged.
Air in the gas supply pipe when the heater is
started up may cause ignition to fail.

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8 | Technical Characteristics and Dimensions
2.9 Technical characteristics
Technical characteristics Symbol Units WR11 WR14 WR18
Power and flow
Nominal useful power Pn Btu/h 65570 80595 104165
Minimum useful power Pmin Btu/h 23905 23905 23905
Useful power (adjustment range) Btu/h 23905-
65570
23905 -
80595
23905 -
104165
Nominal thermal flow Qn Btu/h 74450 92210 117825
Minimum thermal flow Qmin Btu/h 27660 27660 27660
Gas data1)
1) Hi 15 °C - 1013 mbar - dry: Natural gas 34.02 MJ/m3(9.5 kWh/m3)
LPG: Butane 45.65 MJ/kg (12.7 kWh/kg) - Propane 46.34 MJ/kg (12.9 kWh/kg)
Supply pressure
Natural gas H G20 kPa 2 22
LPG (Butane/Propane) G30 kPa 2,8 2,8 2,8
Consumption
Natural gas H G20 m3/h 2,2 2,77 3,5
LPG (Butane/Propane) G30 Kg/h 1,75 2,2 2,79
Number of injectors 12 14 18
Water data
Maximum permissible pressure2)
2) Considering the water dilution effect this value must not be exceeded.
pw psi 170 170 170
Temperature selector in fully clockwise position
Temperature rise °C 50 50 50
Flow range l/min 2 - 5,5 2,0 - 7 2,0 - 8,8
Minimum operating pressure pwmin psi 5,0 5,0 6,5
Temperature selector in fully anti-clockwise position
Temperature rise °C 25 25 25
Flow range l/min 4 - 11 4 - 14 4 - 17,6
Combustion products3)
3) For nominal calorific power.
Minimum low pressure mbar 0,015 0,015 0,015
Flow g/s 13 17 22
Temperature °C 160 170 180
Table 5

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Use | 9
3Use
3.1 Before starting up the heater
▶ Check if the gas indicated on the rating plate is the same as
the one used at the location.
▶ Open the gas valve.
▶ Open the water valve.
3.2 Turning the heater on and off
Turning on
▶ Press the switch , position .
Fig. 3
Green light on = Main burner on
Fig. 4
Turning off
▶ Press the switch , position .
3.3 Water flow
If the red LED starts flashing, check the water pressure.
Fig. 5
Open all water and gas blocking devices.
Purge the pipes.
CAUTION:
The front panel in the burner and pilot burner
area may reach high temperatures, with risk of
burning in case of contact
CAUTION:
▶ Initial startup must be performed by a
qualified technician who will provide the
client with all the necessary information
for optimum operation of the gas heater.
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10 | Regulation
3.4 Power adjustment
Lower water temperature.
Less power.
Fig. 6
Higher water temperature.
More power.
Fig. 7
3.5 Temperature/flow adjustment
▶ Turn anti-clockwise
Increases flow and decreases water temperature.
Fig. 8
▶Turnclockwise.
Decreases flow and increases water temperature.
Regulating the temperature to the minimum required value
reduces energy consumption as well as the possibility of
limescale deposits in the heat exchanger.
3.6 Purge the appliance
If there is a risk of freezing, proceed as follows:
▶ Remove the retaining clip from threaded bushing [1].
▶ Remove threaded bushing [2] from water valve.
▶ Empty the appliance of all water.
Fig. 9 Purge
[1] Retaining clip
[2] Threaded bushing
3.7 Cleaning
▶ Clean the front cover using a damp cloth and detergent.
4Regulation
Any local by-laws and regulations pertaining to installation and
use of gas-heated appliances must be observed. Please refer to
the laws that should be attended in South Africa.
Do not use abrasive or corrosive cleaners.
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