Bosch WR8/11 G Series User manual

Installation and Operating Instructions
Gas Instantaneous Water Heater
WR8/11 G...
6 720 607 845 (2015/05) EN
6720607845
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!

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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 . . . . . . . 4
2.1 Category, Appliance type and Approval
number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2.2 Explanation of Model Code . . . . . . . . . . . . . . 4
2.3 Accessories (Included with Appliance) . . . . 4
2.4 Description of the heater . . . . . . . . . . . . . . . 4
2.5 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.6 Electrical diagram . . . . . . . . . . . . . . . . . . . . . 6
2.7 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.8 Technical characteristics . . . . . . . . . . . . . . . 7
2.9 Product data on energy consumption . . . . . 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
4 Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . 12
5.7 Inlet/exhaust pipe installation . . . . . . . . . . 13
5.8 Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6 Adjustments (must be carried out only by qualified
technicians) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.1 Factory regulations . . . . . . . . . . . . . . . . . . . 13
6.2 Conversion to a different type of gas . . . . . 13
7 Maintenance (must be carried out only by qualified
technicians) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1 Periodic maintenance work . . . . . . . . . . . . 14
7.2 Startup after maintenance work . . . . . . . . 14
7.3 Flue gas safety device . . . . . . . . . . . . . . . . . 14
8 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9 Environment / disposal . . . . . . . . . . . . . . . . . . . . . . . 16

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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 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 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.
Fitting, modifications
▶ The fitting and modification of the installation of the
appliance must be carried out only by an authorized
technician.
▶ 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).
Client information
▶ Inform the client about the function and operation of the
appliance.
▶ Caution clients against performing modifications or repairs
themselves.
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 of8
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
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 | Technical Characteristics and Dimensions
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 Technical Characteristics and
Dimensions
2.1 Category, Appliance type and Approval
number
2.2 Explanation of Model Code
[W] Gas Water Heater
[R] Proportional power adjustment
[8] Capacity (l/min)
[G] Electronic ignition powered Hydrodynamic generator
[31] Indicator number of LPG
[S...] Country code
2.3 Accessories (Included with Appliance)
• Gas water heater,
• Attachment elements,
• Installation accessories,
• Heater documentation.
2.4 Description of the heater
Operating convenience, as the heater is ready to operate by
simply pressing a switch.
• Heater for wall-mounting,
• Ignitionbyelectronicdevice triggeredwhenthe watervalve
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,
• 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,
– Fluegas safetydevicewhichturnsoffthe heaterincase
of inadequate combusted gas evacuation conditions,
– Temperature limiter which prevents overheating of the
heat exchanger.
Model Category
WR8 G BE, CH, ES, FR, GB,
IT, PT, LU, HR
I3+
NL, DE I3B/P
WR11 G CH, ES, GB, IT, PT, HR II2H3+
LU II2E+3+
BE, FR I3+
NL II2L3B/P
DE II2L3B/P
BE I2E+
Type B11BS
Table 2
WR8G31 S....
WR11 G 31 S....
Table 3
0464 BQ 20

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Technical Characteristics and Dimensions | 5
2.5 Dimensions
Fig. 1
[1] Front cover
[2] Hole for fixing to wall
[3] Observation window
[4] Temperature control
[5] LED indicator Fault/ "Burner Out" indicator
[6] On/Off switch
[7] Output control
[8] Gas connection
[9] Flue socket
[10] Draught diverter with flue gas monitor
[11] Heat exchanger
[12] Automatic gas valve
[13] Igniter unit
[14] Water valve
[15] LED indicator for burner status
Dimensions (mm) A B C D E F G
H (Ø)
LPG
WR8B 310 580 228 112,5 463 60 25 3/4”
WR11B
Table 4 Dimensions

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6 | Technical Characteristics and Dimensions
2.6 Electrical diagram
Fig. 2 Electrical diagram
[1] Servo valve (normally open)
[2] Diaphragm valve
[3] Gas valve for pilote burner (normally closed)
[4] Ionisation detector
[5] Igniter electrode
[6] Flue gas safety device
[7] Temperature limiter
[8] Igniter unit
[9] LED indicator for failure
[10] LED indicator for burner status
[11] ON/OFF switch
[12] Hydrogenerator
2.7 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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Technical Characteristics and Dimensions | 7
2.8 Technical characteristics
Technical characteristics Symbol Units WR8 WR11
Power and flow
Nominal useful power Pn kW 11,8 19,2
Minimum useful power Pmin kW 7 7
Useful power (adjustment range) kW 7 - 11,8 7 - 19,2
Nominal thermal flow Qn kW 13,5 21,8
Minimum thermal flow Qmin kW 8,1 8,1
Gas data1)
1) Hi 15 °C - 1013 mbar - dry: Natural gas 34.2 MJ/ m³ (9.5 kWh/ m³)
LPG: Butane 45.72 MJ/kg (12.7 kWh/kg) - Propane 46.44 MJ/kg (12.9 kWh/kg)
Supply pressure
LPG (butane/propane) G30/G31 mbar 28-30/37 28-30/37
Consumption
LPG (butane/propane) G30/G31 kg/h 1,0 1,6
Number of injectors 12 12
Water data
Maximum permissible pressure2)
2) Considering the water dilution effect this value must not be exceeded
pw bar 12 12
Temperature selector in fully clockwise position
Temperature rise °C 50 50
Flow range l/min 2 - 3,5 2 - 5,5
Minimum operating pressure pwmin bar 0,35 0,35
Minimum pressure for maximum flow bar 0,55 0,65
Temperature selector in fully anti-clockwise position
Temperature rise °C 25 25
Flow range l/min 4 - 7 4 - 11
Minimum operating pressure bar 0,45 0,45
Minimum pressure for maximum flow bar 1,0 1,0
Combustion products3)
3) For nominal calorific power.
Minimum low pressure mbar 0,015 0,015
Flow g/s 13 13
Temperature °C 170 170
Table 5

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8 | Technical Characteristics and Dimensions
2.9 Product data on energy consumption
The following product data complies with the requirements of EU Regulations 811/2013, 812/2013, 813/2013 and 814/2013
as supplement to the Directive 2010/30/EU.
Product data Symbol Unit 7701431589
Product type – – WR 8 G 31
Emissions of nitrogen oxides NOxmg/kWh 171
Sound power level, indoors LWA dB(A) 69
Declared load profile – –XS
Water heating energy efficiency class – –A
Water heating energy efficiency wh %75
Annual electricity consumption AEC kWh 0
Daily electricity consumption (average climate conditions) Qelec kWh 0
Annual fuel consumption AFC GJ 2
Daily fuel consumption Qfuel kWh 3,005
Smart control enabled? – –No
Thermostat temperature (factory setting) Tset °C –
Table 6 Product data on energy consumption

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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 sameas
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.
6720680412-02.1av
6720680412-03.1av
6720607845-01.1V

6 720 607 845 (2015/05)
10 | Regulations
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 (Fig. 9,
[1]).
▶ Remove threaded bushing (Fig. 9, [2]) from water valve.
▶ Empty the appliance of all water.
Fig. 9 Purge
[1] Retaining clip
[2] Threaded bushing
[3] Water valve
4Regulations
It is the law in GB that a competent Person in accordance with
the above regulations installs all gas appliances. Failure to
install appliances correctly could lead to prosecution. It is in
your interest , and that of safety, to ensure compliance with the
law.
Caravan & holiday homes:
the installation must meet the following standards Bs 5482:2
LPG and EN721 ventilation.
6720680033-02.1Av
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