Bosch WR11B series Technical Document

Installation Manual and Operating Instructions
Gas Instantaneous Water Heater
WR 11/14/18 .B..
6 720 648 592 (2011/06) 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!

2| Table of contents
6 720 648 592 (2011/06)
Table of contents
1 Key to symbols and safety instructions 3
1.1 Explanation of symbols 3
1.2 Safety Instructions 3
2 Technical Characteristics and Dimensions 5
2.1 Declaration of conformity with relevant EEC
regulations 5
2.2 Explanation of Model Code 5
2.3 Accessories (Included with Appliance) 5
2.4 Description of the heater 5
2.5 Explanation of model code 5
2.6 Special accessories 6
2.7 Dimensions 6
2.8 Functional diagram of the heater 7
2.9 Electrical diagram 8
2.10 Function 8
2.11 Technical characteristics 9
3Use 10
3.1 Before starting up the heater 10
3.2 Batteries 10
3.3 Turning the heater on and off 10
3.4 Power adjustment 11
3.5 Temperature/flow adjustment 11
3.6 Purge the appliance 11
3.7 Cleaning 11
4Regulation 12
5 Installation (must be carried out only by
qualified technicians) 13
5.1 Important information 13
5.2 Selection of the place of installation 13
5.3 Heater mounting 14
5.4 Water connection 14
5.5 Gas connection 14
5.6 Inlet/exhaust pipe installation 15
5.7 Startup 15
6 Adjustments (must be carried out only by
qualified technicians) 16
6.1 Factory regulations 16
6.2 Pressure adjustment 16
6.3 Conversion to a different type of gas 17
7 Maintenance (must be carried out only by
qualified technicians) 18
7.1 Periodic maintenance work 18
7.2 Startup after maintenance work 18
7.3 Flue gas safety device 18
8Problems 20
9 Environment / disposal 21

Key to symbols and safety instructions | 3
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1 Key to symbols and safety instructions
1.1 Explanation of symbols
Warnings
Keywords indicate the seriousness of the hazard in
terms of the consequences of not following the safety
instructions.
•NOTE indicates that material damage may occur.
•CAUTION indicates that minor to medium injury may
occur.
•WARNING indicates that serious injury may occur.
•DANGER indicates possible risk to life.
Important information
Additional symbols
1.2 Safety Instructions
If there is a smell of gas:
BClose the gas valve.
BOpen windows.
BDo not operate any electrical appliances or switches
(on/off).
BExtinguish any naked flames.
BPhone the gas company or an authorized technician
from a safe distance.
If there is a smell of burnt gases:
BDisconnect the appliance.
BOpen doors and windows.
BInform an installation company.
Burn-back (fire in burner tube or chamber)
BIn 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.
BAfter ensuring the flame is extinguished, wait for one
minute and re-light the appliance in the normal
manner.
BShould the appliance again burn back, close the
control valve and call a service technician.
BDo not use the appliance again until the service
technician has declared that it is safe to do so.
Fitting, modifications
BThe fitting and modification of the installation of the
appliance must be carried out only by an authorized
technician.
BThe installation of the water heater may only be
carried out by a registered installer and that such
installations shall comply with the requirements of
SANS 10087-1.
BThe pipes carrying burnt gases must not be modified.
BDo not close or reduce air circulation holes.
Maintenance
BWe reccomend to have the system regularly serviced
in order to ensure that it functions reliably and safely.
BThe installer is responsible for the safety and
environmental compatibility of the installation.
BThe appliance should be serviced annually.
BOnly original spare parts must be used.
Warnings in this document are framed and
identified by a warning triangle which is
printed on a grey background.
Electrical hazards are identified by a
lightning symbol surrounded by a warning
triangle.
Important information in cases where there
is no risk of injury or material losses is
identified by the symbol shown on the left.
It is bordered by horizontal lines above and
below the text.
Symbol Meaning
Ba step in an action sequence
Æa reference to a related part in the
document or to other related documents
•alistentry
– a list entry (second level)
Table 1

4| Key to symbols and safety instructions
6 720 648 592 (2011/06)
Explosive and inflammable materials
BInflammable materials (paper, solvents, ink, etc.)
should not be stored near the appliance.
Combustion air and ambient air
BTo avoid corrosion, combustion air and ambient air
should be free of aggressive substances (for example
halogenated hydrocarbons containing chlorine and
fluoride composites).
Important information for the user
BThis appliance may only be installed by a registered
LP Gas installer.
BAll registered installers are issued with a card carrying
their registration number.
BAsk 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 for
acceptance of the installation when the installation is
completed to your satisfaction.
BNote that your invoice is required in the event that you
wish make a guarantee claim.
Important information for the installer
BThis appliance may only be installed by a LP gas
installer registered with the Liquefied Petroleum Gas
Association of Southern Africa.
BThe 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.
BUpon 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
BInform the client about the function and operation of
the appliance.
BCaution clients against performing modifications or
repairs themselves.
Risk of damage due to operator error
Operator errors can result in injury and damage to
property.
BEnsure that children never operate this appliance
unsupervised or play with it.
BEnsure that only personnel who can operate this
appliance correctly have access to it.

Technical Characteristics and Dimensions | 5
6 720 648 592 (2011/06)
2 Technical Characteristics and Dimensions
2.1 Declaration of conformity with
relevant EEC regulations
This appliance fulfills European directive requirements
2009/142/EC, 2006/95/EC, 2004/108/EC and
corresponds to the specifications described in the
corresponding EEC certificate of proof.
2.2 Explanation of Model Code
WGas Water Heater
RProportional power adjustment
11 Capacity (l/min)
BElectronic ignition powered by 1.5 V batteries
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:
2.3 Accessories (Included with Appliance)
•Gaswaterheater,
• Attachment elements,
• Installation accessories,
• Two 1.5 V batteries type R
•Heaterdocumentation.
2.4 Description of the heater
Operating convenience, as the heater is ready to operate
by simply pressing a switch.
• Heater for wall-mounting,
• Ignition by electronic device triggered when the water
valve opens,
• Great savings in comparison with conventional
heaters, due to the possibility of power adjustment
and no permanent pilot flame,
• 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 safety device which turns off the heater in
case of inadequate combusted gas evacuation
conditions,
– Temperature limiter which prevents overheating of
the heat exchanger.
2.5 Explanation of model code
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.
Model WR 11/14/18 B...
Category II2H3+
Type Type B
Table 2
WR11 B 23
31
S....
WR14 B 23
31
S....
WR18 B 23
31
S....
Table 3
Identification
Code
Wobbe Index
(Ws) (15 °C) Gas type
23 12,7-15,2
kWh/m3
Natural Gas -
Group H
31 20,2-21,3
kWh/m3LPG - Group B/P
Table 4

6| Technical Characteristics and Dimensions
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2.6 Special accessories
• Conversion kit from natural gas to butane/propane.
2.7 Dimensions
Fig. 1
1Front cover
2Hole for fixing to wall
3Temperature control
4Led indicator for battery charge level
5ON/OFF switch
6Led indicator for burner status
7Output control
8Gas connection
9Flue socket
10 Draught diverter with flue gas monitor
11 Heat exchanger
12 Automatic gas valve
13 Igniter unit
14 Battery compartment
Dimensions
(mm) A B C D E F G
H (Ø)
Natural
gas LPG
WR11B 310 580 228 112,5 463 60 25 1/2” 1/2”
WR14B 350 655 228 132,5 510 95 30 1/2” 1/2”
WR18B 425 655 334 132,5 540 65 30 1/2” 1/2”
Table 5 Dimensions

Technical Characteristics and Dimensions | 7
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2.8 Functional diagram of the heater
Fig. 2 Functional diagram
1Pilot burner
2Igniter electrode
3Ionisation detector
4Heat exchanger
5Main burner
6Injector
7a Testing point for burner pressure
7b Testing point for supply pressure
8Venturi
9Temperature/volume selector
10 Water valve
11 Adjusting screw for min. water flow rate
12 Water flow regulator
13 Water filter
14 Cold water supply pipe
15 Diaphragm
16 Microswitch
17 Main gas valve
18 Regulating screw
19 Gas inlet
20 Gas filter
21 Battery compartment
22 Hot water pipe
23 Igniter unit
24 Led indicator for burner status
25 ON/OFF switch
26 Led indicator for battery charge level
27 Servo valve
28 Output control
29 Gas valve
30 Gas valve for pilot burner
31 Pilot burner injector
32 Gas pipe for pilot burner
33 Temperature limiter
34 Flue gas safety device

8| Technical Characteristics and Dimensions
6 720 648 592 (2011/06)
2.9 Electrical diagram
Fig. 3 Electrical diagram
1Servo valve (normally open)
2Diaphragm valve
3Main valve (normally closed)
4Ionisation detector
5Igniter electrode
6Flue gas safety device
7Temperature limiter
8Igniter unit
9LED indicator for battery charge level
10 LED indicator for burner status
11 ON/OFF switch
12 Batteries, 1.5V
13 Microswitch
2.10 Function
This gas heater is equipped with automatic electronic
ignition which simplifies its operation.
BTo do so, just turn on the switch (ÆFig. 6).
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:
BClose 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.

Technical Characteristics and Dimensions | 9
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2.11 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 1,5 1,5 3,0
Minimum pressure for maximum water
flow psi 3,6 5,0 7,2
Temperature selector in fully anti-clockwise position
Temperature rise °C 25 25 25
Flow range l/min 4 - 11 4 - 14 4 - 17,6
Minimum pressure for maximum water
flow psi 8,7 14,5 19
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 6

10 | Use
6 720 648 592 (2011/06)
3Use
3.1 Before starting up the heater
BCheck if the gas indicated on the rating plate is the
same as the one used at the location.
BOpen the gas valve.
BOpen the water valve.
3.2 Batteries
Battery insertion
BInsert the two 1.5 V R20 batteries.
Fig. 4 Inserting the batteries
Replacing the batteries
The batteries must be changed if the red LED starts
flashing.
Fig. 5 Replacing the batteries
Precautions when using the batteries
• Do not dispose of batteries as domestic waste. Take
them to appropriate collecting places for recycling.
• Do not insert flat batteries.
• Only use the type of batteries indicated.
3.3 Turning the heater on and off
Turning on
BPress the switch , position .
Fig. 6
Green light on = Main burner on
Fig. 7
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:
BInitial 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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Use | 11
6 720 648 592 (2011/06)
Turning off
BPress the switch , position .
3.4 Power adjustment
Lower water temperature.
Less power.
Fig. 8
Higher water temperature.
More power.
Fig. 9
3.5 Temperature/flow adjustment
BTurn anti-clockwise
Increases flow and decreases water temperature.
Fig. 10
BTurn clockwise.
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:
BRemove the retaining clip from threaded bushing
(ÆFig. 11, pos. 1).
BRemove threaded bushing (ÆFig. 11, pos. 2) from
water valve.
BEmpty the appliance of all water.
Fig. 11 Purge
1Retaining clip
2Threaded bushing
3.7 Cleaning
BClean the front cover using a damp cloth and
detergent.
Do not use abrasive or corrosive cleaners.
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1

12 | Regulation
6 720 648 592 (2011/06)
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.

Installation (must be carried out only by qualified technicians) | 13
6 720 648 592 (2011/06)
5 Installation (must be carried out only by qualified technicians)
5.1 Important information
BBefore installing, call the gas company and check the
standard relating to gas heaters and ventilation
requirements for rooms.
BInstall a gas cut-off valve as close as possible to the
heater.
BAfter finishing the gas system, the pipes must be
thoroughly cleaned and leak-tested; to avoid
damaging the gas valve by excess pressure, this test
must be performed with the gas valve of the heater
closed.
BCheck if the heater corresponds to the type of gas
provided.
BCheck if the flow and pressure through the installed
reducer are appropriate for the consumption of the
heater (see technical data in the table 4).
5.2 Selection of the place of installation
Requirements regarding the place of installation
• Do not install the heater in rooms with a volume of
less than 8 m3(not including the volume of the
furniture providing this does not exceed 2 m3.
• Comply with the specific instructions for each
country.
• Assemble the gas heater in a well-ventilated location
where it will not be exposed to temperatures below
zero and in a place where there is an evacuation pipe
for combustion gases.
• The gas heater must not be installed over a heat
source.
• To avoid corrosion, the combustion air must be free
from harmful substances. Examples of particularly
corrosive substances: halogenated hydrocarbons
contained in solvents, paints, glues, engine gases and
various domestic detergents. If necessary, take
adequate measures.
• Respect the minimum installation clearances
indicated in Fig. 12.
• The heater must not be installed in locations where
the room temperature can reach 0 °C.
In case of a frost risk:
BTurn off the heater,
BRemove batteries,
BPurge the heater (see section 3.6).
Fig. 12 Minimum clearances
Combustion gases
• All gas heaters must be connected in a leak-roof
manner to a gas evacuation pipe of adequate
dimensions.
•Thefluemust:
– be vertical (reduced horizontal sections or no
horizontal sections at all)
DANGER: Explosion!
BAlways turn off the gas cock before
carrying out any work on components
which carry gas.
Installation, electrical connection, gas
installation, connection of inlet and exhaust
pipes and initial of the 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 appliance can only be sold in the
countries mentioned in the type plate.
DANGER:
Make sure that all flue connections are
tighten sealed.
BFailure to follow this requirement may
cause dangerous exhaust gases to enter
living space which may result causing
personal injury or loss of life.
³
h
3
33
40
³
L
L(m) h(cm)
0-1 3
1-2 6
2-3 9
3-4 24
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180
30
£
140
³
100

14 | Installation (must be carried out only by qualified technicians)
6 720 648 592 (2011/06)
– be thermally insulated
– have an exit above the maximum roof level.
• The combustion gases evacuation pipe must be
inserted in the flue ring. The external diameter of the
pipe must be slightly less than the diameter of the flue
indicated in the table of heater dimensions.
• The extremity of the evacuation pipe must be
protected against wind/rain.
If these conditions cannot be met, a different location
must be selected for the gas intake and evacuation.
Surface temperature
The maximum surface temperature of the heater is less
than 85 °C, with the exception of the combustion gases
evacuation device. No special protection measures are
required for flammable construction materials or built-in
furniture items.
Air intake
The place where the heater is to be installed must have
an area of air supply according to the table.
The minimum requirements are listed above; however,
each country's specified requirements must also be
respected.
5.3 Heater mounting
BRemove the temperature/flow selector and the power
selector.
BUnscrew the front fixing screws.
BWith a simultaneous movement towards you and
upwards, release the front of the two lugs from the
back.
BFix the heater vertically, using the provided screw
hooks and plugs.
5.4 Water connection
It is advisable to purge the installation beforehand,
because the presence of dirt may reduce the flow and,
in extreme cases, cause a blockage.
BIdentify the cold water pipe (ÆFig. 13, item A) and
the hot water pipe (ÆFig. 13, item B), so as to avoid
any possible mis-connection.
BConnect the water pipes to the water valve using the
provided connection accessories.
Fig. 13 Water connection
5.5 Gas connection
Gas pressure regulator
This appliance requires an operating pressure of 2,8 kPa
at the appliance. A suitable LPG regulator that complies
with the requirements of SANS 1237 must be installed.
CAUTION:
Ensure that the extremity of the evacuation
pipe is placed between the ledge and the
ring of the flue.
Heater Minimuum useful area
WR11B ≥60 cm2
WR14B ≥90 cm2
WR18B ≥120 cm2
Table 7 Useful areas for air intake
CAUTION:
Never support the gas heater on the water
or gas connections.
It is advisable to install a non-return valve on
the supply side of the heater to avoid
problems caused by sudden changes in
supply pressure.
DANGER:
If local regulations are not follow exactly, a
fire or explosion may result causing
property damage, personal injury or loss of
life.
Only use accessories recommended in this
manual.

Installation (must be carried out only by qualified technicians) | 15
6 720 648 592 (2011/06)
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 your
country.
5.6 Inlet/exhaust pipe installation
Pipes should be installed according to the instructions in
the relevant manual.
BOnce connected, the pipe should be inspected and
the seal guaranteed.
5.7 Startup
BOpen the water and gas flow valves and check that all
connections are leak-tight.
BCheck the flue gas safety device is functioning
correctly, proceed as explained in “ 7.3 Combustion
gas probe”.
DANGER: Make sure that all flue
connections are tighten sealed.
BFailure to follow this requirement may
cause dangerous exhaust gases to enter
living space which may result causing
personal injury or loss of life.

16 | Adjustments (must be carried out only by qualified technicians)
6 720 648 592 (2011/06)
6 Adjustments (must be carried out only by qualified technicians)
6.1 Factory regulations
Natural gas
Heaters designed for Natural gas H (G 20) are factory
sealed for delivery after the values on the characteristics
panel have been checked.
Liquid gas
Propane/butane heaters (G31/G30) are factory sealed
for delivery after the values on the characteristics panel
have been checked.
Power may be tuned according to the burner pressure
process, for which a manometer with U-shaped
connecting tubes is required.
6.2 Pressure adjustment
Accessing the adjusting screw
BRemove the front part of the heater (see 5.3).
Connecting the pressure gauge
BUnscrew the shut-off screw.
BConnect the pressure gauge to the measuring point
for the burner pressure.
Fig. 14 Pressure measurement points
Maximum gas flow adjustment
BRemove the screw seal (ÆFig. 15).
BTurn on the heater with the power selector set to the
left (maximum position).
Fig. 15 Maximum gas flow adjusting screw
BOpen various hot water taps.
BUsing the adjusting screw, regulate the pressure until
obtaining the values indicated in the table 8.
BSeal the adjusting screw once again.
Minimum gas flow adjustment
Sealed parts must not be interfered with.
Heaters should not be ignited when the
connections pressure is less than 1,7 kPa
more than 2,5 kPa.
Heaters should not be ignited when the
connections pressure is:
- Propane: less than 2,5 kPa more than 4,5
kPa.
- Butane: less than 2,0 mbar more than 3,5
kPa.
The minimum gas flow adjustment is
performed automatically after the
adjustment of the maximum gas flow.
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Adjustments (must be carried out only by qualified technicians) | 17
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6.3 Conversion to a different type of gas
Only use the original conversion kits.
The conversion must only be performed by a qualified
technician. The original conversion kits are supplied with
assembly instructions.
Natural gas H Butane Propane
Injector code
WR11
8708202113
(1,10)
8708202130
(0,70)
8708202124
(1,20)
8708202128
(0,72)
WR14
8708202113
(1,10)
8708202128
(0,72)
8708202116
(1,25)
8708202132
(0,75)
WR18
8708202115
(1,15)
8708202130
(0,70)
8708202116
(1,25)
8708202132
(0,75)
Connection
pressure
(psi)
WR11
WR14
WR18
233
MAX (psi)
WR11 1,27 2,8 3,5
WR14 1,2 2,8 3,5
WR18 1,03 2,55 3,25
Table 8 Burner pressure

18 | Maintenance (must be carried out only by qualified technicians)
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7 Maintenance (must be carried out only by qualified technicians)
To ensure that gas consumption and the environmental
load (pollution, etc.) remain as negligible as possible
over a longer period of time, we recommend that you
assure to have the appliance maintained on an annual
basis (inspection) or if necessary (maintenance).
These jobs can only be done by a Bosch Technical
Assistance delegate.
BOnly use original spare parts.
BOrder the spare parts according to the spare parts
catalogue for the heater.
BReplace the joints and removed O-rings with new
ones.
BOnly the following lubricants must be used:
– Hydraulic part: Unisilikon L 641 (8 709 918 413)
– Threaded joints: HFt 1 v 5 (8 709 918 010).
7.1 Periodic maintenance work
Functional check
BCheck the operation of all safety, adjustment and
monitoring elements.
Heat exchanger
BCheck the heat exchanger is clean.
BIn case of dirt:
– Remove the heat exchanger and take out the
limiter.
– Clean the chamber with a powerful jet of water.
BIf dirt persists: Soak the plates in hot water with
detergent and clean thoroughly.
BIf necessary: De-lime the interior of the heat
exchanger and the connection pipes.
BInstall the heat exchanger using new joints.
BInstall the limiter on the support.
Burner
BCheck the burner annually and clean it if necessary.
BIf it is very dirty (grease, soot): Remove the burner,
soak it in hot water with detergent and clean it
thoroughly.
Water filter
BReplace the water filter installed in the water valve
entry.
Burner and pilot injector
BRemove and clean the pilot burner.
BRemove and clean the pilot injector.
7.2 Startup after maintenance work
BTighten all connections once more.
BRead chapter 3 “Use” and chapter 6 “Adjustments”.
7.3 Flue gas safety device
Operation and safety precautions
The flue gas safety device checks the effectiveness of
flue gas extraction by the flue. If it is inadequate, the
appliance switches off automatically so that the
combustion fumes do not escape into the room in which
the appliance has been installed. The flue gas safety
device resets after a cooling-down period.
If the appliance shuts down while in operation:
Bventilate the room.
BWait about 10 minutes then restart the appliance.
If the problem recurs, call an engineer.
Maintenance
If faults occur on the flue gas safety device, proceed as
follows:
BUndo flue gas safety device fixing screw.
BLoosen temperature limiters connectors.
DANGER:
Explosion!
BAlways turn off the gas cock before
carrying out any work on components
which carry gas.
CAUTION: Leaking water may damage the
appliance!
BAlways empty the system before
disassembly of any hydraulic system part.
WARNING:
Is forbidden to start up the appliance
without water filter correctly assembled.
DANGER:
The flue gas safety device must not under
any circumstances be switched off,
simulated or replaced by any other
component.
DANGER:
The user must never make any
modifications to the flue gas safety device.

Maintenance (must be carried out only by qualified technicians) | 19
6 720 648 592 (2011/06)
BUndo magnetic unit connector.
BRemove thermocouple.
BReplace damaged component with new one and refit
using the reverse of the procedure set out in the table
above.
Function check
Flue gas safety device function check:
BDisconnect flue pipe;
BReplace with pipe (about 50 cm long) with sealed
end;
BFit pipe vertically;
BStart up appliance at rated output and set
temperature control to maximum temperature;
Under those conditions, the appliance should shut
down after two minutes. Remove temporary pipe and
reconnect flue pipe.

20 | Problems
6 720 648 592 (2011/06)
8Problems
Assembly, maintenance and repairs must be performed by qualified technicians only. The following chart offers
solutions to possible problems (solutions followed by an * must be undertaken by qualified technicians only).
Problem Cause Solution
The heater does not ignite.
Slow and difficult ignition of
the burner.
Red LED in switch flashes.
Switch turned off.
Reduced water flow.
Flat batteries.
Check switch position.
Check and correct.
Replace batteries.
Water at low temperature. Check the temperature selector position
and adjust it according to the desired water
temperature.
Water is not heated, no flame. Insufficient gas supply. Check reducer, and if inadequate or
malfunctioning, replace it.
Check if the bottles (butane) freeze during
operation, and if so, move them to a
warmer place.
The burner turns off the
heater is operating.
Temperature limiter has tripped.
Flue gas safety device has tripped.
Wait 10 minutes and restart the heater. If
the problem persists, call a qualified
technician.
Vent the area. Wait 10 minutes and restart
the heater. If the problem persists, call a
qualified technician.
There is spark but the main
burner does not ignite.
No ionisation probe signal. Check:
•Gassupply,
• Ignition system (ionisation electrode and
electrovalves).
Reduced water flow. Insufficient water supply pressure.
Dirty taps or mixers.
Gas valve blocked.
Heat exchanger blocked
(limescale).
Check and correct. *
Check and clean.
Clean filter.*
Clean and de-lime if necessary.*
Table 9