Installation Manual and Operating Instructions
Gas Instantaneous Water Heater
WR8..P...
WR11..P...
6 720 607 884 (2009/05) GB
With piezo ignition and double safety system
consisting of flue gas monitor and heat
exchanger temperature sensor.
Safety instructions:
If
-
you smell gas:
Do not operate any electrical switches.
Do not telephone from inside the danger area.
Turn off the gas cock.
Open windows and ventilate room.
From outside, call the gas company and your approved
installer.
Do not use or store easily combustible materials in the vicinity
of the appliance.
Installation and servicing of the appliance may only be
carried out by an approved technician.
The appliance should be regularly serviced in order to ensure
that it remains in perfect and safe working order.
If there is a risk of freezing, the appliance must be switched
off and drained. If the appliance has not been drained during
a cold spell, when it is switched on again check that it
produces hot water. If problems occur, contact your installer
Contents
1.
Technical Characteristics and Dimensions
1.1
1.2
1.3
1.4
1.5
1.6
Category, Appliance Type and Approval Number ...... 2
General Description ......................................................... 2
Explanation of Model Code ............................................ 2
Dimensions ......................................................................... 3
Appliance design ............................................................... 3
Technical characteristics ................................................. 4
2.
Preconditions for installation
2.1
2.2
2.3
2.4
Regulations ......................................................................... 5
Location .............................................................................. 5
Fixing the appliance .......................................................... 5
Water connection ............................................................. 5
1.
Technical Characteristics and Dimensions
1.1
Category, Appliance Type and Approval Number
2.5 Gas connection ................................................................. 5
2.6 Flue ....................................................................................... 6
2.7 Commissioning .................................................................. 6
3.
Operation and maintenance
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
Function .............................................................................. 7
Water temperature control .............................................. 7
Appliance adjustments ..................................................... 7
Maintenance ...................................................................... 7
Purge the appliance ......................................................... 7
Flue gas safety device ..................................................... 7
Converting to a different gas type ................................ 8
Troubleshooting ................................................................. 8
4.
Operation ............................................................................... 12
0464 BQ 20
MODEL
COUNTRY
BE, CH, ES, FR, GB, IT, PT, LU, HR
WR8/11 P…
NL, DE
B11BS
TYPE
1.2
General Description
This water heater is fitted with a piezo system.
Guaranteed safety provided by:
- Gas-tight ionisation detector that prevents escape of gas
if there is no flame.
- Flue gas safety device that switches off the appliance if
the flue is not functioning properly.
- Temperature limiter which protects the heat exchanger
against overheating.
Heat exchanger has no tin/lead lining.
Automatic water valve made of glass-fibre reinforced
polyamide, 100% recyclable.
Automatic control of water flow maintains constant flow rate
even with fluctuating supply pressure.
Proportional adjustment of gas and water flow rates in order
to ensure an even temperature gradient.
Gas valve with adjustable output via a slide control.
2
1.3
CATEGORY
I3+
I3B/P
Explanation of Model Code
W
R
8
P
31
S…
W
R
11
P
31
S…
W
R
8
P
31
S...
Gas instantaneous water heater
Proportional output control
Flow rate (l/min)
Piezo ignition
LPG (butane/propane)
Country code
6 720 607 884
1.4
Dimensions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Front cover
Hole for fixing to wall
Observation window
Temperature control
Output control
Gas connection
Exhaust pipe union
Draught diverter with flue
gas monitor
Heat exchanger
Automatic gas valve
Piezo
Water valve
Fig. 2
Dimensions
(mm)
WR8..P...
WR11..P...
1.5
A
B
C
D
E
F
G
H (Ø)
LPG
310
580
228
112,5
463
60
25
3/4"
Appliance design
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26a.
26b.
27.
28.
29.
30.
Heat exchanger
Main burner
Injector
Slow ignition valve
Temperature control
Venturi
Adjusting screw for min. water flow rate
Water valve
Water throttle
Water filter
Membrane
Cold water pipe
Magnetic unit
Gas supply pipe
Gas filter
Regulating screw
Pilot filter
Piezo
Hot water pipe
Output control
Igniter button
Main gas valve
Gas valve for pilot burner
Pilot burner injector
Gas valve
Testing point for supply pressure
Testing point for burner pressure
Thermocouple
Igniter electrode
Temperature limiter
Flue gas safety device
Fig. 3
6 720 607 884
3
Technical characteristics
Flue
specifications***
Water system specifications
Gas supply
specifications *
Output and heat
demand
1.6
*
**
***
4
Technical Data
Symbol
Unit
WR8
WR11
Rated max. heat output
Pn
kW
11.8
19.2
Rated min. heat output
Pmin
kW
7.0
7.0
kW
7.0 - 11.8
7.0 - 19.2
Output (modulation range)
Rated max. heat input
Qn
kW
13.5
21.8
Rated min. heat input
Qmin
kW
8.1
8.1
G30/G31
mbar
28-30/37
28-30/37
G30/G31
kg/h
1
1.6
12
12
pw
bar
12
12
Supply pressure
LPG (butane/propane)
Consumption
LPG (butane/propane)
Number of injectors
Max. water pressure**
Temperature control at maximum setting
Temperature increase
°C
50
50
Flow rate
l/min
3.5
5.5
bar
0.1
0.1
Temperature increase
°C
25
25
Min. operating pressure
pwmin
Temperature control at minimum setting
Flow rate
l/min
7
11
Min. operating pressure
bar
1
1
Draught requirement
mbar
0.015
0.015
Flow rate
g/s
13
13
Temperature
°C
170
170
Hi 15°C - 1013 mbar - dry :
LPG: Butane 45.7 MJ/kg (12.7 kWh/kg)
This figure must not be exceeded taking account of water expansion
At maximum rated heat output
Propane 46.4 MJ/kg (12.9 kWh/kg)
6 720 607 884
2.
Preconditions for installation
The appliance can only be sold in the countries mentioned
in the type plate.
2.1
Regulations
Gas safety (installation & use) Regulations 1998.
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.
2.2
Location
The appliance should be sited in a well ventilated room where
it will not be exposed to temperatures below freezing.
To prevent corrosion, the combustion air must not contain
any corrosive substances. Substances classed as corrosionpromoting include halogenated hydrocarbons such as are
found in solvents, paints, adhesives, aerosol propellants and
various household cleaners. Appropriate measures should
be taken where necessary.
With the exception of the flue pipe, the surface temperature
of the appliance is below 85 °C. No special safety measures
are therefore necessary.
Site appliance as shown in Fig. 5.
Always site appliance in a location not exposed to
temperatures below freezing. If this is not possible, the
appliance must be switched off and drained and the batteries
removed whenever there is a risk of freezing.
Do not install the appliance in rooms where the free volume
is less than 8 m3.
in extreme cases, could completely clog up the appliance.
Mark hot water (fig.4, pos.B) and cold water pipes (fig.4,
pos.A) so as to prevent confusion.
Connect pipe to automatic water valve using the connecting
kit supplied.
Fig. 4 Water connection
To prevent problems caused by sudden pressure fluctuations
in the water supply, it is advisable to fit a non-return valve
to the water outlet.
2.5
Gas connection
Take care to ensure dirt is not allowed to enter gas inlet.
Make sure that the type of gas specified on the appliance
type plate is the same as that supplied by the gas authorities.
Select pipe diameter to suit output of instantaneous water
heater being installed.
Fit gas service cock as close to appliance as possible.
Air admission
The room where the appliance is to be installed should be
provided of fresh air inlet areas according with the below
table.
Appliance
WR 8
WR 11
Minimum area
2
≥ 60 cm
Minimum requirements are listed above. Local regulations
should allways be observed.
2.3
Fixing the appliance
Remove the temperature control and the output control.
Remove the outer case by sliding it forwards and then lifting
upwards.
Fix the appliance using the sleeves and hooks supplied so
that it is vertical.
Never allow the appliance to rest against water or gas
pipes.
2.4
Water connection
It is advisable to drain the appliance before installing it as
any dirt or grit inside it could reduce the water flow rate and,
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5
2.6
Flue
It is absolutely essential that all instantaneous water heaters
are connected to a suitably dimensioned flue pipe by means
of a gas-tight connection.
The flue pipe should be made of galvanised iron, aluminium,
stainless steel or fibre concrete. Fit as shown in Fig. 5.
A flexible or rigid pipe should be used, fit it inside the flue
socket. The external diameter of the pipe should be slightly
smaller than the dimension specified in the appliances
dimensions table.
Fig. 5
Minimum distances (cm)
2.7
Commissioning
Turn on the gas and water cocks and check all connections
for leaks.
Check flue gas safety device good functioning, proceed as
explained in section 3.6.
6
6 720 607 884
3.
Operation and maintenance
Sealed parts must not be interfered with.
3.1
Function
This water heater is fitted with piezo ignition that provides
for easy commissioning.
In first place it must dislocate the output control of the off
position to the ignition position (see fig. 7).
Press in the slide control knob and subsequently press the
piezo button. Release the slide control after about 15
seconds, if the pilot flame does not stay alight, repeat the
operation.
Ignition may not be successful due to the presence of air
inside the gas supply pipe, especially if first connected or
after long inactive periods. In this case, keep the output
control knob fully depressed until the gas pipe has been
totally purged.
Slide the gas control slide fully to the right to obtain maximum
output. Sliding the gas control slide to the left reduces the
output.
In order to optimise energy consumption, adjust the output
control to supply the minimum output required.
After following these procedures, ignition of the main burner
will automatically take place whenever you turn on a hot
water tap, since the pilot burner is permanently alight.
When you want to switch off the heater, move the slide
control to the far left. After a few seconds the pilot flame
will go out.
If there is a risk of freezing, switch off the appliance and
drain the appliance.
Danger: the area in front of the burner can reach very high
temperatures, and there is a risk of burning on contact.
3.2
Water temperature control
The water temperature control is used to adjust the water
flow rate, and thereby the water temperature, to the desired
setting.
Turning the control clockwise reduces the water flow rate
and increases the temperature; turning the control anticlockwise increases the water flow rate and reduces the
temperature.
If the temperature is set only as high as required, energy
consumption is reduced and the likelihood of scale deposits
in the heat exchanger minimised.
3.3
Appliance adjustments
All instantaneous water heaters are factory-adjusted and
require no further adjustment.*
Water heaters that use LPG (liquefied petroleum gas, i.e.
butane/propane) are set to the operating pressure stated
on the identification plate (28-30/37 mbar).
Natural gas appliances are set to a Wobbe Index of 15 kWh/
m3 and a supply pressure of 20 mbar.
* Sealed components must not be tampered with.
6 720 607 884
3.4
Maintenance
The appliance should only be serviced by an approved
engineer.
A complete overhaul should be carried out after two years.
The overhaul should involve thoroughly cleaning the heat
exchanger, burner, pilot burner and automatic water valve
filter.
If necessary, the inside of the heat exchanger and the
connecting pipes should be descaled.
Check the gas and water valves for leaks and carry out a
complete function check.
If components need to be replaced, use only genuine Bosch
spare parts.
3.5
Purge the appliance
If there is a risk of freezing, proceed as follows:
Remove the retaining clip from threaded bushing (pos.1).
Remove threaded bushing (pos. 2) from water valve.
Empty the appliance of all water.
Fig. 6
Purge the appliance
3.6
Flue gas safety device
The recommition must be done from a qualified technician
only.
The flue gas safety device must not under any circumstances
be switched off, simulated or replaced by any other
component.
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 coolingdown period.
If the appliance shuts down while in operation, ventilate the
room. Wait about 10 minutes then restart the appliance. If
the problem recurs, call an engineer. The user must never
make any modifications to the appliance.
Maintenance
If faults occur on the flue gas safety device, proceed as
follows:
- Undo flue gas safety device fixing screw.
- Unplug igniter unit connector
- Unplug battery connector
Replace damaged component with new one and refit using
the reverse of the procedure set out in the text above.
7
Function check*
Flue gas safety device function check:
- Disconnect flue pipe
- Replace with pipe (about 50 cm long) with sealed end
- Fit pipe vertically
- Start 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.
* This work may only be carried out by an approved engineer.
3.7
Converting to a different gas type
Use only the genuine Bosch conversion kit. Conversion
may only be carried out by an approved technician.
3.8
Troubleshooting
Installation, servicing and repairs may only be carried out by an approved engineer.
The following table illustrates only a few solutions to straightforward problems.
Problem
Pilot flame stay alight.
Cause
Solution
Blocked pilot burner.
Clean.*
Flue gas safety device has tripped
Ventilate room. Wait 10 minutes then restart
appliance. If problem recurs, call an approved
technician.
Temperature limiter has tripped.
Wait 10 minutes then restart appliance. If
problem recurs, call an approved technician.
Several atempts required to turn pilot flame on.
Yellow pilot flame.
Flame goes out while appliance is in operation.
Water not hot enough.
Water not hot enough, weak flame.
Check output selector position and regulate
according with needs.
Gas supply dynamic pressure too low.
Check gas cylinder governor and replace if
incompatible or damaged. *
Check whether gas cylinder (butane) is freezing
when appliance is in operation and re-site in
warmer location if necessary.
Reduced water flow rate.
Inadequate inlet flow rate.
Check and adjust.
Dirt in water service cock or mixer unit.
Check and clean.
Automatic water valve clogged.
Clean filter.*
Heat exchanger clogged (scale).
Clean and descale as necessary.*
The operations marked with “*” may only be carried out by an approved technician
8
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9
10
6 720 607 884
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11
4.
Operation
Turn on all gas and water taps
Purge air from pipes
Ignition
Depress slide control knob and hold
it in
Release the slide control
knob after approximately 10
seconds
Press the piezo igniter
Repeat these steps if the flame does not stay alight
Output Control
output decrease
output increase
Temperature adjustment
Turning control anti-clockwise
Turning control clockwise
increases water flow rate and
reduces water temperature
reduces water flow rate and
increases water temperature
Switching off
Move slide control to the far left
Fig. 7