Bosch CONDENS 5000W Manual

Installation and Servicing Instructions
HYDRONIC GAS SYSTEM BOILER 18kW
BOSCH CONDENS 5000W
6720646195-00.1Wo
ZSB18 - 2A
6 720 646 195a (2010/11)

10 | Boiler information AU/NZ
6 720 646 195a (2010/11)
Fig. 4 Additional components
1 Burner ON indicator light (green) 9 PRV pipe connection point
2 Power ON/OFF indicator/fault diagnostic light (blue) 10 CH return isolator
3 Position for optional programmer 11 Gas inlet connection BSP ¾ inch thread
4 Reset button 12 CH flow isolator
5 System pressure gauge 13 Condensate connection
6 ECO button (not used) 14 CH temperature control
7 DHW temperature control* 15 Service mode button
8 Boiler identification label
Tab. 7 Additional boiler components
6720644743-04.1Wo
1 2 3 4 5
6
15
14
91011
13 12
7
8
* The DHW temperature control is only
operational when the “optional internal
diverter valve” is fitted.

36 | Commissioning AU/NZ
6 720 646 195a (2010/11)
5.4 Starting the boiler
Fig. 56 Control panel
Switching the boiler on/off:
BTurn on mains power supply, the power on indicator
(5) illuminates blue.
BTurn on any external controls
BSet the thermostatic radiator controls to maximum
temperature
BSet the clock/programmer to continuously ON and the
room thermostat to maximum temperature
Turn the boiler CH temperature control (1) to maximum.
The burner on indicator (2) illuminates green when the
burner has lit.
If the boiler fails to light, the blue power indicator (5)
and reset button (7) will flash.
To reset press and hold the reset button (7) for more
than two seconds. The boiler will be reset.
CAUTION: Running the boiler
BNever run the boiler when the system is
empty or partially filled.
123456789
6720643895-52.1Wo
1 Central heating temperature control
2 Burner indicator (green)
3 Service button
4 Cover or optional Programmer
5 Power ON and fault indicator (blue)
6 ECO button - not used
7 Reset button
8 DHW temperature control (only operational
when option integral diverter valve is fitted)
9 System pressure gauge
Tab. 23 Control panel legend
NOTE: Reset
BDo not press the blue power indicator (5)
to reset the boiler.

Fault finding and diagnosis | 61AU/NZ
6 720 646 195a (2010/11)
7 Fault finding and diagnosis
7.1 Fault finding
The electronic control system for this boiler
incorporates a blue central indicator. This normally
confirms the permanent mains supply but, by flashing at
different rates during a fault, provides a guide to the
cause as listed.
This fault finding system assumes that the boiler has
been operating normally until the time of failure (i.e. not
a first installation error).
Preliminary electrical system checks are the first
electrical checks to be carried out during a fault-finding
procedure. On completion of the Service/Fault-Finding
task which has required the breaking and remaking of
electrical connections, check:
(a) Earth continuity,
(b) Short circuit check,
(c) Polarity and
(d) Resistance to earth.
This fault finding information is for guidance
only. Robert Bosch cannot be held
responsible for costs incurred by incorrectly
diagnosed faults.
Blue light
indication
Lockout
reset button Fault Possible solution/check
Off Off No power at
control board
Permanent mains supply to boiler.
Fuse F1 - 2.5A or Fuse F3 - 0.5A.
Transformer (primary coil below 60 Ω, both secondary coil below
10 Ω).
Otherwise replace control board.
On Off Boiler not
operating
during central
heating demand
Live demand at ST10-LR(from external room thermostat/timer)
Fascia mounted timer (if fitted)
CH knob in winter position
Control board
Boiler operating
without live
demand at
ST10-LR(from
external room
thermostat
timer)
Some older thermostats (containing capacitors) may give a low
voltage return at ST10-LRwhen the thermostat contacts are
open.
Check that there is no permanent live at ST10-LRfrom another
source.
Boiler not
operating
during any
demand.
Fan
Control board
Tab. 28

62 | Fault finding and diagnosis AU/NZ
6 720 646 195a (2010/11)
Slow flash
(mostly
off,
flashes
on)
Flashing
(reset
required)
Ignition lockout BGas present and at correct pressure?
BGas valve
–Check that there is 35V d.c. to each solenoid
–Check the resistance of each solenoid:
Top solenoid = 380 Ω±10% (342 - 418 Ω)
Bottom solenoid = 190 Ω±10% (171 - 209 Ω)
BCombustion CO2level.
BFlue condition.
–Blocked flue?
BBlocked condensate pipe or frozen condensate.
BGas valve adjustment.
BIgnition electrodes/harness/connections.
–Check for condition and continuity
BOtherwise replace control board
Slow flash
(mostly
on,
flashes
off)
Flashing
(reset
required)
Flue overheat BHeat exchanger baffles removed and not refitted.
Fast flash Off Volatile lockout
-
Fan does not
run
BTemperature sensors
–Check condition and continuity of leads/sensors
BFan
–230V a.c. across the live (purple) and neutral (brown)
BFan lead
–Check continuity
BCode plug
–Is code plug missing or not inserted properly.
2 pulses No light Not a fault code Service mode selected to minimum, press service button to
return to normal
5 pulses No light Not a fault code Service mode selected to maximum, press service button to
return to normal
Blue light
indication
Lockout
reset button Fault Possible solution/check
Tab. 28

Fault finding and diagnosis | 63AU/NZ
6 720 646 195a (2010/11)
7.1.1 Circuit diagram
FAN
FSFR NP LP
L
NSN
LSLR
ST8
ST9
ST17
ST18
ST5 ST4
ST10
Earth
MAINS
SUPPLY
PUMP
SUPPLY
SPARK
TRANSFORMER
ST1 DIAGNOSTIC
INTERFACE
CODE PLUG
Fuse F1, slow
2.5 A, AC 230 V
Fuse F3, slow T 0.5 A
Fuse F2, slow T1.6 A
ST6
EXTERNAL
FROST STAT
(OPTIONAL)
CH TEMPERATURE
CONTROL
Neutral Supply
230V WIRING CENTER/
JUNCTION BOX
BOSCH 24V CONTROLS
PLUG IN POINT
(NOT USED)
Live Supply
Live Return
Neutral
Live
Colour sequence †
Purple
Purple
Red
Red
Orange
Orange
7
8
9
Colour sequence †
SL
L
N
230V/AC
9V 25V
*
PRE WIRED LINK
*
*
EMS BUS contacts
(for FX controls not used)
B
B
4
2
1
A
F
PUMP
GAS
VALVE
SAFETY
SOLENOID
SAFETY
SOLENOID
FLAME SENSE
ELECTRODE
SPARK
ELECTRODES
OVERHEAT
STAT
FLUE
OVERHEAT
STAT
Green
DHW TEMPERATURE
CONTROL (NOT USED)
6720646195-23.1Wo
FLOW TEMP.
SENSOR (NTC)
† Fan wiring:
Live = purple
Neutral = brown
SI1
SI2
SI3
Blue
Blue

Australia
Robert Bosch (Australia) Pty. Ltd.
1555 Centre Road,
CLAYTON, Victoria 3168,
Phone: [phone]
Fax: [phone]
www.bosch.com.au/hotwater
New Zealand
Phone 0800 4 bosch or 08 543 352
www.bosch.co.nz