Chaffoteaux & Maury Centora green Manual

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MAINTENANCE AND
SERVICE GUIDE
Fanned Flue Condensing Wall Hung
Combination Boiler
Central Heating and Instantaneous
Domestic Hot Water
Dimensions
Technical Data
Flue types:
C 13: horizontal
C
54 54 54 54
JKLMN I
88
JK
L
MN
232
235
32
Safety valve
centre line
All dimensions in mm
Outer case dimensions :
- Width : 440 (minimum space required 450)
- Height : 850
- Depth : 380
212
360
67
737
850
380
50
ISafety valve outlet
JHeating flow
KD.H.W. flow
LGas supply
MCold water inlet
N Heating return
Gross heat input C.H. max............................ 9.2 to 20,9 kW
Gross heat input D.H.W. max ....................... 9.2 to 27.8 kW
Heat output C.H. 50°C/30°C max.................. 8.3 to 19.5 kW
Heat output C.H. 80°C/60°C max.................. 8 to 18 kW
Heat output D.H.W. max ............................... 8.3 to 24 kW
C.H. operating temperature........................... 80°C max
C.H. circuit pressures Min operating ............. 0.7 bar
C.H. circuit pressures Max operating ............ 2.5 bar
D.H.W. flow rates ∆T30°C............................. 12 l/min
D.H.W. flow rates ∆T35°C ............................ 10.3 l/min
Cold water mains pressures Min operating... 0.5 bar
Cold water mains pressures Max operating.. 10 bar
Flow limiter rate............................................. 8 l/min
Safety discharge ........................................... 3 bar
Expansion vessel - Pre-charge pressure ...... 0.7 bar
Nett capacity at 3 bar in litres........................ 5.44
Supply ........................................................... 230 V~
Consumption ................................................. 150 W
Protection ...................................................... IPX4D
Fuse F1/F2/F3/F4 ......................................... 2 A/1.25 A/0.315 A/0.250 A
External controls ........................................... 24 V~
Natural Gas G20
Gas rate C.H. max .......................... 1.98 m3/h
Gas rate D.H.W. max...................... 2.65 m3/h
Gas rate C.H. & D.H.W. min ........... 0.87 m3/h
Gas valve restrictor diameter.......... 5.55 mm
Propane L.P.G. G31
Gas rate C.H. max. ......................... 1.46 kg/h
Gas rate D.H.W. max...................... 1.94 kg/h
Gas rate C.H. & D.H.W. min ........... 0.64 kg/h
Gas valve restrictor diameter.......... 4.15 mm

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Pump and Expansion Vessel Characteristics
Components Location
Note : The system initial pressure should be over the following value :
System static height (in metre) + 0.7 = Initial pressure (in bar)
10
GV F= high speed by-pass closed
GVO = high speed by-pass open
PV F= low speed by-pass closed
PVO = low speed by-pass open
20 40 60 80 100 120
Pf
140 160 180 200 220 240
0,7
0,8
0,9
1,0
1,1
1,2
1,3
1,4
1,5
1,6
1,7
1,8
1,9
2,0
80°C
70°C
60°C
50°C
40°C
260
Pression à froid pour le circuit chauffage (en bar)
C litre
System capacity chart
Central heating initial pressure when cold (in bar)
0
4
3
2
1
5
6
100 200 800 700
600
500
400
300 900 10001100 l/h
mCE Débit mini (robinets thermostatiques fermés)
Hauteur manométrique
GVF
GVO
PVF
PVO
Pump head available
Minimum flow rate (with all heating thermostatic valves closed)
bar
0
13
4
1
2
3
4
5
6
8
11
12
13
14
7
15
10
9
16
1.- Steel chassis complete with expansion vessel (not visible)
2.- Sealed chamber
3.- Burner and heat exchanger assembly
4.- Air/gas connection
5.- 24 V modulating fan
6.- Gas valve
7.- Ignition electrode
8.- Ionisation probe
9.- Ignitor
10.- Combustion products manifold
11.- 24 V transformer
12.- Siphon
13.- Electrical box
14.- Pump
15.- Secondary heat exchanger
16.- Pressure gauge
17.- Three way valve
18.- Automatic air separator and automatic vent
19 - Central Heating flow switch
20.- Domestic Hot Water flow switch
21.- Central Heating control thermistor
22.- Domestic Hot Water control thermistor
23.- Overheat sensor
37.- Central Heating flow isolating valve
38.- Domestic Hot Water outlet
39.- Gas service tap
40.- Water service tap
41.- Central Heating return isolating valve
43.- Central Heating pressure relief valve
46.- User instructions
47.- Connecting tails (x5)
48.- Condensate drain
49.- Adjustable by-pass
50.- Right hydraulic assy
51.- Left hydraulic assy
23
20
21
17
19
18
22
23
39 40 41
38
37 43
46
47
48
49
50
51

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FUNCTIONING
Control Panel
35
30 24 26 27
25
34
28
33 36
3132 29
24.- Display
25.- Domestic Hot Water switch
26.- Green indicator – Domestic Hot Water mode ON
27.- D.H.W. temperature reducing key
28.- D.H.W. temperature increasing key D.H.W. mode indica-
tor
29.- Central Heating switch
30.- Green indicator – Central Heating mode ON
31.- Central Heating temperature reducing key
32.- Central Heating temperature increasing key
33.- Green indicator – Power ON
34.- Orange indicator - Burner ON
35.- Red indicator - Lock out / flame failure
36.- Reset key
Switching On
1. Check that the pressure in the Central Heating system is above 0.7 bar and below 1.5 bar with the pressure gauge 16.
2. Check that the gas service tap is open at the gas meter and the main power is on. Green indicator Power ON
33.
3. Open the gas tap 39 (Fig.21).
The boiler is now ready to use.
Attention ! If the boiler has been off for a long period of time, some air in the gas pipe can hinder the first attempts to ignite.
(please refer to Section 19 Incorrect Operation).
Switching on Central Heating
Press the key 29, the green indicator 30 will light and the display will show the Central
Heating flow temperature.
Keys 31 and 32 allow the temperature to be adjusted as required for the Central Heating
system depending on the weather conditions.
• press to increase the temperature when the weather is cold
• press to reduce the temperature when the weather is fair
During the temperature setting operation the display will flash.
If the room thermostat is calling for heat, a dot will be displayed at the bottom of the 3rd digit
Switching on the Domestic Hot water
Press the key 25 the green indicator 26 will light :
If there is no water demand
the display will show the following graphic
During draw off
a square made of 4 digits will move clockwise on the display
Keys 27 and 28 allow the temperature to be adjusted as required for the Domestic Hot Water flow. During the tempera-
ture setting operation the display will flash.
Note : The configuration of C.H. system can generate some gravity effect when the boiler is set in D.H.W. mode only. It may result
in a temperature rise of the heating pipes close to the boiler (or eventually a radiator). To avoid this, it is possible to close the heat-
ing flow isolating tap 37 (Fig. 21) during the summer period (Central Heating switched off). Don’t forget to open it again before you
switch on the Central Heating mode again.

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Switching On the Domestic Hot Water and Central Heating Together
Press the key 29, the green indicator 30 will light.
Press the key 25, the green indicator 26 will light.
If there is no water demand the display will show the heating flow temperature
During draw off a square made of 4 digits will move clockwise on the display
Turn Off the Boiler
- Press the key 29 and the key 25, to switch off both the D.H.W. and C.H. mode. The green indicators 30 and 26 will
go off.
- Switch off the main electrical supply
- Shut off the gas service tap 39 (Fig. 21)
Note : In this condition, the anti-freeze system is inoperative.
Stand-by Mode A fixed digit at the centre of the display and the green indicator 33 will illumi
nate.
Putting the boiler in stand-by mode and anti-freeze system. :
Press the key 29 and the key 25, to switch off both the D.H.W. and C.H. mode. The green indicators 30 and 26
will go off.
During the duration of the stand by mode, an automatic anti-sticking system will activate the pump and 3 way valve
for 1 minute every 23 hours.
The stand by mode will disable the anti-freeze function of the room thermostat (if fitted). To leave the room thermo-
stat anti-freeze system operative, leave the Central Heating mode on.
The boiler is equipped with an automatic anti-freeze system which is permanently on.
If the Central Heating temperature falls below 7°C, the pump will start.
If the Central Heating temperature falls below 4°C, the pump and the burner will start.
Domestic Hot Water Mode
To be able to supply Hot Water, the
D.H.W. mode should be ON. Press the
key 25, the green indicator 26 will
illuminate.
If there is no water demand, the display
will show the following graphic
During draw off, a square made of 4 dig-
its will move clockwise on the display
.
Keys 27 and 28 allow the tem-
perature to be adjusted as required for
D.H.W. flow. During the temperature set-
ting operation, the display will flash.
When a tap or a shower is turned on, a
flow of mains water above 2 l/min, will
activate the D.H.W. flow switch 20, the 3
way valve 17 will move to the D.H.W.
position. The pump can now circulate pri-
mary water heated by the main exchang-
er through the secondary heat
exchanger. The C.H. flow switch checks
that the flow rate is over 4 l/min to allow
the ignition sequence to begin.
The fan on the gas valve assembly starts
and when the lighting speed is reached
(detected by a hall effect sensor) the 2
safety solenoids open together to allow
gas to the burner. The ignition sequence
begins and a continuous high speed
spark ignites the gas. As soon as a flame
is detected, the orange indicator bulb 34
will light and the regulation system will
be able to adjust the gas rate according
to the heat load. If a flame is not detect-
ed, after 10 seconds, the security sole-
noids close together and shut off the
gas. The red lockout indicator bulb 35
will light. Press the reset button to re-
attempt ignition.
The Domestic Hot Water temperature is
controlled by the Hot Water control ther-
mistor 22 and the Central Heating control
thermistor 21. The system anticipates
changes of temperature in the secondary
heat exchanger and ensures accurate
temperature regulation.
When the tap is closed, the burner is
extinguished and the pump stops. The
boiler will now stay in the Hot Water
mode for 3 minutes to maintain temper-
ature and to ensure a fast response in
the event of a subsequent Hot Water
demand.
Priority will be given to a demand for Hot
Water. This will interrupt the Central
Heating for the duration of Hot Water
delivery.
Central Heating Mode
To be able to supply Central Heating, the
C.H. mode should be switched ON.
Press the key 29, the green indicator
30 will light, and the display will show the
Heating Flow temperature.
Keys 31 and 32 allow the tem-
perature to be adjusted as required for
the Central Heating system relating to
the weather conditions. During the set-
ting operation, the display will flash.
When there is a demand for heating,
(either from the room thermostat or the
clock) the pump starts. If the boiler tem-
perature control is calling for heat and
the Central Heating flow rate is over 4
l/min, the Central Heating flow switch
operates, allowing the ignition sequence
to begin. The fan on the gas valve
assembly starts and when the lighting
speed is reached (detected by a hall
effect sensor) the 2 safety solenoids
open together to allow gas to the burner.
The ignition sequence begins and a con-
tinuous high speed spark ignites the gas.
As soon as a flame is detected, the
orange indicator bulb 34 will light and the
regulation system will be able to adjust
the gas rate according to the heat load. If
a flame is not detected after 10 seconds,
the security solenoids close together and
shut off the gas. The red lockout indica-
tor bulb 35 will light. Press the reset but-
ton to re-attempt ignition.
The Central Heating flow temperature is
controlled by the Central Heating control
thermistor 21. The boiler has been
designed to minimise cycling and will not
attempt to re-light for at least 3 min. after
the boiler thermostat has been satisfied.
When the room thermostat is satisfied,
the burner will switch off and the pump
will run for a further 3 minutes before
stopping.
Note:
It is possible to override the 3 minute
delay by pressing the reset button 36.

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Lockout Procedure
Flame extinguishes:
When the ionisation probe 8fails to
detect flame presence. The orange indi-
cator bulb 34 will go off and a lighting
cycle starts. If a flame is not detected,
within 10 seconds, the safety solenoids
will close. The red lockout indicator 35
illuminates and the display shows the
error code. The pump runs and the 3
way valve 17 stays in its position. After a
few seconds, it will become possible to
reset the boiler by pressing the reset but-
ton 36.
Overheat Detection :
If a temperature over 100°C is detected
in the primary circuit by the sensor 23,
the safety solenoids close and the fan
stops. The orange bulb 34 will go off and
the pump will run for a further 3 minutes.
It is possible to reset the boiler when the
primary circuit temperature falls below
76°C.
CENTORA GREEN FUNCTIONAL DIAGRAM
Heating mode Hot water mode
40
49
48
43
41
19
39
38
37
22 20
21
23
18
17
16
14
13
12
6
3
8
15
5
7
DIAGRAM
ELECTRICAL WIRING

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5 ”Menu - 1 - Default Register
Records the last 10 defaults
Section Digit 1 Digits 2 and 3
Last default occured 0•code from 01 to 99
Last but one default occurred 1•code from 01 to 99
... ... code from 01 to 99
Last default occurred before the previous one 9•code from 01 to 99
Menu - 2 - Boiler Conditions
Indicates the conditions or the configurations of the boiler
Section Digit 1 Digit 2 and 3
Software version of display P.C.B. 0•10 to 99
Nominal Power of the boiler (type 18 or 24 kW) 1•24
Flue type 2•1: FF
variable speed
Room thermostat is calling for heat 3•0: no
3•1: yes
Theoretical position of the 3 way valve 4•0: D.H.W.
4•1: C.H.
D.H.W. flow temperature in oC5
•from 00 to 99
C.H. flow temperature in oC7
•from 00 to 99
Software version of main P.C.B. 9•10 to 99
DISPLAY
ACTION CONFIGURATION
once
x times
x times
Note -- is displayed if no default is recorded.

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Menu - 3 - Boiler Options
DISPLAY
ACTION CONFIGURATION
Section Digit 1 Digits 2 and 3
Under floor heating system 0 0: no
1: yes
Factory
setting
Menu - 4 - Boiler Settings
Section Digit 1 Digits 2 and 3
Room thermostat operation 0 0: Burner only
01: Burner and pump
Pump speed 1 0: High speed
11: Low speed
Pump post circulation duration 2 0.0 min
From 0 to 5 minutes by step of 0.5 min. 2 0.5 min
21.0 min
25.0 min
Maximum Central Heating flow temperature 4 50°C
C.H. anti cycling delay 4 80°C
TAC 8 0.0 min
From 0 to 5 minutes by step of 0.5 min. 8 0.5 min
82.5 min
85.0 min
C.H. maximum output limitation Power
by step of 1 kW value
For a 24 kW model 9 8 to 18
Factory
setting
DISPLAY
ACTION CONFIGURATION
once
x times
once
x times

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Menu - 5 - Combustion Rate Control Mode
X X
X X
DISPLAY
ACTION CONFIGURATION
wait 5 ”Combustion rate control mode OFF
Switching on the combustion rate
control mode. Central Heating out-
put reaches the maximum power
set in menu 4 section 9.
Central Heating temperature is dis-
played in oC.
The 3 dots indicate that the combus-
tion rate control is ON at maximum
output.
Switching the combustion rate
down to minimum power.
Central Heating temperature is dis-
played in oC.
The dot indicates that the combus-
tion rate control is ON at minimum
output.
Switching on the combustion rate to
maximum output set in menu 4 sec-
tion 9.
Central Heating temperature is dis-
played in oC.
The 3 dots indicate that the combus-
tion rate control is ON at maximum
output.
X X
Switching off the combustion rate
control mode.
press once
press once
press
press once
press once
Effect Display
Locking conditions of the combustion rate control mode :
- boiler in stand by mode
- D.H.W. draw off
- room thermostat is not calling for heat
- room thermostat is calling for heat but the maximum temperature is reached
- boiler in lockout mode
- after a reset or if the main supply fails
- end of the mode (if operator leaves menu 5)
- after 15 minutes if no keys are pressed.
Note: As soon as the combustion rate control mode is on, the Central Heating and Domestic Hot Water
keys will become inactive.

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C.H. Power Output Setting :
If you would like to change the setting of the C.H. power output to 12 kW, please proceed as follows :
Note: the factory setting is 18 kW and the following explanation refers to menu 4 section 9)
- Switch to installer mode, press both
the and keys (D.H.W. side)
for 5 seconds.
The display shows :
-1- then 0•-- if there is no default in the
default register.
- press the menu key (C.H. side ) 3
times to gain access to menu -4-,
The display shows :
-4- then the value set for section 0 ( 00
or 01 respectively action on burner only
or pump and burner)
- change to section 9 (Adjustment of
C.H. Power Output). Press the
(D.H.W. side) 9 times.
The display shows :
918 (which corresponds to the 18 kW
which is the factory setting)
9= section 9 18 = 18 kW
- press the key (C.H. side) once,
the 2nd and 3rd digits flash together.
Press the key (D.H.W. side) to
change to 3.0 on the 2nd and 3rd digits.
The display shows :
912 press the setting key to confirm this
value. The display stops flashing.
Setting procedure is finished.
To exit the setting mode, leave the boil-
er for approx. 1 minute, the computer
will revert to the user mode.
After programming is completed please
close the door P(fig. 17)
1
Display
2x 3
1
2
or
33x 9
44
5 ”

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REGULATION FLOW SWITCHES
Temperature regulation for both C.H. and D.H.W. circuits are controlled by 2
thermistors. The C.H. knob allows the temperature to be adjusted between
35oC and 85°C. The D.H.W. temperature is limited to 60°C. The D.H.W. and
C.H. thermistors are identical and interchangeable.
Resistance value are
- 5000 Ωat 25°C
- 2631 Ωat 40°C
- 620 Ωat 80°C
- 255 Ωat 110°C
Flow in both D.H.W. and Central
Heating circuits are detected by 2 flow
switches. A piston with a magnet at the
top operates a REED switch. The piston
is lifted by the flow rates listed below :
Flow rate threshold :
D.H.W. 120 l/h ±20 l/h
C.H. 250 l/h ±20 l/h
ROUTINE SERVICING
To ensure continued efficient operation of the appliance, it is recommended that it is checked and serviced as necessary at reg-
ular intervals. The frequency of servicing will depend upon the particular installation, condition and usage. In general, once a
year should be adequate.
It is the law that any service work must be carried out by a competent person such as your local Chaffoteaux Service Centre,
British Gas or other CORGI registered personnel in accordance with the current Gas Safety (Installation and Use) regulations.
Attention! The air/gas connection pipe between the gas valve and the burner should never be opened. The seal can only be
checked in the factory.
The service schedule should include the following operations :
- Check the pressure in the system
- Check the correct operation of the appliance
- Check the correct operation of the gas controls
- Check the functions of the safety controls
- Clean the electronic board of the fan located on the gas valve assembly and the different transformers in the sealed chamber.
- Check combustion chamber insulation panels for damage
- Check the condition of the lighting and ionisation electrodes
- Clean the burner (Never use a metallic brush which can damage the stainless steel)
- Clean the heat exchanger (Never use a metallic brush which can damage the stainless steel)
- Clean the siphon and pay attention to the acidity of its contents
- Check the correct seal of the drain system
- Clean the gas and water filters
- Check the expansion vessel charge pressure
- Clean and check the operation of the safety valve
- Check the correct seal of the flue system.
Additional procedures that may be necessary :
- Check the burner pressure and the gas flow rates
- Check, clean and replace components as necessary
- Carry out combustion test utilising the test points in the flue turret
Suggested sequence for servicing :
Before disconnecting or removing any part, isolate the gas and electricity supplies. Ensure that the appliance is cool, and be
careful of the condensate products content in the siphon which are acid.
(For detail, please see section on Parts Removal and Replacement)
Preliminary checks
- Remove the outer case
- Check the system pressure is at least 0.7 bar when cold
- Check the modulation of the gas valve in D.H.W. mode by progressively reducing the flow rate at a tap.
- Check that the burner is extinguished fully when both solenoids are closed and the fan is off.
- Test ionisation functions and check that lockout occurs by turning off the gas tap.
- Whilst the boiler is operating, check the operation of the Central Heating flow switch by closing the Central Heating flow valve
and the by-pass screw (turn clockwise) noting the number of turns so that it may be reset correctly.
- Check the correct flood of condensate in the siphon which is transparent.

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REMOVAL AND REPLACEMENT OF PARTS
Before removing the appliances case,
isolate the gas and electrical supplies.
Isolate the boiler from the system and
drain before removing any component in
the waterways. Ensure that the appli-
ance is cool.
1. Outer Case
Remove the four screws in the base of
the boiler and lift free. When replacing,
carefully place the casing on lugs T
located on the top edge of chassis.
2. Sealed Chamber Front Panel
Unscrew the four self tapping screws
securing the sealed chamber front panel
and lift off of the corner locating lugs.
Reassemble in reverse order.
3. Combustion Chamber Front Panel
and Air/Gas Connection
Carry out steps 1 and 2 as above.
Unscrew the three screws securing the
air/gas connection pipe onto the gas
valve assembly. Disconnect both the
ionisation and lighting electrodes from
their wiring. Unscrew the six nuts to
release the combustion chamber front
panel and pull the assembly towards
you. Reassemble in reverse order.
4. Ionisation Probe
Carry out steps 1 and 2 as above.
Disconnect the ionisation probe from its
wiring. Loosen the 2 screws and pull it
out from the combustion chamber front
panel. Replace the gasket provided.
Reassemble in reverse order.
5. Ignition Electrode
Carry out steps 1 and 2 as above.
Disconnect the ignition electrode from its
wiring. Loosen the 2 screws and pull it
out from the combustion chamber front
panel. Replace the gasket provided.
Reassemble in reverse order.
6. Burner
Carry out steps 1, 2 and 3 as above.
Remove the four Philips screws retain-
ing the burner. Pull it out with care to
avoid any damage to the ceramic panel
protecting the combustion chamber front
panel. Replace the burner gasket.
Reassemble in reverse order.
7. Gas Vale Assembly
Carry out steps 1 and 2 as above.
Unscrew the three screws securing the
air/gas connection pipe onto the gas
valve assembly. Disconnect the connec-
tors from the gas solenoids and fan.
Loosen the gas pipe nut. Unscrew the
six nuts to release the combustion
chamber front panel and pull the assem-
bly towards you. Replace the gas filter
before fitting the full assembly back into
the boiler.
8. Fan Assembly
Carry out all operations mentioned in
step 7. Unscrew the three screws secur-
ing the air/gas connection pipe onto the
gas valve assembly. Separate the gas
valve assembly and the venturi from the
fan assembly by loosening the two
hexagonal head screws. Reassemble in
reverse order and replace the necessary
gaskets.
9. Gas Section
Carry out all operations mentioned in
step 7. Unscrew the three screws secur-
ing the air/gas connection pipe onto the
gas valve assembly. Separate the gas
valve assembly and the venturi from the
fan assembly by loosening the two
hexagonal head screws. The venturi and
the gas section can be separated by
loosening the two screws located at the
top of the gas valve. Replace all neces-
sary gaskets before reassembling in
reverse order.
10. Venturi in the Gas Section
Carry out all operations mentioned in
step 7. Unscrew the three screws secur-
ing the air/gas connection pipe onto the
gas valve assembly. Separate the gas
valve assembly and the venturi from the
fan assembly by loosening the two
hexagonal head screws. The venturi and
the gas section can be separated by
loosening the two screws located at the
top of the gas valve. Replace all neces-
sary gaskets before reassembling in
reverse order.
11. Drain Down
2 drain points are located on the boiler.
1 = D.H.W. circuit drain point
2 = Central Heating circuit drain point
12. Water Filters (D.H.W. and C.H.)
The D.H.W. filter ensures a seal
between the connecting bracket and the
pipe to the D.H.W. flow switch. Drain the
boiler as in step 12. Unscrew the pipe
nut and remove the clip on the hydraulic
assy. Pull the pipe toward you and
remove the water filter from its location.
The C.H. filter is located in the right
hydraulic assembly. Remove the return
pipe as described previously and
remove the filter. Reassemble in reverse
order.
13. Flow Switches
Drain boiler as in step 12. Disconnect
the electrical plug, turn the top cover
anti-clockwise, remove the O-ring and
the brass piston. Reassemble in reverse
order.
14. 3-Way Valve
Drain boiler as in step 12. Remove the
three clips on the 3-way valve. Remove
the clip on the exchanger flow pipe. Pull
the pipe down then pull it out of the 3-
way valve. Disconnect the plug from the
motor. Unscrew the nut on the pipe
between the connecting bracket and the
3-way valve and pull it toward you.
Rotate the 3-way valve body anti-clock-
wise to unclip it from the left hydraulic
assembly.
15. Secondary Heat Exchanger
Drain both circuits of the boiler as in step
12. Unscrew the 2 fixing screws Dand
remove the D.H.W. exchanger from the
front. Prior to reassembly, check that the
4 gaskets are correctly positioned. The
heat exchanger is designed so that it
cannot be remounted incorrectly.
AAAA
TT
1
2
12
Air Separator
D

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16. Main Heat Exchanger
Carry out steps 1 and 2 as above. Drain
down the boiler as in step 12. Unscrew
three screws securing the air/gas con-
nection pipe onto the gas valve assem-
bly. Disconnect the ionisation and
ignition electrodes from their wiring.
Unscrew the six nuts to release the com-
bustion chamber front panel and pull the
assembly towards you. Remove the two
clips for the pipes to the main exchanger
and pull down the pipes. Unscrew the
three screws located at the bottom, top
left and at the right with the retaining
system to be able to pull the main heat
exchanger towards you.
Reassemble in reverse order taking care
about the location of the gasket on the
fumes collector and replace the neces-
sary gaskets.
17. Pump
Drain the boiler as in step 12. Pivot the
electical box downwards. Open the elec-
trical box cover removing the 2 screws.
Remove the pump plug from the power
board and earth plug from earth socket.
Unscrew nut Fon the return pipe from
the volute. Remove the clip Gon the
pump volute and pull the pump toward
you. Reassemble in reverse order.
18. Pressure Relief Valve
The pressure relief valve can be ser-
viced from the front of the appliance.
Drain the boiler first, undo the retaining
screw and pull out the valve.
Reassemble in reverse order.
19. Thermistors
Drain the boiler as step 12. Disconnect
the plug, remove the retaining clip pull
the thermistor out. Reassemble in
reverse order.
22 = D.H.W. thermistor
21 = Central Heating thermistor
20. Safety Thermostat
Remove the casing as step 1 and pivot
the electrical box downwards.
Disconnect the 2 cables, pull out the
sensor with the clip 23. Reassemble in
reverse order.
21. Spark Generator
Carry out steps 1 and 2 as above.
Unplug the connector from the spark
generator located on the right hand side
of the main heat exchanger. Loosen the
two screws to remove the igniter.
Reassemble in reverse order.
22. Main Control Board
Carry out step 1 as above and pivot the
electrical box downwards by pressing
the retaining tabs Pon either side.
Remove the wiring cover C. Undo the
four screws of the electrical rear panel
and remove it. Unplug all cables from the
P.C.B., remove the earth plug from earth
socket. Remove the Main P.C.B.
Reassemble in reverse order.
23. Display P.C.B.
Carry out step 1 as above and pivot the
electrical box downwards by pressing
the retaining tabs Pon either side.
Remove the pressure gauge clip. Rotate
the electrical box back to the upper posi-
tion. Undo the 2 screws retaining the
front panel, put your two hands at the
bottom of the front panel and pull it down
to release it from the 2 clips. Pivot the
electrical box downwards. Undo the four
screws of the electrical rear panel and
remove it. Unplug the display board
cables from the Main P.C.B.
Reassemble in reverse order.
24. Expansion Vessel
Remove the casing as step 1 and drain
the boiler as step 12 above. Unscrew the
connecting tails nuts and lift out the boil-
er from the wall. Place it on its side on
the floor. Remove the expansion vessel
bracket retaining screws, disconnect the
pipe from the vessel and pull it toward
you. Reassemble in reverse order.
25. Pressure Gauge
Carry out step 1 as above and drain the
boiler as step 12. Pivot the electrical box
downwards by pressing the retaining
tabs Pon either sides. Press the clip to
remove it and pull it out. Remove the clip
which holds the connection of the capil-
lary on the pump hose. Pull out the pres-
sure gauge with its capillary.
Reassemble in reverse order.
F
G
21
22
23
P
P
C

Supplied By www.heating spares.co Tel. [phone]
13
FAULT FINDING CHART Part 1
Switch on the main electrical supply
Does the green
L.E.D. light ?
- Check mains electrical
connection
- Check internal fuses
- Check connection between
the 2 P.C.B.s
Replace control P.C.B. or
display P.C.B.
Replace control P.C.B.
Replace D.H.W. flow switch
Switch Domestic Hot Water
mode ON
Release pump rotor
Replace pump
Replace fan assembly
Replace the Central Heating
flow switch
Does the red L.E.D.
light ?
Does the display
show a - XX code ?
Does the fan run ?
Check Central Heating
flow switch
Check voltage on
the fan
Check the 24 V at
the transformer
Press the reset button
Please refer to the list of error
codes and solve the problem
Does the pump run ?
Check that the
pump spins freely
Check voltage in the
pump electrical box
Replace control P.C.B.
Could you see the
spark generation?
Does the spark
generator energize ?
Does the -24 error
display ?
Replace spark generator or
ignition electrods assembly
Replace transformer or the rel-
evant fuse
- Check pressure probes
or
- Check flue duct condition
or
- Replace pressure switch
Yes
Yes
Yes
Yes
No
No
No
No
Ok
Ok
No
Check or replace main or sec-
ondary heat exchangers. They
could be fully scaled.
Check flow in the
boiler primary circuit
Ok
No
Replace heating thermistor Check heating
thermistor
Ok
No
No
No
No
Yes
Yes
Yes
No
No
No
Ok
Ok
Ok
Ok
means a test or a choice means an action means a group of actions error code displayed
PLEASE CHECK THE FOLLOWING POINTS CAREFULLY BEFORE GOING THROUGH THE FAULT FINDING CHART -Gas pressure -Electric mains -Minimum water pressure in the heating circuit (over 0.8 bar) -All isolating valves have been opened -Boiler air vented -Minimum domestic hot water flow of 2 l/min -Check that the heating filter is clear. - Remove the front panel of the sealed chamber
-7
Yes
Check or replace the D.H.W.
flow switch
Draw off Domestic Hot Water
at a tap
Does the pump run ?
No
Check D.H.W. flow
switch operation
No No
Ok
-7
-7
-11
-12
Ok
Ok
No
No
-3
Wait for 4 seconds
-3
Error code Description
1 Overheat Lock Out 3 No flame detection 5 Anti-frost mode on 6 Anti-frost mode on 7 No water circulation 8 Faulty water circulation in the primary circuit 9 DHW thermistor faulty, Open circuit
10 DHW thermistor faulty, Short circuit 11 Central heating thermistor faulty, Open circuit 12 Central heating thermistor faulty, Short circuit 18 Ignition test 20 Faulty connection 23 Low speed fan 24 Faulty control functionning fan 29 3 ways valve locked in Heating position 31 Error communication with EEPROM 32 Error communication with the Main P.C.B.

Supplied By www.heating spares.co Tel. [phone]
14
FAULT FINDING CHART Part 2
Replace control P.C.B.
Can you see the
flame on the burner ?
Replace gas section assembly
Do you feel air
drawing in at the air inlet ?
Do the gas
solenoïds energise ?
Check that air inlet pipe, ven-
turi, fan, air/gas pipe and burn-
er are free of dust and not
blocked
Purge the gas pipe and press
on reset button
Does the D.H.W.
temperature rise?
Does the burner still
light ?
Does the red L.E.D.
light and -3 displayed ?
Does the orange
L.E.D. light ?
Replace control P.C.B.
Replace D.H.W. thermistor
Replace control P.C.B.
Replace display P.C.B. or check
the connection between the 2 P.C.B.s
- Adjust the D.H.W. flow rate to
3 l/min at a tap. - Wait until the temperature becomes stable.
No
No
No
No
No
Yes
No No
Does the orange
L.E.D. light ?
No
Yes
Replace the D.H.W. heat
exchanger
Yes
Yes
Yes
Yes
No
-3
Replace display P.C.B. or check the
connection between the 2 P.C.B.s
Is the combution
chamber full of conden-
sates ?
Yes
Check ionisation
probe
No
Ok
Drain and clean combustion cham-
ber, siphon and drain pipes
Yes
Replace the ionisation probe
No
Stop water draw off
Does D.H.W. tem-
perature rise above 70°C ?
Check D.H.W. ther-
mistor
No
Ok
- Press the D.H.W. key to switch
off D.H.W. mode. - Press the C.H. key to switch on C.H. mode and set CH tempera- ture to maximum. - Press the RESET button to cancel the 3 min. delay. - Ensure that external controls
are calling for heat.
Does the heating
outlet pipe temperature rise
?
Wait until the return pipe
become hot then reduce the
C.H. temperature to minimum
Does the orange
L.E.D. light ?
Replace the 3 way valve
Replace control P.C.B.
No
Yes
The boiler is O.K.
No
Does the heating
outlet pipe temperature
rise ?
Replace the 3 way valve
Yes
-29
No Yes
Yes
Yes

Supplied By www.heating spares.co Tel. [phone]
15
SHORT LIST
102 ELECTRODE KIT 1309624 .
401 GAS VALVE 1308957 .
407 FAN ASSY 1307585 .
505 3-WAY VALVE 1010000 .
507 OVERHEAT THERMOSTAT 100°C 1010572 .
510 THERMISTOR 1000733 .
514 WATER/WATER HEAT EXCHANGER 1011164 .
532 WATER THROTTLE 81471 .
560 AIR SEPARATOR HEAD ASSEMBLY 1002653 .
572 PUMP UP 15/50 230V 1010612 .
606 TRANSFORMER 1308149 .
607 IGNITER 1002105.20 .
615 PRINTED CIRCUIT BOARD 1307645 .
616 PRINTED CIRCUIT BOARD 1307647 .
627 FUSE 250V 2A - TEMPORIZED 1003456 .
628 FUSE 250V 1A - TEMPORIZED 1003634 .
629 FUSE 250V 1.25A - TEMPORIZED 1003635 .
630 FUSE 250V 0.315A - TEMPORIZED 1307845 .
805 PRESSURE GAUGE 1303158 .
938 PRESSURE RELIEF VALVE 1020933 .
DescriptionKey N°
Manf. Pt. N°
Type G.C N°
FF
Manf. date
CENTORA GREEN
from to
102
407
401
532
572
505
606
514
510
507
R41
R37
R31
R30
R29
J7
C38
R102
1
+
+
+
++
+
+
+
8
C68
R28
ST2
FT1A
C19
Z11A
Z10A
Z9A
Z8A
R135
DL1
TH1A
Z7A
Z6A
R132
U5
Z5A
Z4A
TERRE-1
TH1
R48
R27
R91
R89
R47
C83
C78
C80
C79
ST1
R87
Z10
Z9
Z6
Z7
Z5
Z4
Z3
Z2
Z11
Z1
U3
U10
U9
U7
U6
U4
TR1
TH2
TERRE
T8
T7
T5
T4
T3
R46
T2
T6A
T6
T12
T11
T10
T1
SW1
RL8
RL7A
RL7
RL6
RL10
RL5A
RL5
RL4A RL4
RL3A
RL3
RL2A
RL1A
RL9
RL1
RAD1
R118
R114
R113
R111
R112
R110 R109
R108
R107R106
R9
R105
R101
R100
R99
R98
R97
R96
R8
R95
R94 R93
R92
R90 R88
R66
R65 R64
R62
R7
R58
R59
R57
R24
R52
R53
R51
R6
R50
R49
R55
R5
R22
R79
R78
R77
R45
R43
R44
R42
R4
R39
R38
R35
R34
R3
R33R32
R19
R18
R2
R16
R20
R21
R15
R14
R26
R25
R23
R13
R131
R130
C82
C81
T14
T13
D45
D44
RL12
R76
R12
R75
R74
R73
R72
R71
R70
R69
R68
R67
R129
R11
R128
R127
R116
R115
R122
R121
R120
R119
R117
R10
R1
Q1
P2
P1
MOV1
L1
J9
J10A
J8
J6
J4
J3
J2
J1 FT1
F3A
F3
F2A F2
F1A
D9
D7
D6
D5
D34
D31
D30
D32
D4
D42
D41
D40
D39
D38
D37
D36A
D36
D33
D43
D3
D29
D28
D27
D26
D23
D25
D24
D22
D21
D20
D2
D19
D18
D17
D16
D15
D14
D13
D12
D11
D1
CTP1
C8
C13
C49
R54
RL11
C34
C35
C32
C7
J5
C53
C6
C52
C51
C77
C76
C75
C74
C72
C71
C70
C69
C5
C50
C48
C47 C46
C45
C44
C43
C42
C67
C4
C66
C65
C64
C63
C62
C61
C60
C59
C22
C56
C55
C54
C33
C31
C41
C39
C37
C2
C36
C29
C30
C28
C27
C26
C25
C10
C11
C9
C3
C24
C23
C21
C20
C18
C17
C16
C15
C14
C12
C1
K
VD
M/A
VITESSE
K
1
1
1
1
1
EXT
1
P4
P3
P2
P1
BUS
1
PROG TA
K
K
KCD
1
K
K
230V
+5V
TR
COM
REP
8
12 3 4
0
N
616
628
627
629
630
607
805
938
560 615

Supplied By www.heating spares.co Tel. [phone]
Chaffoteaux & Maury Limited
Trench Lock
Trench
Telford
Shropshire
TF1 4SZ
Tel: [phone]
Fax: [phone]
http://www.chaffoteaux.co.uk
Chaffoteaux & Maury are continuously improving their products and therefore reserve the right to change specifications without prior
notice and accepts no liability for any errors or omission in the information contained in this document.
© Chaffoteaux & Maury 2002
1309456 - 03/2002