13
cannot be remounted incorrectly.
16. Main heat exchanger
Carry out steps 1 and 2. Drain down the
boiler as in step 12. Unscrew the three
screws securing the air/gas connection
pipe onto the gas valve assembly.
Disconnect the ionisation and lighting
electrodes from their wiring. Unscrew
the six nuts to release the combustion
chamber front panel and pull the assem-
bly towards you. Undo the two clips of
the pipes to the main exchanger and pull
down the pipes. Unscrew the three
screws located at the bottom, top left
and 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 all neces-
sary gaskets.
17. Pump
Drain boiler as in step 12. Pivot the elec-
tical box downwards. Open the electrical
box cover removing the 2 screws.
Remove the pump plug from the power
board and the earth plug from the earth
socket. Unscrew the nut
F of the return
pipe from the volute. Remove the clip
G
on 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 = DHW thermistor
21 = Heating thermistor
20. Safety thermostat
Remove the casing as step 1 and hinge
down the electrical box as step 5.
Disconnect the 2 cables, pull out the
sensor with the clip (13). Reassemble in
reverse order.
21. Spark generator
Carry out steps 1 and 2. Unplug the con-
nector 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 hinge
down the electrical box by pressing the
retaining tabs
P on either side. Remove
wiring cover
C. Undo the 4 screws of the
electrical rear panel and remove it.
Unplug all cables from the PCB, remove
the earth plug from the earth socket.
Hang out the main PCB. Reassemble in
reverse order.
23. Display PCB
Carry out step 1 and hinge down electri-
cal box by pressing the retaining tabs
P
on either side. Remove the pressure
gauge clip. Rotate the electrical box
back into the upper position. 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. Hinge down again the electri-
cal box. Undo the 4 screws of the electri-
cal rear panel and remove it. Unplug the
display board cables from the main PCB.
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
boiler from the wall. Place it on a 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 and drain the boiler as
step 12. Hinge down the electrical box
by pressing the retaining tabs
P on either
side. Press on the clip to remove it and
pull it out. Remove the clip which holds
the connection of the capillary onto the
pump hose. Hang out the pressure
gauge with its capillary. Reassemble in
reverse order.
26. TSS®
Drain both circuits of the boiler as in
step 11. Unscrew all nuts from the con-
necting bracket and remove the gas pipe
from the gas section. Remove the main
exchanger flow pipe to the 3 way valve.
Remove the pump as in step 17. Unplug
all thermistors, 3 way valve, flow switch-
es. Unscrew the 2 retaining screws of
the hydraulic section to the chassis.
Pull the hydraulic assembly toward you.
Reassemble in reverse order and check
the gas section for soundness and the
water circuits for leakages.
F
G
21
22
24
P
P
C
