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ELECTRoNIC CoNTRoL/IGNITIoN P.C.B.
The spare electronic control/ignition p.c.b. is set for natural gas.
If the boiler is fed with different gas type, go through the Gas
conversion operations described in the Installation manual.
If an external temperature probe (optional) is fitted, the coef-
ficient K has also to be set as described in the Commission-
ing chapter of the installation manual.
1 Gain access to the parts located inside the control panel as
explained in the section "Control panel" page 5.
2 Remove all the wiring connected to the Electronic control/
ignition p.c.b.
To disconnect the connectors delicately flex the hook present
on one side of each socket.
3 Remove the spindles of the c.h. and d.h.w. temperature ad-
justment knobs by delicately pulling them with pliers in the
direction shown by the arrow in Figure 9.13.
figure 9.13
4 Unscrew the four screws that hold the Electronic control/igni-
tion p.c.b. on to the control panel.
5 Remove it by lifting its rear edge and freeing it from any of
the wiring.
6 Re-assemble the Electronic control/ignition p.c.b. following
the removal procedures in the reverse order.
Important
When re-assembling the Electronic control/ignition p.c.b.:
7 It is not necessary to utilise static protections but it is advis-
able to ensure that the p.c.b. is handled with care and held at
the edges and with clean dry hands.
8 Fit the p.c.b. into the control panel by first inserting the front
lower edge under the control knob shafts. Lower the rear
edge and ensure that no wiring is trapped beneath.
9 Insert the spindles in the control panel knobs until the notch A
(Figure 9.14) reaches the potentiometer edge. It is not neces-
sary to force them in the knob.
10 While tightening the screws that fix the Electronic control/igni-
tion p.c.b. on the control panel, keep the p.c.b. towards the
control panel fascia making sure of the contact between the
boiler reset button B and the tab C (Figure 9.14).
figure 9.14
A
A
B
C
Attention
After installing the Electronic control/ignition p.c.b.:
11 Make sure the c.h. (
) and d.h.w. (
) temperature ad-
justment knobs can move freely for the complete range.
If not, remove the spindle again as described at step 3, turn
the knob half a turn and re-insert the spindle.
12 Make sure that the settings comply with the indications given
in section "Setting the boiler control function modes" page 19.
13 Operate the boiler and close the gas inlet cock so that the
boiler goes into the safety lock-out state.
Verify the correct operation of the boiler reset button by
pressing and releasing it.
Warning: After cleaning or replacement as detailed
above, if it deemed necessary to undertake a com-
bustion analysis as detailed in section "Removal"
page 28.