Checks; Removal Of The Electronic Control P.c.b - Biasi M110.24SM/E Service Manual

3
1 1/2
0
B
Fig. 9.10
5 To memorize the setting keep pressed the reset
button C for about 5 seconds until the lights E
briefly blinks simultaneously.
6 To reset the boiler to the normal operation turn it
OFF and ON by the function selector knob A. In
any case, the boiler automatically resets to its nor-
mal operation after 10 minutes.
Factory setting = 3 minutes
9.8

Checks

Check that the fuses are complete
n
If the Electronic control/ignition p.c.b. does not supply
any device (pump, fan, etc.) check that the fuses 2 and
3(Fig. 9.2) are complete.
If a fuse has blown replace it with one that has the same
characteristics after having identified the reason for fail-
ure.
Lock sequence
n
Start the boiler until the burner is ignited.
With the burner firing, interrupt the gas supply. The
Electronic control/ignition p.c.b. must carry out four
complete ignition cycles and then, after about 4 min-
utes, goes to lock ---out state.
By turning the boiler on and off by means of the function
switch the device must not unlock and the burner must
not turn on.
9.9

Removal of the electronic control p.c.b

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
When replacing the Electronic control/ignition
p.c.b. it is advisable to go through the setting modes
of the boiler here described in sections 9.5 to 9.7.
If an external temperature probe (optional) is fitted,
the coefficient K has also to be set as described in
the Commissioning chapter of the installation man-
ual.
4
5 1/2
7
8 1/2
Delay (minutes)
Setting No.
Electronic control/ignition p.c.b.
1 Gain access to the parts located inside the con-
trol panel as explained in the section 2.3 of this
manual.
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. tem-
perature adjustment knobs by delicately pulling
them with pliers in the direction shown by the
arrow in Fig. 9.11.
Fig. 9.11
4 Unscrew the four screws that hold the Electronic
control/ignition 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 re-
verse order.
Important
When re---assembling the Electronic control/ignition
p.c.b.:
7 It is not necessary to utilise static protections but
it is advisable to ensure that the pcb 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 insert-
ing 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 (Fig. 9.12) reaches the potentiometer
edge. It is not necessary to force them in the
knob.
10 While tightening the screws that fix the Electronic
control/ignition p.c.b. on the control panel, keep
the p.c.b. towards the control panel fascia mak-
ing sure of the contact between the boiler reset
button B and the tab C (Fig. 9.12).
19