21
Fig. 27
6.8 PRINTED CIRCUIT BOARD (fi g. 25)
Carry out component removal procedure as described in
6.4. Pull the control fascia forward and lower it. Locate
and remove the screws
which secure the control panel
(fi g. 18), push the clips
(A)
and remove cover, after care-
fully taking note of all wiring connections and jumper tag
confi guration, disconnect all wiring from the PCB, locate
and remove the PCB securing screws, remove the re-
quired PCB. Replace in the reverse order ensuring that
the position of the 2 control knobs are correctly aligned
with the respective potentiometers on the PCB.
Ensure that the correct jumper tag confi guration has been
respected. It will be necessary to check the functioning
of the PCB is set for the correct boiler type/application.
6.9 GAS VALVE (fi g. 26)
Carry out component removal procedure as described in
6.4. The gas valve must be changed as complete unit.
Disconnect the electrical plug and leads from the gas
valve, slacken and unscrew gas valve inlet
and outlet
connections.
Please note,
the sealing washers
(A)
must be discarded
and replaced with new sealing washers. Locate and re-
move gas valve retaining screws
(B)
on the underside of
the boiler if required, the gas valve can now be removed.
Replace in the reverse order. Check and adjust burner
pressure settings.
WARNING, A GAS TIGHTNESS
CHECK MUST BE
CARRIED OUT.
6.10 INJECTOR (fi g. 27)
Carry out component removal procedure as described in
6.4. Unscrew and remove gas pipe connections. Locate
and remove the injector
(A)
inside the pipe. Replace in the
reverse order. Check and adjust burner pressure settings.
WARNING, A GAS TIGHTNESS CHECK MUST BE
CARRIED OUT.
6.11 ELECTRODES & CONDENSE SENSOR (fi g. 28)
Carry out component removal procedure as described in
6.4. Disconnect the electrode leads and ancillary wiring
from their respective connectors. Remove the retain-
ing screws
(A)
for electrodes and remove. Remove the
retaining nut
(B)
for condense sensor
(C)
and remove.
Fig. 28
Fig. 26
Fig. 25
A
A
B
A
B
C
A