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SECTION 3 - SERVICING
3.17 MAIN PCB REPLACEMENT
*Note that production boiler PCBs are factory pre-set to operate for boiler
range and output, but when ordering spare PCBs programming may be
required.
Note.
Fit the earth strap provided with the PCB to your wrist and secure
to a suitable earth on the boiler chassis.
1.
Refer to Section 3.8.
2.
Rotate all control knobs into the upright position.
3.
Remove the 2 screws retaining the control box cover.
4.
Carefully lift the cover at the front & pull forward to remove.
5.
Unplug all connections to the PCB.
6.
Remove the two screws that secure the PCB.
7.
Spring out the four side retaining clips and pull the PCB upwards to
clear the retaining posts.
8.
Unclip the light guide and secure this to the new PCB.
9.
Insert the new PCB and secure all electrical connections. Ensure
control knobs are correctly aligned with PCB.
10.
Reassemble in reverse order.
* If programming of the spare PCB is required, then proceed as follows:
11. a.
Turn power on, display shows uP.
Rotate all three dials fully anti-clockwise.
b.
Press
RESTART, display shows oF.
c.
Turn power off.
d.
Turn power on, display shows F9.
e.
Using central heating knob, rotate clockwise or anticlockwise to
show “ES” (for combi without preheat), then press restart button.
f.
Using central heating knob, rotate clockwise or anticlockwise to
show “p” for propane, then press restart button.
g.
Using central heating knob rotate clockwise or anticlockwise to
show boiler size, select correct 24, or 30 then press restart button.
h.
Display shows “C”, “p”, Boiler size, internal number.
j.
Press restart. New PCB is now programmed.
12.
Check operation of the boiler.
