Zanussi ULTRA COMBI 35 Installation And Servicing page 47

54 MAIN PCB REPLACEMENT
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 Frame 43.
2. Note the control knob positions.
3. Remove the 2 screws retaining the control box cover.
4. Carefully lift the 4 retaining clips and remove control
box cover.
5. Unplug all lead connections to the PCB including
the ribbon cable (to facilitate ribbon cable removal,
ease side clips apart and pull upwards), also where
applicable, push the small plastic clip with an
electrical screwdriver to facilitate plug removal.
6. Spring out the two side retaining clips and pull the
PCB upwards to clear the 4 corner retaining posts.
7. Take the new Primary PCB and attach the appropriate
Boiler Chip Card (BCC) to it (this should correspond
to the output of the boiler: 24kW, 30kW or 35kW).
Note. Ensure the correct orientation of BCC by
placing "TOP" side up as shown.
8. Re-connect all plug connections.
9. Reassemble in reverse order.
10. a. Turn power on
b. Displays "8" blue light on/off, "first digit input",
"second digit input", "1st letter appliance type",
i.e. "3", "0", "c"
c. Move knob to required setting (standby,
summer, winter)
Note. If no BCC fitted on non programmed
board "C2" will be displayed. The correct BCC
for this appliance will need to be fitted.
11. Check operation of the boiler. Refer to Frames 32 & 33.
55 USER CONTROL PCB REPLACEMENT
1. Refer to Frame 43.
2. Remove the main PCB, refer to Frame 54.
3. Unclip the PCB and lift to clear the mounting posts.
4. Fit the new PCB ensuring the 4 potentiometer spindles
line up with the control knobs which must be in a
vertical position.
5. Reassemble in reverse order.
6. Check operation of the boiler. Refer to Frames 32 & 33.
4
PCB
Control Knobs (to be in vertical position)
Installation and Servicing
SERVICING
Note that production boiler PCBs are factory pre-set to operate for boiler range and
output, but when ordering Primary PCB as a spare, an additional Boiler Chip Card
(BCC) MUST also be purchased for your specific boiler range and output.
3
5
Plastic clip
Note. Fit the earth strap provided with the PCB to
your wrist and a suitable earth on the boiler chassis.
4
5
Ribbon
Cable
Connection
7
3
Potentiometer spindle
6
47