Benchmark Procombi Exclusive 24 Installation & Servicing Instructions Manual page 44

49 MAIN PCB REPLACEMENT
* Note. that production boiler PCB's 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.
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 39.
2. Note the control knob positions.
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 lead connections to the PCB including the
ribbon cable.
6. Spring out the two side retaining clips and pull the PCB
upwards to clear the 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).
Ensure the correct orientation of BCC by placing "TOP"
side up.
8. Re-connect all plug connections.
9. Reassemble in reverse order.
Plastic
Clip
6
44
SERVICING
Note.
5
Ribbon Cable Connection
10. a. Turn power on
b. Displays "8" blue light on/off, "first digit input", "second
digit input", "1st letter appliance type", i.e. "2", "4", "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 28 & 29.
5
Procombi Exclusive -
3
7
6
Installation and Servicing