A8 and fault indicator LED are flashing. Bus communication to the programmer interrupted (set value not received)  
CheckAction
1.▶ Switch off the appliance.

▶ Disconnect the appliance power.
▶ Remove the upper section of the programmer mount and slide the programmer out of the wall mount.
▶ Check the wiring between the programmer and the appliance.

Are terminals B being used, the cen- tre terminal must not be used for bus connections.
Check that terminals B are con- nected on the appliance and pro- grammer.

▶ Is there continuity
yes:A8? go to 2
no: Wire up or correct bus cable.
▶ Reconnect appliance power.
▶ Switch on appliance.
A8? go to 2
2.Where multiple bus modules are
installed:
▶ Check the wiring between bus modules and the branch box.
▶ Ensure that the B terminals are employed.
▶ Switch off the appliance.
▶ Disconnect the appliance power. B Is there continuity
yes:A8? go to 3
no:▶ Cable between bus module and branch box is defective.
▶ Repair or replace cable.
▶ Reconnect appliance power. B Switch on appliance.
A8? go to 3
3Where multiple bus modules are installed:
▶ Check the wiring between branch
box and the programmer.
▶ Ensure that the B terminals are employed.
▶ Switch off the appliance.
▶ Disconnect the appliance power. B Is there continuity
yes:A8? go to 4
no:▶ Cable between the branch box and programme is defective.
▶ Repair or replace cable.
▶ Reconnect appliance power. B Switch on appliance.
A8? go to 4
4.Has the programmer been replaced?yes:
A8? go to 5
no:▶ Switch off appliance
▶ Disconnect electrical power B Replace programmer
▶ Reconnect appliance power B Switch on appliance
A8? go to 5
5.Has the bus module been replacedyes:A8? go to 6
no:▶ Switch off appliance
▶ Disconnect electrical power B Replace bus module
▶ Reconnect appliance power B Switch on appliance
A8? go to 5
6.The PCB control board is faulty▶ Reconnect electrical power
▶ Switch on appliance
▶ Make a note of the service function settings B Switch off appliance
▶ Disconnect electrical power
▶ Change PCB control board
▶ Reconnect electrical power
▶ Switch on appliance
▶ Restore service settings noted previously

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