Benchmark ZWB 7-29 CC1 Installation And Servicing page 72

Failure identification procedure
b1
flashing.
The Heatronic does not recognise the code key.
Check
1.
2. Code plug loose, incorrect or defec-
tive.
3. The PCB control board is damaged.
24
Action
B Power OFF the appliance.
B Replace code plug, check code number is cor-
rect.
B Turn ON the appliance.
b1? ↓3.
B Make a note of the altered service settings (see
table 1, "First Service Level; Values that can be
modified" at page 8 and table 5, "Secondary
Service Level; Values that can be modified" at
page 11).
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change PCB control board.
B Reconnect the boiler electrical connection.
B Turn ON the appliance.
B Restore service settings previously noted down.
7 181 465 346 GB (03.02)