Benchmark ZWB 7-29 CC1 Installation And Servicing page 84

Failure identification procedure
EA
and
No flame ionisations signal
Check
19. Check if the 20-pin connector lead
assembly is damaged.
20. The PCB control board is damaged.
1) See installation instructions
36
flashing.
Action
B Power OFF the appliance.
B Disconnect the boiler electrical connection.
B Change the 20-pin connector lead assembly.
B Turn ON the appliance.
B Reconnect the boiler electrical connection.
B Press
, restart the appliance.
EA?
B Power OFF the appliance.
↓20.
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.
To return to normal function mode:
B Press buttons
and
B Regulate the temperature control
temperature control
positions.
simultaneously.
and the
on the previously set
7 181 465 346 GB (03.02)