Benchmark ZWB 7-29 CC1 Installation And Servicing page 79

E9
and
Safety temperature limiter has tripped.
Check
5. Is lead disconnected from CH flow
safety temp. limiter?
B Power OFF the appliance.
6.
B Disconnect lead to CH flow safety
temperature limiter.
B Measure the CH flow safety tem-
perature limiter.
R = ∞?
B Power OFF the appliance.
7.
B Remove fuse SI 3 from appliance
PCB control board and test for
continuity.
R = ∞?
8. The PCB control board is damaged.
7 181 465 346 GB (03.02)
flashing.
yes:
no:
yes:
no:
yes:
no:
Failure identification procedure
Action
B Power OFF the appliance.
B Reconnect lead.
B Turn ON the appliance.
B Press
, restart the appliance.
↓6.
↓6.
B Change CH flow safety temperature limiter.
B Connect CH flow safety temperature limiter lead.
B Turn ON the appliance.
B Press
, restart the appliance.
E9? ↓7.
B Connect CH flow safety temperature limiter lead.
B Turn ON the appliance.
↓7.
B Change the fuse.
B Turn ON the appliance.
B Press
, restart the appliance.
E9? ↓8.
B Remount the fuse.
B Turn ON the appliance.
↓8.
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.
31