Benchmark ZWB 7-29 CC1 Installation And Servicing page 82

Failure identification procedure
EA
and
No flame ionisations signal
Check
8. Is diaphragm in the mixer unit cor-
rectly fitted and functional?
B Open mixer unit (29).
B Check diaphragm for correct ori-
entation, soiling and splitting.
Is diaphragm OK?
9. Is the condensation trap blocked?
10. Check the gas valve?
B Power OFF the appliance.
B Unplug the connectors from the
gas valve.
B Measure the gas valve coils I and
II electrical resistance.
R = 164 ± 40Ω ?
11. Problem with flue?
B Check CO
level in combustion
2
air.
Is CO level above 0,2 % ?
2
B Open up heat exchanger - is it
dirty?
12.
Is flue gas CO
2
34
flashing.
yes:
no:
yes:
no:
yes:
no:
yes:
no:
1) yes:
level incorrect ?
no:
Action
B Close mixer unit.
↓9.
B Insert diaphragm in the fan intake duct as per
installation instructions so that the flaps open
upwards.
B Close mixer unit.
EA? ↓9.
B Clean out condensation trap discharge pipe.
B Press
, restart the appliance.
EA? ↓13.
↓10.
B Reconnect the gas valve.
B Turn ON the appliance.
B Press
, restart the appliance.
EA? ↓11.
B Change the gas valve.
B Reconnect the gas valve.
B Turn ON the appliance.
B Press
, restart the appliance.
EA? ↓11.
B Check flue and clean if necessary.
B Press
, restart the appliance.
EA? ↓12.
↓12.
B Adjust to correct level.
B Press
, restart the appliance.
EA? ↓13.
↓13.
7 181 465 346 GB (03.02)