Benchmark ZWB 7-29 CC1 Installation And Servicing page 91

Excessive burner noise, rumbling noises
Check
7.
B Press buttons
neously.
B Select service-function 5.9.
0 is displayed.
Flue gas levels incorrect, CO level too high
Check
1. Does the gas supply type match the
specifications on the appliance iden-
tification plate?
B Test gas supply pressure - OK?
2.
3. Problem with flue?
B Check CO
level in combustion
2
air.
Is CO level above 0,2 % ?
2
4. Flue gas CO levels measured at
2
min. and max. load do not match
specified levels?
B Measure CO
5. Gas volumetric flow too high when
CO level correctly set.
2
6.
7 181 465 346 GB (03.02)
and simulta-
yes:
no:
yes:
no:
yes:
no:
yes:
no:
levels.
2
yes:
no:
Failure identification procedure
Action
B Set to 1 for high start-up speed.
Action
↓2.
B Convert appliance to correct gas type.
↓2.
↓3.
B Decommission appliance.
B Notify gas company.
B Check flue and repair or replace if necessary.
↓4.
B Adjust CO
levels.
2
↓5.
B Reduce gas volumetric flow rate by means of
adjusting screw on gas valve and/or gas flow
restrictor.
B Check CO
adjustment.
2
↓6.
B Turn off gas cock.
B Power OFF the appliance.
B Change the gas valve.
B Open the gas cock.
B Turn ON the appliance.
B Check appliance for leaks.
43