Worcester ZWBR 7-28 HE plus

7 181 465 347 (01.07)
Rectifying faults
37
Flue gas levels incorrect, CO level too high
Check Action
1. Does the gas supply type match the
specifications on the appliance iden-
tification plate?
yes: ↓2.
no: B Convert appliance to correct gas type
1)
.
2. B Test gas supply pressure
1)
, - OK? yes: ↓3.
no: B Decommission appliance.
B Notify gas company.
3. Problem with flue?
B Check CO
2
level in combustion
air.
> 0,2 % CO
2
?
yes: B Check flue and repair or replace if necessary.
no: ↓4.
4. Flue gas CO
2
levels measured at
min. and max. load do not match
specified levels?
1)
.
B Measure CO
2
levels.
yes: B Adjust CO
2
levels.
no: ↓5.
5. Gas volumetric flow too high when
CO
2
level correctly set
1)
.
yes: B Reduce gas volumetric flow rate by means of
adjusting screw on gas valve and/or gas flow
restrictor.
B Check CO
2
adjustment.
no: ↓6.
6. B Change the gas valve.
1) See installation instructions