Worcester ZWBR 7-30 R 30 HE PLUS COMBI Service Booklet page 29

EA
and flashing.
During operation: flame not detected
Check
7. Is diaphragm in mixer unit fitted correctly
(see installation instructions)?
B Open mixer unit (29).
B Check diaphragm for correct orienta-
tion, soiling and splitting.
Is diaphragm OK?
8. 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 at 20-pin connec-
tor.
R = 164±40 Ω?
9. Problem with flue?
B Open up heat exchanger - is it dirty?
B Check CO
level in combustion air.
2
Is CO level above 0,2 % ?
2
7 181 465 347 (05.01)
Supplied By www.heating spares.co Tel. 0161 620 6677
Action
B Close mixer unit.
yes:
↓8.
B Insert diaphragm in the fan intake duct as per installa-
no:
tion instructions so that the flaps open upwards.
B Close mixer unit.
EA? ↓8.
B Reconnect the connectors.
yes:
B Turn ON the appliance.
B Press
, restart the appliance.
EA? ↓9.
B Power OFF the appliance.
no:
B Turn off gas cock.
B Change the gas valve.
B Open the gas cock.
B Reconnect the boiler electrical connection.
B Reconnect the connectors.
B Turn ON the appliance.
B Check appliance for leaks.
B Press
, restart the appliance.
EA? ↓9.
B Check flue, clean if necessary.
yes:
Combined air/flue stack (LAS):
B Check connection is fully inserted and not leaking.
B Is distance between flue entry and lowest combustion
source at least 2.5 m?;
PLEWA only: at least 1.25 m with 45˚ flue entry.
B Cross-sectional area adequate? If necessary contact
chimney stack manufacturer.
Flue on outside of building:
B Unrestricted cross-sectional area of air intake OK?
If Junkers flue used in stack (counter-flow) and
solid-fuel boiler in adjacent stack:
B Is flue for solid-fuel boiler raised as per ZIV recommen-
dations? (does not apply if approved chimney terminal
fitted)
Then:
B Press
, restart the appliance.
EA? ↓10.
↓10.
no:
Rectifying faults
Error EA
29