Worcester Greenstar 12i System Instruction Manual page 74

If In the unlikely event the boiler does not give
complete sati sfaction, before calling for a service
engineer, the installer should
check
the following:·
For boilers with external diverter valves and
controls
No Central Heatjng but Hot Water OK
Unlikely 10 be
a
boiler fau", please ask your eleclrician lo chock lhe external
conl rols.
No Hot Water but Central Heating OK
Unlikely to be a boiler fault, please ask your electrician to check the external
conlrols.
Ng HW gr CH demand
Is !here
a
demand !Tom external conlrols? To eliminale the boiler
u a
fault,
remove the switched rove !Tom lhe wiring oenlre to LR on ST 1 0, then fit a link
betweeo the La and
LR.
If the boiler and pump run normally theo
it
is likely
there
ia a
fault with lhe external contrOls.
Please
contact
yOU<
electrician.
For boilers with internal diverter valve and controls
No Central Heating but Hgt Water OK
Remove the room stat wiring from Ls, LR and N
on
terminal block STt 0. Frt
a
link between Ls and LR, if the CH now works there is likely to be a problem
with tho room s tat or wiring to
it.
No Hot
Walle
b ut Contcal Heating OK
Remove the cylinder stat wiring from 8 and 10 on the terminal block ST8. Fit
link across 8 and 10.
For all boilers with Internal or external controls
Burnec lights !bon goes out jn DHW or CH mode
Does the boiler run nonnally
with
the front cover oil and then tall
When the cover Is
put back on?
H yes there
ia
likely to be a flue problem • eitller lhe air inlet ia blocked or the
inner flue
is
leaking fuo gases into lhe
u
inlet.
Bollec nglsy or gglng to overheat
1.
Was the
system flushed?
2. Has tho pump been bled and the dust cap released.
General checks
1 . Is all the air bled from the gas supply?
2. Is all
the air bled from the primary water system?
3.
ls
there 230v ac across the boiler live and neutral terminals?
(l&NonST10)
4.
Is
the polarity correct?
5. Is the incoming gas pre....-e at least 18mbar with the boiler at mwnum
output?
EXCELLENCE COMES AS STANDARD
Worcoatar, Boech Group
Cotswold Way, Warndon, Worcester WR4 9f'N'/.
Tel. 01905 754624 Fax. Ot 905 7546t 9
Worcester, Boech Group is a trading name of BBT
Thetmotedmology UK
Ltd.
www.wor<:esler·bosch.co.uk
I 711 112 OOSI04/0l)