If in the unlikely event the boiler does not
give complete satisfaction, before calling
for a service engineer, the installer should
check the following:-
No Central Heating but Hot Water OK
Unlikely to be a boiler fault, please ask your electrician to check the
external controls.
No Hot Water but Central Heating OK
Unlikely to be a boiler fault, please ask your electrician to check the
external controls.
No HW or CH demand
Is there a demand from external controls? To eliminate the boiler as a fault,
remove the switched live from the wiring centre to LR on ST2, then fit a
link between the L on ST1 into LR on ST2 (Pump still connected on Lp
and Np). If the boiler and pump run normally then it is likely there is a fault
with the external controls. Please contact your electrician.
Burner lights then goes out in HW or CH
mode
Does the boiler run normally with the front cover off and then fail when the
cover is put back on?
If yes there is likely to be a flue problem - either the air inlet is blocked or
the inner flue is leaking flue gases into the air inlet.
Boiler noisy or going to overheat
1. Check that the primary flow (left hand pipe) from the boiler is hotter than
the primary return (right hand pipe). If the return is hotter than the flow,
then the primary flow and return could be crossed or the pump is fitted
backwards.
2. Is the pump live supply taken from Lp on ST2 of the boiler’s control
board? This boiler requires the pump to be wired directly into the
control board to provide pump overrun.
3. Was the system flushed?
4. Check the pump.
General checks
1. Is all the air bled from the gas supply?
2. Is all the air bled from the primary water system?
3. Is 230v a.c. across the boiler live and neutral terminals?(L & N on ST10)
4. Is the polarity correct?
5. Is the incoming gas pressure at least 18mbar with the boiler at
maximum output?
Dedicated to heating comfort
Worcester, Bosch Group
Cotswold Way, Warndon, Worcester WR4 9SW.
Tel. 01905 754624 Fax. 01905 754619
Worcester, Bosch Group is a brand name of Bosch Thermotechnology Ltd.
www.worcester-bosch.co.uk
8 716 115 168a (06/2008)
CONTACT INFORMATION
WORCESTER, BOSCH GROUP:
TECHNICAL:
08705 266241
SERVICE:
08457 256206
SPARES:
01905 752571
LITERATURE:
01905 752556
TRAINING:
01905 752526
SALES:
01905 752640
WEBSITE:
www.worcester-bosch.co.uk
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