Instruction manual

FAULT FINDING
INSTALLATION & SERVICING INSTRUCTIONS FOR WORCESTER GREENSTAR DANESMOOR WALL MOUNTED OIL 12/18-18/25
8 718 681 134a (08.08)
52
FAULT FINDING
& DIAGRAMS
Start
No heating/hot water
Press in the power button
No
Is the power button ON?
Is the power light
illuminated?
NOTE: When external
wiring centre and external
programmers are used
together this is a
demand indicator.
Follow the control box
fault finding chart to
locate fault.
No
Is the burner lockout
light illuminated?
No
Is there 230V on terminal
L1 on the boiler connector
block?
Switch the
programmer/timer to ON.
Does the boiler fire up?
UNDER NO
CIRCUMSTANCES MUST
AN APPLIANCE BE LEFT
OPERATING WITH ANY
CONTROL LINKED OUT OR
OVER RIDDEN.
No
Yes Yes
Yes
Is there 230V on
terminal 3 on the boiler
connector block?
Yes
Check external wiring.
Rectify the fault.
No
Check the power switch
and its wiring.
Rectify the fault.
Yes
No power to the boiler.
Check external supply and
wiring. Rectify the fault.
Is the programmer/timer
ON for heating/hot
water?
No No
Yes
Is the flue or boiler
overheat thermostat
tripped out?
Yes
Reset the thermostat and
investigate cause of overheat. If the
thermostat will not reset, replace
the thermostat
Check external wiring.
Rectify the fault.
No
Yes
Lack of system water circulation.
Check the pump, valves and system.
Rectify the fault.
Is there 230V on the
orange wire to the high
limit thermostat?
Check the wiring and
thermostats for open
circuit. Replace the faulty
part.
No
No
Is there 230V on pin 3 of
the control thermostat?
(the red wire)
Replace the control
thermostat
No
Yes
Is there 230V into the
burner control box?
Locate fault between the
control thermostat and
the burner.
Rectify fault.
Yes
No
Yes
Check and correct
programmer/timer
settings.
Replace the burner
control box.
Yes
FAULT FINDING
HEATING/ HOT WATER
These fault finding charts are provided to assist competent and suitably qualified engineers to
locate and rectify faults. Whilst every effort has been taken to ensure the information given is
correct and complete we cannot guarantee that every eventuality has been covered.
Worcester, Bosch Group cannot be held responsible for costs incurred by persons not deemed
to be competent.