Bosch Worcester 400 - Manual (Page 11)

11
OVERHEAT THERMOSTATS
Overheat thermostats are fitted to the appliance which interrupt
the electricity supply to the gas control through the control circuits in
the event of overheating.
If the appliance fails to light, check that an overheat thermostat
has not operated by observing the status of the indicator lights on the
facia.
If the CH and HW lights flash slowly then turn the Heating
Temperature Control fully anti-clockwise and then back to its set posi-
tion to re-set the thermostat.
If the overheat thermostat stops the appliance again call a serv-
ice engineer.
If the CH and HW lights flash alternately then this indicates a
fault of a more complex nature that can only be rectified by a service
engineer.
NOTE: If the electrical supply to the appliance is interrupted at
the isolation switch or a power failure occurs whilst the burner is fir-
ing, the boiler will normally relight automatically when the power
supply is restored. However, depending upon circumstances it may be
necessary to turn the Heating Temperature control OFF and ON
before the appliance will operate.
IGNITION LOCK-OUT AND SAFETY START
(RSF)
If the burner fails to light then lock-out will occur and will
be indicated by CH light flashing slowly. The ignition sequence can
be re-started by turning the Heating Temperature Control fully
ant-clockwise and then back to its set position.
If the lock-out occurs again then call a service engineer.
FLUE SPILLAGE DEVICE (O.F. ONLY)
The appliance is fitted with a device which detects the spillage
of combustion products from the draught diverter. In the event of the
flue becoming wholly or partially blocked this device will cut the gas
supply to the burner indicated by the CH and HW lights flashing
fast. The device automatically resets after a waiting period of approxi-
mately 10 to 15 minutes. If the blockage remains the appliance will
relight briefly before the device operates again. Should the problem
persist consult your service engineer.