Glow-worm BBU 54/4 - Manual (Page 21)

21 2000225024C
8 Servicing
REMEMBER, When replacing a part on this appliance, use only
spare parts that you can be assured conform to the safety and
performance specification that we require. Do not use
reconditioned or copy parts that have not been clearly authorised
by Hepworth Heating Ltd.
Servicing Notes
a) To ensure the continued efficient and safe operation
of the appliance it is recommended that it is checked
and serviced as necessary at regular intervals. The
frequency of the servicing will depend upon the
particular installation conditions and usage, but in
general once a year should be enough.
b) It is the Law that servicing must be carried out by a
competent person.
c) Remove the fire front
d) Refer to the Gas Fire Front Installation and Servicing
Instructions for full details of fire front removal.
e) After completing any servicing always test for gas
soundness with a suitable leak detection fluid and
carry out functional check on controls.
f) Unless stated otherwise reassembly of all components
is in the reverse order to that for removal.
8.1 Isolation of Services
With the fire front removed, see fire front instructions.
Refer to diagram 6.1 to identify the controls.
Turn control thermistor knob “A” anti-clockwise to “Reset”
position.
Isolate the electrical supply to the back boiler.
Turn appliance gas service cock “C” to the OFF position, see
diagram 6.2.
8.2 Sensing Tube Assembly
Remove the sensing tube assembly by unscrewing from the
draught diverter and carefully pulling it away from the flue
blockage safety device, see diagram 8.1.
8.3 Overheat Cut-off Safety Device (Sealed
systems only)
To enable the controls assembly and burner to be removed from
the boiler, pull the plug with the lead off the overheat cut-off
safety device, located on the flow pipe near where it exits from
the heat exchanger, see diagram 10.5.
Note: When replacing the plug ensure that the terminals on the
overheat cut-off safety device engage fully in the plug. Check
also that the overheat cut-off safety device has not been
disturbed and is seated correctly on the flow pipe.
Diagram 8.1
9385
SENSING
TUBE
FLUE
BLOCKAGE
SAFETY
DEVICE
SENSING
TUBE
DRAUGHT
DIVERTER
BODY