Glow-worm 56/3 Back Boiler - Manual (Page 24)

24 221724B
10 Replacement of Parts
Diagram 10.1
7070
IGNITION
LEAD
THERMOCOUPLE
NUT
PILOT PIPE NUT
FLUE
BLOCKAGE
SAFETY
DEVICE
SECURING
SCREW (2)
SILICONE
SLEEVE
Notes.
a) Replacement of parts must be carried out by a
competent person.
b) Unless stated otherwise all parts are replaced in the
reverse order to that of removal.
c) After replacing any gas carrying parts always test for
gas soundness using a suitable leak detection fluid.
Also carry out functional check of controls.
d) Refer to the Gas Fire Installation Instructions for
details of the removal of the fire front.
e) Isolate the electrical supply to the back boiler.
f) Refer to diagram 6.1 to identify the back boiler
controls.
Turn the gas control knob “B” to “Off” position and turn
the appliance gas service cock to “Fire and Boiler Off”, see
diagram 4.12.
10.1 Sensing Tube Assembly.
Refer to Section 8.2.
10.2 Flue Blockage Safety Device
Follow the instructions in Section 8.2 and 8.3 to remove the
sensing tube assembly and controls assembly and burner.
Disconnect the ignition lead from the electrode.
Disconnect the thermocouple nut.
Disconnect the pilot pipe nut.
Remove the safety device securing screws.
Remove the safety device.
10.3 Thermocouple
Proceed as in Section 10.2.
10.4 Electrode
Proceed as in Section 10.2.
10.5 Ignition Lead
Remove the combustion chamber extension, see diagram
4.5.
Remove the control box refer to the relevant parts of Section
8.3.
Remove the lead from the electrode.
Remove the lead from the piezo.
When replacing make sure the lead passes through the
grommet in the rear of the control box and the protective
silicone sleeve is replaced.
10.6 Piezo
Remove the combustion chamber extension, see diagram
4.5.
Remove the control box refer to the relevant parts of Section
8.3.
Remove the lead from the piezo.
Remove the piezo.
10.7 Injector - Main Burner
Follow the instructions in Section 8.4 to remove the burner.
Replace the main injector. Ensure you fit the new copper
washer, see diagram 8.7.
10.8 Gas Control Valve
Remove the combustion chamber extension, see diagram
4.5.
Refer to diagram 10.2.
Disconnect the union nut at the at the gas service cock,
support with a spanner, refer to diagram 4.12.
Disconnect the gas control electrical plug.
Disconnect the thermocouple nut at the gas control valve
and ease out, see diagram 10.1 for position.
Disconnect the pilot tubing nut at the gas control valve.
Undo the securing screws to separate the gas control valve
from the supply pipe flange and gas manifold.
Pull the gas control valve forward releasing it from the
retaining pin, see diagram 8.4.
Remove the liner and union nut.
Transfer the liner and union nut using a small amount of
approved jointing compound on the external threads only to
the replacement gas control valve.
Fit the new 'O' ring seal supplied with new gas control valve.
10.9 Burner
Follow the relevant instructions in Section 8.3 and 8.4 to
remove the burner.
Transfer the flue blockage safety device to the new burner,
see diagram 10.1.