Glow-worm 56/3 Back Boiler - Manual (Page 20)

20 221724B
8 Servicing
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.
g) The Flue Blockage Safety Device MUST NOT be
adjusted or disconnected. If replacing use only the correct
and approved part.
8.1 Isolation of Services
With the fire front removed.
Isolate the electrical supply to the back boiler.
Refer to diagram 6.1 to identify the 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.
8.2 Sensing Tube Assembly.
Remove the combustion chamber extension, see diagram
4.5. Unclip the mains supply cable if required.
Remove the spigot duct, see diagram 8.10.
Remove the sensing tube bracket securing screw, carefully
pull the sensing tube assembly away from the sensing tube
fitting on the draught diverter assembly and from the flue
blockage safety device.
Clean or replace the lint arrester, see diagram 8.1.
Remove the sensing tube fitting and the tubing nut to access
the internal filter.
Clean or replace the internal filter, check the “O” rings for
damage, replace if necessary, see diagram 8.1.
IMPORTANT NOTE: When replacing the sensing tube check
the “O” rings, internal filter and lint arrester are fitted.
8.3 Gas Controls Assembly and Burner.
Remove the control box, hold with both hands squeeze tilt
forward and unhook, see diagram 5.5.
Turn the box over.
Disconnect the ignition lead from the piezo unit and remove
by threading it through the grommet in the rear of the control
box, see diagram 8.2.
Disconnect the union at the gas service cock, support with a
spanner see diagram 4.12.
Remove the thermostat phial and overheat cut-off device
phial if fitted (sealed systems only), from the phial pockets,
unclip the capillary tubes, see diagram 5.4.
Remove the four combustion chamber securing screws.
Pull the gas control valve forward releasing it from the
retaining pin, see diagram 8.4.
Slide the control/burner assembly forwards and up to
remove.
Diagram 8.1
6851
INTERNAL
FILTER
SENSING TUBE
FITTING
BRACKET
SECURING
SCREW
SENSING TUBE
“O” RINGS
SENSING
TUBE
DRAUGHT
DIVERTER
FLUE BLOCKAGE
SAFETY DEVICE
TUBING
NUT
RETAINING
NUT
LINT
ARRESTER
Diagram 8.2
7212
IGNITION
LEAD
GROMMET
PIEZO
UNIT
CONTROL BOX
RETAINING
CLIP
EARTH
POST