6.0 Annual Servicing
6.1
Servicing the Appliance
1. For reasons of safety and economy the appliance
should be serviced annually.
2. Before servicing please read Section 1.3 Important
Information.
3. Turn off the gas supply and ensure that the appliance
is cold.
4. On models not fitted with the Comfortstat control,
remove the control knob by pulling forward.
5. Remove the case by easing upward and forward until
it is clear of its retaining lugs.
6. Undo the heat exchanger retaining nuts and washers
(Fig. 16) and draw the casting forward off the locating
studs.
7. Remove the three screws holding the burner
retaining plate to the airbox and undo the thermocouple
nut from the gas tap (Fig. 17 & 20).
8. Ease the thermocouple and electrode lead from the
rubber grommet (Fig. 18).
9. Disengage the burner from the injector and pull the
electrode lead off the spark electrode (Fig. 17).
10. Check that the insulation is undamaged. Replace if
necessary
.
(Fig. 19).
11. Remove and clean the injector and sealing washer.
The injector must not be cleaned with a needle or wire
(Fig. 20). If the sealing washer is damaged it must be
replaced.
12. Check that the flue outlet tube is clear (Fig. 19).
13. Brush away any dirt from the heat exchanger
casting. If necessary clean the viewing window.
14. With a light brush carefully remove deposits from
the spark electrode, burner flame ports and the burner
gauze (Fig. 17).
15. Replace the rope seal in the heat exchanger casting
if it is damaged in any way (Fig. 16). Also examine the
thermocouple and replace if necessary.
16. Re-assemble the injector, washer and burner
assembly in reverse order of dismantling. Ensure that
the spark gap is correct ie. 3.5mm ± 0.5mm. Check that
the burner is horizontal and correctly positioned on the
injector with the gauze covering the primary aeration
hole.
17. Check the gas pressure at the test point on the gas
control tap. If the pressure is not within the tolerance,
(see Section 2.0 Technical Data) the gas supply to the
unit needs to be investigated.
18. Check that the burner ignition is satisfactory. Ensure
that the thermocouple/electrode lead grommet is
correctly positioned and re-fit the heat exchanger
casting.
19. Check for gas soundness.
20. Fit the case and control knob (where applicable)
and re-check that the ignition is satisfactory.
Burner Retaining Plate
Injector
Thermocouple nut
Gas Tap
Electrode Lead
Washer
Grommet
Electrode Lead
Thermocouple wires
Burner Flame Ports
Spark
Electrode
Burner Gauze
Flue Outlet Tube
Insulation
Heat Exchanger Casting
Rope Seal
Outer Case
Control Knob
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Installer Guide
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