Technical data

14.3 Servicing of Components.
Clean the Fan.
Unscrew the three screws securing the fan mounting plate to the
fan. Unscrew the two screws securing the venturi assembly to
the fan and ease out of the fan outlet. Any dust or fluff
accumulated on the fan or venturi should be removed with a soft
brush or by blowing. Reassemble the venturi and fan mounting
plate in the reverse order. Ensure that the short leg on the venturi
faces into the fan. See Fig. 36.
Clean the Burner.
Brush the blade tops and mixing tube with a soft brush and
check that all the flame ports are clear. Remove any blockages
with a non-metallic brush.
Clean the Main Burner Injector.
Inspect the main burner injector located at the rear of the inner
casing. Clean with a soft brush. Do not use a wire brush or
anything likely to cause damage.
Clean the Pilot Bracket.
Brush with a soft brush. Clean the pilot injector by rinsing it in
warm water. Check the condition of the electrode.
Clean the Gas to Water Heat Exchanger.
Cover the main burner injector and pilot bracket with a cloth.
Clean the heat exchanger using a soft brush. Remove the
deposits from the bottom of the combustion chamber. Take care
not to distort any of the fins.
Combustion Chamber Insulation.
Examine and replace any pads that are damaged. Refer to
Section 15.3.4.
Controls.
Remove any dust or deposits using a soft brush. Take care not to
mishandle any component connections.
NOTE: Should any of the components be damaged they must be
replaced before the service is completed. Refer to the appropriate
item in Section 15 “Replacement of Parts.”
After servicing, reassemble the appliance in the reverse order.
Check that all components are in place and correctly fixed. See
Fig.16 and 36. Leave the cabinet front panel to be fitted after
checking the operation of the appliance.
14.4 Test the Appliance.
On completion of the service and reassembly of the appliance,
check for gas soundness and the correct operation of the
appliance as described in Section 12 - Commissioning.
Refit the cabinet front panel and reset the controls to the users
requirements.
WARNING. Switch off the electricity and gas supplies before
replacing any components. After the replacement of any
components check for gas soundness (where relevant) and carry
out functional checks as described in Section 14.
15.1 COMPONENT ACCESS.
To replace components:
It is necessary to remove one or more sections of the cabinet and
cover plates within the appliance. Refer to Section 14.2 a, b, c and d.
To access the control box:
Place the facia and control box in the Service Position. Refer to
Section 14.2, (b) and Fig. 14.
Unscrew two fixing screws at the top and two on the underside
securing the facia to the control box. Ease the facia clear of the
control box. Take care not to strain the connector or wiring.
Ensure the facia is supported when out of the control box. See Fig. 14.
IMPORTANT:
Comprehensive gasket/ O-ring packs are available for the gas
and water connections on the appliance. Refer to Section 18 -
Short Parts List.
When replacing components that use clip fixings, the
connections must be fully entered so that the clips can pass
completely into the locating groove. The clips must not be forced
into place.
When a component is replaced or disturbed it is recommended
the “O” ring is replaced.
The “O” rings can be lubricated with a silicon based grease or
glycerine which is non-reactive with the ethylene - propylene
nitrile “O” rings.
15.2 Draining The Appliance.
Check that the electricity supply to the appliance is turned off.
Before removing any component holding water it is important
that as much water as possible is drained from the appliance.
CAUTION: Some water will remain in the expansion vessel,
pump, water diverter valve, water to water heat exchanger and
gas to water heat exchanger. Extra care must be taken when
removing these components.
Place a towel or cloth beneath the component to absorb the
excess system water.
The water may be contaminated and any absorbent material
used must be discarded or washed thoroughly after use.
Any inhibitor in the primary water should be replenished.
(a) Appliance Heatbank and Heating Circuit:
Turn off the central heating flow and return valves at the appliance
using a flat blade screwdriver. See Fig. 17. Remove the kick strip
secured to the cabinet side panels and base plate with five screws.
See Fig. 14. Fit a tube to the drain tap located on the right hand
side, front, of the heatbank and open the tap. See Fig. 16.
NOTE: The heatbank contains about 60 litres of primary water
and sufficient time must be allowed to drain the heatbank. Close
the drain tap when the flow has stopped.
(b) Appliance Hot Water Circuit:
Turn off the mains water supply valve at the appliance using a
flat blade screwdriver. See Figs. 16 and17. Fit a tube to the drain
tap located to the left of the gas valve. See Fig. 16.
Open the tap and drain the hot water circuit.
A quantity of water will remain in the water to water heat exchanger,
extra care must be taken when removing this component.
15.3 COMPONENT REPLACEMENT.
1. Automatic Air Vent. See Fig. 36.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position, lower the expansion vessel into the
Service Position and remove the inner casing cover, as described
in Section 14.2 a, b, c and d.
Drain the heating circuit as described in Section 15.2 (a).
Unscrew the automatic air vent and discard. Fit the replacement
assembly. Ensure the plastic cap is removed and discarded.
Open the valves, fill and re-pressurise the system as described in
Section 12.2.
Ensure the joint is water tight. Reassemble the appliance in the
reverse order.
2. Fan. See Fig. 36.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position, lower the expansion vessel into the
Service Position and remove the inner casing cover, as described
in Section 14.2 a,b,c and d.
Remove the fan assembly as described in Section 14.2 (e) and discard.
Fit the replacement fan in the reverse order.
Reassemble the appliance in the reverse order.
15. Replacement of Parts
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