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8 COMPONENT REPLACEMENT
It is the law that any service work must be carried out by a competent person, i.e. Gas Safe
registered boiler engineer.
Warning:
Before replacing any boiler components, isolate the electrical supply and close the
boiler gas service cock. Allow the boiler to cool.
Always test for gas tightness before and after replacing any gas carrying components or
disturbing any gas connections.
Always carry out electrical system checks i.e. Earth Continuity, Resistance to Earth, Short
Circuit and Polarity with a suitable meter after servicing.
Check the operation of the boiler. (Refer to Sections 6.5 and 6.6).
Ensure that all the controls are returned to their original settings.
8.1 GENERAL ACCESS
Ensure the electrical supply is isolated and the gas supply is off.
Gain access by removing the control panel cover, case front panel and lowering the control panel as described in
Section 7.2.
8.2 DRAINING THE BOILER - Fig. 5.4
Isolate the electricity supply and close the boiler gas service cock, see Fig. 5.4. Allow the boiler to cool.
Heating circuit
1. Close the central heating flow and return valves, see Fig. 5.4.
2.
Connect a suitable pipe to the drain point, see Figs. 5.4 and 7.6 and route it to a suitable container. Open the drain point.
Hot water circuit
1. Close the mains water inlet valve, see Fig. 5.4.
2. Open all hot taps to allow as much draining of the boiler as possible.
Note:
Some water will remain in the components and care must be taken when removing them.
8.3 IGNITION AND SENSING ELECTRODES - Fig. 7.6
Gain access as described in Section 8.1.
1. Pull off the ignition lead from the electrode.
2. Remove the cap screws securing the electrode to the front of the combustion chamber using a 3 mm allen key and
carefully withdraw the electrode.
3. Fit the new electrode assembly with a new gasket and re-assemble in reverse order.
4. Test the boiler, check the ignition and test the combustion as described in Section 7.
8.4 MAIN BURNER
1. Remove the complete burner/fan/air inlet assembly as described in Routine Servicing, Section 7.3.
2. Open the three spring clips (see Fig. 7.5) and carefully lift off the insulation panel to gain access to the burner fixings. It
will be necessary to remove the electrode assembly first as described in Section 8.3.
3. Fit the new burner (with a new gasket) and replace the insulation panel, securing it with the three clips.
4. Re-assemble as described in Routine Servicing, Section 7.5.
5. Test the boiler, check the ignition and test the combustion as described in Section 7.
8.5 FAN - Fig. 7.6
Gain access as described in Section 8.1.
1. Remove the single screw securing the top of the air supply pipe and withdraw it from the fan connection.
2. Remove the wiring connector from the fan, support the fan and remove the two screws securing the fan to the air inlet.
3. Remove the gas valve pressure tube from the fan inlet
4. Withdraw the fan assembly forwards.
5. Re-assemble in reverse order.
6. Test the boiler, check the ignition and test the combustion as described in Section 6.
Alpha Evoke 28 and 33 - Component Replacement
