Alpha InTec2 20SE Installation And Servicing Instruction page 40

7.1 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 6.2.
7.2 DRAINING THE BOILER - Figs. 2.2 and 4.4
Isolate the electricity supply and close the boiler gas service cock, see Fig. 4.4. Allow the boiler to cool.
1. Close the central heating flow and return valves, see Fig. 4.4.
2. Connect a suitable pipe to the drain point, see Figs. 4.4 and 6.7 and route it to a suitable container. Open the drain point.
Note: Some water will remain in the components and care must be taken when removing them.
7.3 IGNITION AND SENSING ELECTRODE - Fig. 7.1
Gain access as described in Section 7.1.
1. Unhook the ignition lead from the rear of the control panel, release the grommet and unplug the lead from the PCB.
2. Remove the two nuts securing the electrode to the front of the combustion chamber using an 8 mm socket and carefully
withdraw the electrode.
3. Fit the new electrode with a new gasket and re-assemble in reverse order.
4. Test the boiler and carry out the full calibration as described in Section 5.13.
7.4 MAIN BURNER
1. Remove the burner as described in Routine Servicing, Section 6.3.
2. Re-assemble with a new burner as described in Routine Servicing, Section 6.5.
3. Test the boiler and carry out the full calibration as described in Section 5.13.
7.5 FAN - Fig. 7.1
Gain access as described in Section 7.1.
1. Remove the gas pipe to air/gas manifold retaining clip and unplug the fan wire from the fan.
2. Remove the fan inlet manifold to burner cover screws and lift the fan assembly upwards to unhook it from the gas pipe.
3. Remove the three venturi screws and transfer the venturi and seal to the new fan.
4. Remove the two fan inlet manifold screws and transfer the manifold and seal to the new fan.
5. Re-assemble in reverse order.
6. Test the boiler as described in Routine Servicing and carry out the fast calibration as described in Section 5.13.
7.6 FLUE TEMPERATURE SENSOR - Fig. 7.1
Gain access as described in Section 7.1.
1. Unplug the wire from the flue sensor.
2. Using a 13 mm spanner, unscrew the sensor from the flue outlet manifold.
3. Fit the new sensor and re-assemble in reverse order. Do not overtighten.
7.7 FUSE - Fig. 7.2
The fuse is located on the PCB.
1. Gain access to the PCB as described in Section 7.8.
2. Lift out and remove the fuse. Fit a 3.15 AF fuse as a replacement.
3. Re-assemble in reverse order.
40
Alpha InTec² 20SE and 30SE - Component Replacement
PCB
Pressure gauge
Fig. 7.2
PCB fuse