Alpha Alpha CB24, Installation And Servicing Instructions, Page: 21 / 36

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8.5 MAIN BURNER
1. Remove the burner as described in Routine Servicing, section 7.2.
2. Re-assemble with a new burner as described in Routine Servicing, section 7.4.
8.6 BURNER INJECTORS
1. Remove the burner as described in Routine Servicing, section 7.2.
2. Unscrew the damaged injector and screw in a replacement.
3. Re-assemble as described in Routine Servicing, section 7.4.
8.7 FAN - Fig. 20
1. Gain access to the combustion chamber as in section 8.1.
2. Disconnect the fan wiring.
3. Remove the three screws securing the fan to the flue hood. Fit the new fan and re-assemble in reverse order.
Note: Connect the fan wiring, blue to terminal N, brown to terminal L and green/yellow to terminal .
4. Re-assemble and test the boiler as described in Routine Servicing, section 7.4 paragraphs 5 to 9.
8.8 AIR PRESSURE SWITCH - Fig. 20
1. Gain access to the combustion chamber as in section 8.1.
2. Disconnect the pressure sensing tube.
3. Remove the fixing screw and disconnect the wiring.
4. Connect the wiring to the new switch. The polarity of the wires is not important.
5. Secure the new switch in position and connect the pressure sensing tube to the connection nearest the front.
6. Re-assemble in reverse order.
8.9 OVERHEAT THERMOSTAT - Fig. 20
1. Gain access to the combustion chamber as in section 8.1.
2. Disconnect the wiring from the overheat thermostat.
3. Remove the two fixing screws and remove the overheat thermostat from the heat exchanger.
4. Fit the new overheat thermostat and re-assemble in reverse order.
Alpha CB24/28 - Component Replacement
Fig. 19
Flame sensing electrode
2 to 4 mm
5 to 6 mm
Ignition electrodes
5 to 6 mm