Technical data

24
8.10 GAS VALVE - Fig. 26
1. Gain access as in section 8.1.
2. Remove the two screws securing the bottom panel
and lift out the panel.
3. Disconnect the coil wires and pressure tube from the
gas valve.
4. Loosen the screw (see Fig. 26) securing the solenoid
plug and disconnect the plug.
5. Remove the four manifold screws from beneath the
boiler.
6. Disconnect the burner manifold union within the room
sealed chamber and remove the four screws
securing the manifold to the gas valve.
7. Remove the burner manifold and fit it to the new valve using
the new 'O' ring seal supplied.
8. Fit the new assembly, using new 'O' ring seals supplied.
9. Re-assemble in reverse order.
10. Light the boiler and test for gas soundness. (Refer to
Commissioning, section 5.4).
11. Complete re-assembly as described in Routine Servicing, section 7.4 paragraphs 5 to 9.
8.11 GAS VALVE MODULATING COIL - Fig. 26
1. Gain access as in section 8.1.
2. Disconnect the wires from the coil and remove the spring clip.
3. Lift off the coil and re-assemble in reverse order with a new coil. The polarity of the wires is not important.
8.12 BURNER VIEWING WINDOW
1. Gain access as in section 8.1.
2. Remove the two screws securing the window frame and remove the damaged glass and gasket.
3. Re-assemble in reverse order with a new glass and gasket. Ensure the gasket is next to the inner case front panel.
8.13 INTERNAL FUSE - Refer to Fig. 16
The fuse is located in the boiler terminal block.
1. Gain access as described in Installation, section 4.9.
2. Lift out the fuse holder and remove the fuse. Fit a fast blow 2 A fuse as a replacement, ensuring that the holder snaps into position.
3. Re-assemble in reverse order, ensuring the terminal block is located correctly on the plastic pin.
8.14 IGNITION PCB - Refer to Fig. 27
1. Gain access as described in section 8.1.
2. Disconnect the wiring connectors, then remove the three fixing screws.
3. Connect the wiring to the new PCB and re-assemble in reverse order.
8.15 NEON PCB - Fig. 27
1. Gain access as described in section 8.1.
2. Remove three screws securing ignition PCB.
3. Remove one screw securing neon PCB and disconnect the wiring connectors from the main PCB.
4. Re-assemble in reverse order.
8.16 RELAY PCB - Fig. 27
1. Gain access as described in section 8.1.
2. Disconnect the wiring connector from the PCB.
3. Remove the fixing screw and remove the board.
4. Re-assemble in reverse order.
Alpha 500E - Component Replacement
Burner manifold union
Room sealed
chamber
pressure tube
Solenoid
plug
Modulating
coil spring
clip
Modulating coil
Manifold screws
Fig. 26
Screw