Technical data

25
8.12 GAS VALVE (Alpha 240XP only) - Fig. 24
1. Gain access as in section 8.1.
2. Disconnect the thermocouple, pilot supply and
overheat thermostat leads from the gas valve.
3. Disconnect the wiring and pressure tube from the
gas valve.
4. Remove the screw securing the light grey cover
around the gas control knob.
5. Remove the screw securing the microswitch
assembly to the valve (access from beneath the
boiler).
6. Remove the four manifold screws from beneath the
boiler.
7. Disconnect the burner manifold union underneath
the room sealed chamber.
8. Carefully push the manifold towards the rear of the
boiler (take care not to damage the manifold sealing
washer) and lift out the valve assembly.
9. Remove the burner manifold and fit it to the new
valve using the new 'O' ring seal supplied.
10. Fit the new assembly, using the new 'O' ring supplied
in the bottom of the gas valve.
11. Remove light grey cover from the new valve and fit the microswitch assembly. Replace the cover (ensure the operating arm
is located under the cover).
12. Re-assemble in reverse order.
13. Light the boiler and test for gas soundness. (Refer to Commissioning, section 5.4).
14. Complete re-assembly as described in Routine Servicing, section 7.4 paragraphs 5 to 9.
8.13 GAS VALVE (Alpha 240XE only) - Fig. 25
1. Gain access as in section 8.1.
2. Disconnect the coil wires and pressure tube from the
gas valve.
3. Loosen the two screws (see Fig. 25) securing the
solenoid plug and disconnect the plug.
4. Remove the four manifold screws from beneath the
boiler.
5. Disconnect the burner manifold union underneath
the room sealed chamber.
6. Carefully push the manifold towards the rear of the
boiler (take care not to damage the manifold sealing
washer) and lift out the valve assembly.
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 the new 'O' ring supplied
in the bottom of the gas valve.
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.
8.14 GAS VALVE MODULATING COIL - Refer to Fig. 24 or 25
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.
Alpha 240XP and 240XE - Component Replacement
Burner manifold union
Room sealed
chamber
pressure tube
Solenoid
plug
Modulating
coil spring
clip
Modulating coil
Manifold screws
Fig. 25
Manifold screws
Fig. 24
Pilot supply
Grey cover
screw
Thermocouple
Overheat
thermostat leads
Burner manifold union
Room sealed
chamber
pressure tube
Ignition microswitch
assembly
Modulating
coil spring
clip