Alpha CD50 - Page 31

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Alpha CD50 - Component Replacement
8.26 HEATING EXPANSION VESSEL - Refer to Fig. 2
1. Drain the boiler heating circuit as described in Section 8.2.
2. Disconnect the pipe from the expansion vessel and remove the re-usable support strap (see Fig. 27) by inserting a small
screwdriver into the clip on the strap.
3. Remove the screw securing the vessel to the front casing top bracket.
4. Remove the nut and washers securing the vessel to the hot water storage cylinder and lift the vessel out of the boiler.
5. Re-assemble in reverse order using a new seal.
6. Refill and pressurise the system. (Refer to Commissioning, Section 5.1).
8.27 DHW EXPANSION VESSEL - Refer to Fig. 2
1. Close the mains water supply valve and ensure that all hot water taps are closed. Release the pressure from the hot water circuit.
2. Disconnect the expansion vessel union and remove the re-usable support strap (see Fig. 27) by inserting a small
screwdriver into the clip on the strap.
3. Remove the expansion vessel.
4. Re-assemble in reverse order. Refill and pressurise the hot water circuit by opening the mains water supply valve.
8.28 PRIMARY PRESSURE SWITCH - Refer to Fig. 25
1. Drain the boiler heating circuit as described in Section 8.2.
2. Disconnect the wiring from the pressure switch.
3. Remove the switch by unscrewing it from the manifold.
4. Re-assemble in reverse order using the new washer supplied.
5. Refill and pressurise the system.
8.29 DHW TEMPERATURE/PRESSURE RELIEF VALVE - Refer to Fig. 2
1. Partially drain the hot water circuit, so that the water in the hot water storage cylinder is below the relief valve connection and
drain the boiler heating circuit, as described in Section 8.2.
2. Remove the CH expansion vessel as described in Section 8.26.
3. Remove the valve from the storage cylinder.
4. Re-assemble in reverse order.
5. Refill the storage cylinder by opening the mains water supply valve and opening a hot water tap.
8.30 DHW STORAGE CYLINDER
1. Drain the boiler heating and hot water circuits as described in Section 8.2.
2. Remove the heating and domestic hot water expansion vessels as described in Sections and 8.26 and 8.27.
3. Remove the DHW temperature/pressure relief valve as described in Section 8.29.
4. Remove the storage temperature sensor as described in Section 8.21 and the automatic flow regulator as described in
Section 8.34.
5. Remove the six screws securing the front casing top bracket to both side panels and the room sealed chamber. Remove
the bracket.
6. Disconnect and remove all the pipework from the cylinder and the pipework to the combustion chamber/primary heat
exchanger from the flow and return manifolds.
7. Remove the cylinder retaining screw, positioned beneath the cylinder on the backplate.
8. Lift the cylinder upwards to disengage it from the top of the boiler's backplate. Pull the cylinder forward and out of the boiler.
9. Re-assemble in reverse order using new seals.
10. Refill and pressurise the heating and hot water circuits. (Refer to Commissioning, Section 5.1).
8.31 PRESSURE REDUCING VALVE FILTER/CARTRIDGE - Refer to Fig. 15
1. Close the mains water supply valve and ensure that all hot water taps are closed. Release the pressure from the hot water circuit.
2. Unscrew the cartridge from the valve body.
3. Clean or replace the filter/cartridge and re-assemble in reverse order.
4. Refill and pressurise the hot water circuit by opening the mains water supply valve.