Technical data

26
8.25 MAINS WATER INLET FILTER - Fig. 11
1. Drain the boiler hot water circuit as described in section 8.2. Remove the four screws securing the bottom tray and remove
the tray.
2. Withdraw the filter after disconnecting the unions between the inlet valve and boiler (item H in Fig. 11).
3. Clean or replace and re-assemble in reverse order.
8.26 EXPANSION VESSEL
Note: If there is less than 450 mm clearance above the boiler or a rear exit flue is used, it is not possible to replace the vessel,
in which case an additional vessel should be fitted external to the boiler in the central heating return pipe, as close to the boiler
as possible (see Fig. 5).
1. Gain access behind the casing and drain the boiler heating circuit as described in sections 8.1 and 8.2.
2. Disconnect the pipe from the pump inlet manifold and expansion vessel.
3. Remove the four screws securing the top support plate.
4. Lift the expansion vessel out of the boiler.
5. When replacing the vessel, ensure that the connection is towards the front of the boiler and re-assemble in reverse order
using new seals as necessary.
6. Refill and pressurise the system. (Refer to Commissioning, section 5.1).
Alpha C23/27 - Component Replacement