Table of Contents
Advertisement
Replacement of Parts - Page 34
5.23
Expansion Vessel C.H.
In the unlikely event of a failure of the C.H. expansion vessel
it is recommended that a new vessel be fitted exterior to the
boiler. It should be positioned on the C.H. Return pipe (see
Fig. 6) as close to the boiler as possible. If however, the
vessel must be replaced then the following procedures may
by used. Installations with vertical flue systems must be fitted
with exterior expansion vessels if the flue system can not
easily be raised a minimum of 50mm.
Note: It will simplify fitment of the vessel if a length of string
or flexible wire is attached to the end of the flexible pipe and
passed down the rear of the appliance through the back
panel hole and used as a guide to thread the pipe during
installation.
Procedure 1. Horizontal flues only.
If the clearance above the boiler is greater than 300 mm
proceed as follows:
1. Remove the white front case.
See 4.1 in 'Routine Maintenance'.
2. Lower the control panel assembly by undoing the
securing screw at the top right hand side of the control
panel.
3. Drain the central heating circuit as described on Page
26.
4. Undo the flexible pipe connection on the side of the
pump manifold and remove the grommet. Push the
flexible pipe through the hole in the back panel.
5. For rear outlet flues remove the flue elbow (4 screws)
and withdraw the complete flue assembly from the wall.
Short side outlet flues may also require removal of the
flue system.
6. Remove the top expansion vessel securing bracket
assembly (four screws) and slide the vessel (complete
with flexible pipe) upwards out of the appliance.
7. Remove the flexible pipe from the old vessel and refit
(using a new sealing washer) to the new expansion
vessel (at this stage the pre-charge pressure can be
easily checked and corrected if necessary. The pressure
should be at least equal to the system pressure at the
appliance).
8. Fit the new expansion vessel and re-assemble in
reverse order. Ensure that the vessel is located correctly
in the lower support bracket. Route the flexible pipe
through the hole in the back panel and refit grommet.
Procedure 2
If the clearance above the appliance is less than 300 mm
the appliance must be removed from the wall.
1.
Remove the complete casing assembly (front, base and
sides)
2.
Drain the appliance as described on Page 26.
3.
Lower the control panel assembly by undoing the
securing screw at the top right hand side of the control
panel.
4.
Disconnect the input wiring noting positions of wires
and thread wiring out of control panel grommet/s.
5.
Check the gas supply is isolated at the gas service
cock, (1/4 turn of square head), undo the gas cock
union nut and position nut clear of thread.
6.
Undo the upper isolator valve connections on the C.H.
flow, return and Cold water inlet valves. Similarly
disconnect hot flow pipe, and pressure relief pipes.
7.
Disconnect the flue elbow from the top of the appliance,
(4 screws), lift the flue elbow off the boiler connection
and rotate the elbow 180° to position the flue clear of
the appliance. If a vertical flue system is fitted it will
require raising approximately 50 mm (2") to allow the
boiler to be lifted off its hanging screws.
8.
Remove the bottom boiler securing screw then loosen
the appliance upper securing screws and lift the boiler
off the wall. Place unit face downwards on the floor.
Care should be taken not to damage the pressure
gauge or electronics.
9.
Access can now be made to the expansion vessel.
Undo the flexible pipe connection to the vessel and
remove the screws retaining the upper expansion
vessel bracket to release the vessel from the
appliance.
10. Fit a new expansion vessel and re-assemble in reverse
order, using a new sealing washer. At this stage it is
advisable to check the pre-charge.
Hide quick links:
Advertisement
Table of Contents
