Worcester Highflow 400 RSF Installation And Servicing Instructions page 46

30. Flow Switch. See Figs. 9, 16, 52 and 53.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position and lower the expansion vessel into the
Service Position, as described in Section 14.2 a, b and c.
Drain the hot water circuit as described in Section 15.2 b.
Remove the facia as described in Section 15.1. Unplug the Molex
plug marked X1 'Flow Switch', from the control board. Release
the strain relief bush by compressing the loose section of the
bush and carefully withdraw the leads from the control box.
Unscrew the two flat faced union fittings connecting the flow
switch body to the mains cold water inlet. Remove the flow
switch, leads and sealing washers clear of the appliance and
discard.
Fit a replacement flow switch in the reverse order. Ensure the
arrow on the end of the black plastic body points downwards
and new sealing washers are fitted.
Reconnect the Molex plug.
Open the valve and fill the hot water circuit.
Reassemble the appliance in the reverse order.
31. Water Filter. See Figs. 16 and 52.
Fig. 52. Flow switch, water filter and hot
water flow regulator.
Mains cold water
inlet valve
Water filter housing
Flat face union
fitting
Flow switch body
Ensure arrow
points downwards
Flow
switch
Water
filter
Fibre
washer
Fibre
washer
Hot water flow
regulator
Flat face union
fitting
Pipework to bottom
manifold
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position, as described in
Section 14.2 a, b and c.
Drain the domestic hot water circuit as described in Section 15.2 b.
Undo the flat faced union above the flow switch. Swivel the flow
switch and pipework sideways sufficiently to clear the union.
Remove the sealing washer and discard.
Undo the union below the mains water supply valve and remove
the filter housing clear of the appliance. The water filter is
located in the top of the housing. Remove the filter clean or
replace.
Reassemble in the reverse order and replace the sealing washer.
No sealing compound is required. Open the mains water valve
and fill the hot water circuit.
Reassemble the appliance in the reverse order.
32. Hot Water Flow Regulator. See Figs. 16 and 52.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position, as described in Section 14.2 a, b and c.
Drain the domestic hot water circuit as described in Section 15.2 b.
Undo the flat faced union below the flow switch. Ease the
pipework sideways sufficiently to clear the flow switch. Remove
the sealing washer and discard.
The water flow regulator is located in the union fitting. It may be
necessary to prise the regulator from its housing. Remove and
discard.
Fit a new flow regulator, small diameter section first. Reassemble
in the reverse order and replace the sealing washer. No sealing
compound is required.
Open the mains water valve and fill the hot water circuit.
Reassemble the appliance in the reverse order.
33. Inner Casing Cover Seal. See Fig.16.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position and lower the expansion vessel into the
Service Position, as described in Section 14.2 a, b and c.
Remove the inner casing cover as described in Section 14.2 d.
Remove the inner casing cover seal and discard. Fit a
replacement seal using silicon adhesive. Check that the seal
passes completely around the edge of the inner casing cover
leaving no gaps.
Reassemble the appliance in the reverse order.
34. Operating Switch. See Figs. 9 and 16.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position as described in
Section 14.2 a and b.
Remove the facia as described in Section 15.1.
Remove the terminals from the rear of the switch making note of
their positions. Squeeze together the two plastic retaining lugs to
remove from the facia. Discard the switch.
Snap in the replacement switch and reconnect the terminals
Refer to the wiring diagram Fig. 9. Reassemble the appliance in
the reverse order.
35. Control Board. See Figs. 9 and 53.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box
in the Service Position as described in
Section 14.2 a and b.
Remove the facia as described in Section 15.1.
Carefully pull off all the Molex plugs, note the positions.
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