Worcester Highflow 400 RSF Installation And Servicing Instructions page 42

assembly to the support bracket with screw Nos.13 and 14. Fully
tighten the screws fixing the "O" rings Nos. 11 and 12. See Figs.
47 and 48.
Re-assemble the top manifold in the reverse order.
Ensure the heating flow and heating return and hot water pipes
are fully engaged.
Ensure a new sealing washer and '"O"' ring is fitted when re-
connecting the union securing the top manifold to the inner
casing pipework. Replace the manifold top fixing screws Nos.9
and 10. Tighten screws Nos. 6, 7 and 8 and manifold union
fitting. See Fig. 47.
Re-assemble the pump outlet pipe and tighten screw No. 5. Re-fit
the pump support plate and secure with screw Nos. 3 and 4.
Ensure the flat clip is re-located.
Re-connect the open vent pipe (if applicable). Ensure a new
sealing washer is fitted. Replace the heating thermostat phial
and wire clip.
Re-assemble the heating return pipe using the slip joint in the
bottom manifold to manoeuvre the pipe into position.
Re-assemble the cold water inlet pipe and flow switch ensure the
sealing washer is renewed. Re-connect the union fitting to the
cold water inlet valve. See Fig. 52.
Re-assemble the pressure relief valve ensure clip is replaced. See
Fig. 51.
Re-assemble the domestic drain pipe renewing the "O" seal. Re-
locate the securing clip and fixing bracket to the gas valve. See
Fig. 48.
Before continuing ensure screws 1, 2, 5, 6, 7, 8, 11 and 12
are fully engaged. The "O" ring seals must be pushed fully
into the housing.
Re-assemble the water diverter valve. Re-assemble the 6 mm
diameter pressure pipe to the pump inlet pipe and diverter valve
renewing the "O" ring seals. Ensure the securing clips are
Fig. 46. Water diverter valve.
Copper pressure pipe
Replace the ÒOÓ ring seals (2) on
the copper pressure pipe located
either end of the pipe
Securing clip for copper
pressure pipe
Unscrew the four fixing screws
securing the valve head to the
bottom manifold
VIEW ON FRONT OF WATER
DIVERTER VALVE
replaced.
Re-assemble the circulating pump ensure the securing clips are
re-placed.
Open the valves, fill and repressurise the system as described in
Section 12.2. Reassemble the appliance in the reverse order.
23. Water to Water Heat Exchanger Top Manifold. See Figs. 41,
45, 46, 47, 48, 49, 51 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 and lower the expansion vessel into the
Service Position, as described in Section 14.2 a, b and c.
Drain the heating and hot water circuit as described in Section
15.2
Refer to Section 15.3-22 and remove the Top Manifold
commencing from the instruction:
WARNING: The weight of the water to water heat exchanger is
2 kg. approx. A quantity of water will remain in the heat
exchanger and pipework. Follow the procedure as described in
15.2.
Remove the manifold clear of the appliance Remove and retain
the brass stub connection and nut from the manifold.
Withdraw the by-pass adjuster retaining clip and unscrew the
adjuster from the manifold retaining both items.
Undo and remove the phial pocket securing clip screw and clip.
Retain both the clip and screw. Extract the phial pocket and
retain.
Unscrew and retain all locating screws.
Before reassembling the appliance refit the by-pass adjuster and
phial pocket in the reverse order using new "O" rings.
Screw all locating screws fully home then unscrew each of them
two full turns. Check that none of the screws protrude into their
relevant bores.
Before reassembly ensure the
"O" ring seals are in place with
the smaller diameter "O" ring seal
located on the centre spigot of
the bottom manifold
Fit new ÒOÓ ring seals in the outer
locations on the rear of the diverter
valve. The ÒOÓ ring seals are
identical for the outer connections
Bottom right-hand fixing screw
accessible using a ÒchubbyÓ type
screwdriver
42
WARNING: There will be a small
quantity of water remaining in the
water diverter valve and pipework
Bottom manifold
Ensure the ÒOÓ ring seal is removed
from the bottom manifold spigot
When replacing the ÒOÓ ring seal to
the centre spigot ensure it is the
correct diameter and cross section.
Locate the ÒOÓ ring onto the shoulder
formed on the centre spigot
Fixing holes (4)
VIEW ON REAR OF WATER
DIVERTER VALVE