Technical data

replacement valve. Two of the “O” rings are identical in diameter
and cross - section and are required for the outer ports. The third
“O” ring is smaller in diameter and cross-section and will seal the
centre port.
IMPORTANT: Fit the two larger diameter “O” rings into the outer
locations on the replacement valve. Fit the smaller diameter “O”
ring over the centre spigot on the bottom manifold. Ensure the
“O” ring is located correctly against the shoulder on the centre
spigot.
Fit the replacement valve in reverse order ensure the four fixing
screws are correctly engaged. Replace the “O” ring seals and refit
the pressure pipe. Ensure the securing clips are fully engaged in
the locating holes.
Reconnect the electric cable to the control board and replace the
strain relief bush. Replace the circulating pump as described in
Section 15.3-20.
Open the valves, fill and repressurise the system as described in
Section 12.2. Reassemble the appliance in the reverse order.
22. Water to Water Heat Exchanger. See Figs. 42, 46, 47, 49, 50,
51, 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 as
described in Section 14.2 a, b and c.
Drain the heating circuit as described in Section 15.2 a.
Drain the hot water circuit as described in Section 15.2 b.
CAUTION: 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 circulating pump as described in Section 15.3-20.
Remove the water diverter valve as described in Section 15.3-21.
NOTE: i). It is not necessary to disconnect the electrical cable
from the pump. The length of cable is sufficient to allow it to rest
on top of the appliance cabinet. Do not allow it to be suspended
by the cable. Secure the pump head.
ii). Unless otherwise stated all water joints are sealed with “O”
rings. To disconnect twist the pipe and / or ease the joint apart.
When re-connecting the joint a new “O” ring must be fitted.
Silicone grease must be applied to the “O” ring.
Remove the pressure relief valve and manual air vent assembly
as described in Section 15.3-27 and retain. See Fig. 49.
Unscrew locating screw No.1 in the bottom manifold two full
turns. See Fig. 50.
Unscrew the flat faced union fitting below the flow turbine.
Remove the sealing washer and discard. See Fig. 53. Move the
cold water inlet pipe to the left to clear the flow turbine. Ease the
pipe upwards, 10 mm approx. and remove from the bottom
manifold. Retain the pipe.
Unscrew the union fitting below the cold water inlet valve and
remove the flow turbine and water filter assembly. See Fig. 53.
Place the flow turbine and water filter assembly on top of the
appliance cabinet and secure.
Unscrew locating screw No. 2 in the top manifold two full turns.
See Fig. 50. Ease the heating return pipe downwards 10 mm
approx. into the slip joint in the bottom manifold.
Move the pipe to the left to clear the top manifold. Ease the pipe
upwards 10 mm approx. and remove the pipe from the bottom
manifold. Retain the pipe.
If the appliance is fitted to an open vent system unscrew the
open vent union connection and remove the washer. See Fig. 46.
Remove the flat clip securing the pump inlet pipe to the pump
lower support plate. Retain the clip. See Fig. 46.
Remove the two screws Nos. 3 and 4 securing the pump inlet
pipe support plate and remove the plate. See Fig. 46.
Unscrew two full turns locating screw No. 5. See Fig. 50. Ease the
Fig. 47. Water diverter valve.
Copper pressure pipe
Securing clip for copper
pressure pipe
Replace the “O” ring seals (2) on
the copper pressure pipe located
either end of the pipe
Unscrew the four fixing screws
securing the valve head to the
bottom manifold
Bottom right-hand fixing screw
accessible using a “chubby” type
screwdriver
VIEW ON FRONT OF WATER
DIVERTER VALVE
VIEW ON REAR OF WATER
DIVERTER VALVE
Fit new “O” ring seals in the outer
locations on the rear of the diverter
valve. The “O” ring seals are
identical for the outer connections
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
Ensure the “O” ring seal is removed
from the bottom manifold spigot
WARNING: There will be a small
quantity of water remaining in the
water diverter valve and pipework
When replacing the “O” ring seal to
the centre spigot ensure it is the
correct diameter and cross section.
Locate the “O” ring onto the shoulder
formed on the centre spigot
Bottom manifold
Fixing holes (4)
39