Worcester 26CDi XTRA Installation And Servicing Instructions page 29

Fig. 38. Circulating pump
Unscrew union fittings
Allen screws (4)
remove if changing
pump head only
Pump
Electrical
connection
Unscrew union
cover
fitting
15. Pressure Relief Valve. See fig. 37 and 39.
Check that the electricity supply to the appliance is turned off.
Drain the central heating circuit as described in Section 14.2 (a).
Hinge the facia panel down into the Servicing Position as
described in Section 13.3 (c).
Remove the bottom panel as described in Section 13.3 (d).
Carefully ease the copper capillary tube to one side to clear the
retaining clip. Pull out the retaining clip, undo the discharge pipe
connection and remove the valve from the plastic manifold.
Retain the clip, discard the valve
Fit the replacement valve in reverse order. Reconnect the
discharge pipe.
Reassemble the appliance in the reverse order.
Open the valves and fill and re-pressurise the system as
described in Section 11.
Fig. 39. Filling Loop, Water to Water Heat Exchanger and Domestic Hot Water Flow Regulator
Rear view of
water to water
heat exchanger
showing
connections,
DHW flow
regulator and
seals
Drain tap C.H. flow
Filling loop assembly
Water to water heat
exchanger
Expansion vessel
Left hand union connection
Domestic hot water flow regulator
Union connection from
pump - flow pipe
removed
Support
plate
Water diverting
valve
29
16. Filling Loop. See figs. 37 and 39.
Check that the electricity supply to the appliance is turned off.
Drain the central heating circuit as described in Section 14.3 (a).
Hinge the facia panel down into the Servicing Position as
described in Section 13.3 (c).
Drain the central heating circuit as described in Section 14.3 (a).
Remove the two screws located on the left hand side. Slide the
filling loop assembly to the left until clear of the water diverting
valve. Remove from the appliance. Retain the screws and discard
the filling loop.
Fit the replacement assembly in the reverse order.
Replace the 'O' ring seals.
Open the valves and fill and re-pressurise the system as
described in Section 11.1.
Reassemble the appliance in the reverse order.
17. Water to Water Heat Exchanger. See figs. 37 and 39.
Check that the electricity supply to the appliance is turned off.
Drain the central heating and domestic hot water circuits as
described in Sections 14.2 (a) and (b).
Hinge down the facia panel into the Servicing Position as
described in Section 13.3 (c).
Remove the bottom panel as described in Section 13.3 (d).
Remove the filling loop as described in Section 14.3 (16).
Unscrew the left hand union connection to the diverter valve.
Remove the screw and clamp from the right hand end of the
heat exchanger.
Pull the heat exchanger forwards about 10mm to release from
the other two connections and remove from the appliance.
The plastic hot water flow regulator is located in the cold water
inlet accessible from the rear of the heat exchanger. Remove the
flow regulator (push fit) and retain.
Discard the heat exchanger retain the screw and clamp.
Fit the replacement heat exchanger in the reverse order.
Fit a new fibre sealing washer and 'O' ring seals. Lubricate the
'O' rings seals with silicone based grease.
Reassemble the appliance in the reverse order.
Open the valves and fill and re-pressurise the system as
described in Section 11.
Remove wire clip
Domestic hot water sensor
Wire clips
Copper by-pass pipe
Remove screw
and clamp from
right hand end of
heat exchanger
Pressure valve
Pressure gauge