Worcester 25Si Installation And Servicing Instructions page 25

15.4.8 Flow Switch
Drain the DHW circuit as described in 15.3 preceding.
Remove the cabinet and lower the facia panel.
Carefully pull off the connections from the micro-switch. Undo
the two union connections on the valve and remove the valve.
Refer to Fig 52. Do not omit the gaskets when fitting the
replacement switch.
The new flow-switch must be set to deliver the correct flow rate
to give a temperature rise of 40°C ie 10 l/min (28Si) or 9 l/min
(25Si).
The adjustment is made by turning the red adjuster clockwise to
reduce the flow rate and anti-clockwise to increase the flow rate.
Make the adustment with the gas turned off.
Fig. 52. Water Flow switch.
Flow Switch
RED KNOB NOT
SHOWN
15.4.9 Inlet Water Filter
Remove the flow switch as described in 15.4.8 preceding.
Unscrew the two screws and remove the securing plate. Firmly
withdraw the union connection assembly and pull out the filter.
Refer to Fig 53. Carefully clean or replace the filter.
Fig. 53. Inlet water filter
Securing
Plate and
Screws
Micro Switch
Seal
Outlet Union
Inlet Union
(with seal)
Cold Water
Inlet
Flow Switch
Filter
O-Ring
Seal
Inlet Union
25
15.4.10 Control Board
Remove the facia bottom panel and carefully disconnect all the
electrical connections. Refer to Fig 33.
Remove the cabinet and lower the facia panel as described in
Section 14.3, Inspection and Servicing.
Disconnect the earth connection at the appliance. Refer to Fig
45.
Unscrew the four screws and remove the metal cover. Refer to Fig
54.
Lift out the control board. Refer to Fig 55
Pull out and transfer the transformer to the new board together
with the plastic locating frame.
Re-commission the appliance to check and set the burner
pressures. Refer to Section 12, Commissioning.
Fig.54. Control board cover
Cover panel
Main earth
connection
Facia assembly
pivot point
Transformer
Fig.55. Control board
Control board
fixing screws
Control
board
Facia assembly
Control board
locating frame
Control
board
Facia assembly