Access To Pcb; Replacing Controls - Worcester GREENSTAR 24i Junior Installation, Commissioning And Servicing Instructions

SERVICE AND SPARES

6.8.14 ACCESS TO PCB

Refer to figure 114 and disconnect all electrical connections from the
control.
1. Remove five screws retaining the rear panel of the control.
2. Remove the rear panel.
1.
1.
1.
Fig. 114 PCB access
REFITTING THE CONTROL BOARD COVER:
▶ Ensure that all wires are fully within the control board.
▶ Align the front right hand corner of the cover with the front right hand
corner of the control board.
▶ Align the rear right hand.
▶ Holding the cover level, slide the cover onto the control board,
ensuring that the incoming cables, at the top, are held clear.

6.8.15 REPLACING CONTROLS

NOTICE:
▶ Do not replace the control unit if a
CO/CO analyser is NOT available.
2
The control unit is supplied within its plastic housing.
The complete unit must be replaced.
1. Refer to figure 115 and remove all electrical connections from the
control PCB including where cables run through restraints. These can
be unclipped from the plastic moulding noting their position.
2. Carefully remove the system pressure gauge from the fascia by
parting the plastic retaining lugs securing the gauge in place. Take
care not to damage or kink the capillary tube.
3. Remove the code plug. The code plug should be left attached to the
frame of the boiler by its plastic safety thread.
3.
Fig. 115 Replacing the controls (SMPS)
1. Refer to figure 116 and remove the three screws retaining the front
fascia, the support cable (1) is secured using the nearest left hand
screw. Support the fascia when removing the last screw.
46
1.
2.
1.
1.
2.
2. Remove the front fascia.
1.
1.
Fig. 116 Fascia removal (SMPS)
1. Refer to figure 117 and using a suitable tool, press the button up.
2. Slide the control support bracket to the left.
2.
1.
Fig. 117 Control unit release
▶ Remove appropriate cable restraints from the new control unit.
▶ Fit control unit to the boiler. Ensuring the control support bracket is
fully engaged to the right.
▶ Re-connect all electrical connections and system to the new control.
Refer to figure 118.
▶ Replace the fascia to the new control unit remembering to re-connect
the support cable (1).
▶ Secure the system pressure gauge back in the fascia, routing the
capillary as indicated (2)
1
Fig. 118 Support cable connection
▶ Ensure that the code plug is re-fitted to the new control. If this is not
done, the boiler will indicate an error and will not function.
NOTICE:
▶ After re-assembly, check the CO/CO
described in section 6.6 air/gas ratio setting.
1.
2.
1
2
levels as
2
6 720 802 047 (2013/05)