12.0 CHANGING COMPONENTS
12.17Pressure Relief Valve (Fig. 65)
1.Drain the primary circuit.
2.Disconnect the discharge pipe from the valve. Using a suitable hexagon key undo the grub screw sufficiently to release the valve.
3.Note the orientation of the valve, rotate it and withdraw it from the manifold.
4.Fit the new valve and ‘O’ ring seal and set to the previously noted orientation. Reassemble in reverse order.
12.18P.C.B. (Fig. 67)
1.Note the settings of the temperature control knobs. Rotate the knobs fully anticlockwise and pull them off the drive pins.
2.Completely undo the screws securing the control box cover and release the cover retaining barbs from their slots. Disengage the rear of the cover from the control box hinge pin (Fig. 66).
3.Note the position of all plugs and wires on the P.C.B. and disconnect them. Pull the drive pins off the P.C.B.
4.Undo the securing screws and remove the P.C.B.
5.Reassemble in reverse order, ensuring that the temperature controllers are reset to their previous positions.
12.19Selector Switch (Fig. 67)
‘O’ ring seal
Grub Screw
Pressure Relief Valve
Fig. 65
Discharge Pipe
Fig. 66
Control Box Cover
P.C.B.
1.Note the setting of the selector switch knob and carefully pull it off the facia.
2.Completely undo the screws securing the control box cover and release the cover retaining barbs from their slots. Disengage the rear of the cover from the control box hinge pin (Fig. 66).
3.Note the position of the electrical connections and the orientation of the switch. Remove the electrical connections.
4.Remove the screws securing the switch to the facia panel.
5.Fit the new switch, ensuring that it is correctly positioned and reassemble in reverse order.
Selector
Switch
Facia 
Selector Switch Knob
Drive Pins
Fig. 67
Temperature Control Knobs
Publication No. 5111811 | 35 |
