Potterton Performa 24 Installation & Servicing Instructions Manual page 33

'O' ring seal
Fig. 78
Discharge Pipe
Fig. 79
Control Box Cover
P.C.B.
Selector
Switch
Facia
Selector Switch Knob
Grub Screw
Pressure Relief Valve
1. Drain the primary circuit.
2. Disconnect the discharge pipe from the valve.
Using a suitable hexagon key undo the grub
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.
1. Note the settings of the temperature control
knobs and carefully pull them off the facia
(Fig. 80).
2. Remove 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. 79).
3. Note the position of all plugs and wires on the
P.C.B. and disconnect them.
4. Undo the securing screws and remove the
P.C.B. Reassemble in reverse order, ensuring
that the temperature controllers are reset to their
previous positions (Fig. 80).
1. Note the setting of the selector switch knob and
carefully pull it off the facia (Fig. 80).
2. Remove 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. 79).
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
Fig. 80
facia panel (Fig. 80).
5. Fit the new switch, ensuring that it is correctly
positioned and reassemble in reverse order.
Temperature Control
Knobs
12.0 Changing Components
12.17 Pressure Relief Valve (Fig. 78)
12.18 P.C.B.
12.19 Selector Switch
33