Supplied By www.heating spares.co Tel. 0161 620 6677
9.0 Changing Components
23
9.6
Printed Circuit Board
1. Remove the controls heat shield from its
retaining clips.
2. Undo the two screws retaining the valve cover
assembly and remove the assembly (Fig. 53).
3. Undo the three screws retaining the control
box cover and remove the cover (Fig. 52).
4. Disconnect the three multi-pin plugs, flame
sensing lead and ignition lead from the PCB,
noting their positions (Fig. 52).
5. Pull the valve wiring grommet out of the slot in
the control box.
6. Undo the screw retaining the control box and
remove the box (Fig. 52).
7. Push out the black rivet retaining the PCB
(Fig. 52).
8. Fit the new PCB using the rivet (Fig. 52).
9. Reassemble in reverse order.
To change the Gas Valve, Burner and Main
Injector, Electrode/Leads, and Pilot/A.S.D.
Assembly proceed as follows:-
9.7
Removal of Controls
1. Turn the boiler thermostat to "O".
2. Pull the input plug from the socket on the
P.C.B. (Fig. 55).
3. Disconnect the union at the gas service cock
and remove the fire feed pipe (Fig. 56).
4. Remove the thermostat sensor and retaining
strip from the boiler.
5. Undo the nut on the sensing pipe at the
adaptor (Fig. 54).
6. Loosen the
‘
P
’
clip and slide the sensing pipe
up to clear the burner plate (Fig. 57).
7. Undo the two screws retaining the controls to
the combustion box (Fig. 56).
8. Undo the screw holding the controls to the
combustion box base tray (Fig. 56).
9. Lift the front edge of the controls up and pull
forwards to ensure the burner plate top edge
clears the door panel.
10. Withdraw the controls from the boiler.
Valve Cover Assembly
Control Box Cover
P.C.B.
Control Box
Retaining
Screw
Retaining
Rivet
Fig. 54
Fig. 52
Fig. 53
Input Plug
Base Tray Screw
Securing Screw
Union Nut
Sensing Pipe
Adaptor
Fig. 56
Fig. 55
Fig. 57
‘
P
’
clip
