Changing Components - Main Combi 24 Installation & Service Instructions Manual

12.0 CHANGING COMPONENTS

IMPORTANT: When changing components ensure
that both the gas and electrical supplies to the
boiler are isolated before any work is started.
When the component has been changed turn the
selector switch fully anticlockwise against the
spring pressure to the reset position and hold for at
least 3 seconds to reset the boiler before
recommissioning.
See Section 11.1 "Annual Servicing" for removal of
case panel, door etc.
12.1 Pressure Switch
1. Note the positions of the two sensing tubes and
wires and remove them (Fig. 57).
2. Remove the two screws holding the pressure
switch to the combustion box top panel.
3. Fit the new pressure switch and reassemble all
components in reverse order of dismantling.
12.2 Fan
1. Note the positions of the two sensing tubes on the
outlet elbow and three wires on the fan motor and
remove them (Fig. 58).
2. Slacken the screws on the outlet sealing collar.
Ease the collar upwards as far as possible (Fig. 59).
3. Remove the four screws securing the combustion
box door and remove the door.
4. Remove the spring clips retaining the air box side
baffle plates. Disengage the tabs on the baffles from
the slots in the fan hood (Fig. 61).
5. Undo the screws securing the fan hood to the
appliance back panel, and draw the fan and hood
assembly forwards (Fig. 60).
6. Remove the screws and spring washers securing
the fan to the hood. Transfer the flue outlet elbow to
the new fan (Fig. 60).
7. Fit the new fan to the hood using the screws and
spring washers previously removed.
8. Reassemble in reverse order of dismantling.
Pressure
Switch
Fig. 57
-
+
b
br
Pressure
Switch Wires
Fan Wires
g/y
b
br
-
+
Fan and Hood
Assembly
Fig. 58
Fan
Spring
Washer
Securing Screw
Fan Hood
Fig. 60
Sensing
Tubes
Sensing Tubes
Flue Outlet Elbow
Spring Clip
Fig. 59
Outlet Sealing
Collar
Baffle
Tab
Fig. 61
29