11.0 Changing Components
28
IMPORTANT:
When changing components
ensure that both the gas and electrical supplies
to the boiler are isolated before any work is
started.
See Section 10.0 “Annual Servicing” for removal of
case panel, doors etc.
11.1
Pressure Switch
(Fig. 49)
1. Note the positions of the two sensing tubes and
three wires and remove them.
2. Undo the screws securing the pressure switch to
the combustion box bracket and remove the switch.
3. Fit the new component in reverse order of
dismantling and connect the sensing tubes and
wires as previously noted (see Service Guidance
label on reverse of front panel).
11.2
Fan
(Fig. 51)
1. Note the positions of the two sensing tubes and
three wires on the pressure switch and remove
them.
2. Undo the screws securing the pressure switch to
the combustion box bracket and remove the switch.
3. Remove the screws from the flue adaptor clamp.
Prise the clamp apart and disengage it from the fan
outlet adaptor and boiler flue adaptor. Remove the
clamp.
4. Note the positions of the three wires on the fan
motor and remove them. Remove the two screws
securing the flue hood forward edge.
5. Draw the fan and hood assembly forwards out of
the combustion box.
6. Undo the two screws securing the fan to the fan
hood and remove the fan by disengaging the tabs
from the slots in the hood.
7. Undo the two screws securing the outlet adaptor
to the fan. Transfer the adaptor to the new fan.
8. Fit the new fan to the hood and reassemble in
reverse order.
11.3
Burner
(Fig. 52)
1. Undo the screws securing the combustion box
inner panel and remove. Disconnect the gas supply
from the burner inlet manifold and remove the
electrode lead from the spark electrode.
2. Draw the burner forwards out of the combustion
box and disconnect the flame sensing lead. Take
care not to damage or lose the sealing washer on
the gas inlet flange.
3. Undo the screws securing the injector manifold to
the burner assembly and remove the manifold.
4. Undo the screws securing the electrodes to the
burner assembly and remove them.
5. Fit the electrodes and injector manifold to the new
burner and check the electrode positions.
Reassemble in reverse order.
Burner
Spark Electrode
Sensing Electrode
Securing Screw
Securing Screw
Injector
Injector Manifold
Gas Supply
Pressure Switch
Sensing Tubes
Outlet Adaptor
Flue Adaptor Clamp
Sensing Tubes
Fan Mounting Plate
Fan
Fan Hood
Fig. 52
Fig. 51
Fig. 49
Fig. 50
Sealing Washer
