15.4.13 Fan
Remove the inner casing.
Remove the fan as described in Section 14.3 Inspection and
Servicing. Ensure that all the connections are correctly made to
the new fan. Refer to Fig. 51.
Do not use any sealant on the fan/flue duct connection.
15.4.14 Expansion Vessel
Drain the appliance as decribed in Section 15.3 preceding.
Remove the cabinet front and lower the facia.
Remove the air flow switch and bracket. Refer to Section 15.4.19.
Remove the pump. Refer to Section 15.4.12.
Remove the bypass pipe by removing the clips.
Remove the flow manifold and mid-position diverter valve (if
fitted) and the filling loop assembly.
Disconnect the return pipe from the relief valve. Refer to Fig 43
and 52.
Cut the plastic retaining clip and remove the expansion vessel.
When replacing the components do not omit any seals, gaskets
or O-rings replace any that are damaged
Alternatively the specified replacement can be fitted into the
system return as close to the appliance as possible. Re-fill and
pressurise the system as described in Section 12 Commissioning.
15.4.15 Air Flow Detector
Remove the fan as described in 15.3.13. Unscrew and withdraw,
through the fan outlet, the air flow detector. Refer to Fig .51.
The detector is 'handed' - do not force it into place.
15.4.16 Primary Flow Sensor
Carefully pull-off the connections.
Pull off the clip and remove the sensor. Refer to Fig .49.
15.4.17 Overheat Thermostat
Carefully pull-off the connections. Twist the sensor to expose the
fixing screws. Refer to Fig.49.
Unscrew and remove the sensor.
Carefully position the replacement sensor so that the
connections are away from the flue hood.
15.4.18 Auto Air Vent
Drain the appliance as described in Section 15.3 preceding.
Unscrew and remove the auto air vent.
Do not omit the O-ring when fitting the replacement air vent.
Remove the cap. Refer to Fig.49.
Ensure that the casing seal is not disturbed.
15.4.19 Air Pressure Switch
Carefully disconnect the air (note the position of each tube) and
electrical connections to the switch. Unscrew the fixing screws
and remove the switch. Refer to Fig.53.
Ensure that the connections are correctly made on the
replacement switch.
15.4.20 Sight Glass
Remove and replace the complete inner casing cover if the sight-
glass is damaged. Refer to Section 14.3, Inspection and
Servicing.
27
Fig.51. Fan /Flue Hood Assembly
2
1
1. Fan Assembly Fixing Screws (3)
2. Fan Assembly
3. Flue Hood
4. Auto Air Vent
5. Combustion Products Test Point
6. Air Flow Sensor
Fig.52 . Expansion Vessel
Cut
Fig.53 . Air pressure switch.
1
2
3
4
5
7
6
1. Gas Valve Outlet connection
2. Gas Valve
3. Gas Valve Electrical Connection
4. Gas valve Inlet Connection
5. Air Flow Sensing Pipes, Clear (front), Red (rear)
6. Air Pressure Switch
7. Gas Valve Mounting Bracket
4
3
5
6
1
2
3
4
1. Strap
2. Support bar
3. Pressure valve
4. Connection
