10.3.1 Detection/spark ignition electrode
1. Disconnect the electrode lead and earthing cable.
2. Using a T15 Torx key, remove the retaining screws securing the
electrode to the combustion chamber door and remove the electrode,
noting its orientation.
3. Fit the new electrode with the sealing gasket.
4. Reassemble in reverse order.
10.3.2 NTC flue sensor
1. Turn the sensor 90° anticlockwise to remove — it is a bayonet
connection.
2. Ease the retaining tab on the sensor away and disconnect the
electrical plug.
3. Fit new sensor and reassemble in reverse order.
10.3.3 Flow and return sensors
There is one sensor on the flow (red wires) and one sensor on the return
(black wires).
1. Remove the air/gas unit.
See
Air/gas unit, page 58 to remove.
2. After noting the position prise the sensor clip off the pipe and
disconnect the plug.
3. Connect the plug to the new sensor and ease the clip onto the pipe in
its original position.
10.3.4 Safety overheat thermostat
1. Pull the two spade connections off the safety overheat thermostat.
2. Prise the thermostat clip with the safety overheat thermostat off the
pipe
3. Fit new safety thermostat on the pipe using heat-sink paste.
4. Connect the two spade connections to the safety overheat thermostat
ensuring that they are pushed fully on.
Fig.51
Remove detection/spark ignition
electrode
PN-0000331
Fig.52
Remove NTC flue sensor
PN-0000332
Fig.53
Removing the flow and return
sensors
PN-0000522
Fig.54
Removing the safety overheat
thermostat
PN-0000523
10 Maintenance
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