Ignition And Detection Electrodes; Function; Checks; Removal - Biasi RIVA COMPACT M90E.24S Service Manual

18

Ignition and detection electrodes

18.1

Function

Three electrodes are fitted near the front part of the
burner. The ignition sparks take place between the me-
tallic edges of the ignition electrodes over the central
ramp of the burner during the ignition sequence.
The third electrode is the detection electrode and it de-
tects the presence of the flame.
Fig. 73 shows the electrodes configuration on the mo-
dels M90E.24S, M90E.28S.
Fig. 74 shows the electrodes configuration on the
model M90E.32S.
Ignition
Female
Fig. 73
Detection
Male
Female
Fig. 74
36
Detection
Male
Ignition
18.2

Checks

Check the position of the electrode edges
n
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
2 Check for the correct distance between the me-
tallic edges of the ignition electrodes (see
Fig. 75).
Ignition
Fig. 75
3 Check the integrity of the detection electrode and
ensure that its metallic edge is correctly placed
over the ramp of the burner.
Check the connection wires.
n
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
2 Check for the integrity of the insulation of wires
which connect the electrodes to the ignition de-
vice.
18.3

Removal

Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1 Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
2 Disconnect the electrode wires from the full se-
quence ignition device.
3 Remove the burner by unscrewing the four
screws placed at the right and left sides of the
burner.
3b For model M90E.28S and M90E.32S remove also
the plate C (see Fig. 78 on page 38).
Unscrew the screws A (Fig. 76) which hold the
4
electrodes to the burner.
Two screws are used on the models M90E.24S,
M90E.28S
Three screws, one for each electrode, are used
on the model M90E.32S.
4 mm