Checks; Removal; O Full Sequence Ignition Device S4567A-1019; Function - Biasi RIVA COMBI Service Manual

___________________________________________________________________________________________________
Third Part
_______________________________________________________________
Full Sequence Ignition Device S4567A-
1019

1) Function

2) Checks

3) Removal

4) Ignition and Control Sequence

1 Function
The Full sequence ignition device A (Figure
1)used on the boiler carries out the following
fundamental functions:
A
O does a sequence of operations (ignition cycle)
which lead to the ignition of the gas at the burner.
O checks the presence of the flame during the
entire period in which it is activated.
The Full sequence ignition device is supplied by
the fan and air pressure device when the ignition
of the burner is requested (see Second part of
this manual chapter 6, Circuit Voltages).
The Full sequence ignition device has a safety
function and any incorrect interventions or
tampering can result in conditions of dangerous
functioning of the boiler.
The Full sequence ignition device can lock the
functioning of the boiler (lock state) and stop its
functioning up to the resetting intervention. The
lock is signalled by the lighting of the lock-out
signal lamp and the device can be reset only by
using the boiler reset button and the function
knob placed on the control panel.
The ignition device has some components
connected to it which can cause triggering of the
shutdown condition; these components are:
RIVA COMBI SERVICE MANUAL – REV A
(edition-0106)
B
Figure 1
Full Sequence Ignition Device S4567A-1019
- the modulating gas valve;
- the flame detection electrode.
The causes of a lock state could be:
O A fault on gas supply.
O Faulty ignition (faulty ignition electrodes, their
wiring or connection).
O Faulty flame detection (faulty detection
electrode, its wiring or connection).
O Gas injectors blocked.
O Faulty modulation gas valve (faulty on-off
operators or not electrically supplied).
O Faulty Full sequence ignition device.
Section 4 shows the sequence of the operations
that are carried out at the start of every ignition
cycle and during normal functioning.
2 Checks
A Lock sequence
1) Start the boiler until the burner is ignited.
2) With the burner firing, interrupt the gas supply.
The Full sequence ignition device must carry
out a complete ignition cycle and then stop.
3) By turning the boiler on and off by means of
the function switch the device must not
unlock and the burner must not turn on.
3 Removal
1) Remove the front body panel and tilt the card
holder panel.
D
C
2) Unscrew the screw C and remove protection
cover D of the connection; disconnect flame
F
E
Figure 2
8-1