Service Manual

Page 37
Ignition Electrode
To prevent harder than necessary ignition cycles and to ensure the correct gas supply and burner stability
conditions, the following situation is verified during the safety time period.
During each ignition attempt, the system monitors the ionization signal; this signal drives the start of
normal operation. However, in the case where the ionization signal is not detected during the ignition
sequence, the failure code EA will flash on the display. When this occurs, a non-volatile lock-out is
activated, and only a manual reset will allow the system to resume normal operation. Finally, if the
ionization signal is interrupted during normal operation, the ignition sequence shown below is re-started.
Fan Ignition spark
1
st
& 2
nd
Ignition Sequence
Safety Time = 23 sec
1
st
Attempt
(3 sec)
Purge Period
(3 sec)
2
nd
Attempt
(3 sec)
Purge Period
(3 sec)
3
rd
Attempt
(3 sec)
Post Purge
(8 sec)
+
+ +
3
rd
Ignition Sequence Safety Time of 15 sec + 30 sec
1
st
Attempt
(3 sec)
Purge Period
(3 sec)
2
nd
Attempt
(3 sec)
Purge Period
(3 sec)
3
rd
Attempt
(3 sec)
Post Purge
(30 sec)
+ + +
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