2.3.2 Pilot-ON
In this state the Pilot Flame sequence is executed, and it will lead the system to a
continuous Pilot flame condition through these steps:
- if the previous state was Turn-OFF,
the Pilot Flame detection is turned ON,
a Pilot Flame check sequence is completed to avoid parasitic flame detection,
the spark generator is activated,
the Pilot gas valve solenoid is set to open the gas flow to the pilot hood,
in the mean time the Main Burner gas valve solenoid is set to close the gas flow;
- if the previous state was Turn-ON,
the Pilot Flame detection is maintained ON,
the Pilot gas valve solenoid is set to keep opened the gas flow to the pilot hood,
in the mean time the Main Burner gas valve solenoid is set to close the gas flow.
2.3.3 Turn-ON
In this state both the Pilot, and the Main Burner Flames sequences are executed, and it
will lead the system to a fireplace completely lit:
- if the previous state was Turn-OFF,
the Pilot Flame detection is turned ON,
a Pilot Flame check sequence is completed to avoid parasitic flame detection,
the spark generator is activated,
the Pilot gas valve solenoid is set to open the gas flow to the pilot hood,
in the mean time the Main Burner gas valve solenoid is set to close the gas flow,
the Pilot Flame is let to stabilize,
the Main Burner gas valve solenoid is set to open the gas flow;
- if the previous state was Pilot-ON,
the Pilot Flame detection is maintained ON,
the Pilot gas valve solenoid is set to keep opened the gas flow to the pilot hood,
in the mean time the Main Burner gas valve solenoid is set to open the gas flow.
2.3.4 Lockout state definition
A lockout state is reached when an ignition error occurs, in any case the lockout on this
board is volatile, this means that the lockout state will remain set in memory as long as the
power supplies are applied.
This could mean both an anomalous flame detection, and/or too many unsuccessful
ignition tries.
This state is a safe condition for the appliance, and is entered automatically by the DFC
board.
When the DFC gets into lockout state:
1. both the Pilot, and the Main Burner solenoids in the gas valve are de-energized;
2. a diagnostic code is sent through the diagnostic port: if a signalling device is
applied to the port the signal could be heard or seen by the user and recognized
through a numeric code.
Having no diagnostic mean, the symptom of a lockout could be verified on a not
responding board by trying to set the Pilot-ON command in CPI mode, because
the board will not ignite the pilot flame;
3. the DFC board will ignore any command setting, and remain into Turn-OFF state,
unless the unlock command sequence is met.
The causes of lockout must be investigated under safe conditions by the user and / or the
service personnel.
The return of the system to the normal operation can be done releasing the DFC board
from lockout in one of the following ways:
