Buderus Logano G234X Installation And Service Instructions Manual page 28

8
Boiler inspection and maintenance
START
PHASE 1
Ignition attempt
PHASE 2
Main burner
operating
END
Fig. 40 Troubleshooting the G234X
28
Room thermostat (control) signals heat requirement
Vent damper (if installed) opens.
Ignition spark generator operates
• ignition gas valve opens.
Ignition flame burns, automatic
ignition signals steady ignition
flame.
Pilot flame stand by
• ignition spark generator stops.
• main gas solenoid valve opens.
Main burner operation
• pilot assembly monitors ignition flame.
Specified thermostat value (control) reached
Main and ignition gas valves close, gas burners ex-
tinguished, vent damper (if installed) closes.
Ignition burner operation
or ignition flame does not burn,
pilot assembly starts ignition at-
tempt, switches off after 90
seconds.
Power interruption
System switches off. Does
the system restart when
power is restored?
Pilot flame fault
Main gas valve closes,
ignition module starts
ignition attempt.
6 720 804 440-53
Logano G234X – 6 720 804 886 (2012/08)