Faults
The burner locks out during the
pre-purge phase.
The burner continues to re-
peat the starting cycle without
going on lockout.
8.2
Operating faults
Fault
The burner locks out during op-
eration.
The burner tends to lose the
flame in the passage from the
1st to 2nd stage.
Burner shut down.
20141174
Faults - Possible causes - Solutions
Possible Causes
The air pressure switch does not change over
to the operational position.
The flame exists.
The gas pressure in the gas-mains lies very
close to the value to which the gas pressure
switch has been set.
The sudden drop in pressure when the valve is
opened provokes the opening of the pressure
switch itself, so the valve closes again immedi-
ately and the motor stops.
The pressure then starts to increase again, the
pressure switch closes, the start-up cycle be-
gins again and so on.
Possible Causes
Earth probe.
The flame disappears 4 times.
Air pressure switch opening.
Burner output ratio between the 1st and 2nd
greater than 1:2.
High air excess in 1st stage.
Gas pressure switch opening.
Solution
The pressure switch is faulty, replace it.
The air pressure is too low, (the head is bad adjust-
ed).
Faulty valves: replace them.
Lower and set the pressure switch.
Solution
Check the right position and if necessary set it ac-
cording to the instructions of this manual.
Clean or replace the ionisation probe.
Check the gas pressure in the network and/or ad-
just the solenoid valve according to the instruc-
tions of this manual.
The air pressure is too low, (the head is bad adjust-
ed).
The air pressure switch is defective: change it.
Restore the correct maximum ratio of 1:2 checking
that the burner output of the 1st stage is not less
than the minimum of the firing rate.
Reset the correct air excess value (l min. = 1.3)
see paragraph "4.4 combustion control".
Check the pressure in the network and/or adjust
the solenoid valve according to the instructions of
this manual.
38
GB
Tab. S
Tab. T