BURNER STARTING DIFFICULTIES
DIFFICULTIES
The burner goes through the
pre-purge period normally,
the flame ignites, but the
burner goes to lock-out with-
in 5 seconds after the igni-
tion.
The burner goes to lock-out,
after the pre-purge period,
because the flame does not
ignite.
The burner does not pass
through the pre-purge period
and the control box goes to
lock-out.
The burner does not start at
the limit thermostat closing.
The burner continues to re-
peat the starting cycle with-
out going on lock-out.
OPERATING FAULTS
Re-cycle and lock-out may occur, because of : – Flame failure
The burner goes to lock-out because of . . . . .: – Opening of the air pressure switch
Burner stop because of . . . . . . . . . . . . . . . . . .: – Gas pressure switch opening
2773
The ionization probe is earthed or not in contact with the flame, or its
wiring to the control box is broken, or there is a fault on its insulation to
earth.
The connection of the phase and neutral leads has been inverted: you
need to exchange it.
The wiring to the earth is lacking or ineffective.
The valves are passing too little gas (low pressure in the gas pipe-
work).
The valves are defective.
It is irregular or the ignition arc is not present; in this case remove the
control box and insert it again, taking care that the electrode push-rod
is in the proper seat.
The pipe has not been purged from the air.
The air pressure switch does not change over: it has failed or the air
pressure is too low (combustion head bad set).
Flame simulation exists (or the flame really lights).
Gas is not supplied.
The gas pressure switch does not close its contact due to incorrect set-
ting or a faulty switch.
The air pressure switch is changed over to the operational position.
Before to replace the control box, check that short-circuits are not pres-
ent on the power-line: of the motor, of the gas electrovalve/s and on the
external signaling devices.
This concerns a very particular irregularity, caused by the fact that the
gas pressure in the gas-mains lies very close to the value to which the
gas pressure switch has been set.
As a result of this, the sudden falling-off of pressure at the opening of
the valves causes the opening of the pressure switch.
However this only temporarily, because the valves immediately close
again, so then does the pressure switch, because the pressure builds-
up again the cycle to be repeated over and over.
This can be remedied by lowering the setting of the pressure switch.
– Ionization probe earthed
8
GB
CAUSES