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6.
FAULTS / SOLUTIONS
Here below you can find some causes and the possible solutions for some problems that could cause a fail-
ure to start or a bad working of the burner. A fault usually makes the lock-out lamp light which is situated
inside the reset button of the control box (9, fig. 1, page 1).
When lock out lamp lights the burner will attempt to light only after pushing the reset button. After this if the
burner functions correctly, the lock-out can be attributed to a temporary fault.
If however the lock out continues the cause must be determined and the solution found.
BURNER STARTING DIFFICULTIES
FAULTS
The burner does not start at
the limit thermostat closing.
The burner does not pass
through the pre-purge and
locks out.
The burner locks out, after the
pre-purge period, because the
flame does not ignite.
The burner goes through the
normal pre-purge, the flame ig-
nites but the burner locks out
within 3 seconds after ignition.
The burner continues to re-
peat the starting cycle without
locking out.
N.B.: If problems still occur after all of the above checks have been made, check the electrical connec-
tions on the plug and sockets, the damper and burner motor, gas control wiring ignition transformer
and external interlocks, if the burner still fails to function, replace the control box.
2728
Gas is not supplied.
The actuator is faulty. Replace.
The gas pressure switch does not close its contact due to incorrect setting
or a faulty switch.
The air pressure switch has changed over to the operational position.
The air pressure switch does not change over: it has failed or the air pres-
sure is too low (combustion head incorrectly set).
Flame simulation exists (or the flame really lights).
The gas valve pass too little gas (low pressure in the gas pipework).
The valves are faulty.
The ignition arc is irregular or not present.
The air has not been purged from the pipe.
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 ionization current is weak (lower than 3 µA). (See chapter 4.7).
The gas pressure switch is set too close to its working-pressure.
This concerns a very particular irregularity, caused by the fact that the
pressure in the gas mains is very close to the value to which the gas pres-
sure switch has been set.
Consequently, the sudden falling off in pressure at the opening of the valves
causes the pressure switch to open, the valves immediately close and the
motor stops.
The pressure then increases, the pressure switch closes and the starting
cycle can be repeated, and so on.
This can be remedied by lowering the setting of the pressure switch.
11 GB
SOLUTIONS
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