described above taking care to
respect the indicated measure-
ments.
4.7.3 Substitution of nozzle (fig. 18)
The nozzle should be substituted at
the beginning of every heating system
for guaranteeing the correct fuel flow
and a good spray efficiency.
The nozzle is substituted in the follow-
ing manner:
– Disconnect the high tension cables
from the electrodes.
– Loosen the fixture screw (A fig. 17)
of t he electr odes suppor t and
remove it.
– Block the spray door using a n°19
spanner and unscrew the nozzle
with a n°16 spanner (fig. 18).
4.8
FAULT FINDING
There follow a list of some reasons
and the possible remedies for a series
74
of faults which could happen causing a
failure or an irregular function of the
appliance. A function fault, in most
cases, causes the "lock out" signal on
the control panel to turn on.
When this light turns on, the burner
can only function again after the reset
button has been pressed; once this
has been done and a regular ignition
occurs, the failure can be defined
momentary and not dangerous.
On the contrary, if the "lock out" per-
sists, then the cause of the fault as
well as the remedy must be looked for
in the following faults:
The burner does not ignite
– Check the electric connections.
– Check the regular fuel flow, the
cleanness of the filters, of the nozzle
and air vent from the tube.
– Check the regular spark ignition and
the proper function of the burner.
The burner ignites regularly but the
flame goes out immediately
– Check the flame detection, the air
calibration and the function of the
appliance.
Difficulty in regulating the burner
and/or lack of yield
– Check: the regular flow of fuel, the
cleanness of the boiler, the non
Fig. 18
obstruction of the smoke duct, the
real input supplied by the burner
and its cleanness (dust).
The boiler gets dirty easily
– Check the burner regulator (smoke
analysis), the fuel quantity, the flue
obstruction and the cleanness of
the air duct of the burner (dust).
The boiler does not heat up
– Control the cleanness of the shell,
the matching, the adjustment, the
burner per formances, the pre-
adjusted temperature, the correct
function and position of the regula-
tion stat.
– Make sure that the boiler is suffi-
ciently powerful for the appliance.
Smell of unburnt products
– Control the cleanness of the boiler
shell and the flue, the airtightness of
the boiler and of the flue ducts (door,
combustion chamber, smoke ducts,
flue, washers).
– Control the quality of the fuel.
Frequent intervention of the boiler
shutoff valve
– Control the presence of air in the
system, the function of the circula-
tion pumps.
– Check the load pressure of the appli-
ance, the efficiency of the expansion
tanks and the valve calibration.