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98318_201204
Assistance Service to repair the fault.
MAINTENANCE
The burners do not require particular servicing. It is good practice,
however, to perform the following operations, at least at the end of
the heating season:
1) Disassemble the filters, nozzle, turbulator disk and the
ignition electrodes and clean thoroughly with solvents (petrol,
trichloroethylene, oil). Avoid using metallic tools to clean the
nozzle (use wood or plastic).
2) Clean the photocell.
3) Have the boiler cleaned and the chimney as well, if necessary.
Note:
The nozzle or nozzles should be replaced at least every
two heating seasons. The replacement might be required more
frequently.
DESCRIPTION OF THE TWO-STAGE
BURNER OPERATION
The two stage burner always ignites with a limited amount of air and
fuel (1
st
flame) and, subsequently, after a few seconds, it will switch
to full air and fuel operation (2
nd
flame).
The ignition of the 2
nd
flame is subject to the authorisation of the
control box and control device (pressure switch or thermostat).
When the burner works at full rate it will remain in this position until
it reaches the pressure or temperature limit pre-set on the control
device (pressure switch or thermostat). The control device trips,
disconnecting the 2
nd
flame (fuel and air), when the limit to which it
has been pre-set is reached. Then the burner works only with the
1
st
flame.
Normally the 1
st
flame alone is not sufficient to keep the temperature
or the pressure at the required limit, and so it will decrease until it
reaches the limit to which the control device of the 2
nd
flame (pressure
switch or thermostat) re-activates the total fuel and air delivery rate.
If the burner operates only with the 1
st
flame, it will stop completely
when the pressure or the temperature reaches the tripping point set
on the control device (pressure switch or thermostat).
The burner starts up automatically again when the pressure or
temperature falls below the limit to which the pressure switch or
thermostat has been pre-set.
Note:
It is normally not advisable to connect a burner working on
a boiler for heating water for two-flame working. In this case
the burner works (sometimes for long periods of time) with one
flame alone, the boiler is insufficiently loaded and consequently
the fuels come out at an extremely low temperature (lower than
180°C) generating soot at the chimney outlet. In addition, when
the boiler is working at lower output than that indicated in the
technical data, it is likely that acidic condensate and soot will
form in the boiler, causing corrosion and clogging. When the
two-flame burner is installed on a hot water boiler for heating
use, it must be connected so that it works normally with both
flames, completely stopping without passing to the first flame
when the pre-set temperature is reached. In order for it to work
in this way, do not install the second flame thermostat, and make
a direct bridge connection between the equipment terminals.
This ensures that only the capability of the burner to ignite at
low capacity is used for a gentle ignition, which is essential for
boilers with a pressurised combustion chamber and also very
useful for normal boilers with depression combustion chamber.
The ignition start/stop command is subject to the usual operating
or safety thermostats.
