Ferroli Xignal Service Instructions Manual page 5

GENERAL DESCRIPTION GENERAL DESCRIPTION GENERAL DESCRIPTION
GENERAL DESCRIPTION GENERAL DESCRIPTION
The boiler is able to operate with two types of fuel gas: natural or propane (L.P.G.). The type of gas should
be chosen when the boiler is ordered. Conversions can also be carried out during the installation phase
.The boiler is controlled by an internal microcomputer and all settings to the regulating systems are carried
out on the assembly line by use of software. This ensures that the set values always remain absolutely
accurate throughout plant use
The user may program and select the various options through the control panel. These functions include
summer/winter operation, choice of the sanitary water temperature and that of the plant delivery, daily
program setting and activation, boiler release.
The heating function is only activated when Winter operation is selected (key
handles the heating function either according to the set daily program or according to the temperature
set on the knob of the ambient unit. In both cases, the demand for heat will activate the circulation pump,
the fan and the electronic equipment to start the burner. The burner ignites at a power value that will have
been preset according to the fuelling gas. If the pressure in the heating system is less than 0.5 bar or more
than 2.5 bar, the microcomputer will prevent boiler operation for safety reasons.
During operation, the plant delivery temperature is regulated according to the external temperature
(detected by the relative probe). Temperature regulation will be proportional to the compensating curve
set on installation according to the structural characteristics of both the building and system.
When the temperature of the water in the boiler approaches the value established by the computer, the
valve will reduce the amount of gas (modulating) delivered to the main burner in order to keep the water
temperature near to the required value. If the water temperature reaches the preset value, the burner will
go out and will wait 2 minutes until igniting again. Having terminated the demand for heat, the burner
will stop while the circulator will continue to operate for six minutes so that the temperature is evenly
distributed throughout the system.
If hot water is used during the heating system, the microcomputer will detect this by means of the flowmeter
and will disactivate the heating function. This stops the circulator and activates hot water production. Hot
water is constantly maintained at the set value even during different water flow rates. This is due to a
correct establishment of the outlet flow of hot water and adequate modulation of the burner rating. Once
use of hot water ceases, the computer will wait for 2 minutes before re-activating the heating function.
Only hot water production is activated during "Summer" operation. However, the circulating pump of
the heating function will operate for 1 sec. at the end of each demand for water in order to prevent the
pump itself from sticking.
The microcomputer continuously checks that boiler operation is correct. In the event of faults, these are
immediately visualized (the display will flash) and notified by synthesized voice when the relative button
is depressed. Boiler operation will be inhibited until the fault is rectified or, in some cases, until the boiler
is manually reset.
All faults are memorized by the microcomputer together with the other operational parameters. This
enables the technical assistance service to proceed with a correct diagnosis.
). The microcomputer
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