Supplied By www.heating spares.co Tel. 0161 620 6677
30
DOMINA PLUS F 24 - 30 E
FERELLA EXTRA F 24 - 30 MEL
Version - 09.2002
3. OPERATION
3.1 Operating principle.
The boiler is designed to function with two types of gas: Natural Gas or LPG. It works with systems on the
cutting edge of technology as it uses sophisticated software with a double processor governing the
modulation, power, control and safety equipment. On powering up the boiler from the mains for the first time,
the display will show in succession: 88.-LO-14-HI-06-EO-14 that represent the software release of the
processor for low (LO) and high (HI) voltage and the memories (EO). Lastly, the boiler will go onto stand-by,
with LED 5 on and the delivery temperature on the display.
When there is a call for heating, the circulator and fan start working; then the air pressure switch enables the
control and safety unit to ignite the burner. Via the electronic flame modulation system, the boiler capacity
is gradually metered till it reaches the set delivery temperature. If the power needed for the heating plant is
lower than the minimum boiler power, when the delivery temperature exceeds the setting of 6°C, the burner
switches off and the electronic system enables re-ignition only after another 2 minutes. On reaching the set
ambient temperature (room thermostat), the burner switches off and the circulator keeps on working for
another 6 minutes to enable better heat distribution throughout the system. If the remote control (Ferroli) is
used, the system will try to modulate the ambient temperature according to the setting. In this passage the
remote control can lower the delivery temperature under the setting to maintain the ambient temperature: in
any case, if the ambient temperature exceeds the remote control setting by 1°C the burner switches off and
the circulator stays on for post-circulation.
If hot tap water is drawn off during the heating phase, the electrical heating circuit automatically turns off and
the hot tap water production circuit switches on.
Throughout this phase the heating system circulator stops and the boiler delivers water at the set temperature.
The boiler keeps the tap water temperature constant by means of flame modulation, even when different
quantities are drawn off.
Diagnosis characteristics: the boiler shows the type of trouble directly on the display with an identification
code.
Slow ignition for heating
The power in the ignition phase (10s) is 50% (adjustable) and the increase in temperature is gradual
(10°C/minute - adjustable from 1 to 20°C).
Circulator anti-locking
If not used for 24 h, the heating circulator is turned on for a few seconds to prevent it locking due to an extended
stoppage.
Antifreeze protection
With the heating temperature sensor, if the temperature falls under 5°C, the boiler starts working normally
to then switch off when the temperature exceeds 15°C, and the circulator keeps on working for another
6 minutes. This protection is active even if the boiler is switched off from the control panel.
Tap water circuit antifreeze protection
It is possible to ensure antifreeze protection for the tap water circuit with the 4 heating elements of 10W - 230V
connected to terminal X2 of the control unit. The antifreeze thermostat is connected in series with the heating
elements. The protection is activated when the temperature falls under 5°C and it turns off above 15°C.
