4.2.2
Combustion
The burner heats the heating water circulating in the heat exchanger. When the temperature of the combustion gas is lower
than the dew point (around 55 °C), the water vapour contained in the combustion gas condenses in the flue gas side of the heat
exchanger. The heat recovered during this condensation process (the latent heat or condensing heat) is also transferred to the
heating water. Once cooled, the combustion gases are discharged through the exhaust pipe. The condensed water is
discharged through a siphon.
4.2.3
Heating and domestic hot water production
In boilers used for heating and domestic hot water production, the domestic water is heated by an integrated water plate to plate
heat exchanger. A three-way valve delivers the hot water to the central heating system or to the domestic hot water plate to
plate heat exchanger. A flow sensor detects that a hot water tap has been turned on and communicates this to the PCB, which
switches the three-way valve to the hot water position and activates the pump.
In "heating only" boilers, the heated water is delivered to the heating system or, if present and if requested, to a domestic hot
water tank. A temperature sensor sends the heat request signal from the DHW tank to the power circuit board which switches
the three-way valve to the DHW position and operates the pump.
The three-way valve is a spring valve type and it consumes electricity only switching from one position to another. Priority is
given to a heat request in domestic water mode.
4.3
Control panel description
4.3.1
Description
Fig.15
Key descriptions
F1
F2
1
7804840 - 02 - 20012022
Tab.44
F3
F4
2
BO-0000243
Tab.45
HEATING AND DHW KEYS
HEATING: press the F1 key to set the flow temperature for the
heating installation (heating setpoint 25÷80 °C).
press the F2 key to reduce the temperature;
press the F3 key to increase the temperature;
DOMESTIC HOT WATER: press the F2 key to set the domestic hot
water temperature (heating setpoint 35÷60 °C).
press the F2 key to reduce the temperature;
press the F3 key to increase the temperature;
KEYS
F1
Manual reset/Esc: Return to the previous level.
Decreases the selected value/Scrolling through the menu bar to the
F2
left.
Increases the selected value/Scrolling through the menu bar to the
F3
right.
F4
Enter key: Confirms selection or value.
Chimney sweep function keys
1
Important
Press the F1 and F2 keys simultaneously
Menu keys
2
Important
Press the F3 and F4 keys simultaneously
4 Description of the product
INIDENS
en
55