Instruction Manual
12
The heating process for domestic water:
When the water temperature sensor of the hot water tank detects that the temperature is 5
°
C lower than the set value
(see section 5.5.2), the process of pumping water to the central heating system is stopped. The process for heating domestic
water with a boiler connected to the domestic hot water tank starts as follows:
•
the water temperature sensor detects that the temperature is 5
°
C lower than the set value (for example, as a result of
opening a tap);
•
the boiler controller switches the three-way valve to pump water to the hot water tank circuit while giving a signal to
the spark generator and gas valve (item 8);
•
heating water with temperature described by parameter P21 (default 75
°
C) flows through the coil of the tank (short
circuit);
•
after exceeding the set water temperature in the tank by 1
°
C, the boiler controller switches the 3-way valve to the
hydronic heating circuit. After meeting the below-mentioned conditions, the heating water is pumped into the central
heating system:
•
heating water temperature is 5
°
C lower than the set temperature
•
room temperature regulator gives a signal “HEAT”.
The temperature of hot water at the point of consumption may be different from the set value, and therefore it is advisable
to install a mixing/ tempering valve for domestic hot water systems.
Water heating in the hot water tank is active when the electrical bridge is mounted on the TANK-TIMER input (Fig. 3.9.1.)
and when the set temperature value is higher or equal to the minimum value. If the value is set lower than the minimum,
the hot water tank circuit is closed. This does not apply for frost protection function.
NOTE!
To eradicate Legionella bacteria in the storage tank, the boiler is turned on every 168 h and the water in the tank
is heated to 65
°
C. If the Legionella function does not work in automatic mode, the user at any time can manually initiate a
single cycle of tank heating to 65
°
C.
2.4.3.1 Manual initiation of domestic tank overheating - Anti-Legionella function in manual mode
* (applies to the boilers with tanks):
If the boiler is operating in SUMMER mode:
Press the
button twice. The first press of the button shows (ready to modify) option C.H. setting on the control panel’s
display. Pressing the button a second time displays the symbols characteristic of Legionella Function; a flashing key symbol
on the right of the display, on the left side, you can see the DHW temperature and the symbol MAX placed above it. See Fig.
5.2.1 for an illustration of the control panel display.
If the boiler is operating in WINTER MODE:
Press the
button three times. Pressing the button the first time shows (ready to modify) option C.H. setting on display.
Pressing the button a second time displays the symbols characteristic of the Service Function. The third press of the button
displays the symbols characteristic of the Legionella Function.
In both modes of operation:
To activate the Legionella function, hold the “+” button for 2 seconds. After activation, the symbol ‘key’ will light up with a
solid light. You have about 3 seconds to complete the Legionella function activation. After this time, or when you press the
reset button, the system goes to the “selection of operation mode” (winter or summer).
During the implementation of Legionella Function, the temperature field (on the left side) is dimmed.
2.4.4 Operation of the pump with adjustable speed.
For boilers equipped with a variable speed pump (PWM) while operating in DHW mode the pump speed is determined by
parameter P19.
