37
│
Meanwhile, the heated water from the boiler gradually fills the pipes and the upper part of the
thermal store. When the temperature at the upper sensor of the thermal store reaches the
set value, the heating system pump is activated and pumps the heated water into the heating
system.
As soon as cold water reaches the upper sensor of the thermal store, the system pump
stops again and the process repeats. Only water heated by the boiler enters the system and
is mixed to the desired temperature by the heating system mixing valve. More significant
heating of the thermal store starts to occur as soon as the boiler output exceeds that of the
heating system.
TIP:
By placing the sensor from the upper part of the thermal store (S2) to the outlet pipe
from the load unit to the thermal store (instead of into the thermal store), hot water does not
enter the thermal store and in case of quick heat, space heating gets priority over the DHW
heating.
However, the condition is that a sensor must also be installed in the lower part of the
thermal store and the boiler pump control must be set towards this sensor. If a heating
element is used for space heating, it shall have both a safety and an adjustable thermostat
(it is recommended to set it to the maximum temperature required for heating).
6.2. Frost protection
If the outdoor temperature drops below 1 °C and the heating circuit is turned off, the frost
protection will keep the min. flow temperature at the value set by (5.1.9.).
Warning: Switching the frost protection function off or setting the minimum flow
temperature too low can lead to severe damage to the system!
6.3. Protection against cold water circulation through heating circuit
If the discharge protection is active (6.3.1.=On) and the temperature at the thermal store
sensor or heating water temperature drops below the min. temperature of the heating circuit
(6.3.2.), the mixing valve of the heating circuit will close and the circulation pump will stop.
This will prevent insufficiently warm water from useless circulating in the heating circuit.
7.2.6. PWM maximum
Setting the head of the heating circuit pump. The lower is the set PWM value, the higher is
the pump head – see the values in the table.
Head [m]
8.4
8
7
6
5
4
3
2
1
PWM maximum [%]
5
7
13
18
27
35
44
55
68