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11.5 Anti-Legionella
menus 6.5 / 6.5.1 - 6.5.3
With the “AL function” activated the TDC 4 makes it possible to heat the
storage tank up once at certain intervals (the “AL frequency”) to a higher tem-
perature (“AL Tsetpoint S2”), assuming that the energy source allows this.
AL function setting range: On or Off/default setting: Off
Caution
Danger
During the anti-Legionella function the storage tank is heated up
over the set value “Tmax S2”, which can lead to scalding and dam-
age to the system.
Caution
This anti-Legionella function does not provide complete protection
against Legionella, because the controller is dependent on sufficient
energy being fed in, and it is not possible to monitor the tempera-
tures in the entire range of the storage tanks and the connected
piping system. To provide complete protection against Legionella
bacteria, it must be ensured that the temperature is raised to the
necessary temperature, and at the same time there must be water
circulation in the storage tank and piping system by means of other
additional energy sources and control units.
The anti-Legionella function is switched off at delivery.
This function is only relevant for storage tanks where sensor 2 is
installed. Whenever heating-up has been carried out with the anti-
Legionella function switched on, an information message with the
date appears on the display.
AL Tsetpoint S2 setting range: from 60°C to 99°C/default setting: 70°C
AL frequency setting range: from 1 to 28 days/default setting: 7 days
Protective functions
menu 6
11
11
In hydraulic systems with solar when the recooling function is activated
excess energy from the storage tank is fed back into the collector. This
only takes place if the temperature in the storage tank is higher than the
value “Recool Tsetpoint” and the collector is at least 20°C cooler than the stor-
age tank and before the storage tank temperature has dropped below the
value “Recool Tsetpoint”. In systems with two storage tanks the setting
applies to both storage tanks.
Recooling setting range: on, off/default setting: off
Recooling Tsetpoint setting range: from 0°C to 99°C/default setting: 70°C
Caution
This function causes energy to be lost via the collector! The
recooling should only be activated in exceptional cases. For ex-
ample with solar protection variant V1, since the storage tank is
overheated here, or during holidays when no heat is used.
11.4 Recooling
menus 6.4 / 6.4.1 - 6.4.2