32
Protective functions
6.7. - Anti-Legionella
Caution
Danger
Caution
With the “AL function” activated the STDC makes it possible to heat the storage tank
up to a higher temperature (“AL Tsetpoint S2”, provided that the energy source allows
this. Time periods where the AL heat up is attempted are to be setup in the menu “AL
times” Once the temperature “AL Tset S2” is reached, the controller will try to maintain
this temperature for the time period set in “AL residence time”. When this happened,
the time and date is saved and displayed in the menulog “AL heat”.
AL Function settings range: on / off / Default: off
AL Tset S2 (Thermostat uses both S1 and S2) settings range: 60°C to 99°C /
Default: 70°C
AL residence time - settings range: 1 to 60 minutes / Default: 15 minutes
AL heat. (no setting): Displays the date and time of the last successful AL heat up
AL times - settings range: Mo-Su , 0-24h/ Default: daily 3-5h
During the anti-Legionella function the storage tank is heated up
over the set value “Tmax S2”, which can lead to scalding and
damage to the system.
This anti-Legionella function does not provide complete protection
against Legionella, because the controller is dependent on suffi cient
energy being fed in, and it is not possible to monitor the temperatures 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.
For solar:
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 being switched on, an information message with the
date is shown in the display.
For thermostat:
S1 is used as switch-off sensor. When both S1 and S2
are connected, they both have to reach AL Tset S1 to successfully fi nish
the AL heat up.
