ANTI-LEGIONELLA MANAGEMENT

Owned by Marco Serpelloni
Last updated: Sept 25, 2023
3 min read

The Legionella prevention cycle allows the domestic hot water storage tank to be brought to a higher temperature than the one at which it is normally maintained.

Within the REG system there is a program dedicated to the legionella prevention within the DHW page:

For the legionella prevention to be activated, it is necessary:

  • Enable the domestic hot water in Configuration 1

  • Associate a temperature probe in the DHW page as shown in the first image (for this example we take a constant value)

  • Set a legionella prevention set point (for example, 60/65/70°C)

  • Assign a timetable to the legionella prevention

It should be remembered that is it sufficient in the case of simple houses that the legionella prevention cycle is carried out once a week, therefore a hypothetical timetable may appear like this one below:

The legionella prevention is only activated when its timetable is in Comfort, if it is not in Comfort mode, the DHW set point follows the timetable associated with the DHW subsystem, if present.

Warning

When the legionella prevention is activated, the work mode is Antifreeze, it is not an error, but it is the only free work mode, as the Economy and Comfort set point are already used in “normal” functioning.

This does not affect the functionalities of the system if no manifold is associated with DHW: in this case, the new set point is sent directly to the generators on the OpenTherm page.

On the other hand, if there is an associated circuit, e.g., C8:

It will be necessary to set the antifreeze set of the circuit to at least 70°C in order to correctly transfer the set point to the source that must satisfy the request:

Finally, there is a digital output that is activated when the legionella prevention is activated (legionella prevention timetable in comfort) that can be used to activate an additional booster heater, a boiler or other source that can get to the legionella prevention set point: