Siemens Building Technologies
HVAC Products
23
Function block "Legionella function"
In the case of d.h.w. heating systems with storage tanks, this function prevents the
formation of legionella viruses. This is accomplished by periodically heating the d.h.w.
to a certain temperature level.
23.1 Operating lines
Line Function, parameter
147
Periodicity of the legionella function
148
Time of legionella function
149
Dwelling time at legionella setpoint
150
Circulating pump operation during the legionella function
23.1.1
Periodicity of legionella function
The periodicity is displayed on operating line 147.
• Setting "0" ensures that d.h.w. heating to the legionella setpoint takes place once a day
• Settings "1" through "7" ensure that d.h.w. heating to the legionella setpoint takes place
once a week. Setting "1" means every week on Monday, setting "2" every week on
Tuesday, etc.
23.1.2
Time of legionella function
The time of day the legionella function shall be activated can be set on operating line
148.
23.1.3
Dwelling time at the legionella setpoint
Operating line 149 is used to determine for what period of time the actual d.h.w. tem-
perature must lie above the legionella setpoint (operating line 130) to satisfy the re-
quirement of this function.
23.1.4
Circulating pump operation during the legionella func-
tion
Operating line 150 can be used to select whether the legionella function shall act on the
d.h.w. circulating pump.
• When choosing "0", the legionella function does not act on the d.h.w. circulating pump
• When choosing "1", the legionella function acts on the d.h.w. circulating pump
23.2 Mode of operation
Preconditions for the legionella function:
• The d.h.w. storage tank temperature is acquired with one or 2 sensors (the legionella
function is not possible with thermostats)
• Charging takes place instantaneously with the heating water and not with the electric
immersion heater
• A legionella setpoint is adjusted
• D.h.w. heating is switched on (button
• The holiday function and operating mode changeover via contact H1 are not active
Basic Documentation RVL471
23 Function block "Legionella function"
Unit
Factory
setting
hh:mm
min
lit)
Range
1
0...7
05:00
00:00...24.00
30
0...360
1
0 / 1
81/118
CE1P2524E
23.10.2002