Ariston SUPERLUX 15 PL 3100597 - Инструкция по эксплуатации - Страница 16

16

EN

Anti-legionella recommendations (European standard CEN/TR 16355)

Information

Legionella is a small bacterium, of stick-like form, and is found naturally in fresh water.
Legionnaire's disease is a serious pulmonary infection caused by inhalation of the 

Legionella pneumophilia bacterium

and other species of 

Legionella. The bacterium is frequently to be found in the plumbing of houses, hotels and water

used in A/C and air cooling systems. The most effective measure against infection is to prevent the bacterium proliferating
in water circuits.
European standard CEN/TR 16355 provides guidelines for preventing the proliferation of Legionella in drinking water
systems, without substituting applicable local legislation.

General recommendations

“Conditions favourable to the proliferation of Legionella”. The following conditions are favourable to the proliferation
of Legionella:
•

Water temperature in the range 25 - 50 

°

C. To reduce the proliferation of Legionella, the water temperature be

kept with these limits to prevent them growing or reduce their growth to a minimum. If this is not possible, the
drinking water system must be sanitised thermally;

•

Stagnant water. To prevent water stagnating for a long time, the drinking water system must be flushed or made

to run abundantly at least once a week;

•

Nutrients, biofilms and sediment in the circuit, including boilers, etc. Sediment may promote the proliferation of

Legionella and should be regularly eliminated from water storage devices, boilers and expansion/holding tanks
(for instance, once a year).

As regards storage heater like the present, if:

1)

 the appliance is switched off for several months at a time or

2)

 the water temperature is kept constant in the range 25 - 50

°

C,

the Legionella bacterium may grow inside the tank. If such circumstances, to reduce the proliferation of the bacterium,
one must run a thermal sanitisation cycle.
This cycle is suited to use in domestic hot water systems and complies with the guidelines for the prevention of
Legionella given in Table 2 of standard CEN/TR 16355 (see below).

Table 2 - Types of hot water system

Separate hot and cold water

Mixed hot and cold water

No

storage

Storage

No storage

upline of the
mixer valves

Storage upline

of the mixer

valves

No storage

upline of the
mixer valves

No

circulation

of hot water

Circulation

of hot water

No

circulation

of mixed

water

Circulation

of mixed

water

No

circulation

of mixed

water

Circulation

of mixed

water

No

circulation

of mixed

water

Circulation

of mixed

water

No

circulation

of mixed

water

Circulation

of mixed

water

Ref. in

Enclosure C

Temperature

Stagnation

Sediment

C.1

-

-

-

C.1

-

-

-

C.2

≥

 50 

°

C 

e

≤

 3 l 

b

-

C.2

-

C.3

in

storage

heater

a

-

remove

c

C.2

C.4

≥

 50 

°

C 

e

≤

 3 l 

b

remove

c

C.4

C.5

thermal

disinfection

d

-

-

-

C.5

-

-

C.6

thermal

disinfection

d

≤

 3 l 

b

-

C.6

-

C.7

in

storage

heater

a

-

remove

c

C.7

-

C.8

≥

 50 

°

C 

e

thermal

disinfection

d

≤

 3 l 

b

remove

c

C.6

-

thermal

disinfection

d

C.9

-

-

C.9

-

-

thermal

disinfection

d

C.10

≤

 3 l 

b

-

a Temperature 

≥

 55

°

C all day or at least 1h a day 

≥

60

°

C.

b Volume of water contained in the pipes between the circulation system and the most distant tap.
c Remove the sediment from the storage heater as required by local conditions, but no less frequently than once a year.
d Thermal disinfection for 20 minutes at 60

°

C, for 10 minutes at 65

°

C or 5 minutes at 70 

°

C at all delivery points at least once

a week.

e The water temperature in the circulation circuit may not fall below 50

°

C.

-

Not required

This storage water heater is sold with a thermal disinfection cycle function not enabled for default; as a consequence,
if, for any reason, one of the above said “Conditions for Legionella growth” could occur; it’s hardly recommended to
enable such function rotating the knob up to maximum water temperature (>60

°

C).

However, the thermal disinfection cycle does not kill all Legionella bacteria in the storage tank. It follows that if the
water temperature setting is less than 55

°

C, the Legionella bacterium infection may reoccur.

Caution:

the water temperature in the tank can cause immediate serious burns. Children, disabled persons and
the aged are particularly at risk of burns. Check the water temperature before taking a bath or shower.