Ariston ABS VLS (VELIS) EVO PW 50 [18/28] In storage heate

Anti-legionella recommendations (European standard CEN/TR

16355)

Informative

Legionella are small rod shaped bacteria which are a natural constituent of all fresh waters.

Legionaries’ disease is a serious pneumonia infection caused by inhaling the bacteria Legionella pneu-

mophilia or other Legionella species. This bacterium is frequently found in domestic, hotel and other water

systems and in water used for air conditioning or air cooling system. Hence the main intervention against

the condition is prevention, through control of the organism in water systems.

The European standard CEN/TR 16355 gives recommendations for good practice concerning the preven-

Otherwise, it is necessary to disinfect a drinking water installation by means of a thermal treatment;

• stagnation of the water. To avoid long periods of stagnation, the water in every part of the drinking water

• nutrients, and sediment within the installation including water heaters, etc. Sediment can sup-

port the growth of Legionella bacteria and it should be removed on a regular basis from e.g. storage

Regarding to this storage water heater, if

1) the product is switched-off for a period of time [months] or

2) the water temperature is kept constant in the range 25 - 50°C and the Legionella bacteria could grow in

the tank. In such circumstances, reduce the proliferation of the bacteria by running a “thermal sanitisation

cycle”. Water heaters are sold with software that allows a “thermal sanitisation cycle” to be run when it is

activated in order to reduce the proliferation of Legionella in the tank. This cycle is suitable for domestic

valves

No

circulation

of hot water

Circulation

of hot water

No

circulation

of mixed

water

water

of mixed

water

No

Annex C

C.1 C.2 C.3 C.4 C.5 C.6 C.7 C.8 C.9 C.10

Temperature

- ≥ 50 °C

e

storage

≥ 50 °C

≥ 50 °C

e

thermal

disinfection

- ≤ 3 l

- ≤ 3 l

b

- ≤ 3 l

b

- ≤ 3 l

b

Sediment

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

Electromechanical water heaters are sold with the thermal sanitisation cycle disabled (default setting). If, for

some reason, any of the above “conditions in favour of the proliferation of Legionella” occurs, it is strongly

recommended to enable this function according to the instructions found in this manual [see <<Activating

the “thermal disinfection cycle” (anti-legionella)>>].

However, the thermal disinfection cycle does not kill all Legionella bacteria in the storage tank. It follows that

if the function is disabled, the Legionella bacteria may reoccur.

Note: when the software perfor