Ariston CLAS - Page 13

Manuale didattico CLAS
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Manuale Didattico – ACO
FLAME
MODULATION
Produced till 31/07/2008
Modulation occurs between the value of the
sanitary maximum power (set on the gas
valve) and the value of the minimum power
(also set on the gas valve).
The burner runs until the scale prevention
temperature is reached. The temperature is
checked by the sanitary probe NTCs .
Produced from 01/08/2008
Modulation occurs between the value of the
sanitary maximum power (set on the gas
valve) and the value of the minimum power
(also set on the gas valve).
The burner runs until the scale prevention
temperature is reached. The temperature is
checked by the return probe NTC2 .
Performed from the thermostat with
automatic reset (102±4°C) located on heating
delivery, (even while the burner if off). After
opening the thermostat a safety shot down
occurs (not indicated) and after 5 sec if the
thermostat is already open a block shutdown
of the boiler occurs (non volatile), indicated
on the display with 1 01.
Overheat control
To reduce the formation of scale in the
secondary exchanger.
During the D.H.W. mode the switch off and
switch on of the burner depends on the
following values of temperature:
T set
Antilime
temp.
limit
RE-
START
NTC1
(delivery probe)
Non
influente
85°C
81°C
NTCs
(sanitary probe)
NTC2
(return probe
from
01/08/2008)
> 52°C
65°C
64°C
<52°C
62°C
61°C
SCALE
PREVENTION
temperature
NORMAL BOILER OPERATION
N.B.: The sanitary switch-off logic could be changed by the parameter 2 53:
– 0 : Anti-scale (62 o 65°C)  default
– 1 : Set-point + 4°C