Ariston CLAS HE SYSTEM 24 Installation And Servicing Instructions page 70

user' manual
Appliance shut-off conditions
The boiler is protected from malfunctions by means of internal
checks performed by the electronic P.C.B., which stops the boiler
from operating if necessary. In the event of the boiler being shut off
in this manner, a code appears on the control panel display which
refers to the type of shut-off and the reason behind it.
Two types of shut-off may occur:
Safety shut-off
This type of error is "volatile", which means
that the boiler starts up again automatically
as soon as the problem which caused the
shut-off is removed. The display will flash
"Err" and the error code.
In fact, as soon as the cause of the shut-off disappears, the boiler
starts up again and continues to operate normally.
While the boiler is shut off for safety reasons, it is possible to attempt
to restore normal operation by switching the appliance off and on
again using the ON/OFF button on the control panel.
If the boiler still indicates a safety shut-off, switch it off. Make sure
the external electric switch is in the OFF position, close the gas tap
and contact a qualified technician.
Safety shut-off due to insufficient water pressure
If the water pressure inside the heating circuit is insufficient, the
boiler will perform a safety shut-off. (See table).
Operation shutdown
This type of error is "non volatile", which means that it is not
removed automatically. The display will flash Err and the error
code and the red led lights up ""
In this case the boiler does not restart automatically, but it may
be reset by pressing the
itself again after several attempts to reset the appliance, contact a
qualified technician.
IMPORTANT
IF THIS SHUTDOWN OCCURS FREQUENTLY, CONTACT AN
AUTHORISED SERVICE CENTRE FOR ASSISTANCE. FOR SAFETY
REASONS, THE BOILER WILL ALLOW A MAXIMUM OF 5 RESET
OPERATIONS TO TAKE PLACE IN 15 MINUTES (INDIVIDUAL
PRESSES OF THE BUTTON).
Maintenance
Schedule an annual maintenance check-up for the boiler with a
competent person.
Correct maintenance always results in savings in the cost of
running the system.
Failure to arrange an annual service for the appliance will invalidate
the second year of the manufacturers guarantee.
6
.
button. If the problem manifests
Operation shutdown error table
Display Description
1 01 Overheating
5 01 No flame detection
1 0
1 04
1 05
Insufficient circulation
1 06
1 07
 05 P.C.B error
 06 P.C.B error
 07 P.C.B error
Anti-frost Device.
The anti-frost function acts on the central heating flow temperature probe,
independently from other settings, when the electrical supply is turned
on.
If the primary circuit temperature falls below 8°C the pump will run for 
minutes.
After the two minutes of circulation (fixed) the boiler will check the fol-
lowing:
a) if the central heating flow temperature is > 8°C, the pump stops;
b) if the central heating flow temperature is between 4 and 8°C, the pump
will run for another two minutes;
c) if the central heating flow temperature is < 4°C, the burner will fire
(heating position) at minimum power until the temperature reaches
°C, the burner will go off and the pump will continue to run for two
minutes.
The anti-frost device activates only when (with the boiler operating cor-
rectly):
- the system pressure is correct,
- the boiler is electrically powered,
- there is a supply of gas.
Auto button - Temperature adjustment activation
The AUTO function enables boiler operation to be adapted to
environmental conditions and to the type of system it is installed
on.
Comfortable temperature is reached inside the room in the quickest
way possible, without wasting money, energy or efficiency, while
substantially reducing the amount of wear experienced by the
components.
Your installer will advise you on the devices connectable to
the boiler and will program it according to the system.
In normal boilers the water temperature inside the heating elements
is usually set to a high value (70-80°C), thereby ensuring effective
heating during the few really cold winter days. It then becomes
excessive on less cold days (of which there are many) more typical
of the autumn and winter seasons. This leads to excessive room
heating after the thermostat has been switched off, resulting in
energy waste and uncomfortable conditions inside the room.
The AUTO function "takes control" of the boiler and selects the best
operating regime based on environmental conditions, external
devices connected to the boiler and the performance required. It
constantly decides at which power level to operate based on the
environmental conditions and the room temperature required.