4.2.5
Settings and safety devices
Important
The settings and safety devices are only operational if the boiler is
powered up.
Tab.10 Description of the safety devices
Device
Description
Safety thermostats
The safety thermostats suspend the supply of gas to the burner if the water in the pri
mary circuit overheats. To resume normal operation of the boiler, eliminate the cause of
this interruption.
Caution
The safety thermostats must in no circumstances be switched off or
disconnected.
NTC flue gas sensor
The control panel blocks the gas supply to the burner in the event of overheating. To
resume normal operation of the boiler, switch off the boiler and switch it back on again
with the ON/OFF switch.
Flame detector by ionisation
The boiler is put into safety shut-down in the event of gas shortage or incomplete inter
ignition on the burner.
Hydraulic pressure switch
Thanks to this device, the burner can only operate if the system pressure is higher than
0.5 bar (0.05 MPa).
When the pressure switch detects a pressure lower than 0.8 bar (0.08 MPa), a warning
message is displayed, without stopping the circulating pump.
Post-circulating pump
After the burner stops, depending on the room thermostat setting and if in heating
mode, the circulating pump runs for a further 3 minutes.
Frost protection device
When the flow temperature is lower than 5°C, the burner starts up and runs until the
flow temperature reaches 15°C. This device runs under the following conditions:
The boiler is switched on
The gas supply is working
The pressure in the system is higher than 0.5 bar (0,05 MPa)
Anti-blocking of the pump
If there are no heating or domestic hot water requirements for 24 consecutive hours, the
pumps start up automatically and run for 10 seconds.
The pumps connected directly to the appliance's terminal blocks are started up every
Friday at 10:00 a.m. and run for 30 seconds.
Anticipatory start-up of the circulat
ing pumps
In heating mode only, the appliance can start up the circulating pumps before burner ig
nition. The duration and activation of anticipatory start-up depends on the conditions of
installation and the operating temperatures. The duration of anticipatory start-up of the
circulating pumps therefore varies from a few seconds to several minutes.
4 Description of the product
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7609493 - v08 - 24072018
