Innovative Features - Hotpoint Ariston LFF 825 IT Service Manual

4.4. INNOVATIVE FEATURES

Water filling:
When a programme starts, the first thing the dishwasher does is drain. Immediately afterwards, it begins
filling, which is performed in two stages:
1. Static fill: the PCB opens the solenoid valve and the dishwasher loads between 2.5 and 3 litres of water
(depending on model), checked by the litre counter. On reaching this threshold, the Main PCB runs a
check to verify that the pressure switch is on full.
If the pressure switch is on full, it proceeds to dynamic filling; if it is not on full, it loads more water,
approximately 100cc more. If the pressure switch is on full, dynamic filling begins, if not, the machine
signals a Pressure Switch Non Compliant alarm condition.
2. Dynamic filling: having checked the pressure switch is on full, the Main PCB activates the wash motor
and opens the fill solenoid valve until it reaches approx. 4 litres.
If, after this second filling, the main PCB senses the pressure switch on full, the machine continues
washing. If it does not, it continues loading water until the pressure switch is on full or up to 5.5 litres
(whichever occurs first). If it is full, the appliance will wash as normal. If not, it will drain and proceed to
the next step.
Important:
With the EOS platform, water cannot be loaded manually into the tank: manual loading results in a
"Turbine Alarm". The litre counter turbine and the pressure switch function independently, with one
component monitoring correct operation of the other: if water is loaded manually, the pressure
switch will signal "full" while the litre counter turbine will indicate that no water has been loaded
since it did not detect water filling, thus creating a conflict which will generate an alarm condition.
Salt Indicator Management:
Regeneration salt is managed by an optical sensor with a transmitter led and a receiver led. It is important
to note that the sensors are not positioned on the bottom of the water softener, but about half-way down
(to avoid the chance of impurities in the salt giving a false reading).
The presence of salt interrupts the beam of light, signalling to the Main PCB that the softener contains salt.
When the salt falls below the level of the sensor, this signals to the PCB that the salt container is empty.
Since the sensor is not on the bottom of the softener, in actual fact further regeneration cycles will still be
possible. The PCB will switch on the indicator light when 6 regeneration cycles have been completed since
the salt container empty signal.
The "no salt" signal must be constant, otherwise the 6 regeneration cycle count (to switch on the salt
indicator), starts over.
Important:
If the salt indicator is not on, the dishwasher will not perform the regeneration cycle.
If the salt sensor\ connector is disconnected, this signals to the Main PCB that the container is full,
so the indicator will not switch on. If the technician reconnects it, the indicator will not switch on
immediately even if the salt container is empty. The Main PCB will detect this situation and begin
counting the 6 regeneration cycles, after which it will switch on the salt indicator.
If the salt indicator is on, the dishwasher will not perform the regeneration cycle, even if the number
of litres loaded exceeds the limits set by Editor.
Service Manual
Manual LFF 825 IT/HA
Edition
2008.04.01
10
Language
English