There are two common types of fill systems used by the Electrolux group of dishwashers and both are discussed frequently on UK Whitegoods.
Both systems utilise displacement of air to operate pressure switches, which will cut off the electrical supply to the water valve and thus the supply of water into the machine. They each also have a flood protection system to prevent overfilling should the primary control system become inoperative. This works by diverting air into a pressure cut-off on the water inlet valve, which will remain electrically activated.
The Blue Tubes In The Dishwasher
This is the early system and may be easily identified by looking at the large filter in the appliance. If it has a large dome in the moulding at the 3 o'clock position, you have the early system. This is a very simple set-up and, barring a mechanical failure of the pressure switch itself, is always repairable.
Remove bottom basket, rotor and large filter. This will reveal a translucent dome at the 3 o'clock position, retained by a single screw on the top. When undone, the dome can be removed and will reveal the two blue tubes, and a cranked spout. Lift all three out and clean thoroughly, jetting water through the tubes until clear. 75% of the time, this will clear the problem.
However, if on re-assembly the machine will fill once and then not refill, you will need to clean out the transfer hose. This is a horseshoe shaped hose mounted in a bracket on the underside of the machine. With the power off and the machine tipped back, remove the hose and flush out. Don't forget to clean out the spigots which the hose mounts onto.
The Dishwasher Inlet Water Management (IWMS) System
This is the later set-up and the one which causes all the headaches. In theory, the system is very simple.
The IWMS is a large plastic moulding housed under the left hand side of the dishwasher. It comprises a series of chambers which are filled and emptied as the programme requires, and a "main channel" which allows the water to run down into the machine for circulation in the wash programmes.
The water passes from the IWMS through two tubes; ones is a rigid plastic moulded pipe, the other a flexible plastic one. Both are prone to choking with food detritus, and need to be cleaned out from time to time.
They may be identified as passing across the front underside of the tub and curving round to the sump area. If flushing these tubes out does not restore correct fill function, the IWMS will be at fault. Viewed from the side of the machine, the lowest parts of the moulding frequently appear to be black in colour; this is food detritus which will have built up over time.
Theoretically the moulding can be removed and an attempt made at cleaning it out; however because of the myriad of narrow channels contained within, this rarely works. The only practical solution is a replacement IWMS and in future ensuring that crockery has had any heavy deposits thoroughly rinsed off before insertion into the dishwasher.
There is no circulation through the IWMS area, and the water enters the machine under gravity, so over time sedimentation can and will occur.
It goes without saying that any investigations beyond observation must be carried out with the power off. If you are not confident of your abilities, you must seek professional help and would recommend you towards the engineer search to get your dishwasher professionally repaired.