Bosch Classixx not filling with water

Hi all,

Firstly can I say, great forum!

Secondly I have come to work without the model number but will update the thread if necessary as soon as I get home! 😳

A few days ago my bosch classixx dishwasher stopped filling with water (noise, no filling and when you open the door a whooshing noise as if a vacuum has been created). Firstly checked water supply, hoses and filter all fine. With a little browsing on the web I came to the conclusion it must be either the the water inlet valve or float mechanism.

Alas it is neither. The float mechanism works fine (currently in the lower position as there is no water in it) I have also checked the 3 prong micro switch with a multimeter which is also working fine (continuity across 1 and 3 when open and 1 and 2 when closed). Next to the little float chamber there is also a circular disc flat against the machine (air pressure sensor?) also with a micro switch which is working perfectly.

I have had the water inlet valve off and this is also working fine (using a multimeter showing some resistance) But to be on the safe side, as I believe they can fail mechanically, I replaced it with a new one on the off chance.

I have also checked the voltage across the terminals which supply power to the inlet valve which I presumed should be constant, when trying to fill, which it is not, it fluctuates up and down and only a few millivolts.

I suppose my question is can it be anything else or is it likely to be the PCB?

Many thanks.
Dan