Hi sorry to hear your having problems with your Neff appliance.
My name is ***** ***** will do my best to assist you to resolve your problem.
These are often common faults, you advised you have a filter on the inlet hose, when you have checked the filter, have you turned on the water and watched water flow through the filter into a bucket so we can prove the hose isnt kinked, the filter isnt stopping the water getting to the appliance?
If the pipe is supplying water to the appliance, the check supply light would suggest the valve in the appliance is not working, it may be the actuator which turns the valve open\closed, or it might just be the valve has seize, however this would require an engineer visit to open up the appliance.
Please let me know how you get on.
Please give me a few minutes to investigate further.
Please see attached diagram, it showing one fixed pipe (which is the waste water), and one pipe which screws on which is the inlet water and contains the filter.
Are you able to send me a picture of what you see?
You need to get to the rear of the appliance, you may be able to reach round or failing that need to pull the appliance out from under the counter (if you do this it will require a screw driver to release the holding bracket(s) which stops it coming forward and located on the left and right hand side.
Once you can get to the back of the unit turn off the water under the sick (white valve) and we need to unscrew the water inlet pipe to (have a small bucket to hand as there will be a litre or two in the pipe). Then turn on the valve this will show if the pipe has become kinked or blocked, if the water flows out of the pipe turn off the valve again. At this point we have confirmed the issue is inside of the appliance and requires an engineer to test the sensor, actuator and water valve.
We can check very easily.
Based on the picture you sent me of under your sink, turn the white valve to shut off the water to the pipe (probably only requires a half turn), then unscrew (anti clockwise) the grey bolt which attaches the filter and pipe to the white valve.
Place a bowl by the valve and then reopen the valve slowly, if water comes out this proves the valve is working, and you just need to buy a new inlet hose, it is most likely kinked or got a blockage in it.
Ive not seen one with any electric wires inside a inlet tube, my guess is there are two pipes to allow pressure release.
The white box which fits between the pipe and the valve should be a filter, you could try and give it a clean, its unusual for them to get blocked though.
I would suggest buying a new inlet pipe without a filter, and replace the pipe between the valve and the appliance.
How are you getting on, did cleaning the filter work?
Thank you for getting back to me, I will await your update tomorrow