water dispensor inlet solenoid / should it work all time?

Hello gentlemen
We are currently having problem with the water dispenser on our fridge freezer.
It is coming out slow and does not shut off straight away and dribbles before stopping
I have changed filter and checked supply and pipes and found nothing.
i did notice that the solenoid pump wheel in the clear part of inlet valve not spinning at all no matter what we press on dispenser front
Should this spin up every time i ask for water?
If so i can get a replacement but did not want to spend 65 before knowing if it was worth a try.
Any other advice would be great
regards
Ian