Thanks for the reply, proptech. Good to hear it's probably something straight forward (as I suspected and was hoping!) I do have some silicone grease...somewhere....
As it says in the subject line, the hot water tap on our bathroom wash basin seemed to have lost pressure. However, if I turn it back and forth (on and off), the pressure comes back, so I guess it's just some sort of flow problem. I haven't taken the tap apart yet (been very busy.) I was just wonder...