Hi. I have a leaking cold tap on my washbasin. It is a mixer unit with 2 taps and I have removed the cover and unscrewed the cold tap. However, when fully unscrewed the tap unit does not lift out from the tap housing. It feels as if something is stopping it and I am unwilling to exert too much force or poke a screwdriver in and lever it out in case I cause damage. Any help would be appreciated. Thanks. Balnadrumboy.