Single lever mixer tap stiff

[cheez]

I have a single lever mixer tap in the kitchen. It no longer moves smoothly. It's stiff for both hot and cold and swivelling between the two.
I've opened the cover and unscrewed the handle, but there's nothing in there that makes sense to me. Can it be repaired? If so how. If it can't be repaired, is it easy enough to dismantle and install new one? Thanks.

[Softus]

It's probably either:

1. Scaled up and needs descaling.
or
2. Damaged, i.e. something has broken and making it start to seize up.

You should be able to buy a replacement cartridge, but you'll need to know the make and model. Do you have that information?