I've got a NewTeam 100 mixer valve that works wonderfully apart from the fact that the temperature doesn't change, no mater where the temperature lever is. I took it apart and there's a screw cap that controls the temperature by pressing down on a plunger in the thermostic cartridge. This plunger seems to be seized. Before I take the 3lb lump hammer to it - does anyone know of any easy ways of freeing this up - as my tentative efforts at brute force have failed to budge it so far and I don't really want to spend £140 quid on a new thermostatic cartridge - especailly as the shower functions very well at the moment albeit at one, temperature.
Ta in advance
Jimbo