[folivier]

Yes the watts. When you unscrew the guts (on a new valve body) and pull them out and then look into the body there is a valve that moves up or down to open and close. This is what the thermostatic part pushes down to allow cold water to enter. It doesn't look like there is any way to remove that part. I'm just wondering if that part has calcium on it also. There is no way to look into the watts body while it is soldered in place.