My bathtub drain stopper is stuck. The round control closed the drain, won’t open now, and is stuck in place.
Drain control is large round knob, which is twisted to open or close. It had not been used for a while, so I suspect it is rusted, corroded or just frozen. The tub has several inches of water in it, but now that water is just sitting there.
There is a screw under the cap that controls the stopper in the drain. Remove the screw and gently try raising the control rod up and down. Many times this will do the trick. You can try using a small screwdriver through the grate in the drain hole and attempt to get it loose in that manner.
If all fail, you will need a plumber or mechanically inclined neighbor.